1.
The primary function of the kidneys involves regulating the ________ and the ________ of plasma and interstitial fluid.
Correct Answer
B. Volume : composition
Explanation
The kidneys play a crucial role in regulating the volume and composition of plasma and interstitial fluid. They help maintain the balance of fluids in the body by filtering waste products, excess water, and electrolytes from the blood. The volume of these fluids is important for maintaining blood pressure and overall hydration. The composition, or the concentration of substances like ions, nutrients, and waste products, is also regulated by the kidneys to ensure proper functioning of various bodily processes. Therefore, the correct answer is "volume : composition".
2.
If the plasma colloid osmotic pressure decreases while the glomerular capillary blood pressure and the Bowman’s capsule hydrostatic pressure stays the same the net filtration pressure will _____ leading to ______ fluid being filtered.
Correct Answer
B. Increase : more
Explanation
If the plasma colloid osmotic pressure decreases, it means there is less pressure from proteins in the blood to pull fluid back into the capillaries. This, combined with the glomerular capillary blood pressure and Bowman's capsule hydrostatic pressure staying the same, leads to an increase in net filtration pressure. The increase in net filtration pressure means that more fluid will be filtered out of the capillaries and into the Bowman's capsule.
3.
Excretion:
Correct Answer
D. Is everything that is filtered or secreted and not subsequently absorbed.
Explanation
Excretion refers to the process of eliminating waste products or substances from the body. It includes everything that is filtered or secreted in the kidneys and is not reabsorbed back into the bloodstream. This means that any substances that are removed from the glomerular capillary blood and transported into the tubular lumen, as well as any substances that move from the tubular lumen into the peritubular capillary blood, are considered part of the excretion process.
4.
Secretion:
Correct Answer
B. Is the movement of a substance from the peritubular capillary blood into the tubular lumen.
Explanation
The correct answer is "is the movement of a substance from the peritubular capillary blood into the tubular lumen." This explanation aligns with the definition of secretion, which refers to the movement of substances from the peritubular capillary blood (located outside the tubules) into the tubular lumen (inside the tubules). This process allows for the elimination of certain substances from the blood into the urine.
5.
Filtration:
Correct Answer
A. Is the movement of a substance from glomerular capillary blood into the tubular lumen.
Explanation
Filtration refers to the process of moving a substance from the glomerular capillary blood into the tubular lumen. This process occurs in the kidneys during the formation of urine. The glomerular capillaries have small pores that allow small molecules such as water, ions, and waste products to pass through, while larger molecules like proteins and blood cells are retained. This movement of substances from the glomerular capillary blood into the tubular lumen is the first step in the formation of urine and plays a crucial role in maintaining the body's fluid balance and removing waste products.
6.
Reabsorption:
Correct Answer
C. Is the movement of a substance from the tubular lumen into the peritubular capilliary blood.
Explanation
The correct answer is "is the movement of a substance from the tubular lumen into the peritubular capillary blood." This is because reabsorption refers to the process by which substances that were initially filtered or secreted into the tubular lumen are transported back into the peritubular capillary blood. This process helps in the reabsorption of important substances such as water, glucose, ions, and other solutes, allowing them to be returned to the bloodstream for circulation.
7.
Which of the following is TRUE concerning glucose reabsorption from the proximal tubule?
Correct Answer
B. Glucose is actively transported across the apical membrane by cotransport with sodium.
Explanation
Glucose reabsorption from the proximal tubule involves active transport across the apical membrane through cotransport with sodium. This means that glucose is transported into the cell along with sodium ions. This process is energy-dependent and requires the use of transport proteins. The other options are not true concerning glucose reabsorption.
8.
The loop of Henle in juxtamedullary nephrons sets up the vertical osmotic gradient found in the medulla of the kidney by allowing reabsorption of ______ only in the descending limb and reabsorption of _____ only in the ascending limb.
Correct Answer
D. Water : sodium
Explanation
The loop of Henle in juxtamedullary nephrons allows for the reabsorption of water only in the descending limb and the reabsorption of sodium only in the ascending limb. This creates a vertical osmotic gradient in the medulla of the kidney, with higher osmolarity at the bottom of the loop and lower osmolarity at the top. This gradient is important for the concentration and dilution of urine, as well as for maintaining the body's water and electrolyte balance.
