week 2

Question 1

do we have one thalamus or two thalami?

Answer 1

two thalami

Question 2

approx. how many neurons does a human brain contain?

Answer 2

~86 billion

Question 3

what does brains being expensive mean? (2)

Answer 3

1. expensive in terms of physiology – i.e., in humans, ~3lbs = 2% of body weight, but consumes ~25% of all metabolic energy (about 500cal/day).
2. expensive in terms of time – i.e., in humans, brain develops into mid/late twenties.

Question 4

what comprises the CNS?

Answer 4

brain (brain stem, thalamus) and spinal cord

Question 5

what comprises the PNS?

Answer 5

nerves (cranial, spinal), ANS and SNS

Question 6

which NS is encapsulated in bone?

Answer 6

CNS

Question 7

what is the purpose of gyrification?

Answer 7

more folds = more surface area (and more neurons) without big changes in skull size.

Question 8

t or f: the ratio of cerebrum: brainstem is almost 1:1 in human brain.

Answer 8

false

lizard brain* (humans = much larger)

Question 9

executive brain ratio = ???

Answer 9

cerebrum / brainstem

Question 10

which section of the brain is similar between humans and sheep?

Answer 10

midsection (corpus callosum, thalamus, hypothalamus)

Question 11

medial vs lateral

Answer 11

medial: towards middle
lateral: towards one side

Question 12

ipsilateral vs contralateral

Answer 12

ipsi: same side
contra: opposite sides

Question 13

superior vs inferior

Answer 13

superior: above
inferior: below

Question 14

anterior/rostral vs posterior/caudal

Answer 14

a/r: front/towards head
p/c: back/towards tail

Question 15

proximal vs distal

Answer 15

proximal: near trunk
distal: near periphery/end of limb

Question 16

dorsal vs ventral

Answer 16

dorsal: back of body OR top of brain
ventral: front of body OR bottom of brain

Question 17

whats a fissure

Answer 17

a major separation

Question 18

what does decussate mean

Answer 18

to cross the midline

Question 19

saggital plane

Answer 19

cut in half (long way)

Question 20

horizontal plane

Answer 20

cut across literal middle like slicing a bulka in half (left with top and bottom)

Question 21

frontal/coronal plane

Answer 21

cut across middle (from the front)

Question 22

what are the three ways of organizing the brain?

Answer 22

1. named by parts of skull
2. cellular differences
3. the 5 major divisions in embryonic development

Question 23

what are the 5 major divisions in embryonic development? (what do they start as and what do they develop into)

Answer 23

forebrain
midbrain
hindbrain
spinal cord

forebrain: telencephalon (cerebral hemispheres), diencephalon

midbrain: mesencephalon

hindbrain: metencephalon, myelencephalon (medulla)

spinal cord

Question 24

which of the 5 is most recently evolved and what does it do?

Answer 24

• telencephalon
• regulates mental processes (ex. cognition and forethought)

Question 25

function of frontal lobe (3)

Answer 25

executive functions, language, voluntary movement

Question 26

function of occipital lobe

Answer 26

vision (into parietal + temporal)

Question 27

function of parietal lobe (2)

Answer 27

touch, vision (where)

Question 28

function of temporal lobe (3)

Answer 28

language, hearing, vision (what)

Question 29

what is left (3) vs right (4) brain responsible for?

Answer 29

left: logic, language, reasoning

right: spatial manipulation, music ability, emotion processing, facial recognition

Question 30

function of corpus callosum and what is it made of?

Answer 30

connects left and right hemispheres and facilitates interhemispheric communication (‘bridge’).

made of white matter (largest white matter structure in brain)

Question 31

diff bw white and grey matter?

Answer 31

grey: mainly towards the surface of cortex and houses cell bodies of neurons.

white: occupies middle of brain and houses myelinated axons of those same neurons that connect different parts of the brain together (‘info highway’).

Question 32

what does the diencephalon contain (3)?

Answer 32

thalamus
-directs sensory input to cerebral cortex.

hypothalamus
-clusters of nuclei, the 4 Fs.

pituitary gland
-releases hormones.

Question 33

the limbic system is in the ___. what does it do?

Answer 33

• telencephalon
• regulation of motivated/survival behaviours (ex. locate food, process significance of stimuli, and remember these things over time).

Question 34

which structures compose the limbic system + their functions (4)

Answer 34

hippocampus
-learning and memory

amygdala
-processing significance of events (ex. fear)

cingulate cortex
-communicates info to other parts of brain like frontal cortex

mammillary bodies
-recollective memory

Question 35

a) where are the basal ganglia located?
b) what are they made of
c) basal ganglia ___ system composes of what? (3)

Answer 35

a) distinct masses, deep within cerebral hemispheres
b) grey matter

c) BASAL GANGLIA MOTOR SYSTEM:
-action behaviours/motor control
-striatum (caudate nucleus + putamen)
-globus pallidus

Question 36

two main internal structures of midbrain

Answer 36

tectum: coordination bw auditory [inferior colliculus] and visual input [superior colliculus].

tegmentum: regulatory pathways.

Question 37

tegmentum comprises of (3)

Answer 37

periaqueductal gray (PAIN)
red nucleus (MOTOR CONTROL)
substantia nigra (MOVEMENT)

Question 38

in mike the chicken, which part of his brain was left mostly intact?

Answer 38

hindbrain

Question 39

what is the hindbrain made of? their functions? (4)

Answer 39

pons: arousal, attention, sleep/wakefulness.

cerebellum: voluntary movements, muscle tone, balance.

medulla: autonomic functions ex. respiratory, cardiovascular.

reticular formation: also sleep and arousal.

Question 40

90% of the brain’s neurons are housed where?

Answer 40

the cerebellum

Question 41

describe cellular differences (in terms of organizing brain)

Answer 41

-broadmann used cytoarchitecture to define areas of brain
-e.g., areas 44, 45 = broca’s area
-e.g., form relates function: sensory, association, and motor cortex