Chapter 9 Flashcards
Autonomic Nervous System
Critical for survival, regulates homeostasis and reproduction
Regulates circulation, respiration, digestion, metabolism, secretions, body temperature, reproduction
UNCONSCIOUS, INVOLUNTARY
Sympathetic nervous system
Fight or flight
Maintain optimal blood supply in organs
Parasympathetic
Rest and digest
Mechanoreceptors
Respond to pressure, and stretch
Chemoreceptors
Sensitive to chemical concentrations in the blood
Nociceptors
Responsive to stimuli that threaten or damage tissue
Thermoreceptors
In the hypothalamus respond to small changes in temperature of circulating blood
Visceral
Internal organs, Smooth muscle, cardiac muscle and glands
Somatic
Skeletal muscle
bones
soft tissue
Solitary nucleus
The main visceral sensory nucleus
Information relayed to visceral control areas in the pons and medulla and hypothalamus, thalamus
Preganglionic
The neuron extending from the CNS to the ganglion
Postganglionic
The neuron connecting the ganglion with the effector organ
Autonomic neurons secrete the neurotransmitters:
Acetylcholine, norepinephrine, Epinephrine 
Cholinergic
neurons that secrete acetylcholine
Adrenergic
Neurons that secrete norepinephrine or epinephrine 
Two groups of cholinergic receptors
Muscarinic and nicotinic
Neurotransmitter released My most sympathetic postganglionic neurons
Norepinephrine
Paravertebral ganglia
Sympathetic efferents to the limbs, face, body wall, heart, and lungs synapse in ganglia along side the vertebral column
Drugs that bind with a receptor but do not activate the receptor are called
Blockers
Parasympathetic fibers are distributed in
Cranial nerves 3, 7, 9 and 10
Cranial nerve three
Activates muscles that constrict the pupil and increase convexity of the lens
Cranial nerve seven and nine
Innervate salivary glands and tears
Cranial nerve 10
75%
Innervates the heart, airways, stomach, liver, pancreas, kidney, and intestines
Parasympathetic sacral levels S2 to S4
Control bladder, Lower colon and external genitalia
Locus Coeruleus
Regulates arousal and attention and may trigger anxiety and distress
During a fight or flight
Sympathetic system prepares for vigorous muscle activity by activating the heart skeletal muscles, pupil dilation, and eccrine sweat glands
The parasympathetic system decreases heart rate and suppresses skeletal muscle activity
Horner’s syndrome
Ptosis, constriction of pupils, pale skin, absence of sweating on half of the face
Occurs when lesion affects the sympathetic pathway to the head
Lesion in the brainstem
Interferes with descending control of heart rate, blood pressure, respiration
Orthostatic hypotension
A decrease of at least 20 mm Hg Systolic blood pressure, 10mm Hg Diastolic pressure, or a heart rate increase of greater than 20 bpm during the first three minutes after moving from supine to standing
Gravity induced pooling of blood in the lower limbs
Symptoms include dizziness, lightheadedness, fainting
Syncope
Fainting
Neurocardiogenic syncope
Abnormal autonomic regulation of cardiovascular system causes a sudden drop in blood pressure
Due to emotional distress (stressful situations)
Orthostatic hypotension syncope
Caused by reduced blood volume, autonomic failure, prolonged bedrest, drugs
