Neuronal communication (M5)

The Pacinian corpuscle is a ______ receptor which converts mechanical pressure into a nervous impulse

The Pacinian corpuscle is a sensory receptor which converts mechanical pressure into a nervous impulse

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1. In its resting state the ______ ion channels open in the sensory neurone's membrane are too narrow to allow ______ ions to pass through
2. When pressure is applied the Pacinian corpuscle changes _____, the membrane stretches

1. In its resting state the sodium ion channels open in the sensory neurone's membrane are too narrow to allow sodium ion to pass through
2. When pressure is applied the Pacinian corpuscle changes shape, the membrane stretches

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3. The sodium ion channels _____ so sodium ions can diffuse in the neurone
4. The influx of sodium ions causes _________ of the membrane, resulting in a generator potential
5. This potential creates an _____ potential that passes along the sensory neurone

3. The sodium ion channels widen so sodium ions can diffuse in the neurone
4. The influx of sodium ions causes depolarisation of the membrane, resulting in a generator potential
5. This potential creates an action potential that passes along the sensory n

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Features of sensory receptors:
They are ______ to a single type of stimulus
They act as a _______ (convert stimulus into a nerve impulse)

They are specific to a single type of stimulus
They act as a transducer (convert stimulus into a nerve impulse)

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Type of receptor: Mechanoreceptor
Stimulus: _______ and ________
Receptor: _______ corpuscle
Sense organ: ____

Type of receptor: Mechanoreceptor
Stimulus: pressure and movement
Receptor: Pacinian corpuscle
Sense organ: skin

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Type of receptor: Chemoreceptor
Stimulus: _______
Receptor: _______ receptor
Sense organ: ____

Type of receptor: Chemoreceptor
Stimulus: chemicals
Receptor: olfactory receptor
Sense organ: nose

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Type of receptor: Thermoreceptor
Stimulus: ____
Receptor: end-bulbs of ______
Sense organ: ______

Type of receptor: thermoreceptor
Stimulus: heat
Receptor: end-bulbs of Krause
Sense organ: tongue

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Type of receptor: Photoreceptors
Stimulus: _____
Receptor: ____ cell
Sense organ: ___

Type of receptors: Photoreceptors
Stimulus: light
Receptor: cone cell
Sense organ: eye

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Sensory neurones transmit impulses from a sensory receptor cell to a ____ neurone, _____ neurone, or the brain. They have one ______ which carries the impulse to the cell body, and one ____ which carries the impulse away from the cell body

Sensory neurones transmit impulses from a sensory receptor cell to a relay neurone, motor neurone, or the brain. They have one dendron which carries the impulse to the cell body, and one axon which carries the impulse away from the cell body

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Relay neurones transmit impulses between neurones, such as between _____ and _____ neurones. They have many short ____ and _______

Relay neurones transmit impulses between neurones, such as between sensory and motor neurones. They have many short axons and dendrons

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Motor neurones transmit impulses from a ______ or ______ neurone to an effector. They have one long ____ and many short ________

Motor neurones transmit impulses from a relay or sensory neurone to an effector. They have one long axon and many short dendrites.

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Myelinated neurones are covered in myelin ______. ______ cells produce these layers of membrane, each time they grow around the axon a double ________ bilayer is laid down.

Myelinated neurones are covered in myelin sheath. Schwann cells produce these layers of membrane, each time they grow around the axon a double phospholipid bilayer is laid down.

