t n a c i r b u l s a s t c a : d i u l f l a i v o n y s d i u l f l a i v o n y s s e t e r c e s : e n a r b m e m l a i v o n y s e l b i x e l f d n a g n o r t s s i d n a e n o b o t e n o b s n i o j : t n e m a g i l e l c s u m s t n i o j s e s o l c n e : e l u s p a c s u o r b i f n o i t c e t o r p l a n o i t i d d a s e v i g : e g a l i t r a c f o d a p r e b r o s b a k c o h s s a s t c a d n a d i u l f l a i v o n y s s b r o s b a : e g a l i t r a c e n o b e n o b o t e l c s u m s n i o j : n o d n e t : s i e r e h t t n i o j a t A
d e u n i t n o c t n e m e v o m d n a s t n i o J 6 f o 2 1 of 60
Joints and movement - muscles bring about movement at a joint - muscles can only pull they cannot push so two muscles are needed to move a bone back and forth. - a pair of muscles like these are called antagonistic. - a muscle that contracts to cause extension of a joint is called an extensor - a flexor contracts to reverse the movement - the hip, knee and ankle joints are examples of synovial joints - the bones that move in the joint are separated by a cavity filled with synovial fluid. - the bones are held in position by ligaments that control and restrict movement. -tendons attach muscles to the bones - cartilage protects bones within joints.
. e r e m o c r a s e h t d n a e l c s u m e h t f o h t g n e l e h t g n i n e t r o h s d n a b e t a i d e m r e t n i e h t s p a l r e v o d n a b k r a d e h t s t c a r t n o c e l c s u m e h t n e h w . d n a b d e r u o l o c - e t a i d e m r e t n i a s i e r e h t r u c c o s t n e m a l i f n i s o y m y l n o e r e h t . d n a b k r a d a s i e r e h t r u c c o s t n e m a l i f n i s o y m d n a n i t c a h t o b e r e h w . e r e m o c r a s e h t n o d n a b t h g i l a s i e r e h t n w o r i e h t n o r a e p p a s t n e m a l i f n i t c a e r e h w . s e r e m o c r a s e l c s u m e h t n i h t i w s t n e m a l i f n i e t o r p e s e h t f o g n i d i l s e h t y b e d a m e r a s n o i t c a r t n o c . n i s o y m n i e t o r p e h t m o r f e d a m s e n o r e k c i h t d n a , n i t c a y l n i a m , n i e t o r p f o s e p y t o w t f o p u e d a m s i e r e m o c r a s e h t s e r e m o c r a s d e l l a c s t i n u e l i t c a r t n o c f o p u e d a m e r a e s e h t s l i r b i f o y m f o p u e d a m s i e r b i f e l c s u m h c a e -
e r b i f e l c s u m a e d i s n I 6 f o 4 3 of 60
How do muscles work? - muscle is made up of bundles of muscle fibres, each fibre is a single muscle cell - each muscle cell is multinucleate (has more than one nucleus) this is because a single nucleus could not effectively control the metabolism of such a long cell. - Tendons connect muscle to bone - the muscle is made up of bundles of muscle fibres. these are bound together by connective tissue. - each muscle fibre is a single muscle cell surrounded by a cell surface membrane. - Inside the muscle fibre is the cytoplasm containing mitochondria and the other organelles found in a cell. - Within each muscle fibre there are also numerous myofibrils, each is composed of repeated contractile units called sarcomeres.
. e r e m o c r a s e h t d n a e l c s u m e h t f o h t g n e l e h t g n i n e t r o h s d n a b e t a i d e m r e t n i e h t s p a l r e v o d n a b k r a d e h t s t c a r t n o c e l c s u m e h t n e h w . d n a b d e r u o l o c - e t a i d e m r e t n i a s i e r e h t r u c c o s t n e m a l i f n i s o y m y l n o e r e h t . d n a b k r a d a s i e r e h t r u c c o s t n e m a l i f n i s o y m d n a n i t c a h t o b e r e h w . e r e m o c r a s e h t n o d n a b t h g i l a s i e r e h t n w o r i e h t n o r a e p p a s t n e m a l i f n i t c a e r e h w . s e r e m o c r a s e l c s u m e h t n i h t i w s t n e m a l i f n i e t o r p e s e h t f o g n i d i l s e h t y b e d a m e r a s n o i t c a r t n o c . n i s o y m n i e t o r p e h t m o r f e d a m s e n o r e k c i h t d n a , n i t c a y l n i a m , n i e t o r p f o s e p y t o w t f o p u e d a m s i e r e m o c r a s e h t s e r e m o c r a s d e l l a c s t i n u e l i t c a r t n o c f o p u e d a m e r a e s e h t s l i r b i f o y m f o p u e d a m s i e r b i f e l c s u m h c a e -
e r b i f e l c s u m a e d i s n I 6 f o 4 3 of 60
How do muscles work? - muscle is made up of bundles of muscle fibres, each fibre is a single muscle cell - each muscle cell is multinucleate (has more than one nucleus) this is because a single nucleus could not effectively control the metabolism of such a long cell. - Tendons connect muscle to bone - the muscle is made up of bundles of muscle fibres. these are bound together by connective tissue. - each muscle fibre is a single muscle cell surrounded by a cell surface membrane. - Inside the muscle fibre is the cytoplasm containing mitochondria and the other organelles found in a cell. - Within each muscle fibre there are also numerous myofibrils, each is composed of repeated contractile units called sarcomeres.
. n i a g a s t r a t s e l c y c e h T . n o i t i s o p t h g i r p u s t i o t s n r u t e r t I . d a e h n i s o y m e h t f o e p a h s e h t n i e g n a h c a s e s u a c s i s y l o r d y h s i h T . i P d n a P T A g n i m r o f , P T A e h t s e s y l o r d y h d a e h n i s o y m e h t n o e l u c e l o m e s a P T A n A -
d e u n i t n o c s n e t r o h s e r e m o c r a s e h t w o H 6 f o 6 5 of 60
How the sarcomere shortens When a nerve impulse arrives at a neuromuscular junction calcium ions are released from the sarcoplasmic reticulum. This moves the protein filaments in these steps: - Ca2+ attaches to the troponin molecule, causing it to move. - because of this the tropomyosin on the actin filament moves its position, exposing myosin binding sites on the actin filaments. - Myosin heads bind with myosin binding sites on the actin filament, forming cross-bridges. - When the myosin head binds to t o the actin, ADP and Pi on the myosin head are released. - the myosin changes shape, causing the myosin head to nod forward. This moves the filaments and the actin moves over the myosin. - An ATP molecule binds to the myosin head. this causes the myosin head to detach.
