Physiology Case Studies

Question 1

a) Hemophilla : Hemophilia A (classic hemophilia), is caused by the deficiency of Factor VIII.

Hemophilia B (also called Christmas disease, for the name of the family the disorder was first

observed in), is caused by the deficiency of factor IX.

b) Similarly to most recessive sex-linked, X chromosome disorders, haemophilia is more likely

to occur in males rather than females. This is because females have two X chromosomes

while males have only on lacking a 'back up' copy for the defective gene meaning, the

defective gene is guaranteed to manifest in any male who carries it.

c) Yes there are chances of the boy’s sister being a carrier- Females have two X chromosomes,

while males have one X and one Y chromosome. A female carrier of hemophilia has

the haemophilia gene on one of her X chromosomes. When a hemophilia carrier female is

pregnant, there is a 50/50 chance that the hemophilia gene will be passed on. If the gene is

passed on to a son, he will have the disease. If the gene is passed on to a daughter, she will

be a carrier. 

d) There is no definite cure for haemophilia as it is a genetic disorder , it can be controlled with

regular infusions of the deficient clotting factor, i.e. factor VIII in haemophilia A or factor IX in

haemophilia B.

Question 2:

a) Patient suffering from diabetes mellitus type 2.

b) Polyuria is a condition usually defined as excessive or abnormally large production and

passage of urine. Polydipsia refers to excessive thirst. Polyuria and polydipsia are due to

osmotic diuresis secondary to sustained hyperglycemia Results in loss of glucose,

water, and electrolytes. It may reflect decreased fluid intake, increased urine output, or

excessive loss of water and salt. Polyphagia (increased hunger) initially due to depletion of

water, glycogen, and triglycerides. Then due to reduced muscle mass as amino acids are

diverted to form glucose, and ketone bodies.

c) Diabetes mellitus type 2 is due to non response in insulin not due to the lack of insulin.

Presence of insulin in blood decreases lipolysis which causes a decrease in ketone bodies

production in body as a consequent there is no ketone bodies released in urine. It indicates

patient is not suffering from diabetic ketoacidosis (DKA). DKA results from an absolute

shortage of insulin; in response the body switches to burning fatty acids and producing

acidic ketone bodies that cause most of the symptoms and complications.

Question 3

a) Ovulation test and fertility monitors are designed to predict ovulation by detecting LH (or

Luteinizing Hormone) or measuring the basal body temperature. There is a slight fall in basal

body temperature prior to ovulation. And , the temperature increases after ovulation.

b) Pregnancy tests determine pregnancy through the detection of the hormone hCG (Human

Chorionic Gonadotropin) in a woman's urine.

c) i. Ovulation tests work by detecting luteinizing hormone (LH) in a woman's urine. Just

preceding ovulation, women experience an "LH surge" - a sudden, dramatic, and brief rise in

the level of luteinizing hormone. A positive result on an ovulation test means that the woman

will most likely become fertile over the next three days - with peak fertility at 36 hours

following the LH surge. Second test: measurement of basal body temperature after ovulation

shows an increase in temperature due to thermogenic effect of progesterone.

ii. Pregnancy tests determine pregnancy through the detection of the hormone hCG (Human

Chorionic Gonadotropin) in a woman's urine. Human Chorionic Gonadotropin (hCG) is a

glycoprotein hormone secreted by the developing placenta shortly after fertilization. The

appearance of hCG soon after conception - and its subsequent rise in concentration during

early gestational growth - make it an excellent marker for the early detection of pregnancy.

d) Follow the safe period ( rhythm method ) or advised to use oral contraceptives to control

fertility.

Question 4

a) i. The patient showed an increased BMR (+40 %). This may due to several factors like high

level of stress or thyroid hormones in the body.

ii. The serum cholesterol of the patient are 100 mg% which in a normal range.

iii. The normal pulse rate at rest averages about 72/min, .the patient showed a high basal

rate (120/min) (tachycardia).

b) The patient may be suffering from thyrotoxicosis. Due to sustained palpitations may be

accompanied by tachycardia, dyspnoea on exertion, weight loss despite high appetite,

diarhea, tremors, nervousness, diaphoresis and heart intolerance.

c) Investigate for serum T3, T4 and TSH.

