Anatomy and Physiology II (M8) Comprehensive Lecture Exam

Correct Answer: A. Adipose tissue deposition in the breasts, hips, and thighs.

Explanation of the Correct Answer:

A. Adipose tissue deposition in the breasts, hips, and thighs

Estrogens are primary female sex hormones that play a key role in the development of secondary sexual characteristics. One of their effects is the promotion of fat storage in specific areas of the body, such as the breasts, hips, and thighs. This contributes to the characteristic body shape seen in females, especially during puberty and reproductive years.

Why the Other Options Are Incorrect:

B. Deepening of the voice

Deepening of the voice is typically associated with the effects of testosterone, not estrogen. Testosterone causes the vocal cords to thicken and lengthen, which results in a deeper voice. Estrogen does not have this effect and, in fact, typically results in a higher-pitched voice.

C. Increased erythrocyte production

Erythropoiesis, or the production of red blood cells, is primarily regulated by erythropoietin, a hormone produced by the kidneys. Estrogen does not directly influence erythropoiesis in the same way that erythropoietin does. In fact, increased estrogen levels can sometimes lead to a mild suppression of red blood cell production.

D. Increased skeletal muscle mass

Skeletal muscle mass is primarily influenced by androgens like testosterone. Estrogen generally has a less pronounced effect on muscle growth. In fact, higher estrogen levels can lead to a decrease in muscle mass relative to men who have higher testosterone levels, as testosterone promotes muscle growth.

Correct Answer: C. Homozygous

Explanation of the Correct Answer:

C. Homozygous

When two alleles code for the same trait, such as blonde hair, and are identical (either both dominant or both recessive), the individual is said to be homozygous. For example, if the allele for blonde hair is represented by "bb," both alleles from the mother and father would be the same and would make the individual homozygous for that trait.

Why the Other Options Are Incorrect:

A. Heterozygous

Heterozygous means that the two alleles are different for a particular trait, such as having one allele for blonde hair ("b") and one for brown hair ("B"). This would not fit the scenario where both alleles are for the same trait (blonde hair).

B. Homologous

Homologous refers to chromosomes that are paired and have corresponding loci. It is not a term specifically used for describing alleles that code for the same trait.

D. Autologous

Autologous means originating from the same individual, but this term is not applicable when talking about alleles coding for traits.

Correct Answer:

Appearance of goose bumps.

Explanation:

Arrector pili are small, involuntary muscles attached to hair follicles. When they contract in response to cold or emotional stimuli (like fear), they pull the hair upright, creating what we know as "goose bumps." This reaction is a vestigial reflex meant to trap heat by raising body hair, which was more effective in fur-covered animals.

Why Other Options are Wrong:

Production of sweat.

Sweat production is carried out by eccrine and apocrine glands, not arrector pili muscles.

Acceleration of wrinkling in aging.

Wrinkling results from changes in collagen and elastin in the skin over time, not from muscle contractions.

Increase in skin pigmentation.

Skin pigmentation is controlled by melanocytes and influenced by hormones and UV exposure—not by arrector pili muscles.

Correct Answer: D. Gametes

Explanation of the Correct Answer:

The testes are the gonads in males, meaning they are the reproductive organs responsible for producing gametes (specifically sperm) and sex hormones (such as testosterone).

Similarly, sperm are the gametes produced by the testes in males. Gametes are reproductive cells (sperm in males and ova in females) that combine during fertilization to form a zygote.

Why the Other Options Are Incorrect:

A. Sex hormones:

While the testes produce sex hormones (like testosterone), sperm themselves are not hormones. The relationship in the analogy is about reproductive cells (testes and sperm), not hormones.

B. Ova:

Ova are the female gametes, produced by the ovaries. The analogy is comparing male reproductive cells (sperm) to male reproductive organs (testes), not to female reproductive cells.

C. Estrogen:

Estrogen is a female sex hormone produced primarily by the ovaries. It is not related to sperm directly and does not fit the analogy.

Correct Answer: C. GFR will increase.

Explanation of the Correct Answer:

High blood pressure (hypertension) increases the pressure in the glomerular capillaries. This elevated pressure forces more fluid and solutes through the filtration membrane of the glomerulus into the Bowman's capsule, leading to an increase in the glomerular filtration rate (GFR).

GFR refers to the rate at which blood is filtered by the kidneys' glomeruli, and it is highly dependent on the hydrostatic pressure in the glomerular capillaries. When blood pressure is higher than normal, the filtration pressure increases, which leads to an increased filtration rate.