. d e m r o f s r e t a w s a y g r e n e f o s t n u o m a e g r a l e s a e l e r o t n e g y x o h t i w d e t c a e r s i e s o c u l g e h t m o r f n e g o r d y h . t c u d o r p e t s a w a s a d e s a e l e r s i e d i x o i d n o b r a C . s p e t s l l a m s f o s e i r e s a n i t r a p a t i l p s s i e s o c u l g . l l e c e h t e g a m a d d l u o c d n a y l k c i u q o o t y g r e n e f o s t n u o m a e g r a l e s a e l e r d l u o w s i h t e s u a c e b y l t c e r i d r e h t e g o t t h g u o r b t o n e r a n e g y x o d n a e s o c u l g . P T A e t a r e n e g o t d e s u e b n a c t a h t y g r e n e f o e s a e l e r a s i e r e h t . n i a g a r e t a w m r o f o t n e g y x o h t i w r e h t e g o t t h g u o r b s i e s o c u l g n i d e r o t s n e g o r d y h e h t n o i t a r i p s e r c i b o r e a n i d e s a e l e r y g r e n e + O 2 H 6 + 2 O C 6 > - 2 O 6 + 6 O 2 1 H 6 C . s l e u f f o n o i t a r i p s e r c i b o r e a h g u o r h t d e t a r e n e g e r e b o t P T A e l b a n e o t s l l e c o t d e i l p p u s s i n e g y x o h g u o n e e s i c r e x e y t i s n e t n i w o l n I
n o i t a d i x o e t a r d y h o b r a C 6 f o 8 7 of 60
Releasing energy The minimum energy requirement of the body at rest to fuel basic metabolic processes is called your BMI. Releasing energy: - a series of enzyme-controlled reactions, known as respiration is linked to ATP synthesis. - cells use the molecule ATP as an energy carrier molecule. - ATP is created from ADP and inorganic phosphate (Pi) - when one phosphate group is removed from the ATP by hydrolysis, ADP forms. when removed the phosphate group becomes hydrated, a lot of energy is released as bonds form between the water and phosphate. ATP in water -> ADP in water + hydrated Pi + energy transferred
) D A N d e c u d e r d n a D A F d e c u d e r e m o c e b n e h t h c i h w D A N d n a D A F ( s r o t p e c c a n e g o r d y h y b p u n e k a t e r a s n e g o r d y h e h t . e s o c u l g r e p e c i w t s n r u t e l c y c e h t o s s e t a v u r y p o w t s e d i v o r p e s o c u l g h c a e . e l c y c s b e r K e h t o t s p u o r g l y t e c a C 2 e h t s e i r r a c A e m y z n e o c e h T . n o i t a m r o f P T A n i d e v l o v n i e r a d e s a e l e r s n e g o r d y h o w t e h t ) A o C l y t e c a r o ( A e m y z n e o c l y t e c a m r o f o t A e m y z n e o c h t i w s e n i b m o c e d a m e l u c e l o m n o b r a c 2 e h T ) D A N e m y z n e o c e h t y b p u n e k a t d n a d e v o m e r e r a s n e g o r d y h o w t ( d e t a n e g o r d y h e d ) t c u d o r p e t s a w a s a d e s a e l e r s i e d i x o i d n o b r a c ( d e t a l y x o b r a c e d : s i e t a v u r y p . r e t a w d n a e d i x o i d n o b r a c g n i m r o f , d e s i d i x o y l e t e l p m o c s i t i e r e h T . a i r d n o h c o t i m e h t o t n i s e s s a p s i s y l o c y l g f o d n e e h t t a d e t a e r c e t a v u r y p C 3 e h t e l b a l i a v a s i n e g y x o f I
n o i t c a e r k n i l e h T 6 f o 0 1 9 of 60
Glycolysis The initial stages of carbohydrate breakdown occur in the cytoplasm, including the sarcoplasm of muscle cells. - two phosphate groups are added to glucose from two ATP molecules, this increases its reactivity. It can now split into two molecules of 3-carbon (3C) compounds. - each intermediate 3C sugar is oxidised producing a 3-carbon compound, pyruvate. - two hydrogen atoms atoms are removed during the reaction and taken up by the coenzyme NAD, a non-protein organic molecule. - phosphate from the intermediate compounds is transferred to ADP, creating ATP. - this is called substrate level phosphorylation, because energy for the formation of ATP comes from the substrates ( the intermediate compounds.) - two ATP's are made, two pairs of hydrogen atoms and two molecules of 3-carbon pyruvate.
. n o i t a d i x o r o f e l c y c s b e r K e h t o t n i t u p e b n a c h c i h w d n u o p m o c n o b r a c - 2 e m a s e h t g n i t a r e n e g n w o d n e k o r b e r a s d i c a y t t a f . y g r e n e e s a e l e r o t d e r i p s e r e b o s l a n a c s d i c a y t t a f . s r o t p e c c a n e g o r d y h y b p u n e k a t e r a h c i h w , s m o t a n e g o r d y h f o s r i a p r u o f d n a . n o i t a l y r o h p s o h p l e v e l - e t a r t s b u s y b P T A f o e l u c e l o m e n o . s e l u c e l o m e d i x o i d n o b r a c o w t : f o n o i t c u d o r p e h t n i s t l u s e r e l c y c s b e r K e h t g n i r e t n e e l u c e l o m n o b r a c - 2 h c a E . d e t a e r c e r s i d n u o p m o c n o b r a c - 4 l a n i g i r o e h t s n o i t c a e r f o y a w h t a p r a l u c r i c a n i . s n o b r a c 6 h t i w e n o e t a e r c o t d n u o p m o c n o b r a c - 4 a h t i w s e n i b m o c A o C l y t e c a n o b r a c - 2 h c a e . d e t a c o l e r a s n o i t c a e r e h t e s y l a t a c t a h t s e m y z n e e h t e r e h w , x i r t a m l a i r d n o h c o t i m e h t n i e c a l p s e k a t e l c y c s b e r K e h T
d e u n i t n o c e l c y c s b e r K e h T 6 f o 2 1 11 of 60
The Krebs cycle
e l c i t r a p d e k l a t s h c a e n i e s a P T A y b d e s y l a t a c s i s i s e h t n y s P T A l e n n a h c e h t h g u o r h t s s a p s n o i n e g o r d y h e h t s a e n a r b m e m e h t n o s e l c i t r a p d e k l a t s n i s l e n n a h c n i e t o r p w o l l o h h g u o r h t t n e i d a r g l a c i m e h c o r t c e l e e h t n w o d e s u f f i d s n o i n e g o r d y h e h t x i r t a m e h t n a h t e v i t i s o p e r o m e c a p s e n a r b m e m r e t n i e h t g n i k a m e n a r b m e m r e n n i e h t s s o r c a t n e i d a r g l a c i m e h c o r t c e l e p e e t s a s e t a e r c s i h t . e c a p s e n a r b m e m r e t n i e h t o t n i d n a , e n a r b m e m l a i r d n o h c o t i m r e n n i e h t s s o r c a , x i r t a m e h t m o r f s n o i n e g o r d y h e v o m o t d e s u s i y g r e n e s i h t n i a h c t r o p s n a r t n o r t c e l e e h t g n o l a s s a p s n o r t c e l e s a d e s a e l e r s i y g r e n e : s i s e h t n y s P T A o t s d a e l n i a h c t r o p s n a r t n o r t c e l e e h t w o h
s i s o m s o i m e h c y b s i s e h t n y s P T A 6 f o 4 1 13 of 60
The electron transport chain - reduced coenzyme carries H+ and electron to electron transport chain on inner mitochondrial membrane. - Electrons pass from one electron carrier to the next in a series of redox reactions; the carrier is reduced when it receives the electrons and oxidised when it passes them on. - protons (H+) move across the inner mitochondrial membrane creating high H+ concentrations in the intermembrane space. - H+ diffuse back into the mitochondrial matrix down the electrochemical gradient. - H+ diffusion allows ATPase to catalyse ATP synthesis. -Electrons and H+ ions recombine to form hydrogen atoms which then combine with oxygen to create water. - if the supply of oxygen stops the electron transport chain and ATP synthesis stops.
