BIOL 273 - Unit 2.5

Question 1

the two efferent branches of the peripheral nervous system

Answer 1

1. Autonomic division
2. Somatic division

Question 2

What does the autonomic division consist of

Answer 2

• 2 neuron chain
• goes to innervate smooth and cardiac muscle , glands, adipose tissue
• involuntary division

Question 3

What does the somatic division consist of

Answer 3

• innervates skeletal muscle
• voluntary division

Question 4

2 branches of the autonomic division and what are their functions

Answer 4

1. Sympathetic (prepares the body physical activity and stress) “fight or flight”
2. Parasympathetic “rest and digest”

Question 5

Describe the similarities between the sympathetic and parasympathetic branches

Answer 5

• same structure : two neuron chain between CNS and effector
• synapse between neurons is in cell clusters aka autonomic ganglia

Question 6

What are the cells leading from the central nervous system to the ganglion called

Answer 6

preganglionic

Question 7

What are the cells leading from the ganglion to the effector called

Answer 7

postganglionic

Question 8

What are the two primary neurotransmiitters of the autonomic system

Answer 8

1. Acetylcholine (ACh)
2. Norepinephrine

Question 9

What is the neurotransmitter acetylcholine (ACh) released by and where does it release to

Answer 9

released by ALL pre-ganglionic neurons (sympathetic+parasympathetic) onto nicotinic receptors

Question 10

What post ganglionic neuron does Acetylcholine release from and where does it release to

Answer 10

post ganglionic parasympathetic neurons releases onto cholinergic muscarinic receptors

Question 11

Where does neurotransmitter Norepinephrine release from and where is it released onto

Answer 11

released by most post-ganglionic sympathetic neurons onto adrenergic receptors

Question 12

What does the autonomic pathway innervate (3)

Answer 12

• smooth and cardiac muscle
• Exocrine and endocrine glands
• adipose tissue

Question 13

Varicosity function

Answer 13

allows for a less directed form of communication than that which occurs between a somatic motor neuron and a skeletal muscle

• diffuse release means that a single postganglionic neuron can affect a garge area of target tissue

Question 14

How does the synapse structure differ from model synapse

Answer 14

axon ends with swollen areas at distal ends called a varicosity

Question 15

What does varicosity contain

Answer 15

• vesicles with neurotransmitter to be released into interstitial fluid

Question 16

What does the varicosity encounter

Answer 16

a receptor on the effector cell

Question 17

How does neurotransmitter action terminate on varicosity

Answer 17

terminated by diffusion, metabolism or actively transported back into cells near synapse

Question 18

What are the two types of receptors

Answer 18

1. Adrenergic receptors
2. Cholinergic receptors

Question 19

What kind of neurotransmitters do adrenergic receptors respond to

Answer 19

epinephrine and noreponephrine

Question 20

Describe alpha 1 receptors of adrenergic receptors , where is it found and what receptors does it best respond to

Answer 20

• found on most tissues
• respond best to norepinephrine

Question 21

Describe beta 1 receptors of adregenic receptors , where is it found and what does it respond to

Answer 21

• found in heart muscle and kidney
• responds to norepinephrine and epinephrine equally

Question 22

Describe beta 2 receptors of adregenic receptors, where is it found and what does it respond to

Answer 22

• found in blood vessels, smooth muscle
• responds to epinephrine more than norepinephrine

Question 23

What assists in the neurotransmitter retrieval of adrenergic receptors

Answer 23

G proteins

Question 24

What can beta 1 and beta 2 receptors of adrenergic receptors stimulate production of what

Answer 24

cAMP production

Question 25

What can alpha 1 receptors of adrenergic receptors do

Answer 25

increases calcium ion levels in the cytoplasm

Question 26

What are the two major classes of cholinergic receptors

Answer 26

1. nicotinic
2. muscarinic

Question 27

What are nicotinic receptors of cholinergic receptors stimulated by

Answer 27

ACh and nicotine

Question 28

What are muscarinic rceptors of cholinergic receptors stimulated by

Answer 28

ACh and muscarine

Question 29

Where are nicotinic receptors found (2)

Answer 29

1. on motor end plates on skeletal muscle
2. sympathetic and parasympathetic ganglia

Question 30

Where are muscarinic receptor of cholinergic receptors found

Answer 30

on target tissues of the parasympathetic system

Question 31

How do nicotinic receptors of cholinergic receptors act

Answer 31

act via ion channels (Na+ goes into cell)
*always excitatory

Question 32

How do muscarinic receptors of cholinergic receptors act

Answer 32

act via G proteins
*may be excitatory or inhibitory

Question 33

What are the two parts of the adrenal gland

Answer 33

1. Adrenal cortex
2. Adrenal medulla

Question 34

Function of adrenal cortex of the adrenal gland

Answer 34

secretes steroid hormones

Question 35

Function of adrenal medulla of the adrenal gland

Answer 35

associated with the sympathetic division
- modified sympathetic ganglion

Question 36

How many neurons carrying information from CNS to effector in the somatic division

Answer 36

a single neuron , causing muscle excitation , cannot inhibit function

Question 37

Describe the neuromuscular junction

Answer 37

the synapse between a somatic motor neuron and a skeletal muscle fiber

Question 38

What 2 two strucutres are involved in neuromuscular junction

Answer 38

Schwann cells around the terminal boutons at the synapse

Question 39

What are the three components of the neuromuscular junction

Answer 39

1. Pre-synaptic axon terminal
   - filled with neurotransmitter
2. Synaptic cleft
3. Post-synaptic membrane
   - motor end plate, nicotinic ACh receptor channels