However, this increase in GFR in response to high blood pressure could be detrimental in the long term if regulatory mechanisms (like autoregulation) are not functioning correctly. Normally, the kidneys use intrinsic mechanisms (such as the myogenic response and tubuloglomerular feedback) to maintain a constant GFR despite changes in blood pressure.

Why the Other Options Are Incorrect:

A. GFR will not change.

This is incorrect because high blood pressure does affect the GFR, and in the absence of regulatory mechanisms, it would cause an increase in GFR.

B. GFR will decrease, then increase.

This is incorrect because there is no initial decrease in GFR under high blood pressure in the absence of regulatory mechanisms. Instead, the GFR will directly increase due to the higher pressure in the glomeruli.

D. GFR will decrease.

This is incorrect because high blood pressure generally increases the GFR due to higher pressure driving filtration. In the absence of regulatory mechanisms, the kidneys cannot adjust to this pressure, and GFR will increase.

Correct Answer: A. True

Explanation of the Correct Answer:

A. True

Testosterone is indeed produced by the Leydig cells (also called interstitial cells) in the male testes. These cells are located in the interstitial spaces between the seminiferous tubules of the testes. Leydig cells respond to luteinizing hormone (LH) from the anterior pituitary, which stimulates them to produce and secrete testosterone. Testosterone is the primary male sex hormone and is responsible for the development of male secondary sexual characteristics, including increased muscle mass, deep voice, and facial hair.

Why the Other Option Is Incorrect:

B. False

This statement is false because testosterone is, in fact, produced by the Leydig cells in the male testes. Therefore, "False" is the incorrect answer.

Correct Answer: B. Anterior nares

Explanation of the Correct Answer:

B. Anterior nares

Inhaled air enters the upper respiratory tract through the anterior nares, which are the nostrils. These are the external openings of the nose that lead to the nasal cavity. Once air passes through the anterior nares, it travels into the nasal cavity, where it is filtered, warmed, and humidified before moving further into the respiratory system.

Why the Other Options Are Incorrect:

A. Nasal cavity

While the nasal cavity is where air is processed after entering through the anterior nares, it is not an opening itself. Air does not enter the upper respiratory tract directly through the nasal cavity; it first passes through the anterior nares and then into the nasal cavity.

C. Nasopharynx

The nasopharynx is the upper part of the throat that connects the nasal cavity to the back of the throat (pharynx). While air flows through the nasopharynx after passing through the nasal cavity, it is not an opening but a passageway. Air enters the nasopharynx from the nasal cavity.

D. Posterior nares

The posterior nares, also known as the choanae, are the internal openings of the nasal cavity that connect it to the nasopharynx. However, air does not enter the respiratory system through the posterior nares. Instead, it passes from the anterior nares into the nasal cavity and then moves through the posterior nares into the nasopharynx.

Correct Answer: D. Pancreas

Explanation of the Correct Answer:

D. Pancreas

The pancreas is a dual-function gland—it serves both endocrine and exocrine roles. As an endocrine gland, it contains clusters of cells called islets of Langerhans, which release hormones directly into the bloodstream. These hormones include insulin, glucagon, and somatostatin, all of which regulate blood glucose levels. As an exocrine gland, the pancreas produces digestive enzymes (such as amylase, lipase, and proteases) that are secreted into the small intestine via the pancreatic duct to help break down food. This unique dual function makes the pancreas essential for both hormonal regulation and digestion.

Why the Other Options Are Incorrect:

A. Liver

The liver performs many metabolic and detoxification functions and does secrete some hormones (like insulin-like growth factor-1), but it is not classified as an exocrine gland in the digestive sense, nor does it have the dual structure typical of endocrine/exocrine glands like the pancreas.

B. Adrenals

The adrenal glands are purely endocrine glands. They secrete hormones such as cortisol, aldosterone, and adrenaline but have no exocrine function.

C. Spleen

The spleen is part of the immune and lymphatic systems. It filters blood and helps fight infection. It does not have endocrine or exocrine functions.

Correct Answer:

A. 28

Explanation:

The average menstrual cycle is typically 28 days long, though normal ranges can vary from 21 to 35 days. The cycle begins with the first day of menstruation and includes the follicular phase, ovulation (around day 14), and the luteal phase.

Why Other Options are Wrong:

30

While close to average, 30 is not the textbook value used in physiology; 28 is standard for calculation purposes.

45

This is abnormally long and could indicate hormonal imbalance or pathology.

14

This is the approximate time of ovulation, not the full cycle duration.