d e u n i t n o c ? d e c u d o r p s i P T A h c u m w o H 6 f o 6 1 15 of 60
ATP synthesis by chemiosmosis continued - the hydrogen ions cause a change in shape in the enzymes active site so the ADP can bind - within the matrix the H+ and electrons re combine to form hydrogen atoms - these combine with oxygen to form water - the oxygen acts as the final carrier in the electron transport chain and is therefore reduced - this method of synthesising ATP is known as oxidative phosphorylation
How much ATP is produced? The maximum number of ATP's that can be made per glucose is 38 This is based on the assumption that: - each reduced NAD that is reoxidised forms 3 ATP molecules - each reduced FAD results in the production of two ATP molecules
. e l u c e l o m e s o c u l g r e p s e l u c e l o m P T A 2 t s u j s i d l e i y t e n e h t . P T A f o t n u o m a l l a m s a e k a m o t e s o c u l g n w o d s k a e r b y l l a i t r a p n o i t a r i p s e r c i b o r e a n a . d e t a r e n e g e r s i D A N f o m r o f d e s i d i x o e h t d n a e t a t c a l o t d e c u d e r s i s i s y l o c y l g g n i r u d d e t a e r c e t a v u r y p e h t . n e g y x o t u o h t i w D A N d e c u d e r e h t e s i d i x o o t e l b i s s o p s i t i . e u n i t n o c t o n n a c s n o i t c a e r n o i t a r i p s e r t s o m . d e s i d i x o t o n s i e l c y c s b e r k e h t d n a n o i t c a e r k n i l e h t , s i s y l o c y l g g n i r u d d e t a e r c D A N d e c u d e r e h T : k r o w t o n s e o d n i a h c t r o p s n a r t n o r t c e l e e h t s n o r t c e l e d n a s n o i n e g o r d y h e h t t p e c c a o t n e g y x o t u o h t i w : y l p p u s s d e e c x e s l l e c e h t n i d n a m e d n e g y x o e s i c r e x e n I
n o i t a r i p s e r c i b o r e a n A 6 f o 8 1 17 of 60
Rate of respiration n small organisms the rate of respiration can be determined by measuring the uptake of oxygen using a respirometer. - respiration is a series of enzyme-controlled reactions - it is affected by enzyme concentration, substrate concentration, temperature and pH. - the concentration also has a role in the control of respiration. - ATP inhibits the enzyme in the first step of glycolysis. The enzyme responsible for glucose phosphorylation can exist in two forms: - in the presence of ATP the enzyme has a shape that makes it inactive so it cannot catalyse the reaction. - as ATP is broken down the enzyme becomes an active form and catalyses the phosphorylation of glucose. - this is end point inhibition: the end product inhibits an early step in the metabolic pathway which controls the whole precess.
. n o i t a t n e m r e f c i l o h o c l a d e l l a c s i s i h t . e u n i t n o c o t s i s y l o c y l g s w o l l a d n a D A N d e s i d i x o s e t a e r c e r s i h t . D A N d e c u d e r m o r f n e g o r d y h e h t g n i s u e d i x o i d n o b r a c d n a l o n a h t e o t e t a v u r y p e c u d e r y e h t : s n o i t i d n o c c i b o r e a n a h t i w y l t n e r e f f i d e p o c s l l e c t s a e Y . r e v i l r o e l c s u m e h t n i d e r o t s d n a n e g o c y l g o t n i d e t r e v n o c e b o s l a y a m e t a t c a l e m o s . e t a t c a l f o n o i t a d i x o e h t l e u f o t d e d e e n s i t i . n o i t p m u s n o c n e g y x o e s i c r e x e - t s o p r o t b e d n e g y x o e h t d e l l a c s i t n e m e r i u q e r n e g y x o s i h t . e s i c r e x e r e t f a d o i r e p y r e v o c e r e h t n i l a m r o n n a h t r e t a e r g s i e k a t p u n e g y x o o s . P T A s i s e h t n y s o t y g r e n e s e s a e l e r d n a e l c y c s b e r K e h t a i v r e t a w d n a e d i x o i d n o b r a c o t y l t c e r i d d e s i d i x o s i t i . e t a v u r y p o t n i k c a b d e t r e v n o c s i e t a t c a l t s o m -
e t a t c a l f o d i r g n i t t e G 6 f o 0 2 19 of 60
The effect of lactate bulid-up The end product of anaerobic respiration is lactate: - it builds up in the muscles and must be disposed of - lactate forms lactic acid in solution so as lactate accumulates the pH of the cell falls inhibiting the enzymes that catalyse the glycolysis reactions. - enzymes function best over a narrow pH range. - as hydrogen ions from the lactic acid accumulate in the cytoplasm they neutralise the negatively charged groups in the active site of the enzyme. - the attraction between charged groups on the substrate and in the active site will be affected. - the substrate may no longer bind to the enzymes active site.