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Myelin sheath acts as an ________ layer and allows myelinated neurones to conduct impulses at a _______ speed. Myelinated neurones conduct impulses up to ___m per sec, non-myelinated neurones conduct impulses at _m per sec

Myelin sheath acts as an insulating layer and allows myelinated neurones to conduct impulses at a faster speed. Myelinated neurones conduct impulses up to 100m per sec, non-myelinated neurones conduct impulses at 1m per sec

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Between each Schwann cell there is a gap, which is a node of ______. The impulse ____ from one node to the next along the axon, allowing fast impulse. In non-myelinated neurones the impulse doesn't ____ it continuously transmits along the neurone which is

Between each Schwann cell there is a gap, which is a node of Ranvier. The impulse jumps from one node to the next along the axon, allowing fast impulse. In non-myelinated neurones the impulse doesn't jump it continuously transmits along the neurone which

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Resting potential: For every 3 ______ ions pumped out axon, two _______ ions are pumped in by a ______-________ pump. There is more ______ ions outside membrane than in axon, more _______ ions inside axon than outside membrane

For every 3 sodium ions pumped out axon, two potassium ions are pumped in by a sodium-potassium pump. There is more sodium ions outside membrane than in axon, more potassium ions inside axon than outside membrane

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So ______ ions diffuse back in down its electrochemical gradient, whereas ________ ions diffuse out axon. Most ______ ion channels are closed and many ________ ion channels are open, preventing movement of ______ ions and _______ ions diffuse out axon

So sodium ions diffuse back in down its electrochemical gradient, whereas potassium ions diffuse out axon. Most sodium ion channels are closed and many potassium ion channels are open, preventing movement of sodium ions and potassium ions diffuse out axon

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There are more positively charged ions outside axon than inside axon, this creates a resting potential of -__mV

There are more positively charged ions outside axon than inside axon, this creates a resting potential of -70mV

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1. The resting potential means there is no impulse transmitted. Some ______ ion channels are open but _______ ion channels are closed
2. The energy of the stimulus triggers some ______ ion channels open, diffuse in down ________ gradient, inside neurone l

1. The resting potential means there is no impulse transmitted. Some potassium channels are open but sodium ions channels are closed
2. The energy of the stimulus triggers some sodium ion channels open, diffuse out down electrochemical gradient, inside ne

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3. More ______ ion channels open, allowing more ______ to diffuse in axon (positive feedback)
4. At +__mV, sodium ion channels close and potassium ions channels open. _____ ions no longer enter axon but membrane is more permeable to _______ ions

3. More sodium ion channels open, allowing more sodium to diffuse in axon (positive feedback)
4. At +40mV, sodium ion channels close and potassium ion channels open. Sodium ions no longer enter axon but membrane is more permeable to potassium ions

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5. ________ ions diffuse out axon down electrochemical gradient, inside axon becomes more negative than outside. This is called __________.

5. Potassium ions diffuse out axon down electrochemical gradient, inside axon becomes more negative than outside. This is called hyperpolarisation.

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6. Potassium ion channels now close. The sodium-potassium pump causes ______ ions to move out axon and ________ ions to move in axon. The axon returns to its resting potential (___________)

6. Potassium ion channels now close. The sodium-potassium pump causes sodium ions to move out axon and potassium ions to move in axon. The axon returns to its resting potential (repolarisation)

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After an AP there is a ________ period, the sodium ion channels remain closed which prevents the movements of sodium ions in the axon. It prevents the _________ of new APs backwards and forwards. Ensure APs are ___________.

After an AP there is a refractory period, the sodium ion channels remain closed which prevents the movement of sodium ions in the axon. It prevents the propagation of new APs backwards and forwards. Ensures APs are unidirectional.

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Myelination affects the speed of an AP; the __________ of the axon membrane only occur at nodes of Ranvier where no myelin is present

Myelination affects the speed of an AP; the depolarisation of the axon membrane only occur at nodes of Ranvier where no myelin is present

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Axon diameter; the ______ the diameter the faster the impulse. This is because there's less resistance to the flow of ions in the cytoplasm

The bigger the diameter the faster the impulse. This is because there's less resistance to the flow of ions in the cytoplasm.

