Animal responses Flashcards
1
Q
What are the parts of the nervous system?
A
- Central nervous system
- Peripheral nervous system
PNS:
- Sensory system
- Motor system
Motor system:
- Somatic nervous system
- Auonomic nervous system
ANS:
- Parasympathetic nervous sytem
- Sympathetic nervous system
2
Q
What does the CNS contain?
A
- Brain
- Spinal cord
- Relay neurone
3
Q
What does the PNS contain?
A
- Receptors
- Sensory neurones
- Motor neurones
4
Q
What is the role of the somatic nervous system?
A
Conscious actions
5
Q
What is the role of the autonomic nervous system?
A
Unconscious nervous system
6
Q
What is the role of sympathetic nervous system?
A
Increase in activity (fight or flight)
7
Q
What is the role of the parasympathetic nervous system?
A
Decrease in activity
(Calming down)
8
Q
What are the 5 parts of the brain?
A
- Cerebrum
- Cerebellum
- Medulla oblongata
- Hypothalamus
- Pituritary gland
9
Q
What are the functions of the cerebrum?
5x
A
- Controls voluntary action
- Memory
- Personality
- Learning
- Conscious thoughts
10
Q
What are the functions of the cerebellum?
A
- Coordinates muscular movement such as balance and posture
- Works closely with the cerebrum to have better control of motor functions
11
Q
What is the function of the medulla oblongata?
A
Autonomic control
(heart rate and ventilation)
12
Q
What are the functions of the hypothalamus?
3x
A
- Homeostasis - maintains internal environment
- Produces hormones to coordinate them at a stable level
- Main control of ANS
13
Q
What are the two lobes of the pituritary gland and their functions?
A
- Posterior - stores and releases hormones made by hypothalamus
- Anterior - produces hormones
14
Q
What is a ganglion?
A
A structure containing a number of nerve cell bodies, typically linked by synapses and often form swelling on a nerve fibre
15
Q
What are features of the sympathetic nervous system?
6x
A
- Neurotransmitter is noradrenaline
- Short preganglionic/post ganglionic neurone
- Flight or fight
- Increases breathing rate, diameter of airways and blood flow to skeletal muscle
- Dilates pupil
- Liver releases glucose
16
Q
What are features of parasympathetic nervous system?
6x
A
- Neurotransmitter is acetylcholine
- Long preganglionic neurones/short post ganglionic neurones
- Rest and digest
- Decreases the breathing rate, blood flow to sketetal muscle, diameter of airways
- Constructs pupils
- Liver stores glucose
17
Q
What does the hypothalamus do in flight or fight response?
3x
A
- Hypothalamus activates sympathetic nervous system
- Activates adrenal medulla
- Releases norepinephrine and epinepherine into the bloodstream
18
Q
What are the effects of norepinephrine and epinephrine (neurotransmitters which acts as a hormones)?
6x
A
- Flight or fight
- Increases the breathing rate
- Increases the diameter of airways
- Increase blood flow to skeletal muscle
- Dilates pupils
- Liver releases glucose
19
Q
How is heart rate increased?
7 steps
A
- Low blood pressure detected by baroreceptors
- Low blood pH detected by chemoreceptors
- Both send impulse to the medulla oblongata in cardiovascular centre
- Activates the sympathetic NS
- Impulse sent down accelerator nerve
- An increase in the frequency of wave of excitation from SAN
- Nerve impulse sent from the hypothalamus activate the adrenal medulla to release adrenaline and adrenal cortex to release cortisol
20
Q
How is heart rate decreased?
7 steps
A
- High blood pressure detected by baroreceptors
- High blood pH detected by chemoreceptors
- Both send impulse to medulla oblongata in cardiovascular centre
- Activates parasympathetic NS
- Impulse sent down vagus nerve
- A decrease in the frequency of waves of excitation from SAN
- Less nerve impulse sent from hypothalamus, less activation of the adrenal medulla, release adrenaline and adrenal cortex to release less cortisol
21
Q
What are four important things about reflexes?
