Shared Flashcard Set

Details

Physiology Unit 3 Exam
N/A
147
Physiology
Undergraduate 2
02/27/2012

Additional Physiology Flashcards

 


 

Cards

Term
What is another name for a SKELETAL muscle cell?
Definition
muscle fiber
Term
Define sarco-
Definition
flesh
Term
Define sarcolemma
Definition
plasma membrane of muscle fiber
Term
Define sarcoplasm
Definition
cytoplasm of a muscle fiber
Term
What is the predominant organelle in the skeletal muscle?
Definition
myofibril
Term
What is the characteristic that differentiates pictures of muscle TISSUES from muscle CELLS?
Definition
nuclei; if nuclei are present it is a cell
Term
What are the the proteins that constitute myofibrils?
Definition
contractile (actin and myosin), regulatory (tropomyosin and troponin)
Term
What are the two types of contractile myofilaments?
Definition
actin (thin) and myosicontractile (actin and myosin), regulatory (thick)
Term
What are the five components of the sarcomere?
Definition
Z discs, A band, I band, H zone, and M line
Term
What is the sarcomere?
Definition
the basic unit of contraction in skeletal muscle
Term
What are Z discs?
Definition
the boundary of each sarcomere
Term
What is an A band?
Definition
region where thin and thick filaments overlap
Term
What are I Bands?
Definition
area on either side of an A Band that contains only thin filaments
Term
Define H zone
Definition
central part of A band where no filaments reach
Term
What is the M Line?
Definition
center of the H zone that contains rods that hold thick filaments together
Term
Define myofibril
Definition
contractile organelles of the muscle fiber; help give muscle cell its striped appearance
Term
What are the two types of regulatory proteins?
Definition
Tropomyosin and troponin
Term
Define tropomyosin
Definition
chord-like protein covering myosin binding sites on actin molecues
Term
Define and state the purpose of troponin
Definition
protein complex attached to tropomyosin; binds with Ca and pulls tropomyosin OFF binding sites
Term
Define T-tubules
Definition
invaginations of sarcolemma; T=transverse; lie between myofibrils
Term
Define sarcoplasmic reticulum (SR)
Definition
membranous sacs that encircle each myofibril; stores Ca; equivalent to ER
Term
Sarcolemma are ___
Definition
multinucleiated
Term
___ extend beyond the length of the muscle
Definition
sheaths
Term
What is the substance that stores and carries O2 in muscle cells?
Definition
Myoglobin
Term
Describe the triad of reticulum
Definition
terminal cisternae and transverse tubules; located at the A-I junction
Term
___ actin encircle each myosin thick filament
Definition
6
Term
___ proteins are lighter in color
Definition
thin
Term
What is the crossbridge and its purpose?
Definition
the head portion of the myosin filament; bridges the gap between myosin and actin during contraction
Term
ID:
the regulatory protein that covers Ca binding sites when at rest
Definition
Tropomyosin
Term
Contraction of muscles occurs through a ___ ___ mechanism
Definition
sliding-filament
Term
T/F:
The length of actin and myosin changes during contraction
Definition
FALSE
Term
What is the Ca dependent state of the Crossbridge Cycle?
Definition
step 1: the binding of myosin to actin
Term
What substance releases myosin from actin in the crossbridge cycle?
Definition
ATP
Term
What is formalin?
Definition
Formaldehyde; type of tissue fixative
Term
How does tissue become fixed in the formalin boogie?
Definition
by forming cross-linkages in the proteins of the tissue
Term
ID:
Sequence of events that links that AP from a somatic motor neuron to muscle cell contraction
Definition
Excitation-Contraction Coupling
Term
What causes an EPP?
Definition
the AP of the LMN releases ACh from the LMN's axon terminal onto the sarcolemma
Term
What are the three components of the Neuromuscular junction?
Definition
axon terminal, motor end plate, and synaptic cleft
Term
What is necessary for a muscle to be able to keep contracting?
Definition
ATP
Term
How is ATP created for muscle usage?
Definition
substrate-level phosphorylation; creatine phosphate system
Term
What is the energy source for activity that lasts 1-5secs. 5-45secs, and >45secs?
Definition
ATP-PC; ATP-PC+Glycolysis; Glycolysis + Ox. Phos.
Term
Define muscle twitch
Definition
mechanical response of an individual muscle cell, motor unit, or whole muscle to an AP
Term
Describe muscle twitch (3)
Definition
all-or-none; reproducible; same size every time
Term
What are the three phases of a twitch?
Definition
Latent period, contraction; relaxation
Term
ID:
millisecond time delay between the AP and initiation of contraction (time for ECC)
Definition
Latent Period
Term
Define contraction
Definition
crossbridge cycling is occurring and cystolic Ca levels are rising; time it takes Ca to maximize
Term
Define relaxation
Definition
cytosolic Ca is returned to the SR and the number of crossbridges decline
Term
why is a twitch always the same amplitude/size?
Definition
