BIOL 235 ACTUAL EXAM STUDY GUIDE
2025/2026 | COMPLETE QUESTIONS |
VERIFIED ANSWERS | GRADED A + | PASS
GUARANTEED | RECENT UPDATE
Diffusion - ANSWER most important method of capillary exchange. Oxygen
(O2), carbon dioxide (CO2), glucose, amino acids, and hormones. Water-soluble
substances such as glucose and amino acids pass across capillary walls through
intercellular clefts or fenestrations. Lipid-soluble materials, such as O2, CO2, and
steroid hormones, may pass across capillary walls directly through the lipid bilayer
of endothelial cell plasma membranes. In sinusoids, the intercellular clefts are so
large that they allow even proteins and blood cells to pass through their walls.
transcytosis - ANSWER In this process, substances in blood plasma become
enclosed within tiny pinocytic vesicles that first enter endothelial cells by
endocytosis, then move across the cell and exit on the other side by exocytosis.
This method of transport is important mainly for large, lipid-insoluble molecules
that cannot cross capillary walls in any other way. (Ex. insulin)
bulk flow - ANSWER passive process in which large numbers of ions,
molecules, or particles in a fluid move together in the same direction. Occurs from
an area of higher pressure to an area of lower pressure, and continues as long as a
pressure difference exists. More important for the regulation of the relative
volumes of blood and interstitial fluid.
filtration - ANSWER pressure-driven movement of fluid and solutes from
blood capillaries into interstitial fluid. Promoted by two pressures: blood
,hydrostatic pressure (BHP), the pressure generated by the pumping action of the
heart, and interstitial fluid osmotic pressure (IFOP).
reabsorption - ANSWER pressure-driven movement from interstitial fluid into
blood capillaries. The main pressure promoting this process is the blood colloid
osmotic pressure.
net filtration pressure (NFP) - ANSWER the balance of filtration pressures
(BHP, IFOP) and reabsorption pressures (BCOP). Overall, the volume of fluid and
solutes reabsorbed normally is almost as large as the volume filtered.
NFP = (BHP + IFOP) - (BCOP + IFHP)
Starling's law of the capillaries - ANSWER near equilibrium of filtration and
reabsorption pressures.
blood hydrostatic pressure (BHP) - ANSWER pressure that water in blood
plasma exerts against blood vessel walls. "Pushes" fluid out of capillaries into
interstitial fluid. Opposes IFHP.
Interstitial fluid hydrostatic pressure (IFHP) - ANSWER "pushes" fluid from
interstitial spaces back into capillaries. However, is usually close to zero. Opposes
BHP.
edema - ANSWER abnormal increase in interstitial fluid volume. Occurs if
filtration greatly exceeds reabsorption.
, blood colloid osmotic pressure (BCOP) - ANSWER force caused by the
colloidal suspension of large plasma proteins that averages 26 mmHg in most
capillaries. "Pulls" fluid from interstitial spaces into capillaries.
Interstitial fluid osmotic pressure (IFOP) - ANSWER "pulls" fluid out of
capillaries into interstitial fluid. Normally, IFOP is very small—0.1- 5 mmHg—
because only tiny amounts of protein are present in interstitial fluid.
blood flow - ANSWER volume of blood flowing through vessel, organ, or
entire circulation in given period. Total is cardiac output (CO).
blood pressure - ANSWER the hydrostatic pressure exerted by blood on the
walls of a blood vessel. Generated by contraction of ventricles. Determined by
cardiac output, blood volume, and vascular resistance.
systolic blood pressure - ANSWER the highest pressure attained in arteries
during systole (ventricular contraction).
diastolic blood pressure - ANSWER the lowest arterial pressure during diastole
(ventricular relaxation).
mean arterial blood pressure (MAP) - ANSWER average blood pressure in
arteries. Roughly one-third of the way between the diastolic and systolic pressures.
MAP = diastolic BP + 1/3 (systolic BP - diastolic BP)
, vascular resistance - ANSWER the opposition to blood flow due to friction
between blood and the walls of blood vessels. Depends on:
size of lumen: the smaller the diameter of the blood vessel, the greater the
resistance it offers to blood flow. Normally, moment-to-moment fluctuations in
blood flow through a given tissue are due to vasoconstriction and vasodilation of
the tissue's arterioles.
blood viscosity: the higher the blood's viscosity, the higher the resistance. Depends
mostly on the ratio of red blood cells to plasma (fluid) volume, and to a smaller
extent on the concentration of proteins in plasma.
total blood vessel length: the longer a blood vessel, the greater the resistance. An
estimated 650 km of additional blood vessels develop for each extra kilogram of
fat.
systemic vascular resistance (SVR) or total peripheral resistance (TPR) -
ANSWER refers to all of the vascular resistances offered by systemic blood
vessels. The smallest vessels—arterioles, capillaries, and venules—contribute the
most resistance. The major function of arterioles is to control SVR.
venous return - ANSWER the volume of blood flowing back to the heart
through the systemic veins. Occurs due to the pressure generated by contractions of
the heart's left ventricle. Besides the heart, two other mechanisms "pump" blood
from the lower body back to the heart: (1) the skeletal muscle pump and (2) the
respiratory pump.
