Exam 4 short answer

Question 1

Function of the dorsal root

Answer 1

transmits sensory information

Question 2

Function of dorsal root ganglia

Answer 2

relay the sensory nerve impulses from the periphery to the peripheral nervous system

Question 3

Functions of ventral root

Answer 3

allow motor neurons to exit the spinal cord.

Question 4

Describe the 3 layers of meninges

Answer 4

Dura mater: Superficial meninx, composed of dense, irregular connective tissue

Arachnoid mater: Middle meninx; Composed of epithelium and a delicate network of collagen and elastic fibers ( resembles spider web)

Pia mater: Innermost meninx ; Adheres to the surface of the spinal cord and the brain; Composed of collagen and elastic fibers

Question 5

What are the functions of cerebrospinal fluid?

Answer 5

Serves as a shock absorber
– Carries nutrients, wastes, and dissolved gases

Question 6

Functions of posterior horn

Answer 6

sensory processing

Question 7

Functions of lateral horn

Answer 7

»Contraction of cardiac and smooth muscle tissue
»Glandular secretion

Question 8

Functions of anterior horn

Answer 8

Skeletal muscle contraction

Question 9

List the 4 major plexuses

Answer 9

cervical, brachial, lumbar, sacral

Question 10

What are the functions of the plexuses: cervical, brachial, lumbar, and sacral ( Name at least one major nerve for each plexus)

overall function: communicate information to your brain about pain, temperature, and pressure.

Answer 10

cervical: Supplies the skin and muscles of the head,
neck, thoracic cavity, and diaphragm. MN: Phrenic nerve

Brachial: Supplies the shoulders and upper limbs. MN: subscapular nerve

Lumbar: Supplies the abdominal wall, external genitals, and part of the lower limbs. MN: femoral nerve

Sacral: Supplies the buttocks, perineum, and parts of the lower limbs MN: sciatic nerve.

Question 11

What is a stretch reflex? Provide an example. Describe the withdrawal reflex and the crossed
extensor reflex.

Answer 11

stretch reflex: the contraction of a muscle in response to its passive stretching
Ex: striking the patellar tendon with a reflex hammer
Withdrawl reflex: the automatic withdrawal of a limb from a painful stimulus
Crossed extensor refelx: Crossing of sensory impulses within the reflex center to
produce an opposite effect

Question 12

Identify the 4 parts of the brain along with major functions.

Answer 12

Frontal: reasoning, planning, parts of speech, movement, emotions, and problem solving
temporal: perception, auditory stimuli, memory, and speech
parietal: movement, orientation, recognition, perception of stimuli
occipital: visual processing

Question 13

What fills the ventricles?

Answer 13

cerebrospinal fluid

Question 14

Define the blood-brain barrier.

Answer 14

The separation of the circulating blood and the brain extracellular fluid (CSF) in the CNS

Question 15

Know the functions of the brain stem (midbrain, pons, medulla) and the cerebellum.

Answer 15

Midbrain: movement of body and head
Pons: motor control, sensory analysis
Medulla: vital body functions (breathing, heart rate)
cerebellum: “little brain” , movement, posture, balance

Question 16

hypothalamus Functions

Answer 16

Regulates body temperature –sweating/shivering
- Regulates hunger and satiety in response to nutrient blood levels or hormones
- Regulates water balance and thirst
- Regulates sleep-wake cycles
- Controls endocrine system

Question 17

Understand these structures of the diencephalon: thalamus, hypothalamus, limbic system, pineal
gland. What are their functions?

Answer 17

thalamus: Sorts, edits, and relays ascending input
hypothalamus: Controls autonomic nervous system
limbic system: behavioural and emotional responses
pineal gland: to receive information about the state of the light-dark cycle and secretre melatonin

Question 18

Know the functions of the lobes of the brain. (frontal, parietal, temporal, occipital, insula)

Answer 18

Frontal: Emotions, judgement, understanding, personality self awareness
parietal: Touch, pain & temp sensations from the opposite side of the body
Temporal: Auditory perception, memory.
Occipital: Visual perception, color recognition
Insula: controls autonomic functions

Question 19

sympathetic NS vs parasympathetic NS

Answer 19

• Sympathetic: fight or flight; speeds body functions up (heart rate, respiratory rate, dilate
  pupils, increase glucose)
• Parasympathetic: rest and digest; slows things down (decreases HR, RR, increases digestion
  and elimination)

Question 20

know the functions of Medulla, Hypothalamus, Limbic system

**Understand the important role of the hypothalamus

Answer 20

Medulla: vital center: regulates cardiac, vasomotor, respiratory system.

Hypothalamus: regulates visceral functions, temperature, hunger, thirst, water,
electrolyte balance

Limbic: controls emotional responses and feelings
**Important function: center of ANS activity

Question 21

Why is perception of pain important? What is referred pain? Provide several examples.

Answer 21

refered pain: ccur due to sensory impulses from two regions following a common nerve pathway to brain
ex: The pain of a heart attack is frequently
felt in the left arm
perception of pain is important to let the body know that there is something wrong so it can correct it.

Question 22

Describe the olfactory nerve pathway.

Answer 22

Olfactory nerves > olfactory bulbs >
olfactory tracts > limbic system (for
emotions) and olfactory cortex (for
interpretation)

Question 23

Describe the visual pathway. Include the basic eye and nervous structures: the eye: cornea, iris,
pupil, retina, lens, anterior cavity, aqueous humor, posterior cavity, vitreous body; optic nerve,
optic chiasm, optic radiations, thalamus, occipital cortex.

Answer 23

light enters the eye, sending signals to the retina. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain.

Question 24

Describe the hearing pathway: include structures of the ear and nervous system: auricle, external
acoustic meatus, tympanic membrane, auditory ossicles (malleus, incus, stapes), auditory tube,
bony labyrinth (vestibule, semicircular canals, cochlea, perilymph), membranous labyrinth
(endolymph), hair cells, otoliths, vestibulocochlear nerve, thalamus, temporal lobe.

Answer 24

1. The auricle collects sound waves and directs them into the external acoustic meatus
2. Vibrations are transmitted to the auditory ossicles
3. fluid pressure waves are created
4. Vibrations are passed to the basilar membrane
5. cells depolarize and nerve impulses are generated
6. Nerve impulses travel to the auditory cortex