Nervous System II

Question 1

Describe embryology of the nervous system.

Answer 1

Ectodermal cells come together and form a flat group of cells called the neural plate.
Edges of the plate begin to elevate forming the neural folds.
Edges of the neural folds fuse together forming the neural tube.
Neural tube eventually becomes spinal cord and brain.

Question 2

How long is the average adult human spinal cord?

Answer 2

16-18”

Question 3

How much of the vertebral column does the spinal cord occupy?

Answer 3

2/3

Question 4

Why is the spinal cord shorter than the vertebral column?

Answer 4

Spinal cord grows very little after birth

Vertebral column continues to grow after birth

Question 5

What is the lower third of the vertebral column filled with and what is it called?

Answer 5

Spinal nerves

“Cauda equina” horses tail

Question 6

What does the cervical enlargement do?

Answer 6

Supplies nerves to the upper extremities

Question 7

What does the lumbar enlargement do?

Answer 7

Supplies nerves to the lower extremities

Question 8

What are meninges?

Answer 8

Membranes that surround the spinal cord

Question 9

What is the dura mater?

Answer 9

Outer membrane
“Tough mother”
Tough, leathery membrane

Question 10

Describe the arachnoid layer.

Answer 10

Middle layer
“Spider layer”
Highly vascularized, many blood vessels

Question 11

What does the sub-arachnoid space contain?

Answer 11

Cerebrospinal fluid
Protection
Nutrition

Question 12

Describe the pia mater.

Answer 12

Innermost membrane
“Delicate mother”
Thin membrane that adheres directly to the spinal cord

Question 13

What is a spinal tap?

Answer 13

Between 3-4 or 4-5 lumbar vertebrae

Question 14

What two structures divide the spinal cord into two halves?

Answer 14

Posterior median septum

Anterior median fissure

Question 15

Describe the gray matter.

Answer 15

Integration center for incoming sensory and outgoing motor impulses.
No neurolemma
No myelin sheath

Question 16

Describe the central canal.

Answer 16

Tube the runs the entire length of the spinal cord

Question 17

Describe the ventral roots.

Answer 17

Carry efferent (away) motor impulses away from spinal cord.

Question 18

Describe the dorsal roots.

Answer 18

Carry afferent (toward) sensory impulses to spinal cord.

Question 19

What do roots form when they fuse together?

Answer 19

Spinal nerves (31 pair)

Question 20

What does white matter do?

Answer 20

Carry impulses to and from brain
Has neurolemma
Has myelin sheath

Question 21

Describe the ventral columns of white matter.

Answer 21

Front, pressure
Ventral Corticospinal Tract: carries descending motor impulses down from the brain
Ventral Spinothalamic Tract: carries ascending sensory impulses to the brain

Question 22

Describe the lateral columns of white matter.

Answer 22

Side
Lateral Corticospinal Tract: main descending motor tract from brain
Lateral Spinothalamic Tract: carries ascending sensory impulses of heat, cold, and pain to the brain

Question 23

Describe the dorsal columns of white matter.

Answer 23

Back

Fasciculus Gracilus and Fasciculus Cuneatus: carry ascending sensory impulses of touch and muscle and joint pain

Question 24

What is the intervertebral foreman?

Answer 24

Area where spinal nerve just splits

Question 25

What do spinal nerves branch into?

Answer 25

Primary Ramus

Question 26

What is a reflex arc?

Answer 26

A pathway that sensory and motor impulses travel

Question 27

How much does the average adult human brain weigh?

Answer 27

About 3 pounds

Question 28

Describe the brain stem.

Answer 28

Consists of the medulla oblongata, pons, and mid-brain

Question 29

Describe the medulla.

Answer 29

Lowest part of brain stem Continuation of spinal cord Gray on inside and white on outside

Question 30

What are the functions of the medulla?

Answer 30

Gray matter-integration center for incoming sensory and outgoing motor impulses White matter-carries impulses to and from the brain Controls sneezing, coughing, burping, swallowing, breathing, heart rate, vomiting, hiccuping Impulses from cerebrum cross over at medulla

Question 31

Describe the pons.

Answer 31

Superior to medulla Ventral to cerebellum White on the outside and gray on the inside

Question 32

What are the functions of the pons?

Answer 32

Breathing, many cranial nerves originate here | Serves as a bridge between the 2 hemispheres of cerebellum

Question 33

Describe the mid-brain.

Answer 33

Most superior part of brain stem

Question 34

What are the two parts of the mid-brain?

Answer 34

Ventral- Cerebral Peduncle: carries descending motor impulses down from cerebrum Dorsal-Corpora Quadrigemina: regulates head and eye movements, respond to light and sound

Question 35

What is between the ventral and dorsal parts of the mid-brain?

Answer 35

Cerebral aqueduct-move eyes and eyelids

Question 36

Describe the cerebellum.

Answer 36

Second largest part of brain Dorsad to medulla and pons Gray on the outside and white on the inside Numerous furrows (more surface area)

Question 37

What is the vermis?

Answer 37

Deep groove that divides cerebellum into two hemispheres

Question 38

What are the functions of the cerebellum?

Answer 38

Controls balance, coordination, and muscle tone

Question 39

What is ataxia?

Answer 39

Poor balance, poor coordination, and poor muscle tone (genetic, temporary cause-alcohol)

Question 40

Describe the interbrain or diencephalon.

Answer 40

2 masses of gray matter between mid-brain and cerebrum | Thalamus and hypothalamus

Question 41

What are the functions of the thalamus?

Answer 41

Pain center of brain Relay station for sensory impulses on their way to cerebrum Reticular system: sleep center of brain

Question 42

What are the functions of the hypothalamus?

Answer 42

``` Associated with pituitary gland Regulate sleep Controls metabolism Controls water balance Controls body temperature Controls digestive organs Controls heart rate Hunger and thirst Negative emotions Regulates blood vessels ```

Question 43

Describe the cerebrum.

Answer 43

Highest part of the brain Largest part of the brain Occupies 2/3 of cranial vault

Question 44

What is the longitudinal fissure?

Answer 44

Deep groove that divides cerebrum into 2 hemispheres

Question 45

What is a sulcus?

Answer 45

Dip or valley in cerebrum

Question 46

What is a gyrus?

Answer 46

Peak or ridge in cerebrum

Question 47

What are the two parts of the cerebrum?

Answer 47

Inner (white)- Corpus Callosum: controls emotions Outer (gray)- Cerebral Cortex: Motor- controls all voluntary muscles (skeletal) Sensory- sight, hearing, smell, touch, taste Associative- think, reason, memory, will power, judgement

Question 48

What is an EEG?

Answer 48

Electroencephalogram | Measures brain waves

Question 49

Describe the difference between an unconditioned and conditioned response.

Answer 49

Unconditioned-innate, born with | Conditioned-learned over time

Question 50

How many pairs of each nerve?

Answer 50

``` Cervical-8 Thoracic-12 Lumbar-5 Sacral-5 Coccygeal-1 ```

Question 51

What is the ligamentun denticulatum?

Answer 51

Extremity stemming from white matter that provides stability

Question 52

What is the sub-arachnoid septum?

Answer 52

Membrane that connects the arachnoid and pia mater, provides stability

Question 53

What structures protect the brain?

Answer 53

``` Scalp Muscle Skull Dura Mater Arachnoid Sub-arachnoid space Pia Mater ```

Question 54

What is the Fissure of Rolando?

Answer 54

Deep groove that divides the frontal and parietal lobes

Question 55

What is the Fissure of Sylvius?

Answer 55

Deep groove that divides the Frontal and Temporal lobes