Physiology I Flashcards
What major cations are most abundant in the extracellular fluid?
Na
What major cations are most abundant in the intracellular fluid?
K
What major anions are most abundant in the extracellular fluid?
Cl
What major anions are most abundant in the intracellular fluid?
PO4, organic anions
Which of the following would have to be a transmembrane protein?
A. A receptor protein
B. A protein binding to the cytoskeleton
C. A channel protein
D. A phosphorylase
C. a channel protein
Which of the following organelles is directly associated with the synthesis of proteins for secretion?
A. mitochondria B. golgi apparatus C. nucleus D. rough endoplasmic reticulum E. smooth endoplasmic reticulum
D. rough endoplasmic reticulum
Pits coated with which of the following are often associated with endocytosis?
A. Clathrin B. COPI C. COPII D. Coatamers E. Vinculin
A. Clathrin
Which of the following processes does not require the presence of mitochondria?
A. Oxidative Phosphorylation
B. Production of carbon dioxide and whater
C. Breakdown of glucose to pyruvic acid
D. Electron transfer between cytochromes
E. Utilization of oxygen as a final electron receptor
C. Breakdown of glucose to pyruvic acid
Which of the following transport mechanisms requires energy other than kinetic energy?
A. osmosis
B. diffusion
C. active transport
D. facilitated diffusion
C. active transport
Of the following ions, which is most concentrated in the extracellular environments?
A. sodium
B. potassium
C. chloride
D. calcium
A. sodium
potassium is the most concentrated outside
The sodium-potassium pump is an example of which of the following kinds of transport?
A. diffusion
B. primary active transport
C. secondary active transport
D. facilitated diffusion
B. primary active transport
The sodium-glucose pump is an example of which of the following kinds of transport?
A. diffusion
B. primary active transport
C. secondary active transport
D. facilitated diffusion
C. secondary active transport
The sodium-calcium pump is an example of which of the following kinds of transport?
A. diffusion
B. primary active transport
C. secondary active transport
D. facilitated diffusion
C. secondary active transport
Glucose transporters (GLUT transporters) employ which of the following kinds of transport?
A. diffusion
B. primary active transport
C. secondary active transport
D. facilitated diffusion
D. facilitated diffusion
Which of the following mechanisms would most likely be used to move water from an extracellular environment across an epithelial cell layer into an extracellular environment on the opposite side of the epithelial layer?
A. sodium channels and sodium ATPase pumps
B. calcium channels and sodium ATPase pumps
C. calcium channels and calcium ATPase pumps
D. sodium channels and sodium ATPase pumps
A. sodium channels and sodium ATPase pumps
water follows the increase in sodium concentration
The action potential for both ventricular cardiomyocytes and a Purkinje fiber exhibit a plateau phase (phases 1 and 2). Conductance of which of the following ions is responsible for phase 0?
A. calcium ions
B. potassium ions
C. sodium ions
D. both potassium and calcium ions
C. sodium ions
Which of the following characteristics would be true of cardiac muscle cells but not skeletal muscle fibers?
A. cells have the sarcomeric banded pattern
B. cells utilize T-tubules
C. cells are mononucleated
D. cells utilize ryanodine channels
C. cells are mononucleated
The resting potential of -85 mv is characteristic of which of the following phases of the cardiac fast action potentials?
A. stage 1
B. stage 2
C. stage 3
D. stage 4
D. stage 4
The sodium-calcium exchanger in the sarcolemma of the cardiac muscle cell is an example of which of the following mechanisms?
A. primary active transport involving an antiporter
B. primary active transport involving a symporter
C. secondary active transport involving a symporter
D. secondary active transport involving an antiporter
D. secondary active transport involving an antiporter
Left ventricular isovolumic contraction occurs immediately following which of the following events?
A. closure of aortic valve
B. opening of aortic valve
C. closure of AV valve
D. opening of AV valve
C. closure of AV valve
Which of the following statements is true for the period of rapid ejection?
A. it occurs when the left ventricular pressure is above 80 mm Hg
B. the semilunar valves are closed during this phase
C. it occurs during the last two-thirds of ejection
D. it results in the ejection of about 90% of the total volume of blood
A. it occurs when the left ventricular pressure is above 80 mm Hg
Immediately prior to the ventricular isovolumic contraction, there is a slight but marked elevation in atrial pressure. Which of the following is responsible for this elevated pressure?
A. closure of the AV valve B. opening of the AV valve C. atrial contraction D. diastasis E. opening of the semilunar valve
C. atrial contraction
The Frank-Sterling law is based on which of the following principles?
A. the greater the stretching of cardiac muscle, the greater the force of contraction
B. the more calcium returned to the sarcoplasmic reticulum, the greater the force of contraction
C. the amount of blood received by each tissue is directly related to the immediate needs of that tissue
D. the faster the heart rate, the more likely that the period of diastasis will be eliminated
A. the greater the stretching of the cardiac muscle, the greater the force of the contraction
Stroke volume output can be increased by which of the following mechanisms?