An AP always triggers the same degree of Ca release from the SR which causes the same rise in cytosolic Ca => same # of crossbridges =>same amount of force generated
Term
What are the contractile components of a muscle?
Definition
all sarcomeres of a myocyte
Term
What is the Series Elastic Component?
Definition
parts of a muscle that don't contract but act to transfer tension developed in the sarcomeres to ends of the muscle cell
Term
What are the two factors that determine the force generated in a whole muscle?
Definition
force generated in individual muscle fibers; number of muscle fibers contracting
Term
What are the factors that affect crossbridge formation?
Definition
frequency of stimulationfeiber diameter, and changes in fiber length
Term
What are the factors that affect frequency of stimulation?
Definition
treppe, summation, and tetanus
Term
___ occurs at a frequency of muscle stimulation where independent twitches follow one another closely
Definition
Treppe; "step"
Term
____ and ___ occur at greater stimulus frequencies as twitches overlap in time
Definition
Summation; Tetanus
Term
What is the crucial variable that determines the force-generating capacity?
Definition
Fiber diameter
Term
Why are bigger muscles stronger muscles?
Definition
because they have more sarcomeres
Term
More sarcomeres= more ___ and ____
Definition
myosin; actin
Term
More myofilaments= more potential for ____ ____
Definition
active crossbridges
Term
What does optimal length of sarcomeres ensure?
Definition
optimal overlap of myosin and actin
Term
What percentage of resting length if optimal?
Definition
100-120%
Term
How does the nervous system exert control over muscular force?
Definition
by varying the number of muscle cells contracting
Term
What is a motor unit?
Definition
single somatic motor neuron and all muscle cells it innervates
Term
how does stretching before contracting affect force?
Definition
increases force
Term
T/F:
Larger soma are easier to depolarize to threshold
Definition
False; they need a greater stimulus
Term
How does endurance exercise affect muscle fibers and why?
Definition
enhances oxidative capacity; more and bigger mitochondria, increased capillary density, and fiber diameter decreases
Term
What is the affect of high intensity exercise on muscle fibers?
Definition
enhances glycolytic capacity of fibers; less and smaller mitochondria, decreased capillary density, increased concentration of glycolytic enzymes and fiber diameter increases
Term
How do muscles get bigger?
Definition
but adding new fibrils, NOT new cells
Term
Describe myosatellite cells
Definition
aka satellite cells; help with repair and growth
Term
How do myosatellite cells contribute to hypertrophy?
Definition
by becoming a nucleus
Term
What is the myonuclear domain?
Definition
evenly distributed nuclei; cytosol associated with each nucleus
Term
What are the two protective sensors for skeletal muscles?
Definition
muscle spindles (detect muscle length) and golgi tendon organs (detect muscle tension)
Term
Describe the protective sensors for skeletal muscles
Definition
special sensory receptors and their assoc afferent nerve fibers provide info regarding muscle movement to the CNS
Term
Describe muscle spindle anatomy
Definition
2-12 modified muscle fibers called intrafusal fibers running parallel with extrafusal fibers
Term
What are muscle spindles innervated by?
Definition
la afferents and gamma motor neurons
Term
What is the speed of cross-bridge cycling dictated by?
Definition
the myosin ATPase isoform present in each fiber type
Term
most muscles have ___ fiber types
Definition
all
Term
What does muscle spindle stretch result in?
Definition
activation of alpha motor neuron and muscle contraction
Term
What is the purpose of a stretch receptor?
Definition
protect the muscle fibers from over stretching or contracting
Term
What happens as a result of alpha motor neuron activation?
Definition
contraction
Term
gamma motor neurons stimulate ____ of ____
Definition
contraction; spindles
Term
How do you describe the arrangement of GTOs?
Definition
in series; golgi tendon organs
Term
Describe GTOs
Definition
capsules of CT intertwined with collagen fibers of tendons
Term
What is the purpose of GTOs?
Definition
prevent too much contraction
Term
What are GTOs innervated by and why?
Definition
type 1b afferents; no contractile elements are associated with them (not innervated by motor neurons)
Term
What leads to alpha motor inhibition and muscle relaxation?
Definition
GTO stimulation
Term
What does the CV consist of?
Definition
heart and vessels (heart, blood vessels, blood)
Term
What two systems regulate the CV system?
Definition
nervous and endocrine
Term
ID:
conduit system for blood
Definition
blood vessels
Term
What type of system is the CV system?
Definition
closed
Term
what is the position of the heart?
Definition
upside down backwards leaning cone
Term
What provides lubricant to reduce friction around the heart?
Definition
pericardium
Term
___ receive blood from the vessels
Definition
atria
Term
____ pump blood into the vessels
Definition
ventricles
Term