. s d o i r e p g n o l r o f d e n i a t s u s e b o t e s i c r e x e e h t s w o l l a s i h t . n w o d n e k o r b s i t i s a y l k c i u q s a P T A e t a r e n e g e r n a c n o i t a r i p s e r c i b o r e a . s l l e c e l c s u m e h t o t y l p p u s n e g y x o r e h g i h s e r u s n e s e l c s u m e h t o t y l p p u s d o o l b d e s a e r c n i n a e s i c r e x e e p y t e c n a r u d n e n i . n o i t a r e n e g e r P T A w o l l a m e t s y s n o i t a r i p s e r c i b o r e a n a e h t n e h t d n a m e t s y s C P / P T A e h t t s r i f . n e g y x o g n i s u t u o h t i w d e t a r e n e g e r e b l l i w P T A d n a h g u o n e y l k c i u q n e g y x o g n i r e v i l e d t o n e r a n o i t a l u c r i c d n a s g n u l e h t . t n e i c i f f u s n i s i s e l c s u m e h t o t n e g y x o f o y l p p u s e h t e s u a c e b y g r e n e r o f s d n a m e d e h t t e e m t o n n a c n o i t a r i p s e r c i b o r e a e s i c r e x e f o t r a t s e h t t A -
s m e t s y s y g r e n e e e r h T 6 f o 2 2 21 of 60
Supplying instant energy - at the start of exercise immediate regeneration of ATP is achieved using creatine phosphate (PC) - this is a substance stored in muscles that can be hydrolysed to release energy. - This energy can be used to regenerate ATP from ADP and phosphate, the phosphate is given by the creatine phosphate. - creatine phosphate breakdown starts as soon as exercise starts. creatine phosphate -> creatine + Pi ADP + Pi -> ATP - the reactions do not require oxygen and provide energy for 6-10 seconds of intense exercise. - this is known as the ATP/PC system its is used for regeneration of ATP.
. t u p t u o c a i d r a c d n a e m u l o v e k o r t s s e s a e r c n i s i h t , t n e t x e r e t a e r g a o t d e h c t e r t s s i e l c s u m t r a e h e h t . d o o l b f o e m u l o v r e g r a l a h t i w s l l i f t r a e h e h t e s i c r e x e g n i r u d e l o t s a i d n i . n r u t e r s u o n e v d e l l a c s i s i h t t r a e h e h t o t s n r u t e r d o o l b e r o m o s n o i t c a r t n o c e l c s u m r e t a e r g s i e r e h t e s i c r e x e g n i r u d . y d o b e h t m o r f t r a e h e h t o t g n i n r u t e r d o o l b f o e m u l o v e h t s i s i h t , t r a e h e h t g n i l l i f s i d o o l b h c u m w o h y b d e n i m r e t e d s i n o i t c a r t n o c h c a e h t i w t u o s p m u p t r a e h e h t d o o l b h c u m w o h . s t c a r t n o c e l c i r t n e v e h t e m i t h c a e e l c i r t n e v t f e l e h t f o t u o d e p m u p d o o l b f o e m u l o v e h t s I
e m u l o v e k o r t S ) R H ( e t a r t r a e h x ) V S ( e m u l o v e k o r t s = ) O C ( t u p t u o c a i d r a C : e t a r t r a e h e h t d n a ) e m u l o v e k o r t s e h t ( e l c i r t n e v t f e l e h t m o r f d e t c e j e d o o l b f o e m u l o v e h t n o s d n e p e d t u p t u o c a i d r a C . e t u n i m e n o n i t r a e h e h t y b d e p m u p d o o l b f o e m u l o v e h t
t u p t u o c a i d r a C
e m u l o v e k o r t s d n a t u p t u o c a i d r a C 6 f o 4 2 23 of 60
Peak performance - being able to go for long periods of strenuous exercise depends on maintaining a constant supply of ATP, and this depends on aerobic capacity: ability to take in/transport/use oxygen. - VO2 is the volume of oxygen we consume per minute. - VO2(max) is the maximum amount of oxygen we can consume per minute. - cardiac output is the volume of blood pumped by the heart in a minute. When running oxygen supply is maintained by: • increasing cardiac output • faster rate of breathing • deeper breathing
. r e k a m e c a p e h t s a n w o n k o s l a s i e d o n l a i r t a o n i s e h t . a v a c a n e v r o i r e p u s e h t o t g n i n e p o e h t h t a e n e b m u i r t a t h g i r e h t f o l l a w e h t n i d e t a c o l s e r b i f e l c s u m d e s i l a i c e p s f o a e r a l l a m s a s i N A S e h t . ) N A S ( e d o n l a i r t a o n i s e h t d n a s t r a t s n o i t a s i r a l o p e d . t c a r t n o c o t m e h t s e s u a c d n a s l l e c e h t t s g n o m a s d a e r p s y t i r a l o p s i h t . d e s i r a l o p e d e r a y e h t d e s r e v e r s i e g r a h c s i h t n e h w . d e s i r a l o p e r a y e h t e d i s t u o e h t n o e g r a h c e v i t i s o p t h g i l s a e v a h s l l e c e s e h t n e h w . s l l e c e l c s u m a i d r a c f o e g r a h c l a c i r t c e l e e h t n i s e g n a h c l l a m s y b d e t a i t i n i s i e l c s u m c a i d r a c f o n o i t c a r t n o c . n o i t a l u m i t s s u o v r e n l a n r e t x e t u o h t i w t c a r t n o c n a c t i ; c i n e g o y m s i t r a e h e h t -
? t a e b t r a e h e h t s e o d w o H 6 f o 6 2 25 of 60
Heart rate differences in resting heart rate are caused by: • different size • body size • genetic factors - A larger heart usually has a lower resting hear rate. - It will expel more blood with one beat and so does not have to beat as frequently to keep the circulation of blood constant. - Endurance training produces a lower resting heart rate - this is because increase in size of the heart - resulting from thickening of the muscle cell walls.
. d r a h g n i k r o w s i t r a e h e h t n e h w y l n o s m e l b o r p t r a e h t c e t e d o t d e s u o s l a s i t i t u b . t s e r t a s i t n e i t a p e h t n e h w d e m r o f r e p y l l a u s u s i G C E n a . e c a f r u s s n i k s e h t n o d e t c e t e d e b n a c t a h t t n e r r u c l a c i r t c e l e l l a m s a s i e r e h t . e l c s u m c a i d r a c e h t f o n o i t a s i r a l o p n i e g n a h c a s i e r e h t n e h w . e l c y c c a i d r a c e h t g n i r u d d e c u d o r p s t n e r r u c l a c i r t c e l e e h t d r o c e r o t s b m i l d n a t s e h c s ' n o s r e p e h t o t d e h c a t t a e r a s e d o r t c e l e . t r a e h e h t h t i w s m e l b o r p r o f k c e h c o t t s e t n o m m o c t s o m e h t s i t i . ) G C E ( m a r g o i d r a c o r t c e l e n a n o d e y a l p s i d d n a d e t c e t e d e b n a c y t i v i t c a l a c i r t c e l e e h t -
y t i v i t c a l a c i r t c e l e g n i r u s a e M 6 f o 8 2 27 of 60
How does the heart beat? continued - the SAN generates an electrical impulse this spreads across the left and right atria causing them to contract at the same time. - the impulse then travels to some specialised cells called the atrioventricular node (AVN) - the impulse is then sent to the ventricles after a delay of 0.13 seconds. this delay makes sure the atria have fully contracted. - the signal then reaches the purkyne fibres. these are large specialised muscle fibres that conduct impulses to the apex of the ventricles. - there are right and left bundles of fibres and these together are called the bundle of His. - the purkyne fibres continue around each ventricle so the impulse makes the ventricles contract from the apex upwards. - this is so the blood is pushed upwards into the aorta and pulmonary artery.
