what level of the cervical spine is the phrenic nerve located -
ANSWERS-C3, C4, and C5
what important structure is innervated by the phrenic nerve for
breathing - ANSWERS-the diaphragm
can a cervical fx 3, 4, or 5 interrupt innervation of the phrenic nerve
and contribute to inadequate ventilation? - ANSWERS-yes
decorticate and decerebrate posturing and the significance -
ANSWERS-1. Decerebrate - sustained contraction of extensor
muscles resulted from a lesion in the brainstem. Stiff extended
extremities and retracted head.
2. Decorticate - posture of a patient at or above the brainstem. Arms
are flexed, fist clenched, legs extended
3 factors which may result in less oxygen being absorbed into
bloodstream - ANSWERS-1. decreased amount of oxygen inspired
2. poor flow of air into alveoli from lung disease
3. poor circulation from embolus, plaque, build-up
most sensitive indicator of CNS dysfunction - ANSWERS-level of
consciousness
,define baroreceptors and state their location and function -
ANSWERS-1. sense changes in arterial pressure
2. located in aorta and carotids.
3. sends message to vasomotor center in brainstem.
4. increase pressure stimulates vagus nerve to decrease HR and PVR.
5. decreased pressure stimulates sympathetic nervous system to
increase HR and PVR.
name the approved field procedure used to artificially stimulate
baroreceptors - ANSWERS-valsalva maneuver
main functions of the hypothalamus - ANSWERS-regulates body
temperature, hunger, thirst, sex drive, and emotion. In the infant, the
hypothalamus is less effective in regulating body temperature.
State 2 divisions of the autonomic nervous system - ANSWERS-
Sympathetic and Parasympathetic
Location of the sympathetic and parasympathetic nerve tracts -
ANSWERS-1. Sympathetic nerve originate in the spinal cord between
segments T1 and L2. Sympathetic fibers emerging from the cord first
pass through the sympathetic chain ganglia, and travel on to various
tissues and organs.
2. Parasympathetic nerves are located in the sacral spinal segments
and in cranial nerves III, V, VII, IX, and X. Cranial nerve X, the vagus
nerve, innervates the heart and gastrointestinal tract.
, State the neurotransmitters for the sympathetic and parasympathetic
nervous system - ANSWERS-1. Sympathetic: catecholamines
(epinephrine, norepinephrine, and dopamine) - chemical mediators
"excite" their receptor sites
2. Parasympathetic: acetylecholine - this chemical mediator "inhibits"
their receptor sites
location of autonomic nervous system receptor sites: alpha and beta
receptors - ANSWERS-1. a receptors are located in the peripheral
arterioles and bronchioles, no alpha receptors in the heart
2. b1 receptors are located in heart muscle
3. b2 receptors are located in blood vessels to the skeletal muscle,
vital organs, and bronchioles
describe the function of a and b receptors when they are stimulated -
ANSWERS-1. a receptors cause arterial vasoconstriction and
bronchial constriction.
2. b 1 receptors increase chronotrophy, inotrophy, AV conduction, and
irritability
3. b 2 receptors cause peripheral arterial vasodilation and bronchial
relaxation
explain why a and b receptors are only pharmacological concepts and
not anatomical entities - ANSWERS-they are CHEMICALLY
MEDIATED either endogenously or exogenously by such drugs as
epinephrine, dopamine, and albuterol (b2 receptors are stimulated
with albuterol)