9.
Antidiuretic hormone (ADH) increases ______ reabsorption from the _____ .
Correct Answer
D. Water : collecting duct
Explanation
ADH, also known as vasopressin, is a hormone that regulates the body's water balance. It acts on the collecting ducts in the kidneys to increase the reabsorption of water. This means that more water is taken back into the bloodstream from the urine, leading to a decrease in urine volume and concentration. Therefore, the correct answer is "water: collecting duct."
10.
______ is released from the adrenal cortex and causes and increase in _______ reabsorption and an increase in ______ secretion from the kidneys.
Correct Answer
E. Aldosterone : sodium : potassium
Explanation
Aldosterone is released from the adrenal cortex and causes an increase in sodium reabsorption and an increase in potassium secretion from the kidneys.
11.
______ increases blood calcium levels by increasing calcium reabsorption from the nephrons while _______ decreases blood calcium levels by decreasing calcium reabsorption from the nephrons.
Correct Answer
B. Parathyroid hormone : calcitonin
Explanation
Parathyroid hormone increases blood calcium levels by increasing calcium reabsorption from the nephrons, while calcitonin decreases blood calcium levels by decreasing calcium reabsorption from the nephrons.
12.
Which of the following is the body’s first line of defense against changes in pH?
Correct Answer
A. Chemical buffer systems
Explanation
Chemical buffer systems are the body's first line of defense against changes in pH. These systems work by quickly absorbing or releasing hydrogen ions to maintain a stable pH level in the body. They can be found in various bodily fluids, such as blood and urine, and help prevent drastic changes in pH that could be harmful to the body's cells and organs. Renal compensation, immune compensation, respiratory compensation, and central nervous system depression are not the body's first line of defense against changes in pH.
13.
Excessive vomiting can cause metabolic _____ due to increased _________.
Correct Answer
C. Alkalosis : loss of hydrogen ions
Explanation
Excessive vomiting can cause metabolic alkalosis due to the loss of hydrogen ions. Vomiting leads to the loss of stomach acid, which contains hydrogen ions. This loss of hydrogen ions causes an increase in the pH of the blood, leading to alkalosis.
14.
Which of the following is NOT an appropriate target for the immune system?
Correct Answer
D. Inhaled dust mite feces
Explanation
The immune system is designed to protect the body from harmful pathogens and abnormal cells. Pathogenic bacteria, body cells infected by a virus, intestinal parasites, and body cells that have become cancerous are all appropriate targets for the immune system to recognize and eliminate. However, inhaled dust mite feces is not a pathogen or abnormal cell that poses a direct threat to the body. Therefore, it is not an appropriate target for the immune system.
15.
The symptoms of inflammation, redness and swelling, are due to:
Correct Answer
B. Capillaries in the area of the infection becoming more permeable and allowing more fluid to leave and enter the tissue.
Explanation
When inflammation occurs, the capillaries in the area of the infection become more permeable. This increased permeability allows more fluid to leave the capillaries and enter the surrounding tissue. As a result, the tissue becomes swollen and there may be redness in the area. This process helps to bring immune cells and other substances to the site of infection to fight off the infection and promote healing.
16.
Which of the following parts of the innate or nonspecific immune system causes cells to produce virus blocking enzymes?
Correct Answer
B. Interferon
Explanation
Interferons are a type of signaling proteins that are produced by cells in response to viral infections. When cells detect the presence of a virus, they release interferons to signal neighboring cells to activate their antiviral defenses. One of the defenses activated by interferons is the production of virus-blocking enzymes. These enzymes can inhibit viral replication and spread, providing a nonspecific defense against viral infections. Therefore, interferon is the correct answer for the question.
17.
Which of the following parts of the innate or nonspecific immune system is present in the blood in an inactive form until it comes in contact with a bacteria bound with antibodies or the carbohydrate chains on a bacteria.
