Nervous system

Question 1

What is a ganglion?

Answer 1

Collection of nerve cell bodies

Question 2

What are dendrites?

Answer 2

Extensions from the body that allow us to increase the surface area of a cell

Question 3

What is the difference between a single axon an a named nerve?

Answer 3

Single axons only transmit a single fibre type (motor/sensory) but named nerves are a collection of axons so can transmit several fibre types

Question 4

What are the 6 functions of a single nerve fibre(axon)?

Answer 4

1) Somatic sensory
2) Somatic motor
3) Special sensory
4) Visceral afferent
5) Sympathetic
6) Parasympathetic

Question 5

What is the somatic sensory function?

Answer 5

It gives sensation and tells the spinal cord/brain about a pain somewhere on the body wall

Question 6

What is the somatic Motor function?

Answer 6

It causes something to move/twitch and tell a skeletal muscle to contract

Question 7

What is the special sensory function?

Answer 7

Tells the brain about a “special” sensation: sight, smell,taste,sound,balance

Question 8

What is the visceral afferent function?

Answer 8

Tells the spinal cord/brain about a pain from an organ

Question 9

What is sympathetic/ parasympathetic function?

Answer 9

Part of the autonomic nervous system and tells cardiac or smooth muscle to contract or a gland to secrete

Question 10

What are the components of the central nervous system?

Answer 10

Brain and spinal cord

Question 11

What makes up the peripheral nervous system?

Answer 11

• 12 pairs of cranial nerves mainly in contact with the brain e.g vagus nerves
• 31 pairs of spinal nerves that connect with the spinal cord and have named branches e.g phrenic

Question 12

What nerve supplies the soma (body wall)?

Answer 12

Spinal nerves

Question 13

What does the posterior ramus do?

Answer 13

Supplies the back (posterior part of the body wall) with sensation and motor supply

Question 14

What does the anterior ramus do?

Answer 14

Supplies the rest of the body walls (anterolateral part of the body wall)

Question 15

What is the function of the nervous system?

Answer 15

Allows us to sense our environment and to effect an appropriate response

Question 16

What are the 2 categories of the nervous system?

Answer 16

• somatic- external environment

- autonomic nervous- internal environment

Question 17

What does the somatic nervous system do and where are the neurones found?

Answer 17

Supplies the soma and responds to external environment.

-The neutrons are found in spinal nerve branches i.e intercostal/phrenic

Question 18

What is the functions autonomic nervous?

Answer 18

Senses and responds to internal environment i.e heart rate and is involuntary as we dont need to think about it

Question 19

What is ‘flight or flight’ controlled by?

Answer 19

Sympathetic nervous system

Question 20

Describe the sympathetic supply to the soma?

Answer 20

• in ‘fight or flight’ , action potential are generated in autonomic centres in the brain
• the conducted via the spinal cord into T1-L2 spinal nerves
• sympathetic axons then enter all spinal and then all anterior and posterior ram I to be carried to the body wall

Question 21

What thoracolumbar outflow?

Answer 21

Action potentials conducted into T1-L2 spinal nerves

Question 22

How do sympathetic access head / neck and organs?

Answer 22

• on the arteries to ‘hitch a ride” to head and neck structures
• on arteries or cardiopulmonary splanchnic nerves

Question 23

What do sympathetic connections (rami communications) connect?

Answer 23

Spinal nerves T1 to L2 and the paravertebral ganglia of the sympathetic trunk

Question 24

What neurotransmitter lies in all paravertebral ganglia as part of the sympathetic system?

Answer 24

noradrenaline

Question 25

What do pharmacological agents (drugs) do at synapses as part of the sympathetic system?

Answer 25

Target synapses to block the action of noradrenaline to e.g. modify a patients blood pressure etc

Question 26

What is parasympathetic (craniosacral) “outflow” ?

Answer 26

Nerves containing parasympathetic axons travelling to only the organs - not the body wall

Question 27

What nerves are parasympathetic carried in?

Answer 27

-cranial nerves III, VII,IX,X (mainly the vagus nerves) and sacral nerves

Question 28

What neurotransmitter is found in parasympathetic ganglia system?

Answer 28

acetylcholine

Question 29

What do pharmacological agents (drugs) do at synapses as part of the parasympathetic system?

Answer 29

Target the synapse to block the action of acetylcholine and e.g. dilate an asthmatic patients bronchioles etc