524- Nervous B (PNS)

Question 1

What are sensory nerve receptors? (Function)

Answer 1

nervous system organs found in the PNS that react to different kinds of stimuli. There are multiple types.

Question 2

What are mechanoreceptors?

Answer 2

receptors reacting to:

• pressure,
• touch,
• vibration.

Question 3

What is the role of receptors?

Answer 3

When a stimulus occurs, it changes it to action potentials that are sent along the sensory neurons towards the CNS to be processed. (transduction)

Question 4

Anatomy of nerves

Answer 4

neurons, connective tissues, blood vessels.

• each axon is wrapped by connective tissue (“endoneurium”)
• a bundle of wrapped axons is called a “fascicle”
• the connective tissue layer surrounding the fascicle is the “perineurium”
• within a nerve there are many fascicles and some blood vessels, wrapped in connective tissue called “epineurium”.

Question 5

Difference between cranial and spinal nerves?

Answer 5

they both transport action potentials into and out of

⭐cranial nerves: the brain

⭐spinal nerves: the spinal cord.

Question 6

What are the spinal nerves?

name

Answer 6

are nerves that transmit action potentials into and out of the spinal cord.
They are 31 paired mixed nerves that are named according to the level of the spinal cord they come out of. They are:

⭐Cervical      > C1 - C8
⭐Thoracic     > T1 - T12
⭐Lumbar       > L1 - L5
⭐Sacral         > S1- S5
⭐Coccygeal > Co1

Question 7

Differences between somatic and autonomic nervous system?

Answer 7

⭐ Somatic:
voluntary
effectors: skeletal muscle
1 neuron between CNS and effector
HEAVILY myelinated (conducts action potentials FASTER)

⭐Autonomic:
involuntary
effectors: smooth, cardiac muscle and glands
2 neurons between CNS and effector
LIGHTLY myelinated

Question 8

What are the nerves found in the brain that correlates with the rest of the body? (12)

• are they sensory, motor or both neurons? (12)

Answer 8

⭐ OOOTTAFAGVSH

-olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, auditory, glossopharyngeal, vagus, spinal accessory, hypoglossal

⭐ SSMMBMRSBBMM

Question 9

Difference between sympathetic and parasympathetic nervous system?

Answer 9

⭐Sympathetic

• stress and exercise (emergency, fight/flight)
• Energy use

⭐Parasympathetic

• rest and digest (urinate, defecate)
• energy storage

Question 10

What is a ganglion?

> How does the (2) autonomic neurons reach the effectors?

(what happens here?)

Answer 10

collection of cell bodies where many synapses occur! in the PNS, it’s called “ganglion”,

> between CNS and ganglion (preganglionic)

> ganglion to effector organ (postganglionic)

The 2 autonomic motor neurons SYNAPSE inside a ganglion.

Question 11

1) What is a cholinergic neuron and receptor?

2) What is an adrenergic neuron and receptor?

Answer 11

1) secretes ACh, binds ACh

2) secretes noradrenaline, binds noradrenaline

Question 12

How does noradrenaline (/”norepinephrine) affect its effectors through binding with receptors?
(3)

Answer 12

⭐Alpha receptors: blood vessels (vasoconstriction)

⭐Beta receptors:

• beta 1: mainly in heart
• beta 2: smooth muscles in bronchioles