Correct Answer
A. Complement system
Explanation
The complement system is a part of the innate immune system that is present in the blood in an inactive form. It becomes activated when it comes in contact with a bacteria bound with antibodies or the carbohydrate chains on a bacteria. Activation of the complement system leads to a cascade of reactions that result in the destruction of the bacteria and the recruitment of other immune cells to the site of infection. This process is an important defense mechanism against bacterial infections.
18.
A large, complex molecule that triggers a specific immune response against itself when it gains entry into the body is known as:
Correct Answer
D. An antigen
Explanation
An antigen is a large, complex molecule that triggers a specific immune response against itself when it enters the body. It is recognized by the immune system as foreign and stimulates the production of antibodies or activates immune cells to attack and eliminate the antigen. Antigens can be proteins, carbohydrates, or other molecules found on the surface of pathogens or on abnormal cells in the body. They play a crucial role in immune responses and are essential for the body's defense against infections and diseases.
19.
When virgin B cells come in contact with an antigen they have a receptor for, they proliferate and differentiate into ________, which secrete the antibodies that attack the antigen and _______, which remain in the body and provide a quick response upon re-exposure to the same antigen.
Correct Answer
C. Plasma cells : memory cells
Explanation
When virgin B cells come in contact with an antigen they have a receptor for, they proliferate and differentiate into plasma cells, which secrete the antibodies that attack the antigen, and memory cells, which remain in the body and provide a quick response upon re-exposure to the same antigen.
20.
Which of the following is NOT accomplished by antibodies?
Correct Answer
C. Direct destruction of foreign cells.
Explanation
Antibodies play a crucial role in the immune response by recognizing and binding to specific foreign substances, known as antigens. They can neutralize bacterial toxins by binding to them and preventing them from causing harm. Antibodies can also activate the complement system, which is a group of proteins that work together to destroy pathogens. Additionally, antibodies can enhance phagocytosis by binding to pathogens and marking them for destruction by immune cells. They can also stimulate killer cells, such as natural killer cells, to target and destroy infected cells. However, antibodies do not directly destroy foreign cells themselves.
21.
A secondary response to an invading microorganism is:
Correct Answer
E. Both (a) and (c)
Explanation
The secondary response to an invading microorganism is both launched by memory cells and faster, stronger, and longer-lasting than the primary response. Memory cells are specialized immune cells that "remember" previous encounters with a specific pathogen. When the same pathogen is encountered again, memory cells quickly initiate a secondary immune response, which is faster and more robust than the primary response. This secondary response is also longer-lasting, providing enhanced protection against the invading microorganism.
22.
Receptors on every T cell detect foreign antigens on cells of the body by their association with the ________ on the surface of the infected cells of the body.
Correct Answer
D. Major histocompatibility (MHC) molecule
Explanation
T cells play a crucial role in the immune response by recognizing and attacking cells that are infected or abnormal. The receptors on T cells are responsible for detecting foreign antigens on the surface of these infected cells. The major histocompatibility (MHC) molecules are proteins found on the surface of almost all cells in the body, and they play a key role in presenting antigens to T cells. Therefore, the correct answer is major histocompatibility (MHC) molecule, as it is the molecule that T cell receptors recognize on the surface of infected cells.
23.
Hay fever that occurs when people are exposed to pollen involves an excess release of IgE, which binds to ________ and causes them to ________.
Correct Answer
A. Mast cells : degranulate, releasing histamine
Explanation
When people with hay fever are exposed to pollen, IgE binds to mast cells. This binding causes the mast cells to release histamine through a process called degranulation. Histamine is responsible for the symptoms of hay fever, such as sneezing, itching, and a runny nose. Therefore, the correct answer is mast cells: degranulate, releasing histamine.
24.
Digestive secretions include:
Correct Answer
E. All of the above
Explanation
Digestive secretions include enzymes, which are proteins that help break down food into smaller molecules for absorption. Bile is a substance produced by the liver and stored in the gallbladder, which aids in the digestion and absorption of fats. Mucous is a viscous fluid that helps lubricate and protect the lining of the digestive tract. Bicarbonate ions are produced by the pancreas and help neutralize stomach acid in the small intestine. Therefore, all of the given options (enzymes, bile, mucous, and bicarbonate ions) are correct as they are all components of digestive secretions.
25.
Which of the following does NOT occur in the mouth?
