Exam 2 Flashcards
Autonomic nervous system
composed of the Sympathetic and the Parasympathetic systems that exerts control over the functions of many visceral organs and tissues in the body.
Sympathetic leads to
increased heart rate, constriction of the arterioles of the skin and intestine, raises the blood pressure, dilation of the pupils, sphincters close, hair stands and sweating occurs.
Parasympathetic leads to
Decrease in heart rate, pupil constriction, increased peristalsis, increased glandular activity, sphincters open, bladder wall is contracted.
Where is parasympathetic ganglia located?
in or near the effector organs
Where is sympathetic ganglia located?
paravertebral chain
sympathetic nervous system
prepares and mobilizes the body in the emergency cases (exercise, fear..)
-acetylcholine
-located w/in cns
parasympathetic nervous system
conserves and stores energy (during sleep)
-cns in brain and spinal cord
-acetylcholine, norepinephrine, epinephrine
Sympathetic (thoraco-lumbar) Origin
cell bodies lie the lateral horn of the T1- L2/3 spinal cord
parasympatheic (cranio-sacral) origin
CN III, CN VII, CNIX and CN X and S1, S2, S3 (pelvic splanchnic nerve)
Preganglionic and postganglionic neurons of sympathetic system release what?
Preganglionic release neurotransmitter ACH and post releases norepinephrine
Preganglionic and postganglionic neurons of Parasymatheic system release what?
Both releases ACH
Peptidergic neurons in the parasympathetic nervous system release what?
peptides such as vasoactive inhibitory peptide and substance P.
Adrenergic neurons release what?
norepinephrine as the neurotransmitter
The postganglionic fiber of parasympathetic is _______ then postganglionic fiber of sympatheitic?
Shorter
Alpha 1 receptors location
vascular smooth muscle, splanchnic regions, the GI tract, bladder sphincters, and the radial muscle of the iris.
Alpha 1 receptors Mechanism of action
G protein alpha stimulator, Phospholipase C, formation of inositol 1,4,5-triphospate (IP3) and increase in intracellular (Ca2+).
Alpha 1 receptors function
Vasoconstriction, contraction
Alpha 2 receptors location
located in presynaptic nerve terminals, platelets. Fat cells, and the walls of the GI tract.
Alpha 2 receptors Mechanism of action
G protein alpha inhibitor, inhibition of adenylate cyclase and decrease in cyclic adenosine monophosphate (CAMP).
Alpha 2 receptors function
produce inhibition (relaxation or dilation)
beta 1 receptors location
sinoatrial (SA) node, atrioventricular (AV) node, and ventricular muscle of the heart.
beta 1 receptors Mechanism of action
activation G protein alpha stimulator, activation of adenylate cyclase and increase in cAMP.
beta 1 receptors function
produce excitation (increased heart rate, increased conduction velocity, increased contractility).
beta 2 receptors location
vascular smooth muscle of skeletal muscle, bronchial smooth muscle, and in the walls of the GI tract and bladder
beta 2 receptors Mechanism of action
activation G protein alpha stimulator, activation of adenylate cyclase and increase in cAMP
beta 2 receptors function
produce relaxation (dilation of vascular smooth muscle, dilation of bronchioles, relaxation of the bladder wall.)
Nicotinic receptor’s location
autonomic ganglia of the sympathetic and parasympathetic nervous systems, at the neuromuscular junction, and in the adrenal medulla
Nicotinic receptor’s Mechanism of action
ACh binds to alpha subunits of the nicotinic Ach receptor, The nicotinic Ach receptors are also ion channels for Na+ and K+
Nicotinic receptor’s function
produce excitation
Muscarinic receptors location
located in the heart, smooth muscle, and glands
Muscarinic receptors Mechanism of action (heart SA node)
inhibition of adenylate cyclase, which leads to opening of K+ channels, slowing of the rate of spontaneous Phase 4 depolarization, and decreased heart rate
Muscarinic receptors Mechanism of action (smooth muscle and glands)
formation of IP3 and increase in intracellular (Ca2+)
Muscarinic receptors function
inhibitory in the heart (decreased heart rate, decreased conduction velocity in AV node).
are excitatory in smooth muscle and glands (increased GI motility, increased secretion).