. e l c i r t n e v t f e l e h t n i s l l a w k c i h t y l l a m r o n b a e s u a c s n o i t a t u m e n e g h c i h w n i n o i t i d n o c d e t i r e h n i n a s i : y h t a p o y m o i d r a c c i h p o r t r e p y h w o l f d o o l b e t a u q e d a n i • e g a m a d f o s a e r a • s t a e b t r a e h l a m r o n b a • : t u o b a n o i t a m r o f n i e d i v o r p n a c G C E n a . s e c n a b r u t s i d l a c i r t c e l e y b d e s u a c t r a e h e h t f o s g n i t a e b r a l u g e r r i s i h c i h w d e s u a c s i s a i m h t y h r r a d n a . d e t p u r s i d e b o t t r a e h e h t f o m h t y h r d n a y t i v i t c a l a c i r t c e l e l a m r o n e h t s e s u a c s i h t . s e i r e t r a y r a n o r o c e h t f o e g a k c o l b g n i s u a c s i s o r e l c s o r e h t a o t e u d d o o l b e v i e c e r t o n s e o d e l c s u m t r a e h e h t a i m e a h c s i f o d o i r e p a g n i r u d . a i d r a c y h c a t s a n w o n k s i m p b 0 0 1 n a h t e r o m f o e t a r t r a e h a . a i d r a c y d a r b s a n w o n k s i m p b 0 6 n a h t s s e l f o e t a r t r a e h a -
G C E 6 f o 0 3 29 of 60
What does an ECG trace show us? - P wave: depolarisation of the atria leading to atrial contraction (atrial systole) - PR interval: the time taken for impulses to be conducted from the SAN across the atria to the ventricles, through the AVN. - QRS complex: the wave of depolarisation resulting in contraction of the ventricles (ventricular systole). - T wave: repolarisation (recovery) of the ventricles during the hearts relaxation phase (diastole). - the ECG does not show atrial repolarisation because the signals generated are small and are hidden by the QRS complex. - you can work out the time for one complete cardiac cycle by: multiplying the the number of squares between QRS complexes by 0.2 and then doing 60 divided by the answer.
. e c a r a f o t r a t s e h t e r o f e b e t a r r a e h n i e s a e r c n i y r o t a p i c i t n a n a s e s u a c e n i l a n e r d a . s e l c s u m e v i t c a e h t o t w o l d o o l b s e s i m i x a m s i h t . s n a g r o l a i t n e s s e - n o n r e h t o d n a m e t s y s e v i t s e g i d e h t o t g n i o g s e l o i r e t r a f o n o i t c i r t s n o c s e s u a c o s l a t i s e l c s u m l a t e l e k s g n i y l p p u s s e l o i r e t r a e h t f o n o i t a l i d s e s u a c o s l a e n i l a n e r d a . s d n a m e d l a c i s y h p r o f y d o b e h t e r a p e r p o t e t a r t r a e h e h t g n i s a e r c n i N A S e h t n o t c e r i d s a h t i . e v r e n c i t e h t a p m y s e h t y b n o i t a l u m i t s o t r a l i m i s e t a r r a e h e h t n o t c e f f e n a s a h e n i l a n e r d a . s y e n d i k e h t e v o b a d e t a c o l s d n a l g l a n e r d a e h t m o r f d o o l b e h t o t n i e n i l a n e r d a e n o m r o h e h t f o e s a e l e r a e s u a c k c o h s d n a t n e m e t i c x e , r a e f -
e t a r t r a e h n o s t c e f f e l a n o m r o H 6 f o 2 3 31 of 60
Nervous control of heart rate - heart rate is under the control of the cardiovascular control centre located in the medulla of the brain. - nerves forming the part of the autonomic nervous system lead from the cardiovascular control centre to the heart. - there are two nerves going from the cardiovascular control centre to the heart • sympathetic nerve (accelerator) • vagus nerve which is a parasympathetic nerve (decelerator) - stimulation of the SAN by the sympathetic nerve increases the heart rate whereas impulses from the vagus nerve slow down the heart rate. - the cardiovascular control centre detects accumulation of carbon dioxide and lactate in the blood, reduction of oxygen, and increased temperature. - mechanical activity in the muscles and joins is detected by sensory receptors in muscles, and impulses are sent to the cardiovascular control centre.