2025/2026 | COMPLETE QUESTIONS |
VERIFIED ANSWERS | GRADED A + | PASS
GUARANTEED | RECENT UPDATE
Diffusion - ANSWER most important method of capillary exchange. Oxygen
(O2), carbon dioxide (CO2), glucose, amino acids, and hormones. Water-soluble
substances such as glucose and amino acids pass across capillary walls through
intercellular clefts or fenestrations. Lipid-soluble materials, such as O2, CO2, and
steroid hormones, may pass across capillary walls directly through the lipid bilayer
of endothelial cell plasma membranes. In sinusoids, the intercellular clefts are so
large that they allow even proteins and blood cells to pass through their walls.
transcytosis - ANSWER In this process, substances in blood plasma become
enclosed within tiny pinocytic vesicles that first enter endothelial cells by
endocytosis, then move across the cell and exit on the other side by exocytosis.
This method of transport is important mainly for large, lipid-insoluble molecules
that cannot cross capillary walls in any other way. (Ex. insulin)
bulk flow - ANSWER passive process in which large numbers of ions,
molecules, or particles in a fluid move together in the same direction. Occurs from
an area of higher pressure to an area of lower pressure, and continues as long as a
pressure difference exists. More important for the regulation of the relative
volumes of blood and interstitial fluid.
filtration - ANSWER pressure-driven movement of fluid and solutes from
blood capillaries into interstitial fluid. Promoted by two pressures: blood
,hydrostatic pressure (BHP), the pressure generated by the pumping action of the
heart, and interstitial fluid osmotic pressure (IFOP).
reabsorption - ANSWER pressure-driven movement from interstitial fluid into
blood capillaries. The main pressure promoting this process is the blood colloid
osmotic pressure.
net filtration pressure (NFP) - ANSWER the balance of filtration pressures
(BHP, IFOP) and reabsorption pressures (BCOP). Overall, the volume of fluid and
solutes reabsorbed normally is almost as large as the volume filtered.
NFP = (BHP + IFOP) - (BCOP + IFHP)
Starling's law of the capillaries - ANSWER near equilibrium of filtration and
reabsorption pressures.
blood hydrostatic pressure (BHP) - ANSWER pressure that water in blood
plasma exerts against blood vessel walls. "Pushes" fluid out of capillaries into
interstitial fluid. Opposes IFHP.
Interstitial fluid hydrostatic pressure (IFHP) - ANSWER "pushes" fluid from
interstitial spaces back into capillaries. However, is usually close to zero. Opposes
BHP.
edema - ANSWER abnormal increase in interstitial fluid volume. Occurs if
filtration greatly exceeds reabsorption.
, blood colloid osmotic pressure (BCOP) - ANSWER force caused by the
colloidal suspension of large plasma proteins that averages 26 mmHg in most
capillaries. "Pulls" fluid from interstitial spaces into capillaries.
Interstitial fluid osmotic pressure (IFOP) - ANSWER "pulls" fluid out of
capillaries into interstitial fluid. Normally, IFOP is very small—0.1- 5 mmHg—
because only tiny amounts of protein are present in interstitial fluid.
blood flow - ANSWER volume of blood flowing through vessel, organ, or
entire circulation in given period. Total is cardiac output (CO).
blood pressure - ANSWER the hydrostatic pressure exerted by blood on the
walls of a blood vessel. Generated by contraction of ventricles. Determined by
cardiac output, blood volume, and vascular resistance.
systolic blood pressure - ANSWER the highest pressure attained in arteries
during systole (ventricular contraction).
diastolic blood pressure - ANSWER the lowest arterial pressure during diastole
(ventricular relaxation).
mean arterial blood pressure (MAP) - ANSWER average blood pressure in
arteries. Roughly one-third of the way between the diastolic and systolic pressures.
MAP = diastolic BP + 1/3 (systolic BP - diastolic BP)
, vascular resistance - ANSWER the opposition to blood flow due to friction
between blood and the walls of blood vessels. Depends on:
size of lumen: the smaller the diameter of the blood vessel, the greater the
resistance it offers to blood flow. Normally, moment-to-moment fluctuations in
blood flow through a given tissue are due to vasoconstriction and vasodilation of
the tissue's arterioles.
blood viscosity: the higher the blood's viscosity, the higher the resistance. Depends
mostly on the ratio of red blood cells to plasma (fluid) volume, and to a smaller
extent on the concentration of proteins in plasma.
total blood vessel length: the longer a blood vessel, the greater the resistance. An
estimated 650 km of additional blood vessels develop for each extra kilogram of
fat.
systemic vascular resistance (SVR) or total peripheral resistance (TPR) -
ANSWER refers to all of the vascular resistances offered by systemic blood
vessels. The smallest vessels—arterioles, capillaries, and venules—contribute the
most resistance. The major function of arterioles is to control SVR.
venous return - ANSWER the volume of blood flowing back to the heart
through the systemic veins. Occurs due to the pressure generated by contractions of
the heart's left ventricle. Besides the heart, two other mechanisms "pump" blood
from the lower body back to the heart: (1) the skeletal muscle pump and (2) the
respiratory pump.