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Temperature; the higher the temperature the faster the impulse. This is because ions have more ______ energy so diffuse faster. This only occurs up to about __C because proteins in the pump denature

The higher the temperature the faster the impulse. This is because ions have more kinetic energy so diffuse faster. This only occurs up to about 40C because proteins in the pump denature

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All-or-nothing principle:
A certain level of stimulus, the ________ value always triggers a response, if this is reached then the same sized _____ _______ will be created no matter how large the stimulus. However the bigger the stimulus, the more ________

A certain level of stimulus, the threshold value always triggers a response, if this is reached then the same sized action potential will be created no matter how large the stimulus. However the bigger the stimulus, the more frequently they are generated

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Excitatory neurotransmitter:
Result in the __________ of postsynapse. If the ________ is reached in the presynapse then an AP is triggered. An example is _____________.

Results in the depolarisation of postsynapse. If the threshold is reached then an AP is triggered. An example is acetylcholine.

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Inhibitory neurotransmitter:
Results in the ______________ of the postsynapse, preventing an AP triggered. An example is ____ found in the brain

Results in the hyperpolarisation of the postsynapse, preventing an AP triggered. An example is GABA found in the brain.

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Transmission across cholinergic synapses
1. AP arrives at presynapse, causes ______ ion channels to open, entering the synaptic knob
2. Causing the synaptic ______ to fuse with presynaptic membrane, releases ___________ into synaptic cleft

1. AP arrives at presyanpse, causes calcium ion channels to open, entering the synaptic knob
2. Causing the synaptic vesicles to fuse with presynaptic membrane, releases acetylcholine into synaptic cleft

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3. Acetylcholine fuses with ______ ion channel receptors in postsynapse, causes ______ ion channels to open, ______ ions diffuse in
4. Causing a new _____ _______ in postsynapse

3. Acetylcholine fuses with sodium ion channel receptors in postsynapse, causes sodium ion channels to open, sodium ions diffuse in
4. Causing a new action potential in postsynapse

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5. Acetylcholinsterase hydrolyses acetylcholine into _____ and ______ acid, which diffuse back across synaptic cleft into presynapse to ______ it
6. ATP released by mitochondria used to recombine choline and ethanoic acid into __________, stored for futur

5. Acetylcholinsterase hydrolyses acetylcholine into choline and ethanoic acid, which diffuse back across synaptic cleft into presynapse to recycle it
6. ATP released by mitochonria used to recombine choline and ethanoic acid into acetylcholine, stored fo

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Role of synapses in summation:
In some synapses the amount of ___________ from a single impulse isn't enough to trigger an AP in the postsynapse. But if the amount builds up to reach the ________ then this will trigger an AP. This defines summation.

In some synapses the amount of neurotransmitter from a single impulse isn't enough to trigger an AP in the postsynapse. But if the amount builds up to reach the threshold then this will trigger an AP. This defines summation.

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Spatial summation:
multiple presynapses connect to one ________. Each releases neurotransmitter which builds up to a high enough level to trigger an AP in the single _________ neurone.

Multiple presyanpses connect to one postynapse.
Each releases neurotransmitter which builds up to a high enough level to trigger an AP in the single postsynaptic neurone.

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Temporal summation:
single _________ releases neurotransmitter as a result of an AP several times over a short period. This builds up in the _______ until the _______ is reached to trigger an AP

single presynapse releases neurotransmitter as a result of an AP several times over a short period. This builds up in the synapse until the threshold is reached to trigger an AP.

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Structure of the nervous system:
Central nervous system (CNS) consists of the ____ and _____ cord
Peripheral nervous system (PNS) consists of ______ and _____ neurones that connect the CNS to the rest of the body

CNS consists of the brain and spinal cor
PNS consists of sensory and motor neurones that connect the CNS to the rest of the body

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PNS organised into:
Somatic nervous system which is under ______ control, when voluntarily choosing to do something, carries impulses to body's ______

Somatic nervous system which is under conscious control, when voluntarily choosing to do something, carries impulses to body's muscles

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Autonomic nervous system is under _________ control, body does something automatically and involuntarily, carries impulses to _____ and ______ muscle and ______ muscle

Autonomic nervous system is under subconscious control, body does something automatically and involuntarily, carries impulsses to glands and smooth muscle and cardiac muscle