Question 5

a) From the above statement, the patient can be related to cushing’s syndrome. Cushing’s

syndrome is a hormonal disorder caused by prolonged exposure of the body’s tissues to high

levels of the hormone cortisol. Sometimes called hypercortisolism.

Symptoms are :

severe fatigue

upper body obesity, a rounded face, increased fat around

the neck, and relatively slender arms and legs

skin become fragile and thin, bruises easily, and heals poorly

weak muscles

reddish or pink stretch marks may appear on the abdomen,

thighs, buttocks, arms, and breasts

high blood pressure

high blood glucose

increased thirst and urination

irritability, anxiety, or depression

a fatty hump between the shoulders

b) Increase amount of cortisol. Cortisol reduce the immune system’s inflammatory response.

c) The blood glucose value will increase. This is because of abnormal increase of glucocorticoid.

cortisol counteracts insulin, contributing to hyperglycemia by stimulation of

hepatic gluconeogenesis and inhibition of the peripheral utilization of glucose  by decreasing

the translocation of glucose transporters to the cell membrane.

Question 6

a) hyperparathyroidism

b) Increase serum calcium levels

c) decreased calcium excretion in urine

d) increased phosphate excretion in urine

e) extensive decalcification and, occasionally, large punched-out cystic areas of the bone that

are filled with osteoclasts.

Osteoporosis or fractures associated with hyperparathyroidism is caused by the high

parathyroid hormone secreted by overactive parathyroid gland(s). Excess parathyroid

hormone (PTH) acts indirectly on osteoclasts, which in turn leads to the removal of calcium

from the bones. Thus, the high calcium in the blood comes from the bones. .

Question 7

a) From the biochemical test, it shows that the patient is having polyuria and polydipsia

because the urine that the patient passed out is more than the normal range which is 15 L in

24 hours rather than the normal output is 1.5 L/day and the patient also had excessive thirst

sensations. There is no sugar in urine, therefore the provisional diagnosis is Diabetes

insipidus (DI).

b) Polyuria occurs because of complete or partial failure of ADH secretion or also known as

arginine vasopressin (AVP). It will cause decreased in renal water reabsorption by collecting

ducts, will leads to polyuria (diuresis of dilute urine)(up to 3-20 L/day). It will then stimulate

thirst and increased water intake (polydipsia).

c) Other conditions are Diabetes mellitus, kidney disease and adrenocortical dysfunction.

d) The treatment is administration of a synthetic analog of ADH, desmopressin that can be

given by injection, as nasal spray, or orally and rapidly restores urine output toward normal.

Question 8

a) Endocrine causes for short stature:

pituitary dwarf - due to growth hormone deficiency-secondary to decrease in GHRH

hypothyroid dwarf - due to thyroid hormone deficiency

cushing syndrome - due to excess of circulating glucocorticoids

b) Signs & symptoms:

PITUITARY DWARF

(GHRH)

HYPOTHYROID DWARF

(THYROID HORMONE)

Plumpness (fatness) Gross retardation of ‘mental’ and ‘physical’

development

Delicate extremities, body proportion according to

the chronological age

Body proportion remains infatile

Delayed skeletal and dental development Earlier its onset, more severe is the delay inn

growth and skeletal maturation

Small genital Associated hypothyroidism features

Question 9

a) It indicates the symptoms of myasthenia gravis where difficulty in breathing and swallowing is

present. The parenteral form (neostigmine methylsulphate) should be used.

Although myasthenia gravis may affect any voluntary muscle, muscles that control eye

and eyelid movement, facial expression, and swallowing are most frequently affected.

