Phys. Test 2

Front 1

Three Levels of Central Nervous System Function:

Back 1

1. Spinal Cord Level
2. Lower Brain level
3. Higher Brain or Cortical Level

Front 2

Upper levels of the NS send signals to control centers in the spinal cord

Back 2

Spinal Cord Level

Front 3

Neuronal circuits in the spinal cord can cause:

Back 3

* walking movements
* withdrawal reflexes
* reflexes that stiffen the legs to
support the body against gravity
*reflexes that control local blood
vessels and GI movements

Front 4

Refers to the medulla, pons, mesencephalon, cerebellum, hypothalamus, thalamus, and basal ganglia

Back 4

Lower Brain Level

Front 5

Lower brain level controls subconscious activities of the body such as:

Back 5

**arterial pressure and respiration
**Equilibrium
**feeding reflexes
**emotional patterns

Front 6

arterial pressure and respiration are mainly controlled by

Back 6

the medulla and pons

Front 7

control of equilibrium is through the __a__ and reticular substance of the
____b____.

Back 7

a. cerebellum

b. medulla, pons and mesencephalon

Front 8

Emotional patterns such as anger, excitement, sexual activities, reaction to pain and pleasure (_______ require cerebral cortex)
** does or doesn't**

Back 8

doesn’t

Front 9

*cerebral cortex-large memory storage area
*cortex never functions alone; (w/low)
*helps to fine tune lower brain funct.
*essential to our thought process

Back 9

Higher Brain or Cortical level

Front 10

__a___ signals enter the spinal cord through the dorsal roots of the spinal nerves.
__b___ signals exit the spinal cord through the ventral roots.

Back 10

a. Sensory

b. Motor

Front 11

In the spinal cord, columns of white mater are divided into tracts called:

Back 11

Ascending Tracts (afferent)

Descending Tracts (efferent)

Front 12

Carry sensory information up the cord

Back 12

Ascending Tracts (afferent)

Front 13

*Conduct motor impulses down the brainstem and cord
*Involves two neurons (upper and lower)

Back 13

Descending Tracts (efferent)

Front 14

begin with a soma in the cerebral cortex or brainstem and have an axon that terminates on a lower motor neuron

Back 14

Upper motor neurons

Front 15

are in the brainstem or spinal cord. The axon of the lower motor neuron terminates at the target organ (ex. skeletal muscle).

Back 15

Lower motor neurons

Front 16

Many of the ascending and descending tracts undergo ______ (cross-over).

Back 16

decussation

Front 17

Overall Functions of the Spinal Cord

Back 17

-Conduction
-Locomotion
-Reflexes

Front 18

bundles of fibers passing information up & down spinal cord

Back 18

Conduction

Front 19

repetitive, coordinated actions of several muscle groups

Back 19

Locomotion

Front 20

--involuntary, stereotyped responses to stimuli (remove hand from hot stove)

--involves brain, spinal cord and peripheral nerves

Back 20

Reflexes

Front 21

Each spinal nerve receives sensory input from a specific area of skin called ___a____ which overlap at edges by 50%, a total loss of sensation requires _____b_____.

Back 21

a. dermatome

b. anesthesia of 3 successive spinal nerves

Front 22

**Skin eruptions along path of nerve
**Varicella-zoster virus (chicken pox) remains for life in dorsal root ganglia
**Usually 50+ age (possible younger)
**No special treatment

Back 22

Shingles

Front 23

**Inflammation of the meninges
**Serious disease of infancy and childhood [b/t 3 mo. and 2 yrs]
**Bacterial and viral invasion of the CNS by way of the nose and throat

Back 23

Meningitis

Front 24

Signs of Meningitis include

Back 24

high fever stiff neck
drowsiness intense headache

**may progress to coma
{{Diagnosed by examining the CSF}}

Front 25

**Brain produces & absorbs about 500 ml/day
--filtration of blood thru choroid plexus
--has more Na+ & Cl- but less K+ &
Ca+2 than plasma

Back 25

Cerebrospinal Fluid


[Escapes from 4th ventricle to surround the brain]

Front 26

Functions of Cerebrospinal Fluid

Back 26

*buoyancy -- floats brain so it
neutrally buoyant
*protection -- cushions from hitting
inside of skull
*chemical stability-- rinses away waste

Front 27

_____ is tightly joined endothelium

Back 27

Blood-brain barrier

Front 28

NOTE: Blood-brain barrier
-permeable to lipid-soluble materials (alcohol, O2, CO2, nicotine and anesthetics)
-circumventricular organs in 3rd &

Back 28

4th ventricles at breaks in barrier where blood has direct access
--monitoring of glucose, pH, osmolarity & other variations
--allows route HIV virus invade brain

Front 29

_______ at choroid plexus is ependymal cells joined by tight junctions

Back 29

Blood-CSF barrier

Front 30

NOTE: Brain Metabolism
**Under resting conditions, resting metabolism of the brain accounts for about 15% of total metabolism of the body.
**Brain isn't capable of much anaerobic metabolism due to high energy demand of the neurons, and lack of glycogen.