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Autonomic system organised into:
________ nervous system is involved if the outcome increases activity eg. increasingheart rate
____________ nervous system is involved if the outcome decreases activity eg. decreasing heart rate after exercise

Sympathetic nervous system is involved if the outcome increases activity eg. increasing heart rate
Parasympathetic nervous system is involved if the outcome decreases activity eg. decreasing heart rate after exercise

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Somatic nervous system neurones:
- ___ neurone from CNS to effector
- _____ myelinated axon
- __________ neurotransmitter
- _____ muscle is effector
- __________ effect

- one neurone from CNS to effector
- heavy myelinated axon
- acetylcholine neurotransmitter
- skeletal muscle is effector
- stimulatory effect

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Sympathetic nervous system neurones:
- multiple neurones from CNS to effector
- _____ myelinated preganglionic axon
- _____ myelinated postganglionic axon
- _________ neurotransmitter
- glands, _____ and _____ muscle is effector
-________ or ________ effe

- multiple neurones from CNS to effector
- light myelinated preganglionic axon
- none myelinated postganglionic axon
- noradrenaline neurotransmitter
- glands, smooth and cardiac muscle is effector
- stimulatory and inhibitory effect

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Parasympathetic nervous system neurones:
- multiple neurones from CNS to effector
- _____ myelinated preganglionic axon
- _____ myelinated postganglionic axon
- ____________ neurotransmitter
- glands, _____ and _____ muscle is effector
- _________ or ____

- multiple neurones from CNS to effector
- light myelinated preganglionic axon
- none myelinated postganglionic axon
- acetylcholine neurotransmitter
- glands, smooth and cardiac muscle is effector
- stimulatory or inhibitory effect

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Brain structure:
Cerebrum controls voluntary actions such as _______, ______, personality and thought
Cerebellum controls involuntary actions such as _______ and balance

Cerebrum controls voluntary actions such as learning, memory, personality and thought
Cerebellum controls involuntary actions such as posture and balance

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Medulla oblongata used in autonomic control such as _____ and breathing rate
Hypothalamus regulates _________ and water balance
Pituitary gland stores and releases _______ that regulate many body functions

Medulla oblongata used in autonomic control such as heart rate and breathing rate
Hypothalamus regulates temperature and water balance
Pituitary gland stores and releases hormones that regulate many body functions

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Cerebellum:
It doesn't initiate movement, it _______.
It receives information about balance and muscles and relays it to the ______ cortex.

It doesn't initiate movement, it coordinates.
It receives information about balance and muscles and relays it to the cerebral cortex.

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Hypothalamus:
- Controls complex behaviour such as ______, _______ and aggression
- monitors the composition of blood _____ such as water and blood glucose
- produces _______

- controls complex behaviour such as sleeping, feeding and aggression
- monitors the composition of blood plasma such as water and blood glucose
- produces hormones

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Pituitary gland:
- _______ pituitary gland produces 6 hormones including ___ which is involved in reproduction and growth hormones
- _______ pituitary gland stores and releases hormones produced by hypothalamus eg. ADH

- anterior pituitary gland produces 6 hormones including FSH which is involved in reproduction and growth hormones
- posterior pituitary gland stores and releases hormones produced by hypothalamus eg. ADH

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Reflex arc:
The receptor detects _______ and creates an AP in the sensory neurone
The sensory neurone carries impulse to _____
The relay neurone connects the _____ neurone to the _____ neurone

The receptor detects stimulus and creates an AP in the sensory neurone
The sensory neurone carries impulse to spine
The relay neurone connects the sensory neurone to the motor neurone

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The motor neurone carries the impulse to the _______ to produce a response

The motor neurone carries the impulse to the effector to produce a response

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Knee-jerk reflex:
1. When leg is tapped just below the ______, it stretches the ______ tendon and acts as a stimulus
2. Stimulus initiates a reflex arc, causing the _______ muscle to contract

