Lecture 20: Organization Of Nervous System

Question 1

What are the 2 systems of the peripheral nervous system?

Answer 1

Somatic nervous system and autonomic nervous system

Question 2

What are the 2 systems of the autonomic nervous system?

Answer 2

Sympathetic and parasympathetic

Question 3

What are sensory / afferent fibres?

Answer 3

Fibres that carry impulses towards CNS

Question 4

What are motor / efferent Fibres?

Answer 4

Fibres carrying Impulses away from the CNS

Question 5

What is a ganglion?

Answer 5

Accumulation of neuron cell bodies outside the CNS

Question 6

How do ganglion cells of sensory nerves look like?

Answer 6

Round with large ovoid nuclei and conspicuous nucleoli

Question 7

How do autonomic ganglia look like?

Answer 7

Small, usually multipolar, giving off several dendritic processes and unmyelinated axons

Question 8

What does the somatic nervous system do?

Answer 8

Cope with external environment

Question 9

What does the autonomic nervous system do?

Answer 9

Control the internal environment

Question 10

What kind of organ the somatic nervous system target?

Answer 10

Skeletal muscles

Question 11

What 3 kinds of organs do autonomic nervous system target.?

Answer 11

Smooth muscle, cardiac muscle, glands

Question 12

Where are the 2 places where autonomic preganglionic neurons cell bodies found in the CNS?

Answer 12

Sympathetic - lateral horn in T1-L2 cord segments

Parasympathetic - S2-S4 cord segments and brain stem

Question 13

What are the 3 routes that sympathetic preganglionics can supply the skin via?

Answer 13

1. Synapse at the level of entry
2. Ascend the chain then synapse
3. Descend the chain then synapse

Question 14

How and what does the sympathetic preganglionics supply when it synapses at the level of entry?

Answer 14

Supplies dermatome sat the T1-L2 levels, so postganglionics get to their targets through the T1-L2 spinal nerves

Question 15

How and what does the sympathetic preganglionics supply when it ascends the chain then synapses?

Answer 15

Typically supplies head and neck, post ganglionics get to their targets along the walls of blood vessels

Question 16

How and what do the sympathetic preganglionics supply when it descends the chain then synapses?

Answer 16

Typically supplies lower limbs, get to their targets through the spinal nerves at level L3 and below

Question 17

How do sympathetic nervous system distribute to abdominal viscera?

Answer 17

Can also traverse the chain then synapse in a pre-aortic ganglion and get to their targets along blood vessels

Question 18

How do sensory Fibres travel?

Answer 18

Sensory Fibres also travel along sympathetics destined for the abdomen and relay pain from viscera back to the CNS

Question 19

Where do parasympathetic preganglionic neurons usually synapse?

Answer 19

In ganglia that sit close to their target organs

Question 20

What does the vagus nerve do?

Answer 20

Major source of parasympathetic preganglionic input to the thoracic and abdominal viscera

Question 21

What are the 4 specialized parasympathetic ganglia in the head?

Answer 21

Ciliary, pterygopalatine, submandibular, otic

Question 22

What does the ciliary ganglion do?

Answer 22

Receive parasympathetic preganglionics from the oculo motor nerve, distributes parasympathetic posrganglionics to the eye

Question 23

What does the pterygopalatine ganglion do?

Answer 23

Receives parasympathetic preganglionics from facial nerve and distributes parasympathetic posrganglionics to the lacrimal gland

Question 24

What does the submandibular ganglion do?

Answer 24

Receives parasympathetic preganglionics form the facial nerve and distributes parasympathetic posrganglionics to the submandibular and sublingual salivary glands

Question 25

What does the otic ganglion do?

Answer 25

Receives parasympathetic preganglionics from the glossopharyngeal nerve and distributes parasympathetic posrganglionics to parotid gland