The medulla is the control center for what?
Vasomotor center, Respiratory center, Swallowing, coughing, and vomiting centers
Pons in the control center for what?
Pneumotaxic center
Midbrain is the control center for what?
Micturition center
Hypothalamus is the control center for what?
Temperature regulation center, Thirst, and food intake regulatory centers
Chronotropic
means it influences heart rate by increasing it
Dromotrophic
decreases heart rate
Effects of ANS eye (pupil)
sympathetic: alpha 2 receptor: dialation;
parasympathetic: constriction
Effects of ANS eye (ciliary muscle)
sympathetic: beta receptors: accommodation;
parasympathetic: contraction
Effects of ANS eye (lacrimal gland)
sympathetic: decreased secretion;
parasympathetic: increased secretion
Effects of ANS heart (coronary arteries)
sympathetic: vasodilation; beta 1 rec: +ve chronotropic (increased heart rate); beta 1 rec: +ve dromotropic (increased contraction of myocardium)
parasympathetic: vasoconstriction; -ve chronotropic; -ve dromotropic
Effects of ANS lung (bronchi muscle)
sympathetic: b2 rec: dilation
parasympathetic: constrictor
Effects of ANS lung (vessels)
sympathetic: constriction
parasympathetic: dilation
Effects of ANS lung (glands)
sympathetic: decreased secretion (good)
parasympathetic: increased secretion (bad)
Effects of ANS GI tract (peristalsis (tonus))
sympathetic: b2 rec: relaxation;
parasympathetic: activation
Effects of ANS GI tract (sphincters)
sympathetic: a1 rec: constriction;
parasympathetic: relaxation
Effects of ANS GI tracts (glands)
sympathetic: decreased secretion;
parasympathetic: increased secretion
Effects of ANS (liver)
sympathetic: b rec: gluconeogenesis;
parasympathetic: glycogenesis
Effects of ANS Gall bladder (sphincters)
sympathetic: b2 rec: relaxation;
parasympathetic: constriction
Effects of ANS Pancreas (Insulin)
sympathetic: a rec: inhibits its secretion; b rec: activates its secretion
Effects of ANS Pancreas (Exocrine)
sympathetic: a rec: inhibits secretion;
parasympathetic: activates secretion
Effects of ANS Adrenal Medulla
sympathetic: activates secretion
Effects of ANS Urinary Bladder (Sphincter M.)
sympathetic: a rec: contraction;
parasympathetic: relaxation
Effects of ANS Urinary bladder (Detrusor M.)
sympathetic: b rec: relaxation;
parasympathetic: contraction
Effects of ANS Uterus (pregnant)
sympathetic: A1 rec: contraction
Effects of ANS Uterus (non-pregnant)
sympathetic: b2: relaxation
Effects of ANS Genitals
sympathetic: ejaculation (emission)
parasympathetic: erection (vasodilation) + ejaculation
Sensory transducer Mechanoreceptors
respond to touch/mechanical stimulus. examples are, Stretch receptors in muscle, joint receptors, Hair cells in auditory and vestibular systems, and Baroreceptors in the carotid sinus
Sensory transducer Photoreceptors example
Rods and cones of the retina
Sensory transducer Chemoreceptors examples
Olfactory receptors, Taste receptors, Osmoreceptors, Carotid body O2 receptors
Sensory transducer Nociceptors are used to sense what?
