Physiology I Flashcards
What term refers to the maintenance of nearly constant conditions in the internal environment and is the condition in which the body’s internal environment remains relatively constant within limits?
Homeostasis
An organism is said to be in homeostasis when its internal environment:
Contains the optimum concentraitons of ____, ______, _____ and _______
Has an optimal _______
Has an optimal ______ for the health of the cells
Gases, nutrients, ions and water
Temperature
Pressure
_______ is any stimulus that creates an imbalance in the internal environment
Stress
A change is some a parameter causes a response that results in a return of that parameter to normal. The response reverses the direction of the initial condition is refered to as what?
Negative feedback loop
What are the two characteristics of feedback loops?
Diminishes the original change
Stabilizing
_______ is the degree of effectiveness with which a control system maintains constant conditions
Gain
*** be sure to remember how to calculate gain
Small diameter axons transmit more ______ than large diameter axons
Slowly
_______ conduction is characterisitc of the myelinated axon but not the cell body of dendrites
Saltatory
What is the first thing that happens after the sodium ligand-gated channels open?
End-plate depolarization
During contraction of a skeletal muscle:
Actin filaments form the ____ bands which become ______ in width
I bands
Narrower
During contraction, the ____ band is equivalent to the length of the myosin filaments and doesn’t change in width
A band
The _____ band is the part of the A band that is not overlapped by the actin filaments and becomes ________
H band
Narrower
Skeletal muscle fibers and cardiac muscle fibers both have what 3 characteristics?
DHP channels on T tubules and Ryanodine receptors on sarcoplasmic reticulum
Sarcomeric arrangement
Multinucleated, peripheral nuclei
T tubules are found at the ends of the thick filaments
Two cisternae per T tubule
T tubules form triads with the sarcoplasmic reticulum
Sarcoplasmic reticulum is more extensive
Motor unit arrangement where one nerve fiber synapses with one or more skeletal muscle fibers
Are all characteristics of what type of muscle fiber?
Skeletal muscle fibers
Central, single nucleus per cell T tubules are found along the Z line There is one cisternae per T tubule T tubules form dyads with the sarcoplasmic reticulum SR is less extensive Muscle cells form a syncytium
These are all characterisitics of what type of cell?
Cardiac muscle fibers
There are 4 phases of fast action potentials in cardiac muscle action. What phase is considered resting potential?
Phase 4
During fast action potentials in cardiac muscle, what happens at phase 0?
Rapid depolarization
During fast action potentials in cardiac muscle what happens during phase 1?
Initial, incomplete repolarization
During fast action potentials in cardiac muscle what does phase 3 consist of?
Repolarization
What is the resting potential in cardiac muscle?
-85mV
Greater AP amplitude
More rapid rate of rise of phase 0
Larger cell diameter
Are characteristics of what type of cardiac muscle action potential?
Fast action potential
No fast sodium ion gates
Sunstroke of AP is due to calcium
Resting potential is close to -60mV
Amplitude is smaller
These are all characteristics of what type of cardiac muscle action potential?
Slow action potentials
How can stroke volume output be increased?
By increasing end diastolic volume
Or
By decreasing End systolic volume
How do you calculate ejection fraction?
Systolic volume (actual amount of blood ejected from the heart) / End diastolic volume (the amount of blood in the ventricle just before it contracts)
How do you calculate stroke volume?
(End diastolic volume (the amount of blood in the ventricle just before it contracts)) minus (End systolic volume (the amount of blood left in the ventricle after it has contracted))
What do P waves, QRS waves and T waves represent?
P waves= atrial depolarization
QRS waves= ventricular depolarization
T waves= ventricular depolarization
In regards to ECG vectors, what lead consists of the following characteristics?
Two electrodes on two arms
-R= negative
-L- positive
Direction of the lead = 0 degrees
Bipolar lead I
In regards of ECG Vectors, the following are characteristic of what lead?
Electrodes on right arm and left leg
-A=negative
-L=positive
Direction of the lead 60 degrees
Bipolar lead II
In regards to ECG vectors, the following are characteristics of what lead?
Electrodes on left arm and left leg
A= negative
L= positive
Direction of the lead = 120 degrees
Bipolar lead III
What is the comparison of the pressures in the arterial system and the venule system in the systemic circulation?
Arterial system is 120 mmHg
Once it reaches the venous system becomes 0mmHg
How much of the blood volume is in the veins?
64% or 2/3 of blood volume is in the veins
______ % of blood volume is in the systemic circulation
______ % of blood volume is in the heart and lungs
84
16
How much more compliant is a vein than an artery?