In most cases, the first noticeable symptom is weakness of the eye muscles. In others, difficulty in

swallowing and slurred speech may be the first signs. The degree of muscle weakness involved

in myasthenia gravis varies greatly among patients, ranging from a localized form, limited to eye

muscles (ocular myasthenia), to a severe or generalized form in which many muscles sometimes

including those that control breathing are affected. Symptoms, which vary in type and severity,

may include a drooping of one or both eyelids (ptosis), blurred or double vision (diplopia) due to

weakness of the muscles that control eye movements, unstable or waddling gait, weakness in

arms, hands, fingers, legs, and neck, a change in facial expression, difficulty in swallowing and

shortness of breath, and impaired speech (dysarthria).

b) Myasthenia gravis is caused by a defect in the transmission of nerve impulses to muscles. It

occurs when normal communication between the nerve and muscle is interrupted at the

neuromuscular junction - the place where nerve cells connect with the muscles they control.

Normally when impulses travel down the nerve, the nerve endings release a neurotransmitter

substance called acetylcholine. Acetylcholine travels through the neuromuscular junction and

binds to acetylcholine receptors which are activated and generate a muscle contraction.

In myasthenia gravis, antibodies block, alter, or destroy the receptors for acetylcholine at the

neuromuscular junction which prevents the muscle contraction from occurring. These antibodies

are produced by the body's own immune system. Thus, myasthenia gravis is an autoimmune

disease because the immune system which normally protects the body from foreign organisms -

mistakenly attacks itself.

c) Neostigmine is used to improve muscle tone in people with myasthenia gravis . By interfering

with the breakdown of acetylcholine, neostigmine indirectly stimulates both nicotinic and

muscarinic receptors. Unlike physostigmine, neostigmine has a quaternary nitrogen; hence, it is

more polar and does not enter the CNS. Its effect on skeletal muscle is greater than that of

physostigmine, and it can stimulate contractility before it paralyzes. Neostigmine has short

duration of action, usually thirty minutes to two hours. Neostigmine binds to the anionic site of

cholinesterase. The drug blocks the active site of acetylcholinesterase so the enzyme can no

longer break down the acetylcholine molecules before they reach the postsynaptic membrane

receptors. This allows for the threshold to be reached so a new impulse can be triggered in the

next neuron. In myasthenia gravis there are too few acetylcholine receptors so with the

acetylcholinesterase blocked, acetylcholine can bind to the few receptors and trigger a muscular

contraction.

Question 10

a) Costochondritis-Is the condition in which there is an inflammation or injury at the cartilage

joining the ribs to the sternum, costochondral.Which will then could lead to tenderness and

pain in the anterior chest wall. Costochondritis are closely related and most often confused

and interexchange with Tietze syndrome. However, one very big difference between these

two conditions is that Tietze syndrome does not have swelling at the injured/involved cartilage

of ribs.As the case states that there is only constrictive pain and no swelling stated,thus these

condition could be most probably due to Costochondritis. Pain radiating along the border of

ulnar is due to the many nerve branches away from the chest area. The severity of the pain is

proportional to the exertion is because any activity such as exercise or deep breathing will

stretch the inflamed cartilage, thus will cause significance pain.

b) ECG is normal, because this condition only mimics that of myocardial infarction, however it

has nothing related to heart diseases. Since the affected area is only the cartilage located

behind the sternum, no organs are involved. Thus, it signifies the heart is not affected and in

normal condition.

c) - Careful use of nonsteroidal anti-inflammatory medications.

- Local heat or ice might relieve the pain.

- Avoid unnecessary heavy exercises or activities.

Question11

a) Partial thickness of burn injury and may damage dorsal root ganglia and peripheral nerves.

b) It is because the touch receptors are not damage and only the pain and temperature

receptors are damage.

c) It is the dorsal root ganglia that sense pain and temperature.

d) It may be a disuse atrophy or damage of the peripheral nerves and nerve endings that

innervate the small muscles.

Question 12

a) Hemorragic shock (hypovolumic shock) due to excessive loss of blood.

b) Extreme blood loss can lead to all the signs mention above. Hypotension and oliguria are the

highlight of shock. Vasoconstriction leads to cold clammy hand because shutting down the

blood in periphery will occur and all the remaining blood will be diverted to the major organs

like heart and kidneys. This also will cause pale, cold and extreme weakness. Restlessness

can be due to reflex tachycardia because of hypovolumia. It can progress to confusion.

c) Immediate treatment is infusion. Crystalloid solution and electrolyte to replace the amount of

blood loss. (Crystalloid solution is a hypertonic solution which will be used immediately for

blood loss.