Extremes of temperature and pain
fiber type A (A-alpha)
large, alpha-motoneurons; conduction velocity: fastest
fiber type A (A-beta)
touch, pressure; CV: medium
fiber type A (A-gamma)
gamma-motoneurons to muscle spindles (intrafusal fibers); CV: medium
fiber type A (A-delta)
touch, pressure, temperature, and pain; CV: medium
fiber type B
preganglionic autonomic fibers
CV: medium
fiber type c
slow pain, postganglionic autonomic fibers
CV: slowest
Sensory Pathway Step 1
sensory receptors (epithelial cells or afferent neurons) are activated by environmental stimuli that converts the stimulus into electrical energy
Sensory Pathway Step 2
First-order neurons (primary afferent neurons) in the dorsal portion of spinal cord receive the signal and send the information to the CNS.
Sensory Pathway Step 3
Second-order neurons in the spinal cord or brain stem receives the information and sends it to the contralateral thalamus
Sensory Pathway Step 4
Third-order neurons in the thalamus sends the encoded sensory information to the cerebral cortex
Sensory Pathway Step 5
Fourth-order neurons in the cerebral cortex received the information which results in a conscious perception of the stimulus.
Dorsal column system is a type of ________ that detects________?
pathway in the somatosensory system; sensations of fine touch, pressure, two-point discrimination, and vibration.
Anterolateral system is a type of ________ that detects________?
pathway in the somatosensory system; sensations of temperature, pain, and light touch.
Thalamus information is arranged how?
Has Information from different parts of the body arranged somatotopically
Damage to right side of thalamus could cause what?
loss of sensation on the controlateral side (left side) of the body.
Damage to left side of thalamus could cause what?
loss of sensation on the controlateral side(right side) of the body.
What is referred pain?
Sites on the skin that are innervated by nerves that arise from the same segment of the spinal cord.
What is an example of referred pain?
when ischemic heart pain is referred to the chest and shoulder.
Taste is a sense called ______ that falls under the category of ______?
Gustation; Chemoreception.
What are the 3 Innervations of Taste?
CN VII ( Chorda tympani branch of facial nerve), CN IX ( Glossopharyngeal nerve), and Vagus nerve branch
What are the 4 types of taste and their receptors?
Salt with NaCl receptors, Sour with three different receptor proteins for acidic compounds, Bitter with G-protein coupled receptors (GPCR’s), Sweet with GPCR’s receptors.
What is Ageusia?
loss of sense of taste when the facial nerve is
Damaged.
What is Hypogeusia and Hypergeusia?
Hypogeusia is decreased taste sensitivity and Hypergeusia is increased taste sensitivity
What causes a sore tongue?
some form of trauma, such as biting your tongue, or eating piping-hot or highly acidic food or drink.
What disorders can cause sore tongue?
diabetes, anemia, some types of vitamin deficiency and certain skin diseases
What is Glossodynia?
a burning sensation on the tongue
What is Benign migratory glossitis (geographic tongue)?
it is an unknown condition where there is irregular and inflamed patches on the tongue surface that often have white borders.
Symptoms of Benign migratory glossitis
swollen, red and sore tongue
Where are olfactory receptors located and what do they do?
they are located in the olfactory epithelium and they are true neurons that conduct action potentials into the CNS
What does CN I (olfactory nerve) do?
carries information from the olfactory receptor cells through the cribriform plate to the olfactory bulb.
The Axons of the olfactory nerves are ______ _____ fibers and are the ________ and ________ nerves in the nervous system
unmyelinated C; smallest and slowest
What can happen with cribriform plate fractures?
Fractures of the cribriform plate sever input to the olfactory bulb and reduce (hyposmia) or eliminate (anosmia) the sense of smell.
What nerve is unaffected by cribriform plate fractures and can detect pain?
CN V ( trigeminal nerve)
What is Anosmia?
Anosmia is the lack of olfaction or a loss of the sense of smell.
What is Phantosmia?
Phantosmia is the phenomenon of smelling odors that aren’t really present.
What is Dysosmia?
When things smell differently than they should.
What are the 3 layers that make up the exterior wall of the eyeball in order from outer to innermost layers?
sclera, choroid, and retina.
What is the outermost layer of the eye and what does it do?
The outer layer of the eye is the sclera, which is a tough white fibrous layer that maintains, protects, and supports the shape of the eye.