____ ALWAYS pump blood away from the heart
Definition
arteries
Term
What is the most important ventricle and why?
Definition
the left; it pumps blood to the brain
Term
What are the three layers of the heart wall?
Definition
myocardium, endocardium, epicardium
Term
What is the thickest layer of the heart?
Definition
myocardium
Term
What do the differences in myocardial thickness indicate?
Definition
difference in the distance blood is pumped from certain chambers
Term
T/F:
The atrial myocardium is thinner than ventricular myocardium
Definition
True
Term
Define Atrioventricular valves
Definition
flaps of CT between each atrium and ventricle
Term
What are the parachute chords?
Definition
chordae tendonae
Term
Define semilunar valves
Definition
thicker CT cusps located between each ventricle and the large artery it pumps blood into
Term
What are the three components of vasculature?
Definition
Arteries, veins and capillaries
Term
Define vasculature
Definition
system of blood vessels
Term
What are the three layers of the walls of hollow organs?
Definition
smooth muscle, endothelium, CT
Term
What are the layers of capillaries?
Definition
endothelium and basement membrane (CT)
Term
What are the four components of blood?
Definition
Plasma, leukocytes, platelets, and erythrocytes
Term
ID:
water with dissolved proteins and electrocytes
Definition
plasma
Term
WBCs with immune function
Definition
Leukocytes
Term
cell fragments with clotting fragments
Definition
platelets
Term
RBCs with hemoglobin
Definition
erythrocytes
Term
What percentage of blood volume is plasma?
Definition
55%
Term
What percentage of Erythrocytes are in the blood?
Definition
45%
Term
What is the purpose of the biconcave shape of RBCs?
Definition
flexibility to bend and increased SA
Term
What substances move into and out of the blood in the pulmonary capillaries?
Definition
O2 and CO2
Term
What kind of blood is pumped by the RIGHT heart?
Definition
deoxygenated blood
Term
What kind of blood is pumped by the LEFT heart and where does it go?
Definition
oxygenated; systemic circuit
Term
The systemic organs are said to be in ____ with one another
Definition
parallel
Term
___ ____ take the blood to all organs at the same time
Definition
arterial branches
Term
What is the purpose of parallel blood flow?
Definition
to ensure that all organs receive fully oxygenated blood; independent regulation of flow to each organ
Term
Describe the redistribution of of blood flow
Definition
when you need blood somewhere it comes from another location
Term
What is the order of heart contraction?
Definition
atria then ventricles
Term
T/F:
Atria and ventricles cannot contract at the same time
Definition
True
Term
What coordinates heart contractions?
Definition
conduction system in the myocardium
Term
What term describes the conduction system of the heart and what does that entail?
Definition
myogenic contractile activity; contracts without activation from a neuron
Term
Define autorhythmic cells
Definition
specialized cardiac myocytes
Term
What are the two types of Autorhythmic cells?
Definition
pacemaker cells (spontaneously make AP and est heart rate; conduction fibers (transmit AP)
Term
What are examples of pacemaker cells and conduction fibers?
Definition
SA and AV nodes; large diameter cardiac myocytes
Term
Define ECG
Definition
Electrocardiogram: recording the electrical activity of the heart
Term
how many electrodes are in an ECG lead?
Definition
2
Term
What are the three components of ECG waves?
Definition
P-wave, QRX complex, and T-wave
Term
Larger amplitude deflection indicates what?
Definition
larger mass of depolarized cells
Term
ID:
atrial depolarization
Definition
P-wave
Term
describe the QRX complex
Definition
ventricular depolarization and atrial repolarization
Term
ID:
ventricular repolarization
Definition
T-wave
Term
What are the two phases of the cardiac cycle?
Definition
systole and diastole
Term
Describe the cardiac cycle
Definition
all events that involve the flow of blood through the heart during one beat
Term
What phase of the cardiac cycle is associated with contraction?
Definition
systole
Term
What are the four phases of the cardiac cycle?
Definition
Ventricular filling, isovolumetric contraction, ventricular ejection, and isovolumeric relaxation
Term
ID:
venous blood return
Definition
ventricular filling
Term
ID:
when ventricles contract and the amount of blood present remains constant
Definition
isovolumetric contraction
Term
ID:
exit blood from ventricles during remainder of systole; ending initiates diastole `
Definition
ventricular ejection
Term
ID:
all valves are closed and blood volume remains constant with the relaxation of ventricles; beginning of diastole
Definition
Isovolumetric relaxation
Term
Define SP
Definition
systolic pressure; maximum pressure in the aorta during a cardiac cycle
Term
Define DP
Definition
diastolic pressure; minimum pressure in the aorta during CC
Term
Define MAP
Definition
Mean arterial pressure; avg pressure occuring during a CC
Supporting users have an ad free experience!