Human Anatomy & Physiology: A&P 2402 Chpt. 19 Quiz Flashcards

pic Iphone

What are the smallest blood vessels in the body?

arteries

arterioles

capillaries

veins

Bulk fluid movement across capillary walls is typically through what structures?

plasma membranes

precapillary sphincters

endothelial cells

intercellular clefts

Net (positive) hydrostatic pressure tends to move fluid out of capillaries. The resulting bulk fluid movement is known as __________.

filtration

active transport

reabsorption

diffusion

Net (positive) osmotic pressure tends to move fluid into capillaries. The resulting bulk fluid movement is known as __________.

reabsorption

active transport

facilitated diffusion

filtration

Near the arteriole end of a capillary, what is the relationship between net hydrostatic pressure and net osmotic pressure?

Net hydrostatic pressure is approximately equal to net osmotic pressure.

Net hydrostatic pressure is less than net osmotic pressure.

Net hydrostatic pressure is greater than net osmotic pressure.

How do net hydrostatic pressure and net osmotic pressure each change along the length of a capillary (from arteriole to venule)?

Net osmotic pressure decreases and net hydrostatic pressure stays about the same.

Net osmotic pressure and net hydrostatic pressure both decrease.

Net osmotic pressure stays about the same and net hydrostatic pressure increases.

Net osmotic pressure stays about the same and net hydrostatic pressure decreases.

Which of the following most accurately describes how net filtration pressure (NFP) affects bulk fluid flow across capillary walls?

Negative NFP causes filtration.

Positive NFP causes filtration.

Positive NFP causes intercellular clefts to open.

Negative NFP causes bulk fluid flow to stop.

At a given point along a capillary, the net hydrostatic pressure (Net HP) is 20 mm Hg and the net osmotic pressure (Net OP) is 25 mm Hg. What is the Net Filtration Pressure (NFP) at that point?

The equation for Net Filtration Pressure is:

NFP = Net HP - Net OP

+45 mm Hg

-5 mm Hg

+10 mm Hg

+5 mm Hg

Overall, fluid moves out of capillaries and into the interstitial space. Which of the following best describes why this occurs?

Lymphatic vessel filtration is greater than lymphatic vessel reabsorption

Lymphatic vessel reabsorption removes fluid from the interstitial space.

Capillary filtration is greater than capillary reabsorption

Capillary reabsorption is greater than capillary filtration.

Which of the following most correctly describes the need for a functional lymphatic system?

Lymphatic vessels deliver fluid and solutes to the interstitial space.

Lymphatic vessels return interstitial fluid to the blood.

Lymphatic vessels return nondiffusible plasma proteins to the blood.

Lymphatic vessels return blood to the heart.

Iphone Pic thoracic

Iphone Pic brain

Iphone Pic veins

Iphone Pic arteries upper body

Iphone Pic arteries lower body

Iphone Pic artery & vein structures

Iphone Pic capillary, pg 697

Bonus Clinical Question:

Gary was injured in an automobile accident that severed the motor neurons innervating his quadriceps. Even though he has had extensive physical therapy, he is still suffering muscle atrophy. Why is the therapy not working?

In denervation (disuse) atrophy, fibrous connective tissue replaces the muscle tissue that was lost. When atrophy is complete, fibrous tissue cannot be reversed to muscle tissue.

In Duchenne muscular dystrophy, the muscle enlarges due to fat and connective tissue, but the muscle fibers atrophy and degenerate irreversibly.

In sarcopenia, there is a gradual loss of muscle mass as muscle proteins degrade faster than they can be replaced.

In myasthenia gravis, fibrous connective tissue replaces the muscle tissue that was lost. When atrophy is complete, fibrous tissue cannot be reversed to muscle tissue.

In myotonic dystrophy, there is a gradual loss of muscle mass as muscle proteins degrade faster than they can be replaced.

Bonus Muscle Question:

Action potential propagation in a skeletal muscle fiber ceases when acetylcholine is removed from the synaptic cleft. Which of the following mechanisms ensures a rapid and efficient removal of acetylcholine?

Acetylcholine is degraded by acetylcholinesterase.

Acetylcholine is transported back into the axon terminal by a reuptake mechanism.

Acetylcholine diffuses away from the cleft.

Acetylcholine is transported into the postsynaptic neuron by receptor-mediated endocytosis.

Bonus Questions:

The neuromuscular junction is a well-studied example of a chemical synapse. Which of the following statements describes a critical event that occurs at the neuromuscular junction?

Acetylcholine is released by axon terminals of the motor neuron.

Acetylcholine binds to its receptor in the junctional folds of the sarcolemma. Its receptor is linked to a G protein.

Acetylcholine is released and moves across the synaptic cleft bound to a transport protein.

When the action potential reaches the end of the axon terminal, voltage-gated sodium channels open and sodium ions diffuse into the terminal.

Bonus Questions:

Action potentials travel the length of the axons of motor neurons to the axon terminals. These motor neurons __________.

extend from the brain or spinal cord to the sarcolemma of a skeletal muscle fiber

extend from the spinal cord to the sarcolemma of a skeletal muscle fiber

extend from the brain to the sarcolemma of a skeletal muscle fiber

arise in the epimysium of a skeletal muscle and extend to individual skeletal muscle fibers

Bonus Questions:

Calcium entry into the axon terminal triggers which of the following events?

Synaptic vesicles fuse to the plasma membrane of the axon terminal and release acetylcholine.

Acetylcholine is released into the cleft by active transporters in the plasma membrane of the axon terminal.

Cation channels open and sodium ions enter the axon terminal while potassium ions exit the axon terminal.

Acetylcholine binds to its receptor

Bonus Questions:

Acetylcholine binds to its receptor in the sarcolemma and triggers __________.

the opening of ligand-gated cation channels

the opening of ligand-gated anion channels

the opening of calcium-release channels

the opening of voltage-gated calcium channels

Bonus Questions:

Sodium and potassium ions do not diffuse in equal numbers through ligand-gated cation channels. Why?

The inside surface of the sarcolemma is negatively charged compared to the outside surface. Sodium ions diffuse inward along favorable chemical and electrical gradients.

The outside surface of the sarcolemma is negatively charged compared to the inside surface. Sodium ions diffuse outward along favorable chemical and electrical gradients.

The inside surface of the sarcolemma is negatively charged compared to the outside surface. Potassium ions diffuse inward along favorable chemical and electrical gradients.

The outside surface of the sarcolemma is negatively charged compared to the inside surface. Potassium ions diffuse outward along favorable chemical and electrical gradients.