Assignment About The Biological Studies

Biology assignment

Table of Contents
Question 1..................................................................................................................... 3
Question 2:................................................................................................................. 3
Question 3..................................................................................................................... 4
Question 4..................................................................................................................... 4
Question 5..................................................................................................................... 5
Question 6..................................................................................................................... 6
Question 7..................................................................................................................... 8
Question 8..................................................................................................................... 8
Question 9..................................................................................................................... 9
Question 10.................................................................................................................. 10

Question 1
a. carbonic anhydrase; carbonic acid
b. macrophages; spleen
c. stem cells; differentiate
d. endothelial wall; diapedesis
e. agglutinogens ; AB
f. contraction(contractile cells); conduction (auto-rhythmic cells)
g. atrio-ventricular (AV); ventricular
h. end-systolic; decreased
i. Ca2+ , K+
j. decreases ; decreases
Question 2:
Addison’s disease is caused by the insufficiency of steroidal hormones such as cortisol and
aldosterone which are produced by the adrenal cortex. Aldosterone regulates salt-water balance
and blood pressure. It promotes re-absorption of Na+ ions and secretion of K+ions in the kidneys.
The re-absorption of sodium is accompanied by the re-absorption of water as well. This leads to
an increase in blood volume and blood pressure. Thus, a person with Addison’s disease is likely
to have high potassium levels, low sodium levels and low blood pressure.
Diabetes insipidus is caused by the insufficiency of ADH ( antidiuretic hormone) produced by
the hypothalamus . It can also be caused by the inability of the kidneys to respond to ADH. ADH
is stored in the pituitary gland. Whenever the concentration of the extracellular fluid increases,
the hypothalamus sends a message to the pituitary gland to release ADH. The hormone helps to

conserve water in the body by stimulating the kidneys to reabsorb water. Hence, it contributes to
an increase in blood pressure. ADH also causes constriction of the peripheral blood vessels, due
to which the arterial blood pressure increases. It is now evident that a person with diabetes
insipidus is likely to experience low blood pressure too.
Hence, a patient with both Addison’s disease and diabetes insipidus is likely to exhibit extreme
hypotension and inability to retain water in the body. The chances of dehydration and sudden
loss of consciousness are extremely high. The body of the patient is likely to have great difficulty
in maintaining normal blood pressure and salt-water balance.
Question 3
The path followed by the RBC from the anterior of the right tibia to the heart is given below:
Capillaries in the anterior region of the right tibia ----- post-capillary venule ------muscular
venule -----right anterior tibial vein ------right polipteal vein -----right femoral vein ------right
external iliac vein ------ right common iliac vein------inferior vena cava------right atrium.
The blood from the right atrium reaches the right ventricle through the tricuspid valve. The
right ventricle sends the blood through the pulmonary valve to the pulmonary artery and the
lungs. The blood in the pulmonary capillaries undergoes oxygenation. From here, the course of
the RBC is described below:
Pulmonary vein -----left atrium----left ventricle ------aorta----left subclavian artery---left axillary
artery ----arterioles---capillaries that supply the muscles of the right shoulder ---venules -----left
axillary vein---- left subclavian vein-----brachiocephalic vein-----superior vena cava.
The RBC once again enters the heart through the superior vena cava.
Question 4
T cell activation is essential for proper immune response. The presence of an antigen presenting
cell (APC) along with MHC prepares the T cell for action. However, a T cell gets activated
only through the process of co-stimulation. The first signal is the antigen recognition signal
during which the antigen in the T cell receptor is matched with the peptide complex on the MHC