1.
The micturition center is located in the
Correct Answer
D. The sacral portion of the spinal cord
Explanation
The sacral portion of the spinal cord is responsible for controlling the micturition reflex, which is the process of emptying the bladder. This reflex is initiated by stretch receptors in the bladder wall, which send signals to the micturition center in the sacral spinal cord. The micturition center then coordinates the relaxation of the internal urethral sphincter and the contraction of the bladder muscles, allowing urine to be expelled. The other options, including the medulla oblongata, pons, and hypothalamus, are not directly involved in the control of micturition.
2.
Sperm cells spend several weeks maturing in the
Correct Answer
C. Epididymis
Explanation
Sperm cells spend several weeks maturing in the epididymis. The epididymis is a coiled tube located on the back of each testicle, where sperm cells are stored and gain the ability to swim. It provides the necessary environment for the sperm cells to undergo maturation and become capable of fertilizing an egg. Once matured, the sperm cells are then transported to the ductus deferens, where they will eventually be ejaculated during sexual intercourse.
3.
Urine passes through the ureters by
Correct Answer
A. Peristalsis
Explanation
Peristalsis is the rhythmic contraction and relaxation of muscles that helps propel substances through tubes in the body, such as the ureters. In the case of urine passing through the ureters, peristalsis helps to push the urine from the kidneys to the bladder. This muscular movement ensures a one-way flow of urine and prevents backflow. None of the other options mentioned (contractions of the renal pelvis or suction from the urethra) accurately describe the mechanism by which urine passes through the ureters.
4.
Water leaves the nephron by
Correct Answer
C. Osmosis
Explanation
Water leaves the nephron by osmosis. Osmosis is the process by which water molecules move from an area of lower solute concentration to an area of higher solute concentration across a semipermeable membrane. In the nephron, water is reabsorbed from the filtrate back into the bloodstream. This reabsorption occurs in response to the high solute concentration in the interstitial fluid surrounding the nephron. As a result, water moves out of the nephron and into the surrounding tissues through osmosis, helping to concentrate the urine and conserve water in the body.
5.
To relax after the final examination in this course, a student goes to a local bistro and drinks 2 quarts of beer in which there is a minimal amount of sodium. Which of the following will occur?
Correct Answer
A. A decrease in the solute concentration of the body fluids
Explanation
Drinking 2 quarts of beer, which contains a minimal amount of sodium, would result in a decrease in the solute concentration of the body fluids. This is because beer is a hypotonic solution compared to the body fluids, meaning it has a lower concentration of solutes. When the student drinks the beer, it dilutes the solute concentration in the body fluids, leading to a decrease in concentration.
6.
Place the following in their proper sequence.
1. Release of renin
2. Sodium reabsorption from tubules
3. Formation of angiotensin
4. Release of aldosterone
5. Conversion of angiotensinogen
Correct Answer
D. 1, 5, 3, 4, and 2
Explanation
The correct sequence is 1, 5, 3, 4, and 2. First, there is the release of renin, which triggers the renin-angiotensin-aldosterone system. This leads to the conversion of angiotensinogen into angiotensin. Next, aldosterone is released, which promotes the reabsorption of sodium from the tubules. Therefore, the correct sequence is the release of renin, conversion of angiotensinogen, formation of angiotensin, release of aldosterone, and sodium reabsorption from tubules.
7.
What do the dartos and cremaster muscles do?
Correct Answer
C. Regulate the temperature of the testes
Explanation
The dartos and cremaster muscles are responsible for regulating the temperature of the testes. These muscles help to control the position of the testes in relation to the body, allowing them to be brought closer or further away from the body wall to maintain the optimal temperature for sperm production. This is important because the testes need to be slightly cooler than the rest of the body for proper sperm development. By contracting or relaxing, the dartos and cremaster muscles adjust the position of the testes, ensuring their temperature is regulated.
8.
Menstruation is triggered by a drop in the level of
Correct Answer
D. Estrogen and progesterone
Explanation
Menstruation is triggered by a drop in the level of estrogen and progesterone. These hormones are responsible for regulating the menstrual cycle. When the levels of estrogen and progesterone decrease, the lining of the uterus sheds, resulting in menstruation. FSH and LH are also involved in the menstrual cycle, but they do not directly trigger menstruation. FSH stimulates the growth of follicles in the ovaries, while LH triggers ovulation. Therefore, the correct answer is estrogen and progesterone.
9.
Which of the following is greater?
Correct Answer
B. Facultative reabsorption when the body is dehydrated
Explanation
Facultative reabsorption refers to the process in which the kidneys selectively reabsorb water and solutes based on the body's needs. When the body is dehydrated, the kidneys increase facultative reabsorption to conserve water and prevent dehydration. This means that more water and solutes are reabsorbed by the kidneys when the body is dehydrated compared to when it is hydrated. Therefore, facultative reabsorption when the body is dehydrated is greater than facultative reabsorption when the body is hydrated.
10.
Which hormone present in the female urinary system is the pregnancy test dependent on?
Correct Answer
D. Human chorionic gonadotropin hormone
Explanation
The pregnancy test is dependent on the human chorionic gonadotropin hormone (hCG). This hormone is produced by the placenta after implantation occurs, and its presence in the urine is an indicator of pregnancy. The test works by detecting the hCG hormone in the urine sample, confirming whether or not a woman is pregnant. Adrenocorticotropic hormone and growth hormone are not directly related to pregnancy and are not used in pregnancy tests.
11.