A. Decreasing EDV
B. Increasing EDV
C. Increasing ESV
D. By decreasing EDV and increasing ESV
B. increasing EDV
Excess potassium in the extracellular fluid would have which of the following effects on heart activity?
A. heart will become dilated
B. heart rate will increase
C. heart will go toward spastic contraction
D. heart action potential will increase
A. heart will become dilated
In a typical ECG, which of the following waves occurs at the beginning of the contraction of the atria?
A. T B. R C. S D. P E. Q
D. P
If the end-diastolic volume is 110 ml and the end-systolic volume is 30 ml, the stroke volume is…?
A. 140 ml B. 80 ml C. 70 ml D. 40 ml E. 10 ml
B. 80 ml
SV = end diastolic - end systolic
If the end diastolic volume is 120 ml, and the end-systolic volume is 50 ml, what is the approximate value of the ejection fraction?
A. 42%
B. 60%
C. 214%
D. 240%
B. 60%
SV = end diastolic - end systolic
EF = SV/end diastolic
Isovolumic contraction of the ventricles occurs:
A. at the beginning of systole
B. at the end of systole
C. at the beginning of diastole
D. after the opening of the semilunar valves
A. at the beginning of systole
Neostigmine can be used to alleviate some of the effects of myasthenia gravis, an autoimmune disease in which antibodies attack acetylcholine receptors. Which of the following best represents neostigmine’s effects?
A. neostigmine initiates the opening of more sodium channels creating stronger end plate potentials
B. neostigmine binds to the antibodies and allows more acetylcholine receptors to participate in creating a stronger end plate potential
C. neostigmine inactivates acetylcholinesterase, allowing more acetylcholine molecules to bind to receptors and create stronger end plate potentials
D. neostigmine binds to voltage-gated sodium channels and initiates a stronger action potential
C. neostigmine inactivates acetylcholinesterase, allowing more acetylcholine molecules to bind to receptors and create stronger end plate potentials
Which of the following are anchored to the presynaptic membrane and are associated with synaptic vesicles to which they are tethered by short filaments?
A. synaptic vesicles
B. calcium channels
C. dense bars
D. dihydropyridine channels
C. dense bars
In order for an acetylcholine-gated ion channel to open, how many Ach molecules are necessary to attach to its alpha subunit?
A. one
B. two
C. three
D. four
B. two
Which of the following represents the first thing that happens after Ach binds to the ligand-gated channels on the sarcolemma?
A. an action potential is created on the sarcolemma
B. dihydropyridine channels allow entry of calcium ions
C. an end-plate potential is created on the muscle fiber
D. ryanodingaling channels allow calcium to escape into the myoplasm
C. an end-plate potential is created on the muscle fiber
The vesicles for acetylcholine are transported to the axon terminal from where?
A. rough ER
B. smooth ER
C. the axon terminal membrane
D. golgi
D. golgi
Which of the following can be used to inactivate acetylcholinesterase?
A. methacholine
B. neostigmine
C. physostigmine
D. carbachol
B. neostigmine
Which of the following represents an example of an eccentric contraction?
A. the triceps muscle during the throwing of a ball
B. the triceps muscle while raising the body from the floor during a push-up
C. the triceps muscle while lowering the body to the floor during a push-up
D. the biceps muscle while raising the body during a pull-up
C. the triceps muscle while lowering the body to the floor during a push-up
Ducks, geese, and many other species of birds may make long migratory trips during which they fly for long periods of time. Which of the following characteristics would be expected of their flight muscles (pectoralis complex)?
A. their flight muscle fibers would have relatively small numbers of mitochondria
B. their flight muscle fibers would have relatively small amounts of myoglobin
C. their flight muscle fibers would have small concentrations of ATPase
D. their flight muscles would have a more extensive sarcoplasmic reticulum
C. their flight muscle fibers would have small concentrations of ATPase
During skeletal muscle contraction, myosin heads go through repeated cycles in which they bind to actin, swivel to produce the power stroke, release from actin, and recock to prepare for the next cycle. One ATP molecule is required for each of these cycles. Which of the following events occurs after ATP binds to the myosin?
A. the power stroke resulting in the sliding of the actin along the myosin molecules
B. recocking of the myosin head
C. release of the myosin head from the actin binding site
D. binding of the myosin head to an active site on the actin
C. release of the myosin head from the actin binding site
Which of the following terms refers to a chain of sarcomeres?
A. muscle
B. myofiber
C. myofibril
D. myofilament
C. myofibril
Which of the following sarcomeric bands does not undergo a change in lenght during the contraction of a skeletal muscle?
