ANS anatomy and physiology Flashcards
Which is NOT a division of the autonomic nervous system?
a. sympathetic
b. somatic
c. parasympathetic
d. enteric
b. somatic
Structurally, the nervous system is divided into the
central nervous system and the peripheral nervous system
Functionally, the nervous system can be divided into
somatic and visceral (autonomic) systems or divisions
The ANS has three major divisions:
the sympathetic nervous system
parasympathetic nervous system
the enteric nervous system
The ANS provides ____________ to all parts of the body except for
neural control; skeletal muscle
The ultimate responsibility of the ANS is
homeostasis
Dysregulation of the ANS is the basis of or a secondary response to many diseases including:
hypertension
DM
orthostatic hypotension
Parkinson’s disease
stroke
sleep disorders
The entire CNS is made up of the
spinal cord, medulla oblongata, pons, midbrain, thalamus, and the cerebral hemisphere
The central nervous system is surrounded and protected by
three connective tissue coverings called meninges
The PNS consists of
spinal and cranial nerves (excluding CN 2) that are present outside the CNS
The PNS differs from the CNS in the sense that the components are not
fully surrounded by bones
Autonomic and somatic divisions are components in
both the CNS and PNS
The autonomic nervous system innervates
smooth muscle, cardiac muscle, and glands
The somatic nervous system innervates mainly
musculoskeletal structures and the sense of organs of the skin
Both somatic and autonomic (visceral) divisions contain
efferent (motor, outflow), and afferent (sensory, inflow) components
The SNS and PNS can function
antagonistically, synergistically, or independently to control effector tissues or organs
The SNS system is the
“fight or flight” division
The fight or flight system is also known as the
flight-fight-freeze response, the sympathetic alarm reaction, or the acute stress response
The PNS system is the
rest and digest division
Which type of muscle does NOT receive ANS signals?
skeletal muscle
Preganglionic nerve fibers in the autonomic nervous system are:
a. lightly myelinated B fibers
b. lightly myelinated C fibers
c. heavily myelinated Aa fibers
d. moderately myelinated Ay fibers
a. lightly myelinated B fibers
The autonomic nervous system is also known as the
visceral nervous system
Autonomic pathways have both
efferent (motor) and afferent (sensory) neurons
What is the preganglionic neuron in the autonomic afferent pathway?
lightly myelinated B fiber
What is the postganglionic neuron in the autonomic afferent pathway?
nonmyelinated C fiber
The ANS provides innervation to
smooth muscle
cardiac muscle & pacemaker cells
exocrine and endocrine glands
white & brown adipose tissue
liver cells
lymphatic tissue
What affect does SNS stimulation have on the CV system?
increased cardiac force, rate, conduction, & excitability
constriction (a2) and dilation (b2) of coronary arterioles
What effect does PNS stimulation have on the CV system?
decreased cardiac force, rate, conduction, and excitability
dilation (M3) of coronary arterioles
What effect does SNS stimulation have on the pulmonary system?
relaxation of bronchial smooth muscle
What effect does PNS stimulation have on the pulmonary system?
contraction of bronchial smooth muscle
What effect does SNS stimulation have on the GI system?
little increase in salivary secretion
peristalsis inhibited
sphincters constricted
gall bladder relaxed
glycogenolysis and gluconeogenesis via the liver
What effect does PNS stimulation have on the GI system?
stimulates salivary secretion
peristalsis activated
sphincters relaxed
gall bladder contracted
What effect does SNS stimulation have on the eye?
pupil dilates (mydriasis)
ciliary muscle relaxes (far vision)
What effect does PNS stimulation have on the eye?
pupil constricts (miosis)
ciliary muscle contracts (near vision)
tears (lacrimal glands)
What effect does SNS stimulation have on the genitourinary system?
relaxation of smooth muscle of urinary bladder wall
contraction of urinary bladder sphincter
What effect does PNS stimulation have on the genitourinary system?
contraction of smooth muscle of urinary bladder wall
relaxation of urinary bladder sphincter
What effect does PNS stimulation have on the skin?
none
What effect does SNS stimulation have on the skin?
vasoconstriction
sweating (diaphoresis)
piloerection (goose flesh)
Somatic efferent pathways to effectors are a
1-neuron route from the spinal cord to the target
ANS efferent pathways are normally as
2-neuron route from the spinal cord to the target
The effector organ of the autonomic system is the
smooth muscle, cardiac muscle, cardiac conducting fibers, and glands
The effector organ of the somatomotor system is the
skeletal muscle
Peripheral neurotransmitters of the somatomotor system include
acetylcholine
Peripheral neurotransmitters of the autonomic system include
acetylcholine
norepinephrine
epinephrine
What are two synonyms for “efferent”?
“motor” and “outflow”
Which three structures comprise the brainstem?
medulla
pons
midbrain
What are two synonyms for “afferent”?
“sensory” and “inflow”
What is the receptor type of the somatomotor system?
nicotinic ACh (Nm)
What is the receptor type of the ANS efferent system?
nicotinic ACh (Nn)
muscarinic ACh: effector (target) organs of PNS
Adrenergic: effector (target) organs of SNS
