Question

____ 22. The action potential
a. is a chemical that diffuses across a synapse.
b. transmits information from the cell body to the axon through the synapse.
c. is an electric current that passes through the axon and causes the release of neurotransmitters into
the synapse.

____ 24. Humans need _________ to move parts of the appendicular skeleton, such as the arm.
a. muscles
b. bones
c. joints
____ 25. An MRI reveals that a patient’s heart valves are inflamed. Doctor A says that the patient has coronary artery
disease. Doctor B says that the patient has rheumatic fever. Which doctor is most likely correct?
a. Doctor A, because the heart valves pump blood into coronary arteries.
b. Doctor B, because antibodies attack heart valves in rheumatoid fever.
c. Doctor A, because arterial clogging leads to hear valve fatigue.
____ 26. Which lists the layers of skin from outer to inner?
a. dermis, melanin
b. epidermis, dermis
c. melanin, epidermis
____ 27. A doctor find that her patient’s white blood cell count is higher than normal. What does this most likely
indicate?
a. The patient is healthy.
b. The patient has an infection.
c. The patient’s kidneys are functioning poorly.

Answer 1

Answer 22 :- It is change in membrane potential due rapid influx of positive ions like Na ions into intracellular fluid from extracellular fluid in neuron and muscle cell. It is near about +30mV. When action potential reached at synaptic knob during nerve impulse conduction, it caused opening of calcium voltage gated channel result influx of calcium ions in synaptic knob. Increase concentration of calcium ions in intracellular fluid which promote exocytosis of synaptic vesicle to release neurotransmitters in synaptic cleft of synapse.

Hence the C is the correct option.

Transmission of action potential from axon to cell body called nerve impulse conduction and it always carried out in forward direction.

So the rest option A and B are incorrect.

Answer 24 :- Humans need muscle to move part of appendicular skeleton such as arm. Part of appendicular skeleton such as arm by alternative muscle contraction and relaxation.

So the A is the correct option.

Human skeleton is made up from bones and caryilages. At which place there two bones joint together by the help of ligament called joints. So the rest B and C is the incorrect option.

Kindly creat a separate post for remaining question.