lecture 23

Question 1

thalamus

Answer 1

 Relay station for signal entering the cerebral cortex. It sorts and edits signals, then send them to specific cortical association areas
* The gateway to the cerebral cortex. Important for sensation, learning, memory, and wakefulness

Question 2

hypothalamus

Answer 2

 Is the primary visceral control center. Regulates the autonomic nervous system, hunger, thirst, body temperature, sleep and emotions. Controls the pituitary gland
* Our visceral organs often receive this and help the body to maintain homeostasis.
* Link between nervous and endocrine systems.

Question 3

epithalamus/pineal gland

Answer 3

 Where melatonin is secreted, which is a hormone that helps to regulate the sleep cycle.
* Helps to maintain the body’s circadian rhythm. The light from a phone or computer screen makes the body not produce as much melatonin, and effects the bodies ability to run through awake and sleeping mode.
* On the dorsal or posterior side

Question 4

superior colliculis

Answer 4

vision

Question 5

corpus collosum function

Answer 5

connects the two hemispheres of the brain which allows them to share information

Question 6

mid brain of the brain stem

Answer 6

 A reflex center for visual and auditory responses, the neck of the seahorse
* Corpora quadrigemina: 2 superior colliculi (visual réflex centers), 2 inferior colliculi (auditory réflex centers)

Question 7

pons of the midbrain

Answer 7

 The belly of the seahorse, which bridges the spinal cord, cerebellum, and higher brain centers
* Relays sensory information

Question 8

medulla oblongata in the brainstem

Answer 8

 The tail of the seahorse, in charge of the autonomic reflex center which is responsible for
* Heartrate, breathing rhythm, vomiting, coughing, sneezing, etc
 The decussation of pyramids – the area in the medulla oblongata where the signals cross over each other.

Question 9

ipsilateral

Answer 9

 Ipsilateral – same side control of the body, right controls right side and left controls left side.
* Coordinates complex somatic motor patterns (makes us less clumsy), maintains posture and equilibrium, may play a role into cognition

Question 10

describe the structure and function of Purkinje cells

Answer 10

 Are specialized neurons that are found in the cerebellum
* Have branching dendrites (allows it to receive many signals), most release GABA a inhibitory neurotransmitter

Question 11

what does the GABA neurotransmitter do

Answer 11

o The GABA neurotransmitter helps to make movements smoother

Question 12

limbic system

Answer 12

a group of brain structures that link primitive emotions with higher functions, such as reasoning and memory

Question 13

olfactory bulb of the limbic system

Answer 13

 Process the sensory input of odors, the ends of the olfactory nerves

Question 14

amygdala in the limbic system

Answer 14

imparts the emotional overtones
- what makes us have fear

Question 15

hippocampus

Answer 15

important in learning and memory

Question 16

Henry Gustav Molaison (Case study: H.M.)

Answer 16

after his surgery, yes when his hippocampus was removed his seizures stopped but he was essentially then being stuck in the age 16
- he could not create new memories or remember a lot of old ones

Question 17

describe the functions of the reticular activating system (RAS)

Answer 17

• continuously sends impulses to the cerebral cortex to keep us conscious and alert
• responsible for allowing us to go about our lives without responding to every single thing that touches our body
• helps to control some of the very large motor movements.

Question 18

what are the body’s mechanisms that protect the central nervous system from damage

Answer 18

skull
meninges
cerebrospinal fluid
blood brain barrier

Question 19

dura mater

Answer 19

• is located just deep to the skull, is superficial (tough mother), and is very tough

Question 20

arachnoid matter

Answer 20

• looks like a spider web, is the intermediate layer, and connects to the next layer

Question 21

pia mater

Answer 21

the deepest layer, is located and attaches directly to the brain, is very thin

Question 22

• Describe the functions of cerebrospinal fluid, how it is produced, and where it circulates

Answer 22

o Protects, supports, and nourishes the brain and spinal cord.
 Is made of synthesized ependymal cells. It flows through ventricles, subarachnoid space, and the central canal of the spinal cord
- the body makes about 500ml per day, and the cilia on the ependymal cells allow for the cerebrospinal fluid to move.

Question 23

cerebrospinal fluid is

Answer 23

constantly being removed and replaced.
- approximately every 8 hours

Question 24

is the blood brain barrier fully developed in infants

Answer 24

no

Question 25

• Describe the importance of the blood brain barrier

Answer 25

o This is a highly selective diffusion barrier that helps maintain stable conditions with the brain. Like if you inject someone with a dye, it will never actually get into the brain.

Question 26

identify the 3 components that work together to create this blood brain barrier

Answer 26

 Tight junctions (impermeable junctions between the cells in the brain)
 Basal lamina – surrounds the cell (like a basement membrane) and blocks things from getting in
 Astrocytes – star shaped glial cell which helps keep the neuron and nervous system healthy by reaching out their little projections to surround the capillaries within the brain

Question 27

• Describe the structure and function of the spinal cord

Answer 27

 A long bundle of nervous tissue tunning from the medulla oblongata to the upper lumbar region, connects the brain to the PNS

Question 28

cauda equina

Answer 28

• starts around L1 or L2 and is at the base where the spinal cord separates into smaller portions
  
  • has many branching fibers going out from it that looks like the hair from a horse’s tail

Question 29

where is the spinal tap typically done

Answer 29

between L3 and L4

Question 30

identify the white matter and gray matter in the spinal cord

Answer 30

 White matter is on the outside or superficial part of the bones of the spinal cord
- more superficial
 Gray matter is on the very middle of the bone and often looks like a butterfly or moth
- deep

Question 31

Identify the regions of the spinal cord that are associated with motor function vs. sensory function

Answer 31

 Dorsal horns and roots: sensory function
- smaller, towards the back (posterior)
 Ventral horns and roots: motor function
- bigger, towards the front (anterior)

Question 32

central canal of the spinal cord

Answer 32

a very small hole in the middle of the bone

Question 33

dorsal and ventral horn

Answer 33

 Dorsal horn
* More pointed, on the posterior side, goes completely to the edge
 Ventral horn
* On the anterior side, more rounded, doesn’t go to the edge

Question 34

dorsal root

Answer 34

• Sensory function, primarily composed of cell bodies of sensory neurons located within the ganglion.

Question 35

dorsal root ganglion

Answer 35

• A collection of cell bodies outside of the spinal cord, is a blob looking structure.

Question 36

ventral root

Answer 36

• Motor function, made of motor cell neurons

Question 37

white columns (funiculi)

Answer 37

• Made of bundles of myelinated nerve fibers, that serve as nerve pathways to transmit sensory information up to the brain

Question 38

the dorsal and ventral roots form what?

Answer 38

a spinal nerve

Question 39

what do the dorsal and ventral horns form

Answer 39

they come together to form the gray matter of the spinal cord

Question 40

• Describe the functional implications of spinal cord damage at different vertebral levels

Answer 40

 The higher up the injury the more damage it typically does, is typically irreversible.
o C1 to C6 injury -> quadriplegia or tetraplegia
o C6 to C8 injury -> complete paralysis of hand, trunk, and legs
o T1 to T12 injury -> arm and hand function, paraplegia
o L1 to L5 -> paraplegia
o S1 to S5 -> most patient can walk with some function

Question 41

what of the spine is damaged during polio

Answer 41

the ventral horn