24 times more compliant
When the blood volume is at 5 L then the mean systemic filling pressure is ______ mmHg
When the blood volume is at 4 L then the mean systemic filling pressure is _______ mmHg
7
0
When right atrial pressure = mean systemic filling pressure, what is the venous return?
0
What is the main driving force for filtration in the kidney or has the greatest effect on increasing glomerular filtration rate?
Glomerular Hydrostatic pressure
How much of the total cardiac output do the kidneys receive?
22%
What is the golmerular filtration rate per minute? Per day?
Per min = 125ml/min
Per day= 180 L/day
In what part of the nephron is 65% of filtered electrolytes reabsorbed and all filtered glucose and amino acids reabsorbed using secondary active transport via Na+ glucose cotranpsorter?
Proximal convoluted tubule
Where is aldosterone’s major site of action?
Major site of action is on the principal cells of the cortical collecting ducts to stimulate resorption of Na and secretion of K
What part of the nephron are the intercalated cells located?
Late distal/ cortical collecting tubule
What is the action of the interacalated cells in the LDT and CCT?
Reabsorb K from tubular lumen and secrete H+ into tubular lumen
H+ generated by action of carbonic anhydrase
What buffer system plays a major role in buffering the renal tubular fluid and intracellular fluids?
Phosphate buffer system
If someone is in respiratory acidosis the primary compensatory response of the body would be to:
Increase plasma bicarbonate ion by action of new bicarbonate produced by the kidney
For someone with metabolic acidosis the primary compensatory response of the body would be to:
Increase ventilation rate
An increase in ratio of bicarbonate to H ion concentration is definitive of ________
Alkalosis
A decrease in CO2 concentration caused by hyperventilation is characteristic of _______ _________
Respiratory alkalosis
For someone who is hyperventilating and is in respiratory alkalosis , the compensatory response of the body would be:
Reduction in plasma bicarbonate ion concentration by renal excretion of bicarbonate
What is caused by rise in extracellular fluid bicarbonate ion concentration?
Metabolic alkalosis
What is the compensatory response of alkalosis?
Decreased ventilation
Increased renal bicarbonate excretion
_________________ = the maximum volume of gas the lungs can hold
Total lung capacity
What term describe the volume of air that is inspired or expired with each breath at rest?
A) Inspiratory reserve volume
B) expiratory reserve volume
C) Tidal volume
D) residual volume
C) Tidal volume
What term describes the volume of air that can be inspired in addition to tidal volume with forceful inspiration?
A) Inspiratory reserve volume
B) expiratory reserve volume
C) Tidal volume
D) residual volume
A) Inspiratory reserve volume
What term is used to describe additional volume of air that can be expired at end of tidal volume by forceful expiration?
A) Inspiratory reserve volume
B) expiratory reserve volume
C) Tidal volume
D) residual volume
B) expiratory reserve volume
What term is used to describe the volume of air remaining in lungs after forceful expiration?
Residual volume
What term describes the sum of all the volumes that can be inspired or exhaled and is the inspiration to the maximum extent plus expiration to the maximum extent?
A) Vital capacity
B) Total lung capacity
C) Inspiratory capacity
D) functional residual capacity
Vital capacity
What is the term to describe the sum of all the volumes = vital capacity plus residual volume?
A) Vital capacity
B) Total lung capacity
C) Inspiratory capacity
D) functional residual capacity
B) total lung capacity
What is the term to describe the sum of volume above resting capacity = tidal volume + inspiratory reserve volume
A) Vital capacity
B) Total lung capacity
C) Inspiratory capacity
D) functional residual capacity
C) inspiratory volume
What is the term used to describe the sum of volumes below resting capacity = expiratory reserve volume + residual volume?
A) Vital capacity
B) Total lung capacity
C) Inspiratory capacity
D) functional residual capacity
D) functional residual capacity
What is the term that describes the difference between the alveolar pressure and the pleural pressure?
Transpulmonary pressure
What happens to the gases partial pressures when water vapor is added in the lungs?
The partial pressures of all the gases will be reduced
What is the ventilation-perfusion ratio?
Va/Q= alveolar ventilation / blood flow
What is the normal Va/Q?
0.8
What is the Va/Q when there is an obstruction to the airway?
Va/Q = 0 but there is still perfusion
Blood gas composition remains unchanged
What is the Va/Q when there is a vascular obstruction such as a pulmonary embolism?
Va/Q = infinity
Q=0 but there is still ventilation (no gas exchange bc no blood contact)
At rest, how much oxygen is transported to the tissues?
5 ml O2/dl
About how much CO2 is transported as bicarbonate in the blood?
70%
What establishes ramp signal?
Dorsal respiratory group
What mainly controls rate and depth of breathing?
Pontine respiratory group (pnemotaxic center)