What is not a waste eliminated by the kidneys?
Correct Answer
C. Renin
Explanation
Renin is not a waste eliminated by the kidneys. Renin is an enzyme produced by specialized cells in the kidneys and is involved in regulating blood pressure and fluid balance in the body. It plays a crucial role in the renin-angiotensin-aldosterone system, which helps to control blood pressure and maintain electrolyte balance. Unlike creatinine and uric acid, which are waste products filtered out by the kidneys and excreted in urine, renin is not a waste product but rather an important component of the body's regulatory system. Therefore, the correct answer is Renin.
12.
Angiotensin II brings about a
Correct Answer
D. Increase in blood pressure
Explanation
Angiotensin II is a hormone that constricts blood vessels, leading to an increase in blood pressure. It acts on smooth muscles in the arteries, causing them to narrow and resulting in increased resistance to blood flow. This narrowing of blood vessels leads to an increase in blood pressure. Therefore, the correct answer is "Increase in blood pressure".
13.
Removal of the prostate gland would result in
Correct Answer
B. Urinary incontinency
Explanation
Removal of the prostate gland would result in urinary incontinence. The prostate gland plays a crucial role in the male reproductive system by producing a fluid that helps nourish and transport sperm. However, it also surrounds the urethra, the tube that carries urine from the bladder out of the body. Therefore, removing the prostate gland can disrupt the normal flow of urine, leading to urinary incontinence, which is the inability to control the release of urine.
14.
Fertilization of the ovum usually occurs
Correct Answer
D. In the upper third of the uterine (fallopian) tubes
Explanation
Fertilization of the ovum usually occurs in the upper third of the uterine (fallopian) tubes. This is because after ovulation, the ovum is released from the ovary and travels through the fallopian tube towards the uterus. The fallopian tubes provide the ideal environment for fertilization to occur, as they contain specialized cells and secretions that support the survival and movement of sperm. The upper third of the fallopian tubes is particularly important for fertilization because it is closer to the ovary where the ovum is released, allowing for optimal timing and proximity of sperm and egg.
15.
What does semen contain?
Correct Answer
D. All of these
Explanation
Semen contains spermatozoans, seminal fluids, and prostaglandins. Spermatozoans are the male reproductive cells responsible for fertilizing the female egg. Seminal fluids, produced by the seminal vesicles, prostate gland, and bulbourethral glands, provide nourishment and protection to the spermatozoans. Prostaglandins are hormone-like substances that help in the contraction of the female reproductive tract, aiding the movement of sperm. Therefore, all of these components are present in semen.
16.
ADH production
Correct Answer
C. Causes increased permeability of kidney tubules to water
Explanation
ADH, or antidiuretic hormone, is responsible for regulating the body's water balance. When ADH production is increased, it causes the kidney tubules to become more permeable to water. This means that more water is reabsorbed from the tubules back into the bloodstream, resulting in a decreased volume of urine output. Conversely, when ADH production is decreased, the kidney tubules become less permeable to water, leading to an increased volume of urine output. Therefore, the given answer is correct as it accurately explains the effect of increased ADH production on the permeability of kidney tubules to water.
17.
The corpus luteum produces
Correct Answer
C. Progesterone
Explanation
The corpus luteum is a temporary endocrine structure that forms in the ovary after ovulation. Its main function is to produce and secrete progesterone. Progesterone plays a crucial role in preparing the uterus for pregnancy by thickening the uterine lining and maintaining it to support the implantation of a fertilized egg. If pregnancy does not occur, the corpus luteum degenerates and progesterone levels decrease, leading to the shedding of the uterine lining and the start of menstruation. Therefore, the correct answer is progesterone.
18.
Erection of the penis is the result of
Correct Answer
A. A spinal reflex mediated by the parasympathetic nervous system
Explanation
The correct answer is a spinal reflex mediated by the parasympathetic nervous system. Erection of the penis is a complex process that involves both the parasympathetic and sympathetic nervous systems. However, the parasympathetic nervous system plays a more significant role in initiating and maintaining an erection. When stimulated, the parasympathetic nerves release nitric oxide, which causes the smooth muscles in the walls of the penile arteries to relax. This relaxation allows for increased blood flow into the penis, leading to an erection. Therefore, the parasympathetic nervous system is primarily responsible for the erection of the penis.
19.
Ejaculation is the result of
Correct Answer
B. Rhythmic peristaltic contractions from the epididymis through the urethra
Explanation
The correct answer is "Rhythmic peristaltic contractions from the epididymis through the urethra." Ejaculation is the process by which semen is expelled from the penis. This expulsion is achieved through rhythmic peristaltic contractions, which start in the epididymis (where sperm is stored) and continue through the vas deferens, seminal vesicles, prostate gland, and finally the urethra. These contractions help propel the semen forward and out of the body. The other options listed, such as the parasympathetic nervous system, bulbourethral glands, and prostate gland, are involved in the overall process of ejaculation but are not solely responsible for the rhythmic contractions that expel semen.
20.
In the menstrual cycles that vary in length, it is the _______________ phase that shows the most variations.
Correct Answer
C. Follicular or proliferative
Explanation
In the menstrual cycles that vary in length, the phase that shows the most variations is the follicular or proliferative phase. This phase occurs before ovulation and is characterized by the growth and development of follicles in the ovaries. The length of this phase can vary from cycle to cycle, depending on factors such as hormonal fluctuations and individual differences. Therefore, it is the follicular or proliferative phase that exhibits the most variations in menstrual cycles.