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Possible Clinical Application Questions for Exam 1
1. Gastroenterologists use X-rays to check for ulcers or other stomach and upper digestive tract
disorders. Before the X-rays are taken why is it necessary for the patient to drink large
quantities of a solution that contains barium ions?
Barium is very radiodense, and the contours of the gastric and intestinal lining can be
seen against the white of the barium solution.
2. A patient reports stabbing pains in the right hypochondriac region. Based on your knowledge
of the organs in this area give a probable diagnosis?
The right hypochondriac region contains the gallbladder and a larger portion of the liver.
Initial diagnosis would be gallstones.
3. Mikhail has been diagnosed with a ruptured appendix, which has allowed bacteria from his
intestinal tract to infect his peritoneum. Why is this condition (peritonitis) so dangerous?
The peritoneum, the largest serous membrane in the body, covers most organs in the
abdominal cavity. Therefore, an infection in this structure can spread to any or all
organs in the cavity.
4. Your friend tells you that he is taking the antibiotic streptomycin for an infection. He wants to
know how this particular antibiotic can kill bacterial cells but not kill his own cells. What is your
explanation?
Streptomycin inhibits bacterial protein synthesis by interfering with ribosomal function of
bacteria and has no effect on the ribosomes of humans. If the bacterial are unable to
synthesize new protein (many of which would be essential enzymes), they will die.
5. You over hear a group of teenagers betting each other as to who could drink the most water
within a 30 minute time span. Being the excellent medical student that you are you interrupt
them and explain the dangers of drinking seemingly harmless liquid (water) in such a short
period of time. What is your explanation?
Drinking water is hypotonic to the cells of your body. Taking in too much water in a short
period of time will cause the blood and eventually the interstitial fluid to become
hypotonic to the body cells. The extracellular water then moves by osmosis into the
body cells and cause them to rupture. This could, and has in the past, kill a person.
6. Some pediatricians recommend the use of a 10% salt solution to relieve congestion for infants
with stuffy noses. What effect would such a solution have on the cell lining the nasal cavity,
and why?
The 10% salt solution would be hypertonic with respect to the cells lining the nasal
cavity, because this solution contains a higher concentration of salt than do the cells.
The hypertonic solution would draw water out of the cells, causing the cells to shrink
and adding water to the mucus, thus relieving the congestion.
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7. In a hospital, a nurse gave a patient recovering from surgery a transfusion of 5% salt solution
by mistake instead of a transfusion of physiological saline (0.9% salt). The patient quickly
went into shock and soon after died. What caused the patient to enter into a state of shock and
die?
Because of the increase of solute concentration in the body fluid, it became hypertonic
to the RBCs. The RBCs dehydrated and
shrank – crenation. The crenated RBCs lost their oxygen-carrying capacity and the
body tissues were deprived of the oxygen necessary of cellular metabolism to support
life.
8. Vitamin C is important to maintain health. What relationship does vitamin C have to tissue
development in the body?
Vitamin C is required by key enzymatic reactions for proper collagen formation.
Collagen is a protein substance that forms the framework of connective tissue. The
connective tissue is the building material for bones, cartilage, teeth, tendons, ligaments,
and blood vessels. Without the proper production of collagen many body systems are
affected. Lack of vitamin C can cause the condition known as scurvy.
9. The knee joint is quite susceptible to injury involving the tearing of cartilage pads within the
knee joint. In most cases, why is surgery needed?
Cartilage heals poorly and in many instance does not heal or recover at all after a
severe injury. Cartilage is avascular, because chondrocytes produce a chemical that
discourages the formation of blood vessels. This property makes nutrient and oxygen
delivery difficult. Also the chondrocytes do not readily divide. The lack of cell division
and avascularity contribute to the poor healing of cartilage thus requiring surgery.
10. After many years of smoking, Mr. Butts is plagued by a hacking cough. Explain the causes of
this cough.
The respiratory passages are lined by ciliated pseudostratified columnar epithelium that
contains mucus producing goblet cells. The mucus traps debris and foreign material that
is moved by the beating cilia to the pharynx to be swallowed. Chronic smoking initially
paralyzes the cilia, resulting in a buildup of mucus in the airways. The hot air and
particulates sear and burn off the cilia, which eventually do not get replaced. The
epithelium responds by producing even more mucus which cannot be moved due to the
lack of cilia. The only way that the respiratory system can clear the debris and mucus is
with forceful bursts of air: coughing.
11. Assuming that you had the necessary materials to perform a chemical analysis of body
secretions, how could you determine whether a secretion was merocrine or apocrine?
Because apocrine secretions are released by pinching off a portion of the secreting cell,
you could test for the presence of cell membranes, specifically for the phospholipids in
cell membranes. Merocrine secretions do not contain a portion of the secreting cell, so
they would lack membrane constituents.
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12. A clinical diagnosis has been made that substantiates the presence of a herniated disc and a
severe case of sciatica. What is the relationship between the two conditions?
When the nucleus pulposus (gelatinous interior) of the disc leaks through the annulus
fibrosis (fibrous outer portion) of the disc, the affected disc balloons out from between
the bony parts of the vertebrae. If the bulging or herniated area is large enough, it may
press on a nerve, causing severe or incapacitating pain. Usually, the sciatic nerve is
affected. Sciatica is generally located in the lumbar region and can radiate over the
buttock, rear thigh, and calf, and can extend into the foot.
13. What is the association between the metabolic disorder known as gout, which affects the
joints, and damage to the kidney?
Gout is a metabolic disorder in which there is an increase in uric acid in the body with
precipitation of sodium urate crystals in the kidneys and joint capsules. The presence of
uric acid crystals in the joints can lead to an inflammatory response in the joints. Usually
the great toe and other foot and leg joints are affected, and kidney damage from crystal
formation occurs in more advanced cases.
14. A high school football player notices swelling in the knee joint. He decides he’d better tell the
coach who responds by telling him, “You have water on the knee”. As a student of anatomy,
explain what the coach is talking about.
Diarthroses, or synovial joints such as the knee joint, contain small pockets of synovial
fluid which are called bursae. The “water on the knee” is the synovial fluid that has been
released from the bursae due to ligament damage in or around the joint capsule. The
synovial fluid leaks out of the bursa and fills the cavities in and around the region of the
knee.
15. Steve injured his right knee during a basketball game when he jumped to rebound the ball and
landed off-balance on the right leg. He has been experiencing pain and limited mobility of the
knee joint. What type of injury do you think Steve has? What techniques would be used to
explore the extent of the damage?
Steve probably tore the medial meniscus. This is the most common knee injury and is
caused by the lateral surface of the lower leg being forced medially. The torn cartilage is
painful, usually restricts joint mobility, and may lead to chronic problems. It is possible to
examine the interior of a joint without major surgery, by using an arthroscope. An
arthroscope uses fiber optics – thin threads of glass or plastic that conducts light – to
investigate inside a joint, and if necessary perform surgical modification at that time
(arthroscopic surgery). A totally non-invasive method of examination is MRI (magnetic
resonance imaging).