BIOM 3200 Midterm 2 Exam With
Complete Solutions
Distribution of blood in circulatory system at rest - ANSWER 5L of blood per
person, moved at 5L/min
- takes 1 min to get around body
Most blood contained in venous system
- acts as a reservoir from which more blood can be added to the circulation
under appropriate conditions.
Lungs - 10 to 12%
Heart - 8 to 11%
Systemic arteries - 10-12%
Capillaries - 4 to 5%
Systemic veins - 60 to 70%
Average heart rate and length of all blood vessels in body - ANSWER 70bpm
60000 miles
veins are able to....
Arteries provide.... - ANSWER Most of blood volume is in the venous system.
Unlike arteries, which provide resistance to the flow of blood from the heart,
veins are able to expand as they accumulate additional amounts of blood.
The average pressure in veins vs arteries - ANSWER The average pressure in
veins is only 2 mmHg, compared to a much higher average arterial pressure of
100 mmHg
Skeletal muscle pumps.
Diaphragm contraction - ANSWER The venous pressure is too low to return
blood to the heart.
To help veins of the lower limbs return blood, the veins pass between skeletal
muscle groups which provide contractions to help move blood back. (called -
"skeletal muscle pump")
,To help venous blood from the abdominal and thoracic regions, the act of
breathing + contraction of the diaphram + pressure in the abdomen from
breathing squeezes the veins and helps the venous blood return to the heart.
The one-way flow back to heart is ensured by
How was this first demonstrated and by who. - ANSWER The one-way flow back
to heart is ensured by venous valves.
First demonstrated by William Harvey...
- A touriquet on an arm - push the blood in a bulging then let go, it moves
towards the heart, but not the reverse direction.
Arteries
elastin is found where?
Large arteries will expand when?
Large arteries will recoil when? - ANSWER In the aorta and other larger arteries,
there are numerous layers of elastin fibers between the smooth muscle cells of
the tunica media.
These large elastic arteries expand when the pressure of the blood rises as a
result of the ventricle's contraction.
They recoil like a stretched rubber band when the blood pressure falls during
relaxation of the ventricles.
Arterial elastic recoil function - ANSWER The elastic recoil drives blood during
the diastolic phase when the heart is resting and not providing pressure.
Small arteries and arterioles are less elastic and so their diameter only changes
slightly.
How many capillaries and how close to cells are they - ANSWER Over 40 billion
capillaries in the body.
Number is so great that scarcely any cell in the body is more than 60-80 um
away from a blood capillary.
Effect on blood flow of vasodilation and vasoconstriction in capillaries.
What are the walls of capillaries composed of. Why? - ANSWER Vasoconstriction
decreases blood flow to the capillary bed, vasodilation increases it.
,Unlike the arterial and venule tissues, the walls of the capillaries are composed
of just one cell layer.
- Lack smooth muscle (SM) and contractile tissue (CT) which makes it easier to
exchange materials between blood and tissues.
Capillaries
_____ the arterial end.
_____ the venous end.
How does diffusion occur. - ANSWER Oxygen, nutrients, hormones, small
molecules, etc all enter the arterial end of a capillary.
CO2 and waste exit the venous end.
Diffusion takes place from fluid into tissue cells
At the arterial end, blood pressure forces fluid out of the capillary into the
surrounding tissue cells. At the venous end, fluid is drawn back into the capillary
via osmotic pressure.
Structure of blood vessels
Large vein
Medium Sized vein
Venule
______ capillary - ANSWER Large vein
- tunica externa
- tunica media
- tunica interna
- endothelium
- lumen
Medium Sized vein
- tunica externa
- tunica media
- tunica interna
- valve
Venule
- tunica externa
, - endothelium
- valve
Fenestrated capillary
- endothelial cells
- capillary pores
- basement membrane
Structure of blood vessels
Large artery
Medium Sized artery
Arteriole
______ capillary - ANSWER Large artery
- Tunica externa
- Tunica media
- Endothelium(Tunica interna)
- Elastic layer(Tunica interna)
Medium Sized artery
- Tunica externa
- Tunica media
- Tunica interna
Arteriole
- Endothelium
- lumen
- pre capillary sphincter
Continuous capillary
- endothelial cells
- basement membrane
blood flow calculation - ANSWER Flow = driving forces / resistance
Jean Leonard Marie Poiseuille
who is he and what did he postulate - ANSWER (19th century physician)
resistance depends on three major factors:
- tube/blood vessel length
- viscosity of the blood
Complete Solutions
Distribution of blood in circulatory system at rest - ANSWER 5L of blood per
person, moved at 5L/min
- takes 1 min to get around body
Most blood contained in venous system
- acts as a reservoir from which more blood can be added to the circulation
under appropriate conditions.
