5.5 Plant and Animal responses ... Flashcards
what is the nervous system split in to ?
2
- Peripheral nervous system
- central nervous system
what is the peripheral nervous system spilt into ?
2
- sensory system
- motor system
what is the motor system split into ?
2
- autonomic
- somantic
What is the autonomic nervous system split into ?
2
- sympathetic nervous system
- parasympathetic nervous system
What does the sympathetic nervous system do?
effects name three
total marks :4
- flight or fight response ( response to stress) increased heart rate dilated pupils increased ventilation rate reduced digestive activity
where are the ganglia in the sympathetic nervous system ?
2
- just outside the CNS
- short pre ganglionic neurones but long post ganglionic neurones
where are the ganglia in the parasympathetic system ?
2
- in effector tissue
- long neurones before
- short neurones after
what neurotransmitter does
a) sympathetic nervous system use ?
b) parasympathetic nervous system use ?
- a) symp = noradrenaline
b) para= acetylcholine
what does the cerebrum control ? 1
whats it split into ? 1
- conscious thought
- spilt into LHS/RHS cerebral hemispheres
what does the cerebellum control ?
where is it ?
- movement and balance (leaf like at the back of head )
what do the hypothalamus and pituitary system do ?1
- organise homeostatic resposes
what does the medulla oblongata do ? 1
- coordination of many autonomic functions
what areas are the cerebrum divided into ?
3
- sensory areas -receive AP’s from sensory neurones
- association areas - compare to previous experience and judge an appropriate response
- motor areas - AP to effector
what are the 4 lobes of the brain ?
4
- frontal lobe
- parietal lobe
- temporal lobe
- occipital lobe
what does the corpus callosum do ? 2
- separates the RIGHT and LEFT hemispheres of the brain
- also connects both half of the brain
list the parts of the Brian that’d be involved in driving a car
6
- The visual area / visual association area
- the auditory area / auditory association area
- the motor area in the cerebrum.
- Also the cerebellum
list part of the brain involved in answering a question verbally ?
4
- Auditory area
- auditory association area
- speech areas (Broca’s area)
- motor area in cerebrum.
why are reflexes so quick ?
4
- they don’t involve the CNS
- Myelinated neurones
- few synapses involved
- nervous pathway is short
When we pick up an expensive china plate , we don’t just drop it - why ?
4
- The eyes and nose detect that the object is of value;
- the association areas of the brain send impulses
- which inhibit the action of the synapse
- this prevents the response to let go.
why must the action potentials to override the neurones be carried by myelinated neurones ? 1
- so that they are quick and arrive at the synapse in time to stop the reflex action
what’s the difference between blinking and knee jerk reflex?
3
- blinking reflex is a cranial reflex so it passes through the brain = reflex arc ( 3 neurones = sensory , relay , motor)
- the knee jerk reflex = spinal reflex so it passes through he spinal cord instead of the brain
- it only has 2 neurones involved : sensory to motor
why are digestive disorders signs of long term stress?
2
- One action of adrenaline is to reduce blood flow to the digestive system.
- Therefore the digestive system may not receive sufficient blood flow to operate effectively.
how is it possible for an imagined threat to stimulate the fight or flight response ?
2
- The higher centres of the brain send impulses down the sympathetic part of the autonomic nervous system to the adrenal glands.
- This stimulates the release of adrenaline.
what are the steps to coordinate the fight or flight response ?
5
1- AP to sensory centre in brain
2- then AP to association centre
3-if threat is recognises then CEREBRUM STIMULATES HYPOTHALAMUS
4-HYPOTHALAMUS increases activity in SYMPATHETIC NERVOUS SYSTEM .
5-PITUITARY gland secretes hormones …
why is adrenaline a first messenger ?
1
- it can’t go inside of cells , but it must cause an effect inside the cell
so how does adrenaline cause action ?
4
- binds to receptor which is attached to G protein on plasma membrane
- activates enzyme adenyl cyclase
- adenyl cyclase converts ATP to cAMP (secondary messenger )
- the cAMP causes the effect inside the cell
whats the mechanism fro adrenaline action ? 4
- adrenaline binds to receptor (complementary ) on the plasma membrane
- This is attached to a G protein , which is stimulated to activate the enzyme - ADENYL CYCLASE
- Adenyl cyclase converts : ATP –> cAMP= secondary messenger
- this causes an effect by activating enzyme action
- adrenaline binds to receptor (complementary ) on the plasma membrane
what does adenyl cyclase do ? 1
- converts ATP to cAMP
what does the hypothalamus secrete ? 1
- releasing factors into the blood
- this stimulates activity in the endocrine glands
what does CRH cause ? and where is it secreted ? 3
- secreted by hypothalamus
- causes the release of ACTH—-> RELEASES CORTICOSTEROID HORMONES SUCH AS CORTISOL
What does TRH cause ? where is it secreted ?
3
- hypothalamus
- causes the release of thyroid stimulating hormone
- which makes the thyroid gland release thyroxine .
what does thyroxine do ? 1
- makes cells more sensitive to adrenaline .
where do we change the frequency of the heart rate?
- medulla oblongata
what route does an AP take to increase heart rate ?
2 neurotransmitter ?
- AP down sympathetic nerve - accelerans nerve .
- causes release of noradrenaline at SAN
route taken to decrease heart rate ?
neurotransmitter ? 2
- Vagus nerve
- acetylcholine
how can we decide whether to increase or decrease the heart rate ? 3
- chemoreceptors
- baroreceptors
- stretch receptors
- temperature recepetors
How do chemoreceptors change the frequency of the heart rate ?
5
how does it come back to normal ?
1- CO2 level increases
2-blood ph drops
3-chemoreceptors in carotid arteries increases frequency
of impulses to medulla oblongata
4-medulla oblongata = increases hear rate via sympathetic nervous system
5-heart rate increases = breathing rate increases so more CO2 is exhaled and blood PH comes back to normal .
what do stretch receptors in muscles do ? 3
- detect movement of limbs so send impulses to cardiovascular centre in the medulla oblongata
-informing that more O2 will soon be needed
= increase in heart rate !
what do stretch receptors in carotid sinus do ? 2
-monitor blood pressure
-if pressure is top high they send AP’s to medulla oblongata to reduce heart rate .
and so forth
what are the three types of muscle ?
3 what kinds are they ?
- skeletal ( striated and voluntary )
- involuntary : smooth and cardiac muscle
How is cardiac muscle specialised ?2
- intercalated discs - allow diffusion of ions between cells
- cross bridges to make a squeezing action
which kind of muscle is uninucleate , what does that mean ? 2
- involuntary
- cardiac
it means that each cell has its own nucleus .