Correct Answer
D. Protein digestion begins.
Explanation
The mouth is responsible for the mechanical digestion of food through the action of teeth tearing and grinding food. Saliva, produced by the salivary glands, moistens and lubricates food to aid in swallowing. The tongue helps in the manipulation of food and monitors the quality of the food through taste buds. The lips are involved in the process of procuring and retaining food. However, protein digestion begins in the stomach with the action of the enzyme pepsin, not in the mouth.
26.
Which of the following is the primary absorptive organ of the digestive system?
Correct Answer
D. Small intestine
Explanation
The small intestine is the primary absorptive organ of the digestive system. It is responsible for the majority of nutrient absorption, including carbohydrates, proteins, fats, vitamins, and minerals. The walls of the small intestine are lined with tiny finger-like projections called villi, which increase the surface area for absorption. These villi contain specialized cells that transport nutrients into the bloodstream for distribution to the body's cells. The small intestine also plays a role in the absorption of water and electrolytes.
27.
The major chemical digestive activity occurring in the stomach is:
Correct Answer
B. Digestion of protein
Explanation
The major chemical digestive activity occurring in the stomach is the digestion of protein. The stomach produces gastric juices that contain enzymes, such as pepsin, which break down proteins into smaller peptides. This process is essential for the body to absorb and utilize the amino acids present in proteins for various physiological functions.
28.
The chyme entering the intestine from the stomach is:
Correct Answer
E. Very acidic and quickly buffered by bicarbonate excreted from the pancreas.
Explanation
The chyme entering the intestine from the stomach is very acidic because it contains stomach acid. However, it is quickly buffered by bicarbonate excreted from the pancreas. Bicarbonate helps to neutralize the acidity of the chyme, creating a more favorable environment for digestion and absorption in the intestines.
29.
Which of the descriptions of the absorption of nutrients from the small intestine is correct?
Correct Answer
A. Glucose is absorbed by secondary active transport across the apical membrane and facilitated diffusion across the basolateral membrane of enterocytes.
Explanation
Glucose is absorbed by secondary active transport across the apical membrane and facilitated diffusion across the basolateral membrane of enterocytes. This means that glucose is transported against its concentration gradient using energy from another molecule, and then it diffuses passively across the basolateral membrane. This process allows for efficient absorption of glucose from the small intestine into the bloodstream.
30.
Dietary fat:
Correct Answer
E. All of the above.
Explanation
The correct answer is "all of the above." Dietary fat is emulsified by bile, digested by lipases, packaged into chylomicrons in the epithelial cells lining the intestine, and enters the lymph system.
31.
The exocrine portion of the pancreas:
Correct Answer
E. Both (b) and (c).
Explanation
The correct answer is both (b) and (c). The exocrine portion of the pancreas secretes digestive enzymes into the duodenum, which is the first part of the small intestine. These enzymes help in the breakdown of food and aid in digestion. Additionally, the exocrine portion of the pancreas also secretes bicarbonate into the duodenum. Bicarbonate helps to neutralize the acidic chyme coming from the stomach, creating a more favorable environment for digestion. Therefore, both (b) and (c) are correct as they describe the functions of the exocrine portion of the pancreas.
32.
Which of the following is NOT one of the functions of the liver?
Correct Answer
D. Secretion of H+
Explanation
The liver performs various functions, including secretion of bile, synthesis of albumin, removal of aged erythrocytes, and synthesis and modification of hormones. However, the liver does not secrete H+.
33.
The bacteria in the large intestine:
Correct Answer
E. All of the above.
Explanation
The bacteria in the large intestine are beneficial because they ferment fiber, produce vitamin K, and enhance intestinal immunity by outcompeting pathogenic bacteria. Fermenting fiber helps break it down and release nutrients for absorption. The production of vitamin K by these bacteria is important for blood clotting. Additionally, the presence of beneficial bacteria in the large intestine helps to prevent the growth of harmful bacteria and strengthens the immune system in the intestines. Therefore, all of the given statements are correct.
34.
Gametes like eggs and sperm are haploid containing ____ chromosomes, while somatic cells are diploid containing ___ chromosomes.
