Physiology Subject Review

Question 1

The motor neuron and muscle fiber connect at the neuromuscular junction. What space is crossed by the neurotransmitter to send the message from the neuron to the muscle fiber?

a. Motor end plate

b. Sarcolemma

c. Synaptic cleft

d. Synaptic vesicle

Answer 1

c. Synaptic cleft

Question 2

A patient sustains a myocardial infarction (heart attack) that damages the ventricular septum of the heart. What effect on the heart is most likely to be seen immediately after the heart attack?

a. Blood flowing from the left side of the heart to the right

b. Changes in the electrical conduction of the heart

c. Damage to the valves of the heart

d. Reduction in blood pressure

Answer 2

b. Changes in the electrical conduction of the heart

Question 3

At what point of fetal development does sexual differentiation begin?

a. 4-5 weeks

b. 6-8 weeks

c. 9-12 weeks

d. 14-16 weeks

Answer 3

c. 9-12 weeks

Question 4

Some postsynaptic receptors cause excitation upon activation, where others cause inhibition. What is associated with excitation?

a. Activation of ionotropic receptors

b. Decreased conduction through chloride channels

c. Increased conductance of potassium ions out of the neuron

d. Opening of chloride ion channels through the postsynaptic neuronal membrane

Answer 4

b. Decreased conduction through chloride channels

Question 4

The renal system is able to regulate the rate of renal blood flow and glomerular filtration rate (GFR) over a wide range of blood pressures. Which description applies to an intrinsic mechanism for autoregulation of blood flow?

a. Acts to reduce renal blood flow to limit fluid loss

b. Promotes reabsorption of sodium by the nephron

c. Reduces excess filtrate formation to maintain normal GFR

d. Stimulates the release of renin

Answer 4

c. Reduces excess filtrate formation to maintain normal GFR

Question 5

Arteriosclerosis is a leading cause of hypertension.
Which variable that influences blood pressure and blood flow does arteriosclerosis affect?

a. Blood viscosity

b. Blood volume

c. Cardiac output

d. Compliance

Answer 5

d. Compliance

Question 6

What cells of the nephron in the kidneys will secrete hydrogen ions or bicarbonate to regulate acid-base balance in the body?

a. Intercalated cells

b. Mesangial cells

c. Principal cells

d. Proximal convoluted tubular cells

Answer 6

a. Intercalated cells

Question 7

How is eukaryotic translation different from prokaryotic translation?

a. Eukaryotic translation is not coupled with transcription

b. Eukaryotic translation does not require ribosomes

c. Eukaryotic translation does not require elongation factors

d. Eukaryotic translation does not require a start codon to initiate translation

Answer 7

a. Eukaryotic translation is not coupled with transcription

Question 8

How do general transcription factors work?

a. Binding DNA to position RNA polymerase at its promoter

b. Bringing ribonucleotides to RNA polymerase at its promoter

c. Bringing ribosomes to DNA

d. Removing non-essential proteins from the RNA polymerase promoter

Answer 8

a. Binding DNA to position RNA polymerase at its promoter

Question 8

Case:
A 10-year-old boy is admitted to the hospital with chest pain. An ECG is done revealing a normal sinus rhythm.

Question:
This is an indication that electrical excitation originates from what location?

a. Sinoatrial node

b. Atrioventricular node

c. Bundle of His

d. Purkinje fibers

Answer 8

a. Sinoatrial node

Question 9

What hormone affects bone metabolism by directly stimulating osteoclast activity?

a. Calcitonin

b. Growth hormone

c. Parathyroid hormone

d. Thyroxine

Answer 9

c. Parathyroid hormone

Question 10

Lipodystrophy is a condition characterized by atrophy or genetic deficiency of the adipocytes. What would a patient with lipodystrophy present with?

a. Excessive fat storage

b. Excessive plasma protein formation in the liver

c. Inability to desaturate fatty acids

d. Inability to transport lipid components in the blood

Answer 10

a. Excessive fat storage

Question 10

What enzyme is secreted by the kidneys to increase blood pressure in response to low blood flow through the kidneys?