. n o i t a l a h x e p e e d g n i r u d t c a r t n o c y l n o s e l c s u m l a t s o c r e t n i l a n r e t n i e h t . s b i r e h t r e w o l o t g n i p l e h y t i v a r g d n a s g n u l e h t f o l i o c e r c i t s a l e e h t y b d e s u a c s i n o i t a l a h x e . n o i t a l a h x e g n i w o l l a d n a n o i t a l a h n i g n i p p o t s x a l e r s e l c s u m e h t d n a p o t s s e l c s u m e h t o t s e s l u p m i . e r t n e c n o i t a l i t n e v e h t o t k c a b s e s l u p m i y r o t i b i h n i d n e s s r o t p e c e r h c t e r t s e h t . d e t a l u m i t s e r a s e l o i h c n o r b e h t n i s r o t p e c e r h c t e r t s e t a l f n i s g n u l e h t s a -
n o i t a l a h x E . d e s u o s l a e r a s e l c s u m m g a r h p a i d d n a s l a t s o c r e t n i l a n r e t x e e h t g n i l a h n i n e h w . n o i t a l a h n i g n i s u t c a r t n o c s e l c s u m f o s t e s h t o b . s e l c s u m m g a r h p a i d d n a s e l c s u m l a t s o c r e t n i l a n r e t x e e h t o t s d n o c e s 3 - 2 y r e v e s e s l u p m i e v r e n s d n e s e r t n e c n o i t a l i t n e v e h t -
n o i t a l a h n I . g n i h t a e r b s l o r t n o c n i a r b e h t f o a t a g n o l b o a l l u d e m e h t n i e r t n e c n o i t a l i t n e v e h T -
g n i h t a e r b f o l o r t n o c e h T 6 f o 4 3 33 of 60
Lung volumes - the volume of air we breathe in and out at each breath is our tidal volume (at rest around 0.5 dm3). - the maximum volume of air we can inhale and exhale is out vital capacity (most people 3-4 dm3). - lung volumes can be measured using a spirometer. - the volume of air taken into the lungs in one minute is the minute ventilation. This is calculated by: minute ventilation = tidal volume x breathing rate
. e r t n e c n o i t a l i t n e v e h t a i v g n i h t a e r b f o e t a r d n a h t p e d e h t e s a e r c n i e r u t a r e p m e t d o o l b n i s e g n a h c o t d n a s l e v e l 2 O C o t e v i t i s n e s s r o t p e c e r o m e h c s u o i r a v e h t . t n e m e v o m n i d e v l o v n i s e l c s u m d n a s n o d n e t n i s r o t p e c e r h c t e r t s m o r f e r t n e c n o i t a l i t n e v e h t g n i h c a e r s e s l u p m i o t e s n o p s e r n i d e s a e r c n i o s l a s i n o i t a l i t n e v . y l p r a h s n o i t a l i t n e v g n i s a e r c n i a l l u d e m e h t n i e r t n e c n o i t a l i t n e v e h t n o t c e f f e t c e r i d a e v a h x e t r o c r o t o m e h t m o r f s e s l u p m i : ? g n i h t a e r b s l o r t n o c t a h w
e s i c r e x e g n i r u d g n i h t a e r b g n i l l o r t n o C 6 f o 6 3 35 of 60
Controlling breathing rate and depth an important stimulus controlling the breathing rate and depth is the concentration of dissolved CO2 in the arterial blood. a small increase in CO2 concentration causes a large increase in ventilation: - carbon dioxide dissolves in the blood plasma, making carbonic acid. - carbonic acid dissociates into hydrogen ions and hydrogencarbonate ions, this lowers the pH of the blood CO2 + H2O <=> H2CO3 <=> H+ + HCO3- chemoreceptors sensitive to hydrogen ions are located in the ventilation centre of the medulla oblongata. they detect a rise in H+ concentration. - impulses are sent to other parts of the ventilation centre - impulses are sent from the ventilation centre to stimulate the muscles involved in breathing.
. g n i t c a r t n o c n e h w s n o i t c a e r n o i t a r i p s e r c i b o r e a e s u o t m e h t g n i w o l l a a i r d n o h c o t i m e r o m e v a h d l u o c y e h t e l p m a x e r o f s e r b i f h c t i w t w o l s f o s c i t s i r e t c a r a h c e h t f o e m o s n o e k a t n a c s e r b i f h c t i w t t s a f g n i n i a r t c i b o r e a h t i w y l i s a e e u g i t a f s e r b i f e l c s u m h c t i w t t s a f e h t o s , e t a t c a l f o p u d l i u b d i p a r a s i e r e h t s n a e m h c i h w n o i t a r i p s e r c i b o r e a n a n o y l e r y e h t . s e i r a l l i p a c d e t a i c o s s a w e f d n a n e g y x o f o s e v r e s e r w e f e v a h y e h t o s n i b o l g o y m e l t t i l y r e v e v a h o s l a y e h t . m u l u c i t e r i m s a l p o c r a s e v i s n e t x e d n a , t n e t n o c n e g o c y l g h g i h , a i r d n o h c o t i m w e f e v a h s e r b i f h c t i w t t s a f e h t . s i s y l o c y l g c i b o r e a n a m o r f y l e r i t n e t s o m l a d e c u d o r p s i s n o i t c a r t n o c e s e h t n i d e s u P T A e h t s n o i t c a r t n o c t s a f e c u d o r p o t d e s i l a i c e p s e r a y e h t -
s e r b i f h c t i w t t s a F 6 f o 8 3 37 of 60
Slow twitch fibres - slow twitch fibres are specialised for slower sustained contraction - they can cope with long periods of exercise to do this they carry out a lot of aerobic respiration - they have many mitochondria and high concentrations of respiratory enzymes to carry out the aerobic reactions. - they also have a little sarcoplasmic reticulum and a low glycogen content. - they also contain large amounts of the dark red pigment myoglobin. - it has a high affinity for oxygen, and only releases it when the concentration of oxygen in the cells falls very low. - it acts as an oxygen carrier within muscle cells - slow twitch fibres are associated with numerous capillaries to ensure a good oxygen supply.
. p m e t m r o n o t n r u t e r o t d e d e e n n e h w s r o t c e f f e n o s n r u t d n a s e g n a h c s t c e t e d s u m a l a h t o p y h y e h t . s u m a l a h t o p y h e h t n i d e t a c o l e r a s r o t p e c e r e s e h t . e r u t a r e p m e t d o o l b e h t n i s e g n a h c t c e t e d t a h t s r o t p e c e r s e v l o v n i m e t s y s e h t . m e t s y s k c a b d e e f e v i t a g e n a y b d e n i a t n i a m s i e r u t a r e p m e t s n a m u h n i . e r u t a n e d d l u o c s e m y z n e e h t s p m e t r e h g i h t a d n a , e v i t c a n i a m e r o t y d o b e h t r o f y l w o l s o o t r u c c o d l u o w s n o i t c a e r e h t s e r u t a r e p m e t r e w o l t A . e t a r e l b a n o s a e r a t a r u c c o o t s n o i t c a e r d e l l o r t n o c - e m y z n e s w o l l a s i h t , s e e r g e d 7 3 d n u o r a t a s y a t s y d o b r u o . e r u t a r e p m e t y d o b f o l o r t n o c e h t s i n o i t a l u g e r o m r e h t -
l o r t n o c e r u t a r e p m e T 6 f o 0 4 39 of 60
Homeostasis - homeostasis is the maintenance of a stable internal environment. - this is partly achieved by maintaining stable conditions within the blood. - in the blood the concentration of glucose, ions, carbon dioxide, water potential, pH and temperature of the blood also needs to be kept within narrow limits. - each condition that is controlled has a norm value or a set point that the homeostatic mechanisms are trying to maintain. - receptors are used to detect changes from the norm. - these receptors are connected to a control mechanism which turns on or off effectors to bring conditions back to the norm.