A
- Involuntary actions - prevents overloading of the brain
- Innate - do not have to learn to protect ourselves
- Fast - only involves 1-2 synapses, reliant on speed of diffusion of neurotransmitter
- Part of our everyday action
22
Q
What is the knee jerk reflex used for?
A
It is a spinal reflex used to test for problems with nerves or cerebllar diseases
23
Q
What happens in the knee jerk reflex?
5 steps
A
- Tap under kneecap causes patellar tendon to stretch, which also stretches extensor
- Sends reflex arc impulse through sensory neurone
- Reflex signal goes along one motor neurone, extensor muscle to contract
- Relay neurone inhibits the motor neurone of flexor muscle, causing it to relax
- Leg kicks due to antagonistic muscle action
24
Q
What is the blinking reflex used for?
A
It is a cranial reflex
Asses if unconscious patients are brain dead (if the brain stem is still functioning or not)
25
What happens in the blinking reflex?
1. Cornea irritated (touching = corneal, light = optical)
2. Triggers impulse along sensory neurone
3. Relay neurone in the lower brain stem pass impulse along
4. Signal branches pff in motor neurone to eyelid muscles
26
What are the organelles in a muscle cell?
* Bundle of muscle fibres -> muscle fibres (nucleus, sarcoplasm, sarcoplasmic reticulum, multi nucleated)
* Myofibrils -> sarcomeres - contain protein filaments (actin and myosin)
Other things:
* Fibres arranged into myfibrils
* Myofibrils divided into sarcomeres
27
What makes up a sarcomere?
* Z line
* Thin filaments (actin)
* Thick filaments (myosin)
* H zone
* A band
* I band
28
What are the steps of the stimulation of a contraction?
| 5x
1. Action potentials arriving at the end of the axon open calcium ion channels in the membrane. Calcium ions flood into the end of the axon
2. Vesicles of acetycholine move towards and fuse with the end membrane
3. Acetylcholine molecules diffuse across the gap and fuse with the receptors in the sarcolemma
4. This opens sodium ion channels, which allow sodium ions to enter the muscle fibre, causing depolarisation of the sarcolemma
5. A wave of depolarisation spreads along the sarcolemma and down transverse tubules into the muscle fibres
29
What are the steps for the control of the contraction?
| 6 steps
1. When the muscle is stimulated, the action potential passes along the sarcolemma and down the transverse tubules into the muscle fibres
2. The action potential is carried to the sarcoplasmic reticulum which stores calcium ions and causes the release of calcium ions into the sarcoplasm
3. The calcium ions bind to the troponin which alters the shape, pulling the tropomyosin aside. This exposes the binding sites on the actin
4. Myosin heads binds to the actin forming crossbridges between the filament
5. The myosin heads move, pulling the actin filaments past the myosin filaments
6. The myosin heads detach from the actin and can bind again further up the actin
30
What is the role of ATP in muscles?
Part of the myosin heads act as ATPase and can hydrolyse the ATP to ADP +Pi which releases energy
31
What is ATP hydrolysed in muscles?
| 4 steps
1. Myosin head attaches to the actin filaments and forms crossbridges
2. Myosin head moves causing thin filament to slide past the myosin filament (power stroke) where ADP+Pi are released from the myosin head
3. After the power stroke new ATP molecule attaches to the myosin head which breaks the crossbridge
4. Myosin head returns to its original position as the ATP is hydrolysed, releasing the energy to make this movement occur
* Myosin head can now make a new cross bridge further along the actin filament
32
What are the three mechanisms by which ATP supply is maintained?
* Aerobic respiration
* Anaerobic respiration
* Creatine phosphate
33
What is the mechanism for flight or fight?
| 5 steps
1. Adrenaline binds to specific and complementary receptor within membrane of target cell
2. Triggers G protein to activate adenyl cyclase (effector)
3. Causes cyclic AMP to form
4. Triggers a response inside the cell
5. E.G hepatocytes: break down stores of glycogen into glucose so it can be used for aerobic respiration, making ATP
34
What is creatine phosphate?
* Occurs in sarcoplasm
* Phosphate group from creatine is transferred to ADP to form ATP
* Sufficient to support muscle contraction for 2-4 seconds
