Very Hard

Question 1

where is PNS and SNS

Answer 1

PNS is the cranial and sacral SNS is the lumbar and thoracic

Question 2

Electrical stimulation of postganglionic parasymaethic fibre to vessels

Answer 2

Acetylcholine and nitric oxide produce a rapid relaxation
The vasoactive intestinal peptide can produce a slow delayed response

Question 3

Electrical stimulation of postganglionic sympathetic fibre to vessel

Answer 3

ATP produces a fast contraction in the smooth muscle
Noradrenaline produces a moderately fast response
Neuropeptide Y produces a slow response

Question 4

Noradrenaline and adrenaline

Answer 4

Noradrenaline and adrenaline are endogenous agonist of a family of adrenoreceptors that are GPCRS
A adrenoceptors -> noradrenline -> adrenaline -> isoprenaline
B adrenoreceptors -> isoprenaline -> adrenaline -> noradrenaline

Question 5

what is motor neurons

Answer 5

Motor neurons - cell bodies in the cerbeal cortex and their axons extend down the spine

Question 6

what is a lower motor neuron

Answer 6

Lower motor neuron is neuron synapses are directly responsible for stimulating contraction which allows the generation of force that can lead

Question 7

what is extrafusal and intrafusal

Answer 7

extrafusal is a motorneuron and is the bulk of skeletal muscle fibres
Intrafusal is by y motorneuron and is the remaining speclaised fibres

Question 8

Stretch Myotatic Reflex

Answer 8

muscle stretch and group 1a afferent fibres in the muscle spindle start firing
these synapses on the motorneuron same muscle from which the group 1a afferent relayed the sensory information a motorneuron indcue contraction of skeletal muscle and the muscle returns to resting and firing la decrease

Question 9

Inverse Myotatic Reflex

Answer 9

muscle contracts, extrafusal fibres shorten and stimulate golgi tendon
group 1b afferent start firing and send sensory information to inhibitory interneurons they synapse on the spinal cord
inhibitory interneuron synapse on the a motorneuron muscle returns tot he resting length and firing frequency of group 1b decreases
synergist muscle also relax and antagonist muscle contracts

Question 10

Flexion withdrawl reflex

Answer 10

The leg that feels the pain the reflex inhibits in reflex inhibits the spinal cord extensor and estimates flexor
the opposite leg reflex stimulates spinal cord the motor neurons to extensor muscle and inhibits the motor neurons to the flexor

Question 11

Cardiopulmonary Baroreceptors

Answer 11

veno arterial stretch mechanoreceptors in pinkish bit
baroreceptors in the aorta
Non-myelinated mechanoreceptors below bit
Chemoreceptors left side

Question 12

Not all baroreceptors are created equal

Answer 12

Carotid sinus baroreceptors are more sensitive
the cause greater changes in blood pressure that aortic arch baroreceptors

Question 13

Long-term control differs

Answer 13

Long-term control differs
Relies on the control of blood volume
Think control of cardiac output by Starling’s law of the heart
Involves kidney