Week 10 - Somatic Nervous System

Question 0

What are the characteristics of the arachnoid mater?

Answer 0

• Flimsy layer
• contains csf
• arachnoid villi protrude through gaps in dura

Question 1

What are the characteristics of the dura mater

Answer 1

• dense, tough, made up of collagen
• outer periosteal layer adheres to periosteum
• inner meningeal layer
• these two layers separate to accommodate meningeal vessels and dural sinuses containing CSF
• dural septa: where layers meet; falx cerebri

Question 2

What are the characteristics of pia mater?

Answer 2

• Very thin layer that closely adheres to lining of brain and spinal cord surfaces

Question 3

What is the ventricular system for?

Answer 3

See picture

Question 4

What is the function for cerebrospinal fluid?

Answer 4

See picture

Question 5

Name the 4 ventricles and identify them on the image and CT scan

Answer 5

See picture

Question 6

Where dies the csf drain into after it reaches the fourth ventricle?

Answer 6

It is resorbed into the venous system by arachnoid villi

Question 7

What are the four functional types of nerve axon?

Answer 7

General sensory afferent - sensory from muscles, skin joints (somatic)
General visceral afferent - sensory from viscera

General visceral efferent - motor to visceral organs
General somatic efferent - motor to skeletal muscles

Question 8

What Re upper motor neurones?

Answer 8

Neurones contain completely within CNS
They serve to;
Control lower motor neurone activity

Question 9

What are Lower motor neurones?

Answer 9

Neurones whose cell body is in the CNS and axon passes into peripheral nerve to innervate skeletal muscle e.g. Spinal nerve

Serve to signal to motor end plate or muscle to initiate contraction

Question 10

What is a motor unit?

Answer 10

Lower motor neurone and all the skeletal muscle it innervates

Question 11

Where are the cell bodies of the lower motor neurones found?

Answer 11

Ventral horn of spinal cord

Question 12

Spinal cord receives afferent information from where to cause movement?

Answer 12

• motor spindles found in between extrafusal myofibres

- golgi tendon organs

Question 13

What do muscle spindles and golgi tendon organs detect?

Answer 13

Muscle spindles detect muscle length and golgi tendon organs detect muscle tension

Question 14

What are the 5 areas of control of movement?

Answer 14

• cortex
• basal ganglia
• cerebellum
• descending pathways and spinal cord circuits
• lower motor neurones

Question 15

What is the difference between neuromuscular junctions and synapses?

Answer 15

-

Question 16

What are the meningeal layers of the brain starting with directly below the skull

Answer 16

• dura mater
• arachnoid mater
• pia mater