Exam 1 Flashcards
muscular dystrophy
mutations in the genes for the various components of the dystrophin-glycoprotein complex are a prominent cause
duchenne muscular dystrophy
dystrophin protein is absent from muscle - it is X linked and usually fatal by the age of 30 (resp failure)
Becker muscular dystrophy
less serious form of muscular dystrophy, dystrophin is present but altered or reduced in amount
limb-girdle muscular dystrophies
associated with mutations of the genes coding for the sarcoglycans or other components of the dystrophin-glycoprotein complex
amyotrophic lateral sclerosis
neuro-degenerative disease that results in progressive loss of the ability to control voluntary movement, however, without appropriate neural tone muscles atrophy and become sclerotic (stiff/fibrous)
How are graded contractions produced?
by progressively increasing the number of motor units recruited
The force of muscle graded contraction depends on what 4 factors?
- number of fibers
- size of fibers
- frequency of stimulation
- muscle length
isotonic muscle contraction
tension develops and remains constant while muscle shortens
isometric muscle contraction
tension developed is not sufficient to shorten muscle, tension is maintained but no change in muscle length occurs
What is active tension of a muscle?
difference between total and passive tension; aka the tension generated by muscle contraction
response to alpha 1 in eye - radial (dilator) muscle
contraction - mydriasis
response to alpha 1 in the arterioles (skin, viscera)
contraction: increase TPR, increase diastolic pressure, increase afterload
response to alpha 1 in the veins
contraction: increase venous return, increase preload
response to alpha 1 in the bladder trigone and sphincter
contraction: urinary retention
response to alpha 1 in the male sex organ
vas deferens: ejaculation
response to alpha 1 in the liver
increase glycogenolysis
response to alpha 1 in the kidney
decrease renin release
response to alpha 2 in prejunctional nerve terminal
decrease transmitter release and NE synthesis
response to alpha 2 in platelets
aggregation
response to alpha 2 in pancreas
decrease insulin secretion
response to beta 1 in SA node of heart
increase heart rate (positive chronotropy)
response to beta 1 in AV node of heart
increase conduction velocity (positive dromotropy)
response to beta 1 in atrial and ventricular muscle
increase force of contraction (positive iontropy), conduction velocity, cardiac output, and oxygen consumption
response to beta 1 in His - Purkinje of heart
increase automaticity and conduction velocity
response to beta 1 in kidney
increase renin release
response to beta 2 in all blood vessels
vasodilation: decrease TPR, decrease diastolic BP, decrease afterload
response to beta 2 in uterus
relaxation
response to beta 2 in bronchioles
dilation
response to beta 2 in skeletal muscle
glycogenolysis - contractility (Tremor)
response to beta 2 in liver
glycogenolysis
response to beta 2 in pancreas
insulin secretion
response to D1 (peripheral) in renal tissue, mesenteric tissue, and coronary vasculature
vasodilation
in kidney - increase glomerular filtration rate, increase renal blood flow, increase Na excretion (due to vasodilation)
response to M3 in sphincter of eye
contraction - miosis
response to M3 in ciliary muscle of eye
contraction - accommodation for near vision
response to M2 in SA node of heart
decreased heart rate - negative chronotropy
response to M2 in AV node of heart
decrease conduction velocity - negative dromotropy
effect of M2 on the ventricles and purkinje system of the heart
There isn’t one!
response to M3 of bronchioles
contraction - bronchospasm
response to M3 of glands in the lung
secretion –> narrow lumen (resistance of air flow is high)
response to M3 in stomach
increased motility, cramps
response to M1 in glands of GI tract
secretion
response to M3 in intestine
contraction - diarrhea, involuntary defacation
response to M3 in bladder
contraction (Detrusor), relaxation (trigone/sphincter), voiding, urinary incontinence
response to M3 in sphincters
relaxation, except lower esophageal sphincter which contracts
response to M3 in glands
secretion - sweat (thermoregulatory), salivation and lacrimation
response to M3 in blood vessels (endothelium)
dilation (endothelium derived relaxing factor) - no innervation, no effects of indirect agonists
response to M2 in atrial muscle
decrease atrial contraction
response to M2 in ventricular muscle
decrease ventricular contraction (weak effect)
response to Nn in adrenal medulla
secretion of epinephrine and NE
response to Nn in autonomic ganglia
stimulation - net effects dependent on PANS/SANS innervation and dominance
response to Nm in neuromuscular junction
stimulation - twitch/hyperactivity of skeletal muscle