Question 13

a) The pain is due to increased secretion of gastric acid in the stomach. This may be a case of

peptic ulcer disease.

b) It is a substance to stimulate gastric acid secretion. Hence it is tested in this patient to

increase his stomach’s gastric secretion.

c) Acetylcholine

d) Duodenal ulcer pain usually occurs between meals when the stomach is empty and relieved

by food especially milk. Food would neutralise the acid in stomach.

e) Vagotomy will reduce the acidity of the stomach, by denervating the partial cells that produce

acid.

Question 14

a) There is lesion on the neural pathway above the anterior horn cell or motor nuclei of the

cranial nerves and this cause the nerve fibers traveling from the anterior horn of the spinal

cord to the relevant muscle are affected. Because of these reasons the child has pain in the

back and neck and had a fever.

b) According to the symptoms and signs of the child, the lesion is the upper motor neuron

lesion, which is in contrast to a lower motor neuron lesion and it is caused by the lesion of the

neural pathway above the anterior horn cell or motor nuclei of the cranial nerves.

c) Diagnosis — hemiplegia.

Hemiplegia is a condition in which the limbs on one side of the body have severe weakness.

Hemiplegia is more severe than hemiparesis, where one half of the body has less marked

weakness. Hemiplegia may be congenital or acquired from an illness or stroke.

Hemiplegia is not an uncommon medical disorder. In elderly individuals, strokes are the most

common cause of hemiplegia. In children, the majority of cases of hemiplegia have no

identifiable cause and occur with a frequency of about one in every thousand births. Experts

indicate that the majority of cases of hemiplegia that occur up to the age of two should be

considered to be cerebral palsy until proven otherwise.

Question 15

a) The patient has hemiplegia, paralysis of one side of the body.

b) Damage to Corticospinal tract(descending tract or motor tract) at the level of internal

capsule. Damage to the lenticulostriate arteries in the internal capsule.

Question 16

a) It is a pernicious anemia which is one type of megaloblastic anemia.

b) It is caused by deficiency of vitamin B12 absorption. Vitamin B12 and folic acid are essential

for formation of red blood cell. From the investigation, the most important result revealed is

the presence of achlorhydria. Achlorhydria is where the production of gastric acid in the

stomach is absent. Gastric acid is important because it secrete together with intrinsic factor

(IF) by parietal cell. When there is less or no secretion of IF, Vitamin B12 cannot be

absorbed and leads to pernicious anemia.

c) The treatment for pernicious anemia by two ways either by ingestion or by injection. Ingestion

of vitamin B12 tablet is done either orally or sublingual (under the tongue) and both equally

well absorb. Oral supplementation allows B12 to be absorbed in places other than the

terminal ileum (where B12 absorption usually takes place). However, if oral and sublingual

repletion of B12 is inadequate, the patient may require B12 injections, which are usually

given once a month, bypassing the need for gastrointestinal absorption altogether.

Question 17

a) The patient is diagnosed with obstructive jaundice. This is caused by obstruction of bile duct

which prevents the passage of bile into intestine due gall stone or any tumor.

b) The stool are pale in colour due to the absence of stercobillinogen. The feaces contains

excess fat which indicate impairment of fat digestion and absorption in absence of bile. This

condition is known as steatorrhea.

c) Van den Bergh is a test to indentify in an increase in serum billirubin . As than the patients’s

serum billirubin is excessively high normal level (0.2 -1.0 mg/100day). Hence it gave a direct

positive result.

Question 18

a) The patient had incomplete transaction of spinal cord. Due to spinal shock, the patient

suffered from temporary quadriplegia.

b) The incomplete lesion of spinal cord at cervical level.

c) As there is no inhibitory effect of the descending tract (due to lesion of upper motor neuron),

It lead to the hyperactive reflexes for a stimulation.

d) Functional activity of urinary bladder recovers first during the recovery stage or stage of reflex

activity.

Question 19

a) Anterior cord syndrome

b) Damage is in the Anterior column /portion of Spinal cord at thoracolumbar region

c) Touch sensation is intact because the tract that carries touch sensation is in the dorsal or

posterior white column.

d) Temperature and pain sensation is absent due to interruption of the spinothalamic tract.