a. Angiotensin I

b. Angiotensin II

c. Angiotensinogen

d. Renin

Answer 10

d. Renin

Question 11

Cardiac output is the volume of blood the heart pumps in one minute. If a person’s heart rate is 80 beats per minute, moving 75 mL from the left ventricle with each contraction, what is their cardiac output?

a. 4.5 L/min

b. 5 L/min

c. 5.5 L/min

d. 6 L/min

Answer 11

d. 6 L/min

CO = SV x HR

Stroke volume of 75 mL x heart rate of 80 bpm = 6000 mL/minute, or 6 L/minute.

Question 12

Atropine is a drug designed to paralyze the cholinergic nerve endings of the myenteric plexus. What impact is atropine likely to have on peristalsis?

a. Increasing peristalsis because the cholinergic nerve endings will be paralyzed

b. Nearly blocking peristalsis because myenteric plexus activation is required

c. Not directly impacting peristalsis because the parasympathetic nervous system is still functioning

d. Slightly decreasing peristalsis because intestinal contents will redirect around the myenteric plexus

Answer 12

b. Nearly blocking peristalsis because myenteric plexus activation is required

Question 13

A woman has recurrent viral infections. Her physician orders a series of tests and discovers that the level of the cells most responsible for fighting virus-infected cells is depleted. What cells are depleted in this patient?

a. Thrombocytes

b. Mast cells

c. Schwann cells

d. Cytotoxic T lymphocytes

e. Erythrocytes

Answer 13

d. Cytotoxic T lymphocytes

Question 14

What substance uses osmosis to cross the cell membrane?

a. Oxygen

b. Potassium

c. Sodium

d. Water

Answer 14

d. Water

Question 15

What substance crosses the cell membrane through simple diffusion?

a. Carbon dioxide

b. Glucose

c. Potassium

d. Sodium

Answer 15

a. Carbon dioxide

Question 16

What symptom is most likely to present in a patient with hyperthyroidism?

a. Cold intolerance

b. Constipation

c. Depression

d. Weight loss

Answer 16

d. Weight loss

Question 17

The process of chemical digestion breaks down large food molecules into smaller units that can be absorbed in the alimentary canal. The digestion of protein begins in which part of the gastrointestinal tract?

a. Large intestine

b. Mouth

c. Small intestine

d. Stomach

Answer 17

d. Stomach

Question 18

During mitosis and meiosis, where are spindle microtubules attached to the chromosome?

a. Actin-myosin filaments

b. Cohesin

c. Kinetochore

d. P-arm of the chromosome

Answer 18

c. Kinetochore

Question 19

What electrical signal unique to muscle and nerve cells is created by a change in voltage across the cell membrane?

a. Action potential

b. Aerobic respiration

c. Eccentric contraction

d. Graded muscle response

Answer 19

a. Action potential

Question 20

Respiration refers to the use of oxygen and removal of carbon dioxide by the body as a whole, or by individual cells. What is the primary determinant of ventilatory rate (respiratory minute volume)?

a. Blood levels of CO2

b. Blood levels of O2

c. Blood pH

d. Blood temperature

Answer 20

a. Blood levels of CO2

Question 21

Case:
A patient is diagnosed with peripheral arterial disease (PAD), which is the buildup of inflammatory plaques within the arteries that can restrict blood flow to tissues or flow back to the heart. A classic symptom is pain in the legs with activity referred to as claudication. This patient reports that his pain gradually resolves with rest and that his symptoms are not otherwise bothersome.

Question:
What recommendation would this patient most likely receive from their healthcare provider?

a. High-fat diet

b. Hormone replacement therapy

c. Increased supervised exercise

d. Peripheral bypass surgery

Answer 21

c. Increased supervised exercise

Question 22

In the microcirculation, the direction of passive exchange of water between the plasma and interstitial fluid is determined by the hydrostatic and oncotic pressures existing between the two compartments. What is true about the arterial side of capillary exchange? a. Capillary hydrostatic pressure is at the highest level. b. Interstitial hydrostatic pressure is at the highest level. c. Interstitial oncotic pressure is at a high level. d. Plasma oncotic pressure is at a low level.