. n o i t a l u s n i r e h t r u f r o f s e h t o l c r a e w s u f o t s o m . s n a m u h h t i w d e r a p m o c s d r i b d n a s l a m m a m r e h t o n i r e t t e b s i s i h t r i a h n i e g a t r o h s r u o o t e u d h g u o h t l a . y d o b e h t s e t a l u s n i t a h t r i a f o r e y a l a p a r t o t s i m i a e h t . r e v o l o r t n o c o n e v a h e w x e l f e r a s i s i h t . s e l c s u m r o t c e r e e h t f o s n o i t c a r t n o c y b r e h t a e w d l o c n i d e s i a r e r a y e h t : s r i a H s u m a l a h t o p y h e h t m o r f s e v r e n y b d e t a l u m i t s e r a s d n a l g t a e w s n i k s e h t m o r f y g r e n e g n i k a t s e t a r o p a v e s t c u d t a e w s e h t a i v d e s a e l e r t a e w s : t a e w S
s r i a h d n a t a e w S : l o r t n o c e r u t a r e p m e T 6 f o 2 4 41 of 60
Temperature control continued Heat loss centre: stimulates - sweat glands to produce sweat. inhibits - contraction of arterioles in skin (dilates capillaries in the skin) - hair erector muscles (relax - hairs lie flat) - liver (reduces metabolic rate) - skeletal muscles (relax - no shivering)
Heat gain centre: Inhibits - sweat glands stimulates - arterioles in the skin to constrict - hair erector muscles to contract - liver to raise metabolic rate - skeletal muscles to contract in shivering
. n o i t a l i d o s a v s a n w o n k s i s i h t . t s o l s i y g r e n e e r o m o s e c a f r u s e h t o t r e s o l c s w o l f d o o l b . e t a l i d m e h t g n i k a m s e l o i r e t r a e h t h g u o r h t s w o l f d o o l b . x a l e r s e l o i r e t r a e h t f o s l l a w e h t n i s e l c s u m d n a s t c i r t s n o c l e s s e v t u h s e h t s n o i t i d n o c m r a w n i . s u m a l a h t o p y h e h t y b d e l l o r t n o c s i s t n u h s d n a s e l o i r e t r a e h t f o n o i t c i r t s n o c : m r a w n e h w
n i k S : l o r t n o c e r u t a r e p m e T 6 f o 4 4 43 of 60
Temperature control: Skin when cold: - energy is lost from the blood flowing through the surface capillaries by radiation. - in cold condition the muscles in the arteriole walls contract causing the arterioles to constrict - this reduces the blood supply to the surface capillaries. - blood is diverted through the shunt vessel which dilates as more blood goes through it. - blood flows further from the skin surface so less energy is lost. - this is known as vasoconstriction.
. r e h t o e h t o t e n o m o r f r e f s n a r t y g r e n e d n a , s t c e j b o n e e w t e b t c a t n o c t c e r i d s e v l o v n i n o i t c u d n o c y b s s o l y g r e n e : n o i t c u d n o C
. y g r e n e e t a i d a r e w o s t n e m n o r i v n e g n i d n u o r r u s e h t n a h t r e m r a w y l l a u s u e r a s e i d o b r u o . n o i t a i d a r c i t e n g a m o r t c e l e s a , m u u c a v a h g u o r h t r o , r i a h g u o r h t r e h t o n a o t t c e j b o e n o m o r f d e t a i d a r e b n a c y g r e n e : n o i t a i d a R
r e f s n a r t y g r e n e f o s d o h t e M 6 f o 6 4 45 of 60
How energy is transferred to and from the body Energy transfer: - sweat evaporation increases energy loss. - evaporation from moist surfaces of lungs increases energy loss. - arteriole vasoconstriction decreases blood flow to skin reducing energy loss by conduction, convection and radiation. - arteriole vasodilation increases blood flow to skin increasing energy loss by conduction, convection and radiation. - Hairs raised by contraction of erector muscles reduces energy loss by conduction, convection and radiation. - voluntary muscle contraction and involuntary shivering release energy, raising body temperature.
. e s i c r e x e f o t n u o m a d n a n o i t c e f n i f o k s i r n e e w t e b p i h s n o i t a l e r d e p a h s - U a s i e r e h t e v e i l e b s t s i t n e i c s e m o s e s i c i r e x e d r a h h t i w y t i n u m m i d e s s e r p p u s d n a • s n e g o h t a p o t e r u s o p x e d e s a e r c n i • : s e t a r n o i t c e f n i r e h g i h o t e t u b i r t n o c n a c t a h t s r o t c a f n i a m o w t . n o m m o c t s o m e r a ) s m o t p m y s e k i l - u l f d n a t a o r h t e r o s ( s n o i t c e f n i t c a r t y r o t a r i p s e r r e p p u . l a m r o n n a h t n o i t c e f n i o t e n o r p e r o m m e e s s e m m a r g o r p g n i n i a r t y v a e h n i d e g a g n e s e t e l h t a -
n o i s s e r p p u s e n u m m i d n a e s i c r e x e e v i s s e c x E 6 f o 8 4 47 of 60
Methods of energy continued Convection: - air lying next to the skin will be warmed by the body - as the air expands and rises it will be replaced by cooler air which is then warmed by the body. - the energy loss by bulk movement of air is called convection. Evaporation: - energy is needed to convert water from liquid to vapour. - the energy required to evaporate sweat is drawn from the body cooling it. - in conditions with high humidity it is much harder to evaporate sweat. - some animals pant to keep cool, by evaporation of water from gas exchange surfaces.
. m e t s y s e n u m m i e h t s s e r p p u s o t n w o n k e r a s e n o m r o h e s e h t f o h t o b . l o s i t r o c d n a e n i l a n e r d a s a h c u s s e n o m r o h f o n o i t e r c e s e s u a c s s e r t s l a c i g o l o h c y s p d n a e s i c r e x e l a c i s y h p . d e c u d o r p g n i e b y d o b i t n a f o t n u o m a e h t s e c u d e r n e h t s i h t . s e t y c o h p m y l e t a v i t c a o t e l b a l i a v a s e n i k o t y c f o t n u o m a e h t s e c u d e r s l l e c r e p l e h T n i e s a e r c e d e h t s l l e c r e p l e h T • s l l e c B • s e t y c o g a h p • s l l e c r e l l i k l a r u t a n • : s l l a f m e t s y s e n u m m i e h t n i s l l e c e m o s f o r e b m u n e h t e s i c r e x e s u o r o g i v r e t f a : e s i c r e x e s u o r o g i V
d e u n i t n o c y t i n u m m i n o e c i r e x e f o s t c e f f E 6 f o 0 5 49 of 60
Effects of exerice on immunity - components of the non-specific and specific immune systems are effected by both moderate and excessive exercise.
Moderate exercise: - increases the number of a lymphocyte called natural killer cells. - they are found in the blood and lymph - they are not like B and T cells because they do not use specific antigen recognition. - they provide non-specific immunity against cells invaded by viruses and cancerous cells. - they are sctivated by cytokines and interferons and they target cells that are non self - they release the protein perforin which makes pores in the targeted cell membrane.
