BPK 105 – FINAL EXAM 2025
QUESTIONS AND ANSWERS
Describe the process by which more red blood cells are made in response to low oxygen. What
nutrients are required for this process? - ANS Low blood oxygen levels stimulate red blood
cell production by increasing the formation and release of the glycoprotein erythropoietin.
Erythropoietin stimulates red bone marrow to produce more red blood cells. This negative-
feedback mechanism increases the blood's capacity to transport oxygen and maintains
homeostasis.
Describe the functions of the heart, including the heart structure responsible for each function -
ANS Generating blood pressure
o Contractions of the heart generate blood pressure, which is required to force blood through
the blood vessels.
Routing blood
o The heart separates the pulmonary and systemic circulations, which ensures the flow of
oxygen-rich blood to tissues.
Ensuring one-way blood flow
o The vales of the heart ensure a one-way flow of blood through the heart and blood vessels.
Regulating blood supply
o Changes in the rate of heart contraction match blood flow to the changing metabolic needs of
the tissues during rest, exercise, and changes in body position.
Trace the flow of blood through the heart. Specify the various chambers, valves, and vessels
and the function of each. - ANS 1. Deoxygenated Blood enters R. Atrium from systemic route
via the superior and inferior vena cavas and from heart via the coronary sinus.
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,2. R Atrium contracts, and deoxygenated Blood passes through tricuspid valve into R. Ventricle
3. R. Ventricle contracts and pushes blood against the tricuspid valve forcing it closed. High
pressure in the ventricle forces the pulmonary semilunar valve open, and blood flows into the
pulmonary trunk.
4. R. Ventricle relaxes and the pressure decreases, the pressure in the pulmonary trunk
becomes higher causing blood to flow back into the pockets of the pulmonary semilunar valve,
forcing it closed
5. Pulmonary trunk branches to form L and R pulmonary arteries carrying blood to the lungs.
6. Returning oxygenated blood enters the L atrium 4 pulmonary veins.
7. L atrium contracts, forcing blood the flow through the mitral valve to fill L ventricle.
8. As the L ventricle begins to contract, blood is pushed against the bicuspid valve forcing it
closed
9. Presure increases from contraction of L ventricle, forces the aortic semilunar valve open, and
blood flows into aorta & to rest of the body
10. As the L ventricle relaxes, pressure in aorta becomes greater causing the blood to flow back
against the aortic semilunar valve forcing it closed.
Describe the important similarities and differences between cardiac and skeletal muscle cell
structure and function. - ANS Cardiac triations are less regularly arranged and less numerous
than skeletal muscle
Skeletal muscles are voluntary muscles attached to bones via tendons
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, Cardiac muscles are involuntary muscles found along the heart wall.
cardiac muscle fiber action potential lasts longer bc of slow diffusion of Ca2+ into the cell
Cardiac muscle has a Depolarization phase followed by a period of slow repolarization called
the plateau phase. At the end of the plateau phase, a rapid repolarization phase
Similarities:
Actin and myosin myofilaments form sarcomeres, which are joined to form myofibrils,
responsible for muscle contraction and organization
striated (banded) appearance relies on Ca2+ and ATP for contraction
Use same ions, K Ca, Na opening and closing of membrane channels is responsible for the
changes in the permeability of the cell membrane that produce action potentials
What are the major differences between the cardiac action potential and the skeletal muscle
action potential? What causes these differences, why is it important for how the heart
functions? - ANS DEPOLARIZATION:
Skeletal:
the only ions involved are Na+ and K+.
Cardiac:
Thee initial diffusing on Na+ in stimulates volatage-gated Ca2+ channels to open, and Ca2+
diffuses into the membrane, contributing to the overall depolarization
PLATEAU PHASE:
Skeletal muscle
No plateau phase
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QUESTIONS AND ANSWERS
Describe the process by which more red blood cells are made in response to low oxygen. What
nutrients are required for this process? - ANS Low blood oxygen levels stimulate red blood
cell production by increasing the formation and release of the glycoprotein erythropoietin.
Erythropoietin stimulates red bone marrow to produce more red blood cells. This negative-
feedback mechanism increases the blood's capacity to transport oxygen and maintains
homeostasis.
Describe the functions of the heart, including the heart structure responsible for each function -
ANS Generating blood pressure
o Contractions of the heart generate blood pressure, which is required to force blood through
the blood vessels.
Routing blood
o The heart separates the pulmonary and systemic circulations, which ensures the flow of
oxygen-rich blood to tissues.
Ensuring one-way blood flow
o The vales of the heart ensure a one-way flow of blood through the heart and blood vessels.
Regulating blood supply
o Changes in the rate of heart contraction match blood flow to the changing metabolic needs of
the tissues during rest, exercise, and changes in body position.
Trace the flow of blood through the heart. Specify the various chambers, valves, and vessels
and the function of each. - ANS 1. Deoxygenated Blood enters R. Atrium from systemic route
via the superior and inferior vena cavas and from heart via the coronary sinus.
1 @COPYRIGHT THEBRIGHT 2025/2026
,2. R Atrium contracts, and deoxygenated Blood passes through tricuspid valve into R. Ventricle
3. R. Ventricle contracts and pushes blood against the tricuspid valve forcing it closed. High
pressure in the ventricle forces the pulmonary semilunar valve open, and blood flows into the
pulmonary trunk.
4. R. Ventricle relaxes and the pressure decreases, the pressure in the pulmonary trunk
becomes higher causing blood to flow back into the pockets of the pulmonary semilunar valve,
forcing it closed
5. Pulmonary trunk branches to form L and R pulmonary arteries carrying blood to the lungs.
6. Returning oxygenated blood enters the L atrium 4 pulmonary veins.
7. L atrium contracts, forcing blood the flow through the mitral valve to fill L ventricle.
8. As the L ventricle begins to contract, blood is pushed against the bicuspid valve forcing it
closed
9. Presure increases from contraction of L ventricle, forces the aortic semilunar valve open, and
blood flows into aorta & to rest of the body
10. As the L ventricle relaxes, pressure in aorta becomes greater causing the blood to flow back
against the aortic semilunar valve forcing it closed.
Describe the important similarities and differences between cardiac and skeletal muscle cell
structure and function. - ANS Cardiac triations are less regularly arranged and less numerous
than skeletal muscle
Skeletal muscles are voluntary muscles attached to bones via tendons
2 @COPYRIGHT THEBRIGHT 2025/2026
, Cardiac muscles are involuntary muscles found along the heart wall.
cardiac muscle fiber action potential lasts longer bc of slow diffusion of Ca2+ into the cell
Cardiac muscle has a Depolarization phase followed by a period of slow repolarization called
the plateau phase. At the end of the plateau phase, a rapid repolarization phase
Similarities:
Actin and myosin myofilaments form sarcomeres, which are joined to form myofibrils,
responsible for muscle contraction and organization
striated (banded) appearance relies on Ca2+ and ATP for contraction
Use same ions, K Ca, Na opening and closing of membrane channels is responsible for the
changes in the permeability of the cell membrane that produce action potentials
What are the major differences between the cardiac action potential and the skeletal muscle
action potential? What causes these differences, why is it important for how the heart
functions? - ANS DEPOLARIZATION:
Skeletal:
the only ions involved are Na+ and K+.
Cardiac:
Thee initial diffusing on Na+ in stimulates volatage-gated Ca2+ channels to open, and Ca2+
diffuses into the membrane, contributing to the overall depolarization
PLATEAU PHASE:
Skeletal muscle
No plateau phase
3 @COPYRIGHT THEBRIGHT 2025/2026