Question 20

a) The patients has a parkinson’s disease. It is characterized by tremor, a slowing of physical

movement (bradykinesia), muscles rigidity and monotonous speech.

b) It is a degenerative disorder of substantia nigra. The primary symptoms are the results of

decreased stimulation of the motor cortex by the basal ganglia, normally caused by the

insufficient formation and action of dopamine, which is produced in the dopaminergic

neurons of the brain (specifically the substantia nigra). Secondary symptoms may include

high level cognitive dysfunction and subtle language problems.

c) It is due to the loss of dopamine neurons in the substantia nigra. Dopamine is involved in

planning and programming of movements and act as muscle tone inhibition. Loss of

dopamine neuron unnatural stillness or frozen quality. Tremor may or may not be present.

d) Levodopa (or L-dopa) has been the most widely used treatment for over 30 years. L-dopa is

transformed into dopamine in the dopaminergic neurons by dopa-decarboxylase. Since motor

symptoms of PD are produced by a lack of dopamine in the substantia nigra the

administration of L-dopa temporarilly diminishes the motor symptomatology.

Carbidopa and benserazide are peripheral dopa decarboxylase inhibitors They help to

prevent the metabolism of L-dopa before it reaches the dopaminergic neurons and therefore

reduce side effects

Muscles and nerves that control the digestive process may be affected by PD, therefore, it is

common for patients to experience constipation and gastroparesis. A balanced diet is hence

recommended to help improve digestion. Diet should include high-fiber foods including whole

grain breads and cereals as well as fruits and vegetables and plenty of water, while it is

important to avoid caffeine and alcohol and iron salts. Excessive protein should also be

avoided because affects the absorption of Levodopa.

Question 21

a) Provisional diagnosis is Tabes dorsalis; it is due to syphilis. There is degeneration of sensory

neurons and stabbing pains in the trunk and legs and unsteady gait and incontinence and

impotence. The degenerating nerves are in the dorsal columns (posterior columns) of

the spinal cord 

b) Sensory tract- posterior column tract -  fasciculus gracilis and fasciculus cuneatus

c) Incoordination of lower limbs while walking: The person having problem to sense of the

ground he touch, thus he need to see the place where he put his foot as this also have

relation with the loss of proprioception. This type of walk is known as the tabetic gait.

Loss of sense of position: The person already have problem in sensory system thus it give

effect on the sense of positioning the stimulus when the physician do the sensory test on him.

Altered muscle tone: Destruction of the sensory limb of the spindle reflex. The deep tendon

reflexes are also diminished or absent; for example, the "knee jerk" or patellar reflex may be

lacking (this is known as Westphal's sign).

Question 22

a) Presence of albumin in urine shows nephrotic failure. Right ventricular hypertrophy and

elevated P wave show that patient is suffering from cardiac failure. Oliguria shows a kidney

failure..

b) Backward failure of the right ventricle leads to congestion of systemic capillaries. This

generates excess fluid accumulation in the body. This causes swelling in foot and ankle. In

progressively severe cases, ascites (fluid accumulation in the abdominal cavity causing

swelling) and hepatomegaly (enlargement of the liver) may develop.  JVP is a good

approximation of right atrial pressure, which is a major determinant of right ventricular end

diastolic volume. The increased JVP is due to right sided heart failure.

c) Elevated P wave is because of Right sided heart failure, which is due to right ventricular

hypertrophy.

d) The patient suffered of elevated JVP, this causes the enlargement of right ventricular heart.

Elevated P wave is due to the increase in the atria depolarization before atrial contraction

begins.

Question 23

a) Type of anemia does this patient have is Iron Deficiency Anemia.

b) Cause of the anemia is due to parasitic infection (by hook worm).This parasite cause

intestinal bleeding which lead to iron deficiency. The other possible cause is due to blood lost

during menses as this woman can be categorized in premenstrual woman.

c) For iron deficiency anemia, the main treatment is done by iron supplement.

d) Eosinophilia is caused by increase in eosinophil count due to allergic condition of parasitic

infection.