Struggle Deck Flashcards
In the dark, what is the polar state if photoreceptors?
They are depolarized.
What retinal cells are responsible for color vision?
cones
Equation: Reynold’s number (turbulent flow)
Re = vd/(n/p)
v = velocity
d = vessel diameter
n = viscosity
p = density
What does pKa represent for a solution?
It is the pH at which acid and conjugate base forms are present in equal quantities.
What retinal cells are responsible for black and white vision?
rods
A flat lens is best for near/far vision?
far vision
What is the primary muscle involved in respiration?
diaphragm
A local anesthetic can penetrate tissues in its neutral, basic form. Would a local with a lower or higher pKa penetrate faster?
lower pKa
How does excess fat affect a blood pressure reading?
It makes the reading falsly high.
Define fovea centralis
The area with the highest density of cones
Upon expiration, what is the pressure change of the interpleural fluid?
It increases slightly.
What affect does hyperventilation cause on the blood pH and why?
It causes alkalosis because you are expiring more CO2 than the body can produce, decreasing the amount of H+ that ionized from its stored form of carbonic acid.
Which structures in the circulatory system carry the largest blood volume?
veins and venules
Increased resistance in precapillary vessels has what effect on pressure in capillaries?
It reduces the pressure in the capillaries.
What are adherens?
actin bands that encircle a cell
Does phosphate (PO34-) have a higher concentration in the intracellular or extracellular fluid?
intracellular (involved in many phosphorylating reactions)
What is meant by laminar fluid flow?
The fluid moves in layers of different velocities.
Which structures in the circulatory system are the strongest (least distensible)?
systemic arteries
As the blood becomes more alkaline, what happens to hemoglobin’s affinity for oxygen at low pressure?
Its affinity for oxygen increases.
How does fetal hemoglobin (HbF) aid in the uptake of oxygen during fetal growth?
It has a higher affinity for oxygen at a given pressure, so O2 is transferred from HbA to HbF.
How does cortisol affect gluconeogenesis?
It increases gluconeogenesis.
A drug that is absorbed in the small intestine will be metabolized by which organ?
liver
Does post-synaptic binding of Na+ always cause an action potential?
no
Does a neurons plasma membrane or cytoplasm conduct action potentials?
plasma membrane
Which structures in the circulatory system have the largest total cross-sectional area?
capillaries
Equation: Force of moving ion
Force = Em - Eion
Em = resting membrane potential
Eion = equilibrium potential for the ion
The sympathetic nervous system controls which pupillary muscle to cause what reaction?
The SNS controls the radial muscle, which stretches the pupil open.
Which organelles do red blood cells contain?
none
Does bicarbonate (HCO3-) have a higher concentration in the intracellular or extracellular fluid?
extracellular (breakdown of CO2 waste)
Define optic disc
The area where the optic nerve leaves the eye and retinal blood vessels enter (blind spot).
On which part of the eye do light rays focus?
retina
How does aldosterone affect sodium and potassium in the kidneys?
It increases sodium (and water) reabsorption and potassium secretion.
The parasympathetic nervous system controls which pupillary muscle to cause what reaction?
The PNS controls the circular muscle, which contracts the pupil.
Urea structure
What is the major characteristic of mineralocorticoids?
their influence on electrolytes and water balances
What is the major characteristic of glucocorticoids?
their role in glucose metabolism
Define hypokalemia
deficiency of K+ in bloodstream
What is the role of parathyroid hormone?
It removes bone, releasing calcium and phosphate.
Describe the contradiction between calcium’s typical role in muscle contraction vs. tetany.
Low levels of extracellular calcium lower the threshold for Na+ channels in the membrane, causing excitability and muscle twitches.
What class of compounds are norepinephrine and epinephrine?
catecholamines
What is a zygota called when it has 16 blastomeres?
morula
What do granulosa cells secrete?
progesterone
Define aneuploidy
a deviation from the normal chromosomal complement of 46
Define polyploidy
multiples of the haploid number of chromosomes
How does gestational diabetes affect birthweight?
It increases birthweight.
What are the two sites of gluconeogenesis?
liver and kidneys
The production of fetal steroids during early gestation is dependent upon which hormone?
human chorionic gonadotropin (hCG)
Do gram positive or gram negative bacteria have an outer membrane?
gram negative
How does the flow of blood through a vessel relation to the radius of that vessel?
It is proportional to r4.
How can a transmembrane receptor be isolated?
through a detergent wash
How do insulin affect glycolysis?
It increases glycolysis.
