HUBS 191 Lecture 22

Question 1

why are our brains extensively folded

Answer 1

it allows us to increase the surface area of our brains without needing to make the brain case bigger

Question 2

what does the central sulcus seperate

Answer 2

the frontal and parietal lobes

Question 3

what does the lateral sulcus seperate

Answer 3

the temporal lobe from the frontal and parietal lobes

Question 4

what does the transverse fissure seperate

Answer 4

the cerebrum from the cerebellum

Question 5

what is the frontal lobe associated with

Answer 5

language and personality as well as motor control

Question 6

what is the parietal lobe associated with

Answer 6

somatosensory - it also contains the secondary processing centre for visual stimuli

Question 7

what is the occipital lobe associated with

Answer 7

vision - V1 is located here

Question 8

what is the temporal lobe associate with

Answer 8

memory and hearing

Question 9

what composes the diencephalon

Answer 9

thalamus
hypothalamus

Question 10

what is the thalamus associated with

Answer 10

it is were sensory information comes through

Question 11

what is the hypothalamus associated with

Answer 11

the pituitary gland and is involved in hormonal regulation and homeostasis

Question 12

what is the cerebellum involved in

Answer 12

fine motor control

Question 13

what is the brainstem composed of

Answer 13

mid brain, pons and the medulla oblongata

Question 14

what is the brainstem responsible for

Answer 14

it is in control of all basal functions such as HR, breathing, blood pressure etc

Question 15

what does the cerebrum sit on top of

Answer 15

the corpus callosum which is white matter (axons)

Question 16

why does the white matter appear as white

Answer 16

because the axons are myelinated (wrapped in lipids)

Question 17

what are the three types of white matter

Answer 17

commissural tracts, projection tracts, association tracts

Question 18

what are commissural tracts

Answer 18

a type of white matter in which axons cross from side to side in both directions. these tracts are very tough similar to like a bundle of wires

Question 19

of the three types of white matter which is the corpus callosum

Answer 19

a commisural tract - it is one of only 3 points in which the two hemispheres of the brain communicate with each other

Question 20

what are projection tracts

Answer 20

axons that extend between the cortex and other CNS areas outside the cerebrum. for example the corticospinal tract (somatic motor pathway)

Question 21

what are association tracts

Answer 21

axons on the same side within the cerebral cortex. they allow communication between brain areas and can be either short or long distance. they are ipsilateral meaning connections between nuceli that don’t cross the hemispheres

Question 22

in the somatic efferent division how many neurons are there and are they myelinated

Answer 22

2 - the upper and lower motor neurons both of which are myelinated

Question 23

in the somatic efferent division what neurotransmitter is used and what is the effector

Answer 23

acetylcholine is used and the effectors are skeletal muscles

Question 24

where is the primary motor cortex

Answer 24

in the frontal lobe - pre central gyrus

Question 25

where is the primary somatosensory cortex

Answer 25

in the parietal lobe - post central gyrus

Question 26

what is the corticospinal pathway responsible for

Answer 26

somatic efferent

Question 27

in the corticospinal pathway where is the upper motor neuron located

Answer 27

the cell body is in the primary motor cortex and the axons extends to the spinal cord on the opposite side

Question 28

in the corticospinal pathway where is the lower motor neuron located

Answer 28

the cell body is in the ventral horn of the spinal cord and the axon extends out of the spinal cord (ventral root) into the body

Question 29

what does damage to the primary motor cortex lead to

Answer 29

muscle weakness and paralysis in the region of the body corresponding to the location of the damage on the opposite side

Question 30

what is the dorsal column pathway responsible for

Answer 30

fine touch, vibration, pressure and proprioception - somatic afferent

Question 31

in the dorsal column pathway how many neurons are between the sensory receptor and the somatosensory neuron in the post central gyrus

Answer 31

3

Question 32

in the dorsal column pathway where is neuron 1 located

Answer 32

the cell body is in the dorsal root ganglion (unipolar) peripheral fibre (input zone) from sensory receptor in the skin central fibre (output zone) ascends towards the brain in the dorsal columns (spinal cord white matter) and makes a synapse on neuron #2 in the medulla oblongata.

Question 33

in the dorsal column pathway where is neuron 2 located

Answer 33

the cell body is in the medulla oblongata the axon crosses to the opposite side and ascends makes a synapse on neuron 3 in the thalamus

Question 34

in the dorsal column pathway where is neuron 3 located

Answer 34

cell body is in the thalamus axon ascends to the somatosensory cortex makes a synapse on the cell body of a somatosensory neuron

Question 35

what information is the spinothalamic tract involved in

Answer 35

pain, temperature - more immediate than the dorsal column pathway - somatic afferent

Question 36

in the spinothalamic tract where is neuron 1 located

Answer 36

cell body in the dorsal root ganglion (unipolar neuron) makes a synapse on neuron 2 in the spinal cord

Question 37

in the spinothalamic tract where is neuron 2 located

Answer 37

cell body is in the spinal cord axon crosses to the opposite side via anterior white comminsure cells are called tract cells makes a synapse on neuron 3 in the thalamus

Question 38

in the spinothalamic tract where is neuron 3 located

Answer 38

the cell body is in the thalamus the axon ascends to the somatosensory cortex makes a synapse on the cell body of a somatosensory cortex neuron

Question 39

what happens in if a cell in the somatosensory cortex that receives information from the dorsal column pathway dies

Answer 39

ascending information has no where to go so there will be no perception of touch in that area of the body on the opposite side