Chapter 14: The Brain And Cranial Nerves

Question 1

4 major regions of the brain

Answer 1

1. Cerebral hemispheres - cerebrum and the basal nuclei
2. Diencephalon - includes the thalamus and hypothalamus
3. Brain stem - include the midbrain, pons, and medulla oblongata
4. Cerebellum - includes important control centers

Question 2

Longitudinal fissure

Answer 2

Separates the right, and left cerebral hemispheres

Question 3

What are the 4 visible lobes on the brain?

Answer 3

1. Frontal lobe
2. Parietal lobe
3. Temporal lobe
4. Occipital lobe

Question 4

Grey matter

Answer 4

Makes up the cerebral cortex and is full of neuronal dendrites to communicate with nearby neurons

Question 5

White matter

Answer 5

Lies underneath the cerebral cortex (grey matter). It is full of neuronal axons to transmit impulses to the spinal cord

Question 6

What are the 3 functional areas of the cerebral cortex?

Answer 6

1. Sensory area - receive and interpret info from sensory receptors. Located in the posterior (back) half of the hemisphere
2. Motor area - control the motor functions. Located in the posterior (back) of the frontal lobe
3. Association area - located in areas throughout all the lobes (associated with sensory and motor functions)

Question 7

Primary somatosensory area

Answer 7

Located in the sensory area at the postcentral gyrus (parietal lobe)

• receive input from skin receptors for touch, pain, and temp.
• will also receive input from muscle, tendon, and ligament receptors about the bodies position/movement.

Question 8

Primary visual area

Answer 8

Located in the sensory area on the medial surface of the occipital lobe

• receive impulses from the retina to the thalamus

Question 9

Primary auditory area

Answer 9

Located in the sensory area on the superior part of the temporal lobe

• it will interpret sound, pitch, rhythm from the ears

Question 10

Primary gustatory area

Answer 10

Located in the sensory area at the base of the postcentral gyrus

• will interpret taste info, allows us to perceive different tastes (taste discrimination)

Question 11

Primary olfactory area

Answer 11

Located in the sensory area on the medial part of the temporal lobe

• will allow us to distinguish between various odours

Question 12

Primary motor area

Answer 12

Located in motor area the precentral gyrus

• controls voluntary contractions of specific skeletal muscles

Question 13

Bronca’s speech area

Answer 13

Located on the motor area that is close to the lateral sulcus (usually in the left hemisphere)

• it will direct muscles of the tongue, throat, and lips in order to produce speech

Question 14

Non-fluent aphasia

Answer 14

A condition that can occur from damage to Broca’s speech area

• one with this condition will be able to come up with thoughts as to what they want to say, but their muscle can’t coordinate properly to actually say it.

Question 15

Somatosensory association area

Answer 15

The association area located behind the somatosensory area

• will analyze, recognize, and act on sensory input in relation to past experiences. Stores these past experiences you’ve had in relation to pain, touch, and temp and allows you to make a proper similar reaction to it.

Question 16

Visual/auditory association areas

Answer 16

Will store memories of past visual and auditory experiences to help you understand sights and sounds

Question 17

Premotor area

Answer 17

The association area that is in front of the primary motor cortex

• will control learned motor activities involving complex sequential muscle contractions

Ex. Remembering a dance routine, typing on a keyboard (essentially it’s the muscle memory)

Question 18

Prefrontal cortex

Answer 18

The association area that lies at the front of of the frontal lobe (forehead).

• involved with intellect, complex learning abilities, personality, judgment, moods.
• it also helps with planning for the future, and your “conscience”

Question 19

Language areas

Answer 19

The association area near the lateral sulcus in the left hemisphere.

• involved in recognition of spoken words and written language
• it interprets meaning of words and converts words to thoughts (Wernicke’s area)

Question 20

Fluent aphasia

Answer 20

A condition caused by damage to wernickes area.

One with this condition can speak words, but can’t put the words together into a coherent order.

Question 21

Basal nuclei

Answer 21

3 masses of grey matter located deep in the cerebral hemispheres. (Also associated with the midbrain and diencephalon)

• help in starting and ending body movements
• they stop unnecessary movements (allows you to move gracefully)
• regulate muscle tone

Question 22

Cerebral white matter

Answer 22

Consists of mainly myelinated axons that bundle together into large tracts to allow for extensive communication within the brain.

3 types of tracts:
1. Association tracts - axons connect to the gyri in the same hemisphere.
2. Commissural tracts - axons connect gyri in one hemisphere to the corresponding gyri in the other.
3. Projection tracts - axons run vertically to connect cerebrum to lower parts of the brain/spinal cord

Question 23

Thalamus

Answer 23

A “nucleus” of about 7 masses of grey matter.

• acts as a relay station to conduct sensory impulses to the primary sensory areas of the cerebral cortex.
• transmits motor info from the cerebellum and basal nuclei to primary motor areas of cerebral cortex
• plays a role in maintaining consciousness

Question 24

Hypothalamus

Answer 24

Cluster of a dozen nuclei (neuron cell bodies) located below the thalamus

• regulates body temp, water balance, and food intake (homeostasis!)

Question 25

Midbrain

Answer 25

Area between the diencephalon and the pons.

• coordinates movements of head, eyes, and spine in response to visual/auditory stimuli (ex. Reading)
• responsible for the “startle reflex” (ex. Someone drops a textbook at the back of the room, you reflex to look at it)

Question 26

Pons

Answer 26

A “bulge” in the brainstem in between the midbrain and the medulla oblongata.

• relays motor information from the cerebrum to the cerebellum
• contains nuclei involved in respiration (reflex to breathe)

Question 27

Medulla oblongata

Answer 27

Located right below the pons

• helps in controlling heart rate, blood pressure, and breathing rhythm, coughing

Question 28

Cerebellum

Answer 28

Located at the back of the brain and right behind the spinal cord. Contains 2 hemispheres connected by the vermis

• functions to smooth and coordinate skeletal muscle contractions.
• it also controls posture and balance.