Human Movement And Sensation

Question 1

Sections of the brain

Answer 1

Question 2

Major sucli, gyri and fissures

Answer 2

Question 3

Functions associated with lobes of the cerebrum (cerebral cortex)

Answer 3

Question 4

Major divisions of the brain

Answer 4

Question 5

Anatomy of the ventral aspect

Answer 5

Question 6

Internal structures of the brain - coronal view

Answer 6

Question 7

Three types of white matter

Answer 7

White matter is categorised based off where axons go
1 - commusurial tracts
2 - projection tracts
3 - association tracts

Question 8

Commusurial tract

Answer 8

• axons move from side to side across the brain so left and right side can communicate
  E.G corpus callosum

Question 9

Projection tract -type of white matter

Answer 9

• axon extends from cortex to other area of CNS outside cerebrum
  E.g corticospinal tract

Question 10

Association tracts

Answer 10

• co ordination of areas through axons on same side
• axons on same side within cerebral cortex
• communication between brain areas - short or long

Question 11

Parietal lobe - post central gurus

Answer 11

• post central gurus is the place where the primary somatocortex is - thus there are cell bodies in the post central gurus and they are the final recipeieetns of that information - allows you to have conscious awareness of a stimulius
• post central gyrus functions as the primary somatosensory cortex
• specific regions of the somatosensory system receive sensory information form specific regions of the body

Question 12

Pre-central gurus - major coritacal area for efferent motor control

Answer 12

• the pre central gyrus functions as the primary motto cortex
• specific regions of the motor cortex control specific regions of the body
• upper motor neuron extends axon to lower motor neuron to control effector - effector being controlled depends on location of cell body of upper neuron on cerebral cortex (primary motor cortex - pre central gyrus)

Question 13

The corticospinal Pathway

Answer 13

• somatic efferent pathway
• two neurons between brain and effector
  UPPER AND LOWER MOTOR NAURONS

UPPER MOTOR NEURON:
- Cell body in pre central gyrus of motor cortex
- axon extends from motor cortex to spinal cord on opposite side during the medela
- makes synapse on Lower motor neuron

LOWER MOTOR NEURON:
- cell body extend in ventral horn of spinal cord
- axon extends out of the spinal cord (ventral root) into body
- makes synapse on skeletal muscle

Question 14

Damange to primary motor cortex

Answer 14

Damage to motor cortex —-> muscle weakness + paralysis in reguion of body corresponding to the location of damage, opposite side

Question 15

Dorsal column pathway

Answer 15

• three neurons between sensory receptor in body and somatosensory neuron in post central gyrus

NEURON ONE:
- cell body in dorsal root ganglion
- peripheral fibre (input) from sensory receptor in skin
- axon (central fibre) (output zone) ascends towards Brian in dorsal columns (spinal cord white matter)
- makes synapse on neuron 2 in medulla oblongata

NEURON TWO:
- cell body in medulla oblongata
- axon crosses to opposite side and ascendes
- makes synapse w neauron 3 in thalamus

Neuron THREE:
- cell body in thalamus
- axon extends to somatosensory cortex
- makes synapse on cell body of a somatosensory sensory cortex neuron
= perception

Question 16

Primary somatosensory cortex damage:

Answer 16

Cell in somatosensory cortex that receives information form dorsal column pathway dies
- ascending information has no place to go
- no perception of touch in that area of body on opposite side