Answer 22

a. Capillary hydrostatic pressure is at the highest level.

Question 22

What is the function of luteinizing hormone? a. Ensures healthy body growth in children b. Ensures normal function of ovaries and testes c. Stimulates hormone production by the adrenal glands d. Stimulates hormone production by the thyroid gland

Answer 22

b. Ensures normal function of ovaries and testes

Question 23

What is normally produced by alveolar cells? a. Alpha-1 antitrypsin b. Elastase c. Erythropoietin d. Surfactant e. Vasopressin

Answer 23

d. Surfactant

Question 24

Case: A patient presents with lower extremity edema and is found to have a serum albumin level of 2 g/dL (reference range: >3.5 g/dL) secondary to liver failure. Question: What force is responsible for the development of this patient's edema? a. Increased intravascular hydrostatic pressure b. Decreased extravascular hydrostatic pressure c. Decreased intravascular oncotic pressure d. Decreased extravascular oncotic pressure

Answer 24

c. Decreased intravascular oncotic pressure

Question 25

What portion of the autonomic nervous system involves very long pre-ganglionic fibers, very short post-ganglionic fibers, and primary usage of the neurotransmitter acetylcholine? a. Somatic nervous system b. Sympathetic nervous system c. Parasympathetic nervous system d. Enteric nervous system e. Limbic nervous system

Answer 25

c. Parasympathetic nervous system

Question 26

What molecule is a naturally occurring anticoagulant? a. Antithrombin b. Fibrinogen c. Proconvertin d. Prothrombin

Answer 26

a. Antithrombin

Question 27

What substance is most often transported through the cell membrane via active transport? a. Cholesterol b. Glucose c. Potassium d. Water

Answer 27

c. Potassium

Question 28

The cardiac cycle is a process that begins with atrial contraction and ends with ventricular relaxation. Initially, both the atria and ventricles are relaxed. As the tricuspid and mitral valves are both open, 70-80% of ventricular filling occurs. What mechanism contributes the remaining 20-30% of filling? a. Atrial diastole b. Atrial systole c. Ventricular diastole d. Ventricular systole

Answer 28

b. Atrial systole

Question 28

Considering the direction of visual pathways in the brain, what part of the eyes does the left occipital lobe receive images from? a. Left visual field of both eyes b. Right visual field of both eyes c. Visual field of the right eye d. Visual field of the left eye

Answer 28

b. Right visual field of both eyes

Question 29

How does the renal system contribute to the control of blood pH in response to acidosis? a. Collecting duct cells reabsorb hydrogen b. Excretion of ammonium is lowered c. Hydrogen ion secretion is decreased d. Tubular cells reabsorb more bicarbonate

Answer 29

d. Tubular cells reabsorb more bicarbonate

Question 29

How does cortisol prevent the development of inflammation? a. Increasing permeability of the capillaries b. Increasing release of interleukin-1 from white blood cells c. Stabilizing erythema d. Stabilizing the lysosomal membranes

Answer 29

d. Stabilizing the lysosomal membranes

Question 30

A 65-year-old woman reports that she is experiencing difficulty hearing, having to ask people to repeat what they have said. What is the primary factor associated with age-related hearing loss? a. Abnormal growth of bone near the middle ear b. Damage to the sensory hair cells in the cochlea c. Dislocation of the ossicular chain in the middle ear d. Gradual loss of sensory hair cells in the cochlea

Answer 30

d. Gradual loss of sensory hair cells in the cochlea

Question 31

At what level of the brain or spinal cord do ascending sensory pathways decussate (cross over) to make the sensory fibers from the spinal cord provide signaling to the contralateral cortex? a. Medulla b. Pons c. Spinal cord d. Thalamus

Answer 31

a. Medulla

Question 32

The initial stages of spermatogenesis take place in the testes. Developing gametes mature and are stored in which internal structure of the reproductive system? a. Epididymis b. Prostate gland c. Seminal vesicles d. Vas deferens