Correct Answer
C. 23,46
Explanation
Gametes like eggs and sperm are haploid, meaning they have half the number of chromosomes as somatic cells. In humans, haploid cells have 23 chromosomes. On the other hand, somatic cells are diploid, meaning they have the full set of chromosomes. In humans, diploid cells have 46 chromosomes. Therefore, the correct answer is 23,46.
35.
Which of the following statements concerning sex determination and sex differentiation is correct?
Correct Answer
D. Both (a) and (b) above.
Explanation
Both statement (a) and (b) are correct. An XY combination of sex chromosomes is a genetic male, indicating that the presence of a Y chromosome determines maleness. Additionally, the secretion of testosterone by the fetal gonads, which are present in males, induces the development of male external genitalia and reproductive tract. Therefore, both genetic factors (XY chromosomes) and hormonal factors (testosterone secretion) contribute to sex determination and sex differentiation in males.
36.
Leydig or interstitial cells:
Correct Answer
D. Secrete testosterone.
Explanation
Leydig or interstitial cells are responsible for secreting testosterone. Testosterone is a male sex hormone that plays a crucial role in the development of male reproductive tissues, such as the testes and prostate, as well as promoting secondary sexual characteristics like muscle mass, bone density, and facial hair growth. It also stimulates the production of sperm and regulates the male sex drive. Therefore, the correct answer is that Leydig or interstitial cells secrete testosterone.
37.
The penis becomes erect:
Correct Answer
D. Due to parasympathetic induced vasodilation of penile arterioles.
Explanation
The correct answer is "due to parasympathetic induced vasodilation of penile arterioles." This means that the penis becomes erect because the parasympathetic nervous system causes the blood vessels in the penis to widen, allowing more blood to flow into the area and resulting in an erection.
38.
Spermatogenesis:
Correct Answer
A. Occurs in the seminiferous tubules.
Explanation
Spermatogenesis is the process of sperm production in males. It occurs in the seminiferous tubules, which are located in the testes. The seminiferous tubules are responsible for the production and maturation of sperm cells. Therefore, the given answer is correct as it accurately identifies the location where spermatogenesis takes place.
39.
Which of the following is an incorrect pairing of a structure in the female reproductive system and its function?
Correct Answer
C. Uterus - site of fertilization
40.
The number of primary oocytes in a female:
Correct Answer
A. Is fixed prior to birth.
Explanation
The correct answer is "is fixed prior to birth." This means that the number of primary oocytes, which are immature eggs, is determined and established before a female is born. Unlike males who continuously produce sperm throughout their lives, females are born with a finite number of primary oocytes, and this number does not increase or decrease after birth. This is why women have a limited number of eggs available for fertilization and eventually go through menopause when their supply runs out.
41.
During the ovarian cycle after the secondary oocyte has been ovulated the follicle cells become the _______ which secretes estrogen and progesterone.
Correct Answer
C. Corpus luteum
Explanation
After the secondary oocyte has been ovulated, the follicle cells undergo a transformation and become the corpus luteum. The corpus luteum is responsible for secreting estrogen and progesterone, which are important hormones in the ovarian cycle. These hormones help prepare the uterus for potential implantation and support the development of the uterine lining.
42.
Ovulation is triggered by the release of _______ from the anterior pituitary.
Correct Answer
D. Luteinizing hormone (LH)
Explanation
Ovulation is triggered by the release of luteinizing hormone (LH) from the anterior pituitary. LH is responsible for stimulating the release of a mature egg from the ovary during the menstrual cycle. It causes the follicle to rupture and release the egg, allowing it to be fertilized. This surge in LH is a crucial step in the reproductive process and is necessary for successful ovulation to occur.
43.
If fertilization and subsequently implantation occur what hormone is produced by the embryo to prevent the corpus luteum from degenerating?
Correct Answer
D. Human chorionic gonadotropin
Explanation
Human chorionic gonadotropin (hCG) is produced by the embryo to prevent the corpus luteum from degenerating. The corpus luteum is responsible for producing progesterone, which is essential for maintaining the uterine lining and supporting early pregnancy. hCG acts as a signal to the corpus luteum to continue producing progesterone, ensuring the survival of the embryo and the maintenance of the pregnancy.