1. When leg is tapped just below the patella, it stretches the patellar tendon and acts as a stimulus
2. Stimulus initiates a reflex arc, causing the extensor muscle to contract

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3. At the same time a relay neurone inhibits the motor neurone of the _____ muscle, it ______
4. This contraction coordinated with the __________ of the flexor muscle causes the leg to kick

3. At the same time a relay neurone inhibits the motor neurone of the flexor muscle, it relaxes
4. This contraction coordinated with the relaxation of the flexor muscle causes the leg to kick

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Blinking reflex:
1. ______ is irritated by a foreign body
2. Stimulus triggers an impulse along sensory neurone (_____ cranial nerve)
3. Impulse passes through _____ neurone in lower brain stem

1. Cornea is irritated by a foreign body
2. Stimulus triggers an impulse along sensory neurone (fifth cranial nerve)
3. Impulse passes through relay neurone in lower brain stem

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4. Impulses sent along branches of motor neurone (______ cranial nerve) to initiate the eyelids to close
5. Reflex initiates a ________ response so both eyes close in response to the stimulus

4. Impulses sent along branches of motor neurone (seventh cranial nerve) to initiate the eyelids to close
5. Reflex initiates a consensual response so both eyes close in response to the stimulus

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Survival importance:
- reflex are involuntary which means the ______-making regions of the brain aren't involved so the brain is able to deal with complex responses. It prevents the brain from being _________ when the response is always the same

- reflexes are involuntary which means the decision-making regions of the brain aren't involved so the brain is able to deal with complex responses. It prevents the brain from being overloaded when the response is always the same

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- reflexes aren't learnt which means they provide immediate ________
- reflexes are fast as the arc is _____, the two synapses involved are the ______ part of nervous transmission
- reflexes are everyday actions, they prevent us from ______ and control __

- reflexes aren't learnt which means they provide immediate protection
- reflexes are fast as the arc is short, the two synapses involved are the slowest part of nervous transmission
- reflexes prevent us from falling and control digestion

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Types of muscle:
Skeletal muscle is responsible for ________
Cardiac muscle is ______ meaning they contract without the ned for stimulus so the heart beats in a natural ______
Involuntary (smooth) muscle are _______ cells which constrict and dilate blood

Skeletal muscle is responsible for movement
Cardiac muscle is myogenic meaning they contract without the need for stimulus so the heart beats in a natural rhythm.
Smooth muscle are involuntary cells which constrict and dilate blood vessels

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Skeletal muscle:
- ______ fibres
- ______ control
- ____ contraction speed
- ____ length of contraction
- tubular fibres and multi_______

- striated fibres
- voluntary control
- rapid contraction spped
- short length of contraction
- tubular fibres and multinucleated

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Cardiac muscle:
- ______ fibres
- ________ control
- _________ contraction speed
- ________ length of contraction
- faint ________, branched and multi_______

- striated fibres
- involuntary control
- intermediate contraction speed
- intermediate length of contraction
- faint striations, branched and multinucleated

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Involuntary (smooth) muscle:
- non-______ fibres
- _______ control
- _____ contraction speed
- ______ length of contraction
- spindle shaped and uni________

- non-striated fibres
- involuntary control
- slow contraction spped
- long length of contraction
- spindle shaped and uninucleated

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Muscle fibres (skeletal muscle):
- enclosed within a membrane called ________
- formed from _______ muscle cells fused
- this makes them stronger
- shared cytoplasm is called _________

- enclosed within a membrane called sarcolemma
- formed from embryonic muscle cells fused
- this makes them stronger
- shared cytoplam is called sarcoplasm

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- parts of the sarcolemma fold inwards forming _ tubules, _____ up impulses through sarcoplasm
- lots of __________ to provide ATP for contraction
- __________ reticulum contains calcium ions for muscle contraction

- parts of the sarcolemma fold inwards forming T tubules, speeds up impulses through sarcoplasm
- lots of mitochondria to provide ATP for contraction
- sarcoplasmic reticulum contains calcium ions for muscle contraction

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Myofibrils (skeletal muscle):
- _____ is the thinner filament containing two strands twisted around each other
- _____ is the thicker filament containing of long rod-shaped fibres

actin is the thinner filament containing two strands twisted around each other
myosin is the thicker filament containing of long rod-shaped fibres

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- _ bands (light) is where the actin and myosin filaments don't overlap
- _ bands (dark) is where the actin and myosin filaments do overlap

- I bands (light) is where the actin and myosin filaments don't overlap
- A bands (dark) is where the actin and myosin filaments do overlap

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- _ line is at the centre of each light band, the distance between each line is the ________ and when the muscle contracts it shortens
- _ zone is found in the centre of each dark band, when the muscle contracts the H zone _______

- Z line is at the centre of each light band, the distance between each line is the sarcomere and when the muscle contracts it shortens
- H zone is found in the centre of each dark band, when the muscl contracts the H zone decreases

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Sliding filament model:
The _____ filaments pull inwards towards the centre of the sarcomere
- the _ band becomes narrower
- the _ lines move closer together
- the _ zone becomes narrower

The actin filaments pull inwards towards the centre of the sarcomere
- the I band becomes narrower
- the Z lines move closer together
- the H zone becomes narrower

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Structure of myosin:
- ______ heads allow them to move back and fowards
- head has a binding site for _____ and ___
- ____ have hundreds of myosin molecules which wrap around each other to form myosin

- globular heads allow them to move back and forwards
- head has a binding site for actin and ATP
- tails have hundreds of myosin molecules which wrap around each other to form myosin

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Structure of actin:
- ____-_____ binding sites for myosin to bind
- often blocked by _________ which is held in place by troponin

- actin-myosin binding sites for myosin to bind
- often blocked by tropomyosin which is held in place by troponin

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Muscle is relaxed:
- actin-myosin sites blocked by _________
- myosin sites can't bind to actin
- ________ can't slide past each other

- actin-myosin sites blocked by tropomyosin
- myosin sites can't bind to actin
- filaments can't slide past each other

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Muscle is contracted:
- actin-myosin cross ______ formed by myosin heads forming bonds with actin
- myosin heads ____, pulling actin filament along myosin
- myosin ______ from actin and returns to its original angle using ___

- actin-myosin cross bridges form...
- myosin heads flex, pulling actin filament along myosin
- myosin detaches from actin and returns to its original angle using ATP
- myosin reattaches further along actin, repeats

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How contraction occurs:
1. AP arrives at ___________ junction
2. Stimulates ______ ion channels to open
3. They diffuse from ______ into synaptic knob
4. Causing _____ to fuse with presynaptic membrane

1. AP arrives at neuromuscular junction
2. Stimulates calcium ion channels to open
3. They diffuse from synapse into synaptic knob
4. Causing vesicles to fuse with presynaptic membrane

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5. ___________ released into synpatic cleft by exocytosis and diffuse across synapse
6. Binds to _______ on postsynaptic membrane
7. Opening ______ ion channels, resulting in depolarisation

5. Acetylcholine released into synaptic cleft by exocytosis and diffuse across synapse
6. Binds to receptors on postsynaptic membrane
7. Opening sodium ion channels, resulting in depolarisation

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8. Acetylcholine broken down by ______________ into choline and ethanoic acid
9. Diffuse back into neurone, recombined with ___________ using ATP

8. Acetylcholine broken down by acetylcholinsterase into choline and ethanoic acid
9. Diffuse back into neurone, recombined with acetylcholine using ATP

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What happens in the sarcoplasm:
1. AP reaches ________ reticulum, opening ______ ion channels
2. ______ ions diffuse into the sarcoplasm
3. They bind to _______ causing it to change shape

1. AP reaches sarcoplasmic reticulum, opening calcium ion channels
2. Calcium ions diffuse into the sarcoplasm
3. They bind to troponin causing it to change shape

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Neuronal communication (M5)

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