. n o i t c n u f l a m r o n o t r a e n n i a g e r o t r e h r o m i h e l b a n e o t y t i l i b a s i d a h t i w e n o e m o s y b d e s u t r a p y d o b l a i c i f i t r a n a s i : s e s e h t s o r P . y r e g r u s e l o h y e k h t i w l l e w y r a l u c i t r a p d e l k c a t e b n a c e e n k e h t n i s t n e m a g i l e t a i c u r c e h t o t e g a m a d . y p o c s o r h t r a s a n w o n k s i s t n i o j n o y r e g r u s e l o h y e k . s e l o h l l a m s h g u o r h t s n a g r o d e s a e s i d e v o m e r o t r o s t n i o j d e g a m a d r i a p e r o t e l b i s s o p s i t i s a r e m a c o e d i v e t u n i m r o s c i t p o e r b i f g n i s u : y r e g r u s e l o h y e K
? p l e h y g o l o n h c e t l a c i d e m n a c w o H 6 f o 2 5 51 of 60
How are joints damaged by exercise - professional athletes risk developing joint injuries bue to high forces the sport generates on their oints. - repeated forces on such joints of the knee can lead to wear or tear in the joint. - knees are particularly susceptable to wear and tear injuries: • the articular cartilage covering the surfaces of the bones wears away and they grind on eachother causing damage. • Patellar tendonitis occurs when the kneecap (patella) does not glide smoothly across the femur due to damage of the articular cartilage on the femur. • the fluid sacs swell up with extra fluid, as a result they may push against other tissues in the joint causing inflamtion. • sudden twisting or abrupt movement of the knee often result in damage to the ligaments.
s y e n d i k n i r e t a w f o n o i t p o s b a e r s e s u a c s e i r a v o d n a s e t s e t s e l o r t n o c h t w o r g s e t a l u m i t s - n o i t c n u F e n o m r o h c i t e r u i d i t n a e n o m r o h g n i t a l u m i t s - e l c i l l o f e n o m r o h h t w o r g - e n o m r o h : d n a l g y r a t i u t i p
- : s e n o m r o h d n a s d n a l g . s i s o t y c o x e y b t n e t n o c r i e h t g n i s a e l e r e n a r b m e m e c a f r u s l l e c e h t h t i w e s u f s e l c i s e v e h t . s u t a r a p p a i g l o g e h t y b s e l c i s e v y r o t e r c e s n i h t i w d e g a k c a p r o m r o f e v i t c a n i n a n i r e h t i e d e c u d o r p e r a t s o m . s d n a l g e n i r c o d n e m o r f d o o l b e h t o t n i y l t c e r i d d e s a e l e r e r a t a h t s r e g n e s s e m l a c i m e h c e r a s e n o m r o h -
s e n o m r o H 6 f o 4 5 53 of 60
Taking enough exercise Advantages of doing exercise: - increasing arterial vasodilartion lowers blood pressure (reduces the risk of CVD) - increases the lovel of blood HDLs which transport cholesterol to the liver where it is broken down. - reduces LDLs which are associated with the development of atherosclerosis. - helps maintain a healthy weight. - increased sensitivity of muscle cells to insulin improves blood glucose regulation, and reduces the likelihood of getting type II diabetes. - increases bone density and reduces its loss during old age. - reduces the risk of getting some cancers - improves mental well-being.
. s e n a r b m e m l l e c e h t f o e d i s t u o e h t n o s e l u c e l o m r o t p e c e r y r a t n e m i l p m o c o t d n i b y e h t r o s l l e c t e g r a t e h t r t n e r e h t i e y e h t m a e r t s d o o l b e h t y b d n u o r a d e i r r a c e r a s e n o m r o h y t i v i t c a r i e h t g n i y f i d o m s l l e c t e g r a t c i f i c e p s y l n o s t c e f f a e n o m r o h h c a e s c i t s i r e t c a r a h c l a u x e s y r a d n o c e s e l a m f o t n e m p o l e v e d s e t o m o r p - n o i t c n u f e n o r e t s o t s e t - e n o m r o h : s i t s e t s c i t s i r e t c a r a h c l a u x e s y r a d n o c e s e l a m e f s e t o m o r p s e i r a v o f o t n e m p o l e v e d s e t o m o r p - n o i t c n u f n e g o r t s e o - e n o m r o h : y r a v O : s e n o m r o h d n a s d n a l g
d e u n i t n o c s e n o m r o H 6 f o 6 5 55 of 60
Hormones continued glands and hormones:Thyroid gland: hormone - thyroxine function - raises basal metabolic rate
Adrenal gland: hormone - arenaline function - raises basal metaboic rate - dilates blood vessels - prepares the body for action
Pancreas: hormone - insulin function - lowers blood glucose concentration
. n o i g e r r e t o m o r p e h t o t e s a r e m y l o p A N R e h t h c a t t a s r o t c a f n o i t p i r c s n a r t e h t n o i g e r r e t o m o r p e h t o t x e l p m o c n o i t a i t i n i n o i t p i r c s n a r t e h t f o t n e m h c a t t a d n a n o i t a m r o f l u f s s e c c u s y b n o d e h c t i w s e r a s e n e g . x e l p m o c n o t a i t i n i n o i t p i r c s n a r t e h t f o g n i d n i b e h t e t a l u m i t s s e l u c e l o m r o t a v i t c a : s e l u c e l o m r o t a v i t c A . l l e c e h t n i h t i w d e b i r c s n a r t t o n s i d n a f f o d e h c t i w s s i e n e g e h t o s . x e l p m o c n o i t a i t i n i n o t p i r c s n a r t e h t g n i m r o f m o r f m e h t s t n e v e r p s i h t s r o t c a f n o i t p i r c s n a r t e h t o t h c a t t a n a c s e l u c e l o m r o s s e r p e r n i e t o r p : s e l u c e l o m r o s s e r p e R . d e m r o f s i x e l p m o c n o i t a i t i n i n o i t p i r c s n a r t e h t n e h w s r u c c o y l n o n o i t p i r c s n a r t n I
k r o w s r o t c a f n o i t p i r c s n a r t w o H 6 f o 8 5 57 of 60
How hormones affect cells - peptide hormones are protein chains - even though they are relatively small molecules they can not pass through cell membranes easily because they are charged - they bind to a receptor on the cell membrane - this receptor activates another molecule in the cytoplasm called a second messenger - the second messenger brings about chemical changes in the cell by affecting gene transcription - steroid hormones are formed from lipids and have complex ring structures. - the hormone- receptor complex functions as a transcription factor, switching enzyme synthesis on or off.