Answer 32

a. Epididymis

Question 33

Through the "symport" process in the kidneys, several molecules and ions are co-transported in the proximal convoluted tubules of the kidneys along with sodium. What molecule is reabsorbed with sodium in this process? a. Ammonium ions b. Bicarbonate ions c. Calcium ions d. Urea

Answer 33

b. Bicarbonate ions

Question 34

You are caring for a patient who sustained a brain injury secondary to a motor vehicle collision. The patient is assessed to be very emotional and demonstrates impaired decision-making. The patient most likely sustained damage to which part of the brain? a. Frontal lobe b. Parietal lobe c. Occipital lobe d. Temporal lobe

Answer 34

a. Frontal lobe

Question 35

The immune system consists of two major classes: innate immunity and adaptive immunity. What is the role of mast cells in innate immunity? a. Circulate throughout the body to engulf and destroy potential threats b. Contain granules toxic to bacteria and fungi c. Destroy infected host cells d. Release cytokines and chemical molecules initiating inflammatory cascade

Answer 35

d. Release cytokines and chemical molecules initiating inflammatory cascade

Question 36

Right heart catheterization can determine the mean pulmonary blood pressure. What is the range of this blood pressure in a healthy person? a. 5-10 mm Hg b. 11-20 mm Hg c. 25-35 mm Hg d. 35-45 mm Hg

Answer 36

b. 11-20 mm Hg

Question 37

Central and peripheral respiratory chemoreceptors serve to regulate breathing. In which of the following situations would one expect the chemoreceptors to decrease the respiratory rate? a. A patient diagnosed with acidosis b. A patient experiencing an anxiety attack c. A patient admitted with hypoxia d. A person who has been snorkeling

Answer 37

b. A patient experiencing an anxiety attack

Question 37

Pulmonary ventilation is the process of air flowing into and out of the lungs because of pressure differences between atmospheric pressure and the gases inside the lungs. What is true about the mechanics of inspiration? a. Decreases thoracic cavity volume b. Includes elastic recoil of tissue c. Increases intra-alveolar pressure d. Is the active phase of ventilation

Answer 37

d. Is the active phase of ventilation

Question 38

What neuron is directly inhibited to allow deep tendon reflex to occur as a result of tapping the knee? a. Afferent neuron b. Extensor motor neuron c. Flexor motor neuron d. Interneuron

Answer 38

c. Flexor motor neuron

Question 39

What female hormone is directly responsible for the classic "let-down reflex" that occurs during breastfeeding? a. Estrogen b. Oxytocin c. Progesterone d. Prolactin

Answer 39

b. Oxytocin

Question 40

With each heartbeat, the heart generates a sequence of electrical impulses. The electrical impulse from the sino-atrial (SA) node is recorded as the P wave on an electrocardiogram tracing. What is the effect on cardiac activity? a. Allowing the atria to continue emptying into the ventricles b. Beginning relaxation of the two lower chambers of the heart c. Contracting of the two upper chambers of the heart d. Pumping blood into the pulmonary artery and aorta

Answer 40

c. Contracting of the two upper chambers of the heart

Question 41

Most hypothalamus hormones that have amine or peptide structures have rapid action in the body from the time they are secreted. In contrast, why can the full action of a steroid hormone take hours or even days to achieve? a. Action at the nuclear hormone-receptor complex slows the process. b. Activation of a secondary messenger is slower with steroid hormones. c. Steroid hormones are enzyme-linked, slowing the process. d. Steroid hormones are much larger than peptide hormones.

Answer 41

a. Action at the nuclear hormone-receptor complex slows the process.

Question 42

If a patient ingests a poison that inhibits protein synthesis, what cellular organelle(s) is/are being targeted? a. Lysosomes b. Golgi apparatus c. Plasma membrane d. Mitochondria e. Ribosomes

Answer 42

e. Ribosomes

Question 43

What hormone is associated mainly with ovulation? a. Oxytocin b. Progesterone c. Luteinizing hormone d. Prolactin

Answer 43

c. Luteinizing hormone