Lungs - 10 to 12%
Heart - 8 to 11%
Systemic arteries - 10-12%
Capillaries - 4 to 5%
Systemic veins - 60 to 70%
Average heart rate and length of all blood vessels in body - ANSWER 70bpm
60000 miles
veins are able to....
Arteries provide.... - ANSWER Most of blood volume is in the venous system.
Unlike arteries, which provide resistance to the flow of blood from the heart,
veins are able to expand as they accumulate additional amounts of blood.
The average pressure in veins vs arteries - ANSWER The average pressure in
veins is only 2 mmHg, compared to a much higher average arterial pressure of
100 mmHg
Skeletal muscle pumps.
Diaphragm contraction - ANSWER The venous pressure is too low to return
blood to the heart.
To help veins of the lower limbs return blood, the veins pass between skeletal
muscle groups which provide contractions to help move blood back. (called -
"skeletal muscle pump")
,To help venous blood from the abdominal and thoracic regions, the act of
breathing + contraction of the diaphram + pressure in the abdomen from
breathing squeezes the veins and helps the venous blood return to the heart.
The one-way flow back to heart is ensured by
How was this first demonstrated and by who. - ANSWER The one-way flow back
to heart is ensured by venous valves.
First demonstrated by William Harvey...
- A touriquet on an arm - push the blood in a bulging then let go, it moves
towards the heart, but not the reverse direction.
Arteries
elastin is found where?
Large arteries will expand when?
Large arteries will recoil when? - ANSWER In the aorta and other larger arteries,
there are numerous layers of elastin fibers between the smooth muscle cells of
the tunica media.
These large elastic arteries expand when the pressure of the blood rises as a
result of the ventricle's contraction.
They recoil like a stretched rubber band when the blood pressure falls during
relaxation of the ventricles.
Arterial elastic recoil function - ANSWER The elastic recoil drives blood during
the diastolic phase when the heart is resting and not providing pressure.
Small arteries and arterioles are less elastic and so their diameter only changes
slightly.
How many capillaries and how close to cells are they - ANSWER Over 40 billion
capillaries in the body.
Number is so great that scarcely any cell in the body is more than 60-80 um
away from a blood capillary.
Effect on blood flow of vasodilation and vasoconstriction in capillaries.
What are the walls of capillaries composed of. Why? - ANSWER Vasoconstriction
decreases blood flow to the capillary bed, vasodilation increases it.
,Unlike the arterial and venule tissues, the walls of the capillaries are composed
of just one cell layer.
- Lack smooth muscle (SM) and contractile tissue (CT) which makes it easier to
exchange materials between blood and tissues.
Capillaries
_____ the arterial end.
_____ the venous end.
How does diffusion occur. - ANSWER Oxygen, nutrients, hormones, small
molecules, etc all enter the arterial end of a capillary.
CO2 and waste exit the venous end.
Diffusion takes place from fluid into tissue cells
At the arterial end, blood pressure forces fluid out of the capillary into the
surrounding tissue cells. At the venous end, fluid is drawn back into the capillary
via osmotic pressure.
Structure of blood vessels
Large vein
Medium Sized vein
Venule
______ capillary - ANSWER Large vein
- tunica externa
- tunica media
- tunica interna
- endothelium
- lumen
Medium Sized vein
- tunica externa
- tunica media
- tunica interna
- valve
Venule
- tunica externa
, - endothelium
- valve
Fenestrated capillary
- endothelial cells
- capillary pores
- basement membrane
Structure of blood vessels
Large artery
Medium Sized artery
Arteriole
______ capillary - ANSWER Large artery
- Tunica externa
- Tunica media
- Endothelium(Tunica interna)
- Elastic layer(Tunica interna)
Medium Sized artery
- Tunica externa
- Tunica media
- Tunica interna
Arteriole
- Endothelium
- lumen
- pre capillary sphincter
Continuous capillary
- endothelial cells
- basement membrane
blood flow calculation - ANSWER Flow = driving forces / resistance
Jean Leonard Marie Poiseuille
who is he and what did he postulate - ANSWER (19th century physician)
resistance depends on three major factors:
- tube/blood vessel length
- viscosity of the blood
