The structures involved in the production of semen include the prostate, the seminal vesicles, and the bulbourethral gland, along with the testes and epididymis.
Semen is produced as a combination of secretions from the different regions of the male reproductive tract.
Each fraction differs in chemical composition and function.
Spermatozoa are produced in the testes. They mature in the epididymis. The testes also produce testosterone and inhibin.
Fluid from the seminal vesicles accounts for approximately 70% of semen volume. The seminal vesicles are the source of fructose in semen. Fructose is used by the spermatozoa as an energy source.
The prostate gland supplies about 20% of the volume of semen. Its fluids include acid phosphatase and proteolytic enzymes that lead to coagulation and subsequent liquefaction of semen. The prostate also contains most of the IgA found in semen.
The bulbourethral gland produces mucoproteins that make up about 5% of the volume of semen.
The pituitary gland is not directly involved in the production of semen; instead hormones are released which stimulate the production of sperm. The urethra is not involved in the production of semen.
Which of the following are directly involved in the production of semen?
Beta-thalassemia major, also known as Cooley's anemia, has inherited two genes for beta thalassemia without a normal beta-chain gene. This disease is assoicated with a marked deficiency in beta chain production and in the production of normal Hb A. These patients exhibit increased amounts of iron due to the mutliple transfusions that keep them alive. There is also a striking increase in hemoglobin F and an elevation in hemoglobin A2.
Hematology
A 5-year-old African American child with hepato-splenomegaly and skeletal abnormalities has the following lab results:
WBC = 4,800/cu.mm
20 NRBC/100 WBC
RBC = 2.70 X 106
HGB = 6.2 g/dL
Many target cells
Marked hypochromasia, anisocytosis & poikilocytosis
Serum Iron = 200 µg/dL (elevated)
Sickle Solubility = negative
Hemoglobin F = elevated
What is the PROBABLE cause of these findings?
A young man is experiencing difficult breathing after fainting. The physician orders a blood gas analysis which shows the following results:
pH = 7.25
pCO2 = 62 mmHg
pO2 = 70 mmHg
HCO3 = 23 mEq/L
Which condition is most likely afflicting this patient?
The Fc portion of immunoglobulin can activate the classical complement pathway, where the heavy chains, light chains, hinge regions and Fab portions cannot.
Which part of the immunoglobulin molecule is responsible for activating complement?
During primary hypothyroidism, where a defect in the thryoid gland is producing low levels of T3 and T4, the TSH level is increased. TSH is released in elevated quantities in an attempt to stimulate the thryoid to produce more T3 and T4 as part of a feedback mechanism.
Serum TSH levels five-times the upper limit of normal in the presence of a low T4 and low T3 uptake could mean which of the following:
