CNS Organization

Question 0

What happens if you disconnect at the hindbrain?

Answer 0

A low decerebrate animal

Question 1

What structure compose the hindbrain?

Answer 1

Cerebellum, medulla, and pons

Question 2

Describe the state of a low decerebrate animal.

Answer 2

Unconscious, incapable of purposeful activity. Sensory input from head (cranial nerves 4-12) can’t reach cerebrum. Inactive without stimulation. No thermoregulation.

Question 3

What would we call the state of a low decerebrate human?

Answer 3

Persistent vegetative state

Question 4

What is the disconnection between the thalamus and the midbrain?

Answer 4

High decerebrate disconnection

Question 5

Describe the state of a high decerebrate animal.

Answer 5

Can walk, climb, run, and stand when stimulated. May attack moving objects, but bump into stationary ones. Capable of grooming, chewing food, and drinking.

Question 6

What is a high decerebrate baby (e.g., anencephalic) capable of?

Answer 6

Gazing, sucking, crying, visual tracking, and stretching

Question 7

What kind of posturing is caused by damage to the upper brainstem?

Answer 7

Decerebrate posturing

Question 8

decerebrate posturing (n.)

Answer 8

hands adducted and extended, wrists pronated, fingers flexed; legs are stiffly extended, with plantar flexion

Question 9

What kind of posturing is caused by damage to one or both corticospinal tracts?

Answer 9

Decorticate posturing

Question 10

decorticate posturing (n.)

Answer 10

arms are adducted and flexed, with wrists and fingers flexed on chest; legs are stiffly extended and medially rotated, with plantar flexion

Question 11

What is disconnection act the thalamus called?

Answer 11

Diencephalic disconnection

Question 12

Describe an animal with diencephalic disconnection.

Answer 12

behavior is not motivated or voluntary; exhibit “sham-rage” and other sympathetic arousal activity; capable of thermoregulation; intact sense of smell

Question 13

What is disconnection of the cortex called?

Answer 13

Decorticate disconnection

Question 14

Describe an animal with decorticate disconnection.

Answer 14

normal sleep-wake cycle; superficially normal behavior; no biologically adaptive behavior; conditioning intact; no planning or prospective behavior

Question 15

The brain can be subdivided on the basis of cell types into the following four categories:

Answer 15

Primary sensory cortex, primary motor cortex, association (secondary) areas, higher-order (tertiary) areas

Question 16

Are spiny neurons typically excitatory or inhibitory?

Answer 16

Excitatory

Question 17

Are aspiny neurons typically excitatory and inhibitory?

Answer 17

Inhibitory

Question 18

What are the neurotransmitters typically used by spiny neurons?

Answer 18

Glutamate and aspartate

Question 19

What percentage of synapses are found on spines?

Answer 19

95%

Question 20

What are two major classes of spiny neurons?

Answer 20

Pyramidal cells and stellate cells

Question 21

Describe aspiny neurons.

Answer 21

Interneurons with short axons and no dendritic spines

Question 22

cortical layers II and III (n.)

Answer 22

primarily receive afferent neurons from other regions of the cortex

Question 23

cortical layer IV (n.)

Answer 23

primarily receives afferent sensory neurons from other parts of the brain

Question 24

cortical layers V and VI (n.)

Answer 24

have efferent neurons to other parts of the brain

Question 25

Pyramidal cells are mostly in layers ____, ____, ____, and ____.

Answer 25

II, III, V, and VI