Somatic nervous system

Question 1

What are the functions of the nervous system?

Answer 1

Perception
Control
Communication
Memory

Question 2

What is the somatic nervous system?

Answer 2

Part of the nervous system that is under direct command of the human organism
Voluntary division of the NS

Question 3

What are the main divisions of the somatic nervous system?

Answer 3

Central nervous system (CNS)

Peripheral nervous system (PNS)

Question 4

What is the direction of signalling that takes place in the nervous systems?

Answer 4

Afferent system - to the brain (sensory)

Efferent system - from the brain (motor)

Question 5

What makes up the CNS?

Answer 5

Brain and spinal cord

Question 6

What are the various types of nervous tissue?

Answer 6

Neurones
Nerves - bundles of neurones
Macroglia
Microglia

Question 7

What are the 3 main types of neurone?

Answer 7

Multipolar
Bipolar
(Pseudo) Unipolar

Question 8

What is a multipolar neurone?

Answer 8

Large cell body
single axon
many dendrites

Question 9

What is a bipolar neurone?

Answer 9

single dendrite
short single axon
generally sensory

Question 10

What is a Pseudounipolar neurone?

Answer 10

Single dendrite from a common stem
short axon
Often sensory.

Question 11

What protects the CNS?

Answer 11

Bone - Skull & Vertebral column

Meninges - Connective tissue acting as a membrane around the brian and spinal cord

CFS - fluid present in the subarachnoid space.

Question 12

What are the layers of the Meninges?

Answer 12

Dura Matter
Arachnoid Matter
Pia Matter

Question 13

What is Grey matter?

Answer 13

Groups of neuronal cell bodies

Question 14

What is White matter?

Answer 14

Mainly myelinated axons

Question 15

What does the spinal cord consist of?

Answer 15

Grey matter
White matter
Spinal nerves

Question 16

What is the PNS?

Answer 16

Part of the NS outside of the CNS that connects the CNS to its target organs and tissues.
It also connects the sensory organs to the CNS

Question 17

What does the PNS consist of?

Answer 17

Cranial Nerves - 12
Spinal Nerves - 31 pairs of nerves
Ganglia - 25 pairs of autonomic, 31 pairs of sensory
Nerve Plexuses - Brachial, Lumbar, Sacral
Enteric Nervous System (ENS)

Question 18

What are the membranous envelops of the nerves?

Answer 18

From out to in:
Epineurium - Ensheathes the entire nerve
Perineurium - Ensheathes a nerve fascicle (collection of axons)
Endoneurium - Ensheathes a single cells axon.

Question 19

What are Dermatomes?

Answer 19

Areas of skin supplied by a single spinal nerve

Question 20

What are some features of Somatic Motorneurones?

Answer 20

Multipolar morphology
Cell bodies located in Ventral horn of spinal cord of cranial motor nuclei of the brain.
Largely Myelinated

Question 21

What are some features of Somatic Sensory Neurones?

Answer 21

Pseudo-unipolar morphology
Varying myelination levels between subtypes
- Some myelinated
- Some unmyelinated

Question 22

What are some properties of the somatic nervous system?

Answer 22

Exists in a bi-stable state (active/inactive)
Largely paralysed during REM sleep
Effector organ is skeletal muscle

Question 23

What is the Redlich-Obersteiner’s Zone?

Answer 23

Formal boundary between the CNS and PNS located where cranial nerves join the substance of the brain stem or spinal cord.

Question 24

What is different between the CNS and PNS?

Answer 24

They methods of myelination on axons.
CNS - Oligodendrocytes
PNS - Schwann Cells

Question 25

What type of tumours are found in the PNS?

Answer 25

All tumours are Benign

Question 26

What are malignant tumours a feature of in the CNS?

Answer 26

Features of Glia

Question 27

What are some diseases of the CNS?

Answer 27

Raised intercranial pressure

MS

Question 28

What are some diseases of the PNS?

Answer 28

Nerve compression syndrome

Demyelinating Polyneuropathies