Back 30

**Very little oxygen is stored. Must have glucose and oxygen from bld.
**Sudden cessation of bld flow to brain or sudden lack of oxygen can cause unconsciousness w/in 5- 10 sec

Front 31

Hindbrain: Medulla Oblongata

________center adjusts rate & force of heart beat

Back 31

Cardiac

Front 32

Hindbrain: Medulla Oblongata

______ center adjusts blood vessel diameter

Back 32

Vasomotor

Front 33

Hindbrain: Medulla Oblongata

_____ centers control rate & depth of breathing

Back 33

Respiratory

Front 34

Hindbrain: Medulla Oblongata
______ centers for coughing, sneezing, gagging, swallowing, vomiting, salivation, sweating, movements of tongue & head

Back 34

Reflex

Front 35

Nuclei concerned with sleep, hearing, balance, taste, eye mvt., facial expression, facial sensation, respiration, swallowing, bladder control & posture

Back 35

Pons

Front 36

Functions of _________:
*hormone secretion & pituitary *autonomic NS control
*thermoregulation (thermostat)
*food & water intake
*sleep & circadian rhythms
*memory (mammillary bodies)
*emotional behavior

Back 36

Diencephalon: Hypothalamus

Front 37

Functions of Cerebrum Lobes:

contains voluntary motor functions and areas for planning, mood, smell and social judgement

Back 37

Frontal

Front 38

Functions of Cerebrum Lobes:

contains areas for sensory reception & integration of sensory information

Back 38

Parietal

Front 39

Functions of Cerebrum Lobes:

is visual center of brain

Back 39

Occipital

Front 40

Functions of Cerebrum Lobes:

contains areas for hearing, smell, learning, memory, emotional behavior

Back 40

Temporal

Front 41

*12 pair of nerves that arise from brain & exit through foramina leading to muscles, glands & sense organs in head & neck
*Input & output remains ipsilateral except CN II & IV

Back 41

The Cranial Nerves (PNS)

Front 42

Which of following statements would NOT BE TRUE of blood-brain barrier?
A. It is permeable to lipid-soluble materials.
B. Protects the brain from potentially harmful substances that may be circulating in the blood.
C. Drugs are sometimes applied through nasal sprays to reach the brain to avoid the problem presented by the blood-brain barrier.
D. There are no breaks in the barrier for the brain to have direct access to the blood.

Back 42

D. There are no breaks in the barrier for the brain to have direct access to the blood

Front 43

convert the energy of a stimulus into the energy of a nerve signal

Back 43

Sensory Receptors

Front 44

process of converting stimulus energy to nerve energy is _________.

Back 44

sensory transduction

Front 45

Sensory receptors transmit four kinds of information:

Back 45

*modality- type of stimulus or
sensation produced
* location
* intensity
* duration

Front 46

_____ make us conscious of tissue injuries
--forces us to care for minor injuries to prevent serious problems
Found in all tissues except the brain

Back 46

Nociceptors [ pain ]

Front 47

_____ pain arises from skin, muscles & joints
_____ pain from stretch, chemical irritants or ischemia of viscera (poorly localized)

Back 47

Somatic

Visceral

Front 48

Injured tissues release chemicals that stimulate pain fibers. ex:

Back 48

bradykinin
histamine
prostaglandin

Front 49

______ is misinterpreted pain
*brain “assumes” pain is coming from skin or superficial sites
*heart pain felt in shoulder or arm because both send pain input to spinal cord segments T1 to T5

Back 49

Referred pain

Front 50

Physiology of Taste (Gustation)

Back 50

To be tasted, molecules must dissolve in saliva
Floods the taste pores on the epithelial surface of the tongue

Front 51

_____(receptors) which are the apical microvilli of gustatory cells of taste buds project into the pit.

Back 51

Taste hairs

Front 52

Taste buds stimulate:

Back 52

facial nerve
glossopharyngeal nerve
vagus nerve

Front 53

NOTE: Physiology of Smell (Olfaction)
*Olfactory cells are neurons and the only neurons in the body directly exposed to the environment
*Live approx. 60 days and are replaced

Back 53

*Odor molecules must be volatile
*Odor molecules bind to receptor on an olfactory hair triggering production of a second messenger; opens the ion channels& creates a receptor potential

Front 54

______is any audible vibration of molecules.
Vibrating object pushes air molecules into eardrum making it vibrate

Back 54

Sound

Front 55

determined by frequency


amplitude of vibration

Back 55

Pitch


Loudness

Front 56

^^Stimulation of Cochlear Hair Cells:^^
*Sound waves enter auditory canal
*Strike the eardrum -large surface area
*Ear drum vibrates and transfers the vibration to the middle ear ossicles

Back 56

cont'd
*Ossicles concentrate the energy of the vibration at the oval window (also help dampen noise for protection)

Front 57

cont'd
*Stapes pushes the window which pushes the perilymph of the inner ear
*Pushes on the endolymph in the cochlear duct

Back 57

cont'd
*Basilar membrane moves up and down
*Hair cells are embedded in the basilar membrane (organ of Corti)

Front 58

NOTE: Potassium Gates of Cochlear
Hair Cells
Stereocilia (hair cells) bathed in high K+ concentration creating electrochemical gradient from tip to base

Back 58

*Movement of basilar membrane bends stereocilia
*Bending pulls on tip links and opens ion channels
K+ flows in -- depolarizing it & causing release of neurotransmitter stimulating sensory dendrites at its base (cochlear nerve)

Front 59

*Control of coordination and balance
*Receptors in vestibular apparatus
--patch of hair cells with their stereocilia & one kinocilium buried in a gelatinous otolithic membrane weighted w/granules called otoliths

Back 59

Equilibrium