A. A band
B. H band
C. I band
D. J band
A. A band
Which of the following sarcomeric bands is composed entirely of actin filaments?
A. A band
B. H band
C. I band
D. J band
C. I band
Dihydropyridine (DHP) channels are part of which of the following structures?
A. Sarcoplasmic reticulum
B. Plasmalemma
C. T tubules
D. Z discs
C. T tubules
Ryanodine-sensitive calcium ion release channels are part of which of the following structures?
A. sarcoplasmic reticulum
B. plasmalemma
C. t tubules
D. z discs
A. sarcoplasmic reticulum
Which of the following events occurs first during the transmission of a signal from an alpha motor neuron to a skeletal muscle fiber?
A. end-plate depolarization (EPP)
B. calcium ion influx into axon terminal
C. exocytosis of synaptic vesicles
D. sarcolemma action potential
B. calcium ion influx into axon terminal
Which of the following represents the factor by which the concentration of calcium ions increases in the cytosol after release from the sarcoplasmic reticulum?
A. 10
B. 50
C. 100
D. 1000
C. 100
from 0.1 umol/L to 10 umol/L
Which of the following maintains an optimum calcium concentration gradient to facilitate return of calcium to SR?
A. calsequestrin
B. SERCA
C. DHP
D. ryanodine
A. calsequestrin
Fast twitch fibers have which of the following characteristics?
A. they are reddish in color compared to slow twitch fibers
B. they have more mitochondria than slow twitch fibers
C. they have more myoglobin than slow twitch fibers
D. they are more fatigable than slow twitch fibers
D. they are more fatigable than slow twitch fibers
Which of the following represents an example of an eccentric contraction?
A. the triceps muscle during the throwing of a ball
B. the triceps muscle while raising the body from the floor during a push-up
C. the triceps muscle while lowering the body from the floor during a push-up
D. the biceps muscle while raising the body during a pull-up
C. the triceps muscle while lowering the body to the floor during a push-up
Which of the following types of neurons would transmit an action potential the fastest?
A. small diameter, non-myelinated
B. small diameter, myelinated
C. large diameter, myelinated
D. large diamter, non-myelinated
C. large diameter, myelinated
Saltatory conduction is characteristic of which part of a typical neuron?
A. dendrite
B. nerve cell body
C. axon hillock
D. axon
D. axon
jumps from node to node
A selectivity filter with carbonyl oxygens is associated with which of the following kinds of ion channels?
A. gated sodium
B. non-gated sodium
C. potassium
D. chloride
C. potassium
The resting potential for a typical neuron, such as a motor neuron, is best represented by which of the following potentials?
A. 74 mV
B. -74 mV
C. 90 mV
D. -90 mV
D. -90 mV
What is the role of calcium in muscle contraction?
binds to Troponin, exposing the myosin binding site on tropomyosin
What is the role of ATP in muscle contraction?
- used by SERCA to pump calcium back into the sarcoplasmic reticulum
- causes myosin to release from actin
- pumping of sodium/potassium to reestablish resting potential
3 major characteristics of an action potential
- all or none; either occurs or it doesn’t
- self-propogating
- non-decremental; no strength decrease
What covers the:
- muscle
- fascicle
- myofiber
- epimysium
- perimysium
- endomysium
Structural organization of a muscle from largest to smallest
Muscle –> fascicle –> myofiber -> myofibril –> myofilament
Isometric vs Isotonic
Isometric - inc tension, no change in length
Isotonic - inc. in length
Eccentric vs Concentric
Eccentric - muscle lengthens
Concentric - muscle shortens
Fast Twitch Fiber characteristics
- light and white
- lower levels of mitochondria/myoglobin
- high levels of ATPase
- anaerobic
- lower stamina
Slow Twitch Fiber characteristics
- dark and red
- high levels of mitochondria/myoglobin
- low levels of ATPase
- aerobic
During the conduction of a signal from the SA node to the ventricular fibers, there is a .16 sec delay from the initial origin of the signal until onset of ventricular contraction. More than half of this delay occurs in which of the following areas of the transmission pathway?
A. SA node
B. AV node
C. SA fibers
D. penetrating bundles
B. AV node
In a typical ECG, which of the following waves occurs at the beginning of the contraction of the atria?
A. T B. R C. S D. P E. Q
D. P
Which of the following events is generally not seen on a typical ECG?
A. Atrial depolarization
B. Atrial repolarization
C. Ventricular depolarization
D. Ventricular repolarization
B. atrial depolarization
Which of the following is the direction of bipolar lead III?
A. 0 degrees
B. 60 degrees
C. 90 degrees
D. 120 degrees
D. 120 degrees
Of the three bipolar leads, which one is connected to both left and right arms?
A. lead I
B. lead II
C. lead III
D. all leads are connected to only one arm each
A. lead I