Week 2; anatomy of the CNS

Question 1

What is white matter ?

Answer 1

Predominated by myelinated axons/fibers. This matter is deep in the brain, and superficial in the spinal cord

Question 2

What is grey matter ?

Answer 2

Predominated by unmyelinated dendrites and soma (cell body). Grey matter is superficial in the brain and deep in the spinal cord.

Question 3

What are the main functions of the cerebrum ?

Answer 3

1. conscious thought and intellect
2. movement
3. memory
4. sensation

Question 4

4 sections of the cerebrum and their functions

Answer 4

1. frontal (motor)
2. parietal (proprioception)
3. Temporal (seeing)
4. Occipital (hearing)

Question 5

What separates the two hemispheres of the cerebrum ?

Answer 5

longitudinal fissure

Question 6

What separates the frontal and parietal lobe ?

Answer 6

Central suculus

Question 7

What are the two gyrus’s in the cerebrum ?

Answer 7

Precentral gyrus (site of primary motor cortex). Postcentral gyrus (site of primary sensory cortex)

Question 8

What are the three regions of the cerebral hemisphere ?

Answer 8

1. Cerebral cortex (outer grey matter)
2. Inner white matter
3. Basal nuclei (grey matter located deep within the white matter)

Question 9

What does contralateral mean for the brain?

Answer 9

Each hemisphere receives/sends from/to the contralateral side of the body

Question 10

3 Main different functions of the cerebral cortex:

Answer 10

1. motor areas - controlled voluntary movement
2. sensory areas - awareness of sensation
3. Association areas - multiple inputs and outputs

Question 11

3 types of white matter

Answer 11

1. association fibers - connect different parts of the same hemisphere
2. commissural fibers - connect grey areas of two hemispheres (e.g. corpus callosum and dorsal/ventral fibers)
3. projection fibers - vertical tracts that connect the cerebral cortex with subcortical structures

Question 12

What are basal nuclei and their functions ?

Answer 12

Grey matter found deep within the white matter. Involved in control of skeletal muscle, cognition and emotion, and receive input from entire cerebral cortex

Question 13

3 parts of the diencephalon

Answer 13

1. thalamus, relay and processing for sensory information
2. hypothalamus, emotion, hormones, body temp, autonomic
3. epithalamus, sleep and melatonin

Question 14

3 parts of the brain stem

Answer 14

1. mid brain
   contains nuclei for visual/auditory information and controls reflexes
2. pons
   ascending, descending and transverse tracts involved in respiration
3. medulla oblongata
   most inferior, joins spinal cord at the foramen magnum of skull. Autonomic reflexes; swallowing, hiccup, heart rate etc.

Question 15

Cerebellum function:

Answer 15

equilibrium, balance and coordination
- spheres are connected by vermis
- connected to brain stem via cerebellar pendules
- happens subconsciously

Question 16

What is the spinal cord and its main function ?

Answer 16

• cylindrical extension of the medulla oblongata
• enclosed in vertical column
• The spinal cord provides two communication from the bran and body and is the major reflex center, initiated and completed at the spinal cord.

Question 17

How do the spinal nerves connect to the spinal cord ?

Answer 17

Through the dorsal root (sensory) and ventral root (motor)

Question 18

3 important parts in the cord :

Answer 18

1. conus medullaris
2. cauda equina
3. filum terminale

Question 19

where does the spinal cord end ?

Answer 19

L1-L2 at conus medullaris

Question 20

the 3 meninges and their function/role :

Answer 20

1. dura mater, composed of 2 layers, the outer layer is fused to the periosteum. The dura venous sinuses to collect blood and the dura folds to anchor
2. Arachnoid matter, loose connective tissue, the trabeculae attaches to pia. The LSF in subarachnoid space provides fluid for cushioning
3. Pia mater, follows the contour of sulci and gyri, is rich will small blood vessels that drain venous blood to dura

Question 21

In the spinal cord, what else do they have?

Answer 21

epidural space surrounds the dura of the spinal cord