Autonomic Nervous System

Question 1

What are the two main anatomical divisions of the nervous system?

Answer 1

1. Central nervous system- brain and spinal cord
2. Peripheral nervous system- neurons outside the brain and spinal cord, including any nerves that enter or leave the CNS

Question 2

What are the subdivisions of the efferent division of the PNS?

Answer 2

1. somatic nervous system- includes motor neurons, controls voluntary functions and contraction of skeletal muscles of locomotion.
2. autonomic nervous sytsem- regulates involuntary functions not under direct concsious control

Question 2

what are divisions of the autonomic nervous sytem(ANS)?

Answer 2

1. parasympathetic nervous sytsem- restores the body to homeostasis( rest and digest response)
2. sympathetic nervous sytem- prepares the body for emergancy ( fight or flight response)
3. enteric nervous sytem(GIT)- linkd the CNS and peipheral organs

Question 2

How is the peripheral nervous system subdivided?

Answer 2

Efferent division- neurons carry signals from the brain and spinal cord to the periphery
Afferent division- neurons carry signals from the periphery to the CNS

Question 2

What are the two types of neurons in the ANS pathway?

Answer 2

prepanglionic and postganglionic neurons

Question 2

what are the main processes regulated by the autonomic nervous sytem?

Answer 2

contraction and relaxaion of visceral and vascular smooth muscle
all exocrine and some endocrine secretions
heartbeat
energy metabolism( mainly in liver and skeletal muscle)
cardiac output(heartrate, blood pressure)
blood flow distribution
digestion
respiration

Question 3

What are the two main types of acetylcholine (ACh) receptors?

Answer 3

nicotinic and muscarinic receptors

Question 3

What are the two main neurotransmitter types in the ANS?

Answer 3

acetylcholine (ACh) and Noradrenaline (NA)

Question 4

What are the two main types of noradrenaline (NA) receptors?

Answer 4

Alpha and Beta receptors

Question 5

What do postganglionic parasympathetic and sympathetic fibres release?

Answer 5

parasympathetic- acetylcholine (ACh) and act on muscarinic receptors
sympathetic- noradrenaline (NA) and act on alpha or beta receptors

Question 5

What do all preganglionic fibres in the ANS release?

Answer 5

Acetylcholine (ACh) and act on nicotinic receptors

Question 6

What neurotransmitters are involved in the sympathetic nervous sytsem?

Answer 6

adrenaline (A) / epinephrine, acetylcholine (ACh), noradrenaline (NA)

Question 7

what is the main neurotransmitter in the parasympathetic division?

Answer 7

acetylcholine (ACh)

Question 8

What are the primary types of cholinergic receptors and their locations?

Answer 8

Muscarinic Receptors:
M1: Nerves
M2: Heart (myocardium, SA and AV node, smooth muscle, nerves)
M3: Glands, smooth muscle, endothelium
M4 & M5: CNS

Nicotinic Receptors:
N1/NN: Autonomic ganglia (post-ganglionic cell body), CNS
N2/NM: Skeletal muscle (neuromuscular junction)

Question 9

What is the primary neurotransmitter for adrenergic receptors?

Answer 9

noradrenaline

Question 10

What are the primary adrenergic receptors and where are they located?

Answer 10

Alpha (α) Receptors:
α1: Found in postsynaptic cells, mainly in smooth muscle.
α2: Located in presynaptic nerve terminals, platelets, lipocytes, and smooth muscle.
Beta (β) Receptors:
β1: Present in postsynaptic effector cells (cardiac muscle, SA node, lipocytes, brain), presynaptic cholinergic and adrenergic nerve terminals, renal tubules, and ciliary body epithelium (eye).
β2: Found in postsynaptic effector cells (cardiac muscle, smooth muscle in lungs).
β3: Located in postsynaptic effector cells (lipocytes, heart).

Question 10

What are the key steps in the lifecycle of neurotransmitters?

Answer 10

1. transmitter synthesis
2. transmitter storage
3. transmitter release
4. transmitter recognition by receptor
5. termination of action of transmitter