The Brain

Question 1

What are the 3 main sections of the brainstem?

Answer 1

medulla, pons, midbrain(mesecephalon)

Question 2

What are the two section of the mesencephalon? and their fucntions

Answer 2

1. Tectum
   -Rostral colliculi: receives visual information and controls eye movement, particularly during visual tracking
   -Caudal colliculi: receives acoustic information and coordinates reflexes to turn head toward sound
   2.Tegmentum
   -nuclei associated are critical for control of voluntary movement and motivated behavior

Question 3

What are the functions of the pons and medulla?

Answer 3

Medulla: regulates biological functions
Pons+ Medulla: important relay site for auditory and vestibular information, gustatory sensations and associated motor reactions

Question 4

What makes up the hindbrain?

Answer 4

pons, medulla, cerebellum

Question 5

Where is the reticular formation? and what is its function?

Answer 5

the central portion of the pons and medulla. It is responsible for wakefulness and generalized sensory arousal

Question 6

How many nerves are in the forebrain?the midbrain? the pons and medulla?

Answer 6

2 in the forebrain, 2 in the midbrain, 8 in the pons/medulla

Question 7

Which cranial nerve is the only one to innervate structures outside of the head and neck?

Answer 7

CN X: vagus

Question 8

What are the 12 CN?

Answer 8

1. olfactory
   2.optic
2. oculomotor
3. trochlear
4. trigeminal
5. abducent
6. facial
7. vestibulochoclear
8. glossopharyngeal
9. vagus
10. accessory
11. hypoglossal

Question 9

Which CN are involved in eye movement?

Answer 9

I optic, III oculomotor, IV trochlear, VI abducent

Question 10

Which major reflexes are involved in maintaining balance and posture?

Answer 10

1. vestibulo-ocular reflex: this reflex allows retinal images to remain stable while the head is moved
   2.Tonic neck reflexes: signals from muscle spindles in the neck and sense the change in the position of the head relative to the trunk
2. Righting reflex: signals in the vestibular system sense acceleration relative to gravity, muscle spindles in neck sense the position of the head and proprioceptors sense the position of the body relative to gravity

Question 11

What are the general functions of the cerebellum?

Answer 11

-constant sensory information processing
-planning, adjusting, and executing movements of the body, the limbs, and the eyes.
-regulates fine motor coordination of head for intentional movements

Question 12

True/False: the cerebellum sends information to motor neurons directly?

Answer 12

False

Question 13

What are the two parts of the diencephalon? what are their functions?

Answer 13

1. Thalamus: relay station for information from sense organs to the cortex and other brain regions
2. Hypothalamus: contains numerous nuclei that work to maintain homeostasis. one of the highly conserved areas of the brain

Question 14

What are the 4 parts of the cerebrum and their functions?

Answer 14

1. Frontal lobe: contains motor cortex (UMN)
   2.Parietal lobe: somatosensory cortex
2. Temporal lobe: auditory cortex
3. Occipital lobe: visual cortex

Question 15

Discuss the topographic organization of the primary cortical areas in mammals and why they vary by species

Answer 15

• The size of the cortical surface is based on function, the greater the sensitivity of a body region the larger cortical representation. It varies by species due to different needs

Question 16

What are the 5 major motor pathways?

Answer 16

1. Rubrospinal tract
2. Vestibulospinal tract
3. reticulospinal tract
4. tectospinal tract
   5 corticospinal tract

Question 17

Describe the rubrospinal tract

Answer 17

originates: the red nucleus of the midbrain
function: voluntary and skilled movement of non primate mammals

Question 18

Describe the vestibulospinal tract

Answer 18

origin: vestibular nuclei
function: regulates posture against gravity

Question 19

Describe the reticulospinal tract

Answer 19

origin: reticular formation
function: regulates posture against gravity (different muscle groups than vestibulospinal)

Question 20

Describe tectospinal tract

Answer 20

origin: tectum of the brain
function: orienting to auditory and visual stimuli

Question 21

Describe the corticispinal tract

Answer 21

origin: motor cortex
function: controls voluntary motor activity and is particularly important in fine motor movement

Question 22

What is the function of basal nuclei?

Answer 22

-key in motor planning
-receive input from other brain regions to coordinate motor response based on motivation, emotion, and prior learning

Question 23

Which motor neurons synapse on skeletal muscle?

Answer 23

lower motor neurons