Anatomy and Physiology II (M8) Comprehensive Lecture Exam

Correct Answer: D. Collapse

Explanation of the Correct Answer:

D. Collapse

Under normal conditions, the intrapleural pressure (the pressure within the pleural cavity between the lungs and the chest wall) is slightly lower than atmospheric pressure. This negative pressure is crucial because it helps keep the lungs expanded by creating a suction effect that holds the lungs against the inner chest wall.

If the intrapleural pressure rises to equal or exceed atmospheric pressure, this suction is lost, and the lungs will recoil and collapse. This condition is known as pneumothorax. It can occur due to trauma (such as a punctured chest wall or ruptured alveoli), allowing air to enter the pleural space and disrupting the pressure balance.

Why the Other Options Are Incorrect:

A. Inhalation

Inhalation occurs when intrapleural pressure drops further below atmospheric pressure, allowing the lungs to expand and air to flow in. If intrapleural pressure increases to match or exceed atmospheric pressure, inhalation becomes impossible, not more effective.

B. Overinflation

Overinflation of the lungs happens when there's excessive air trapped inside, such as in conditions like emphysema. However, if intrapleural pressure equals or exceeds atmospheric pressure, it would oppose lung inflation, not promote it. Overinflation is not the outcome in this case.

C. Burst

Lungs do not burst from increased intrapleural pressure. Instead, they recoil inward and collapse due to the loss of the negative pressure keeping them expanded. Bursting would require excessive internal pressure, not an increase in surrounding pressure.

Correct Answer: A. ADH

Explanation of the Correct Answer:

ADH stands for antidiuretic hormone, also known as vasopressin. ADH is produced by the hypothalamus and stored and released by the posterior pituitary gland. It has a direct effect on blood pressure by promoting water retention by the kidneys. When ADH is released, it signals the kidneys to reabsorb more water back into the bloodstream, rather than excreting it as urine. This increases blood volume, which in turn raises blood pressure. ADH also causes vasoconstriction (narrowing of blood vessels), which further contributes to elevating blood pressure.

Why the Other Options Are Incorrect:

B. Oxytocin

Oxytocin is incorrect because its primary functions are related to uterine contractions during childbirth and milk ejection during breastfeeding. It does not have a direct role in regulating blood pressure or promoting water retention by the kidneys.

C. Testosterone

Testosterone is incorrect because it is mainly involved in male secondary sex characteristics, muscle and bone mass development, and reproductive functions. It does not directly regulate blood pressure through water retention by the kidneys, although high levels of testosterone can have indirect cardiovascular effects.

D. FSH (Follicle-Stimulating Hormone)

FSH is incorrect because it is involved in reproductive processes. In females, it stimulates ovarian follicle development, and in males, it promotes sperm production. FSH does not have a role in regulating blood pressure or fluid balance.

Correct Answer: C. Movement of food particles through the wall of the small intestine

Explanation of the Correct Answer:

C. Movement of food particles through the wall of the small intestine

Absorption is the process by which nutrients from digested food pass through the epithelial lining of the small intestine into the bloodstream or lymphatic system. This is a critical function of the digestive system that allows nutrients like amino acids, simple sugars, fatty acids, vitamins, and minerals to be transported to the body’s cells for use in growth, repair, and energy.

The small intestine, especially the jejunum and ileum, is the primary site for this process. Its inner surface is lined with villi and microvilli, which increase the surface area to maximize absorption.

Why the Other Options Are Incorrect:

A. Elimination of feces and some metabolic wastes

This describes defecation, not absorption. It refers to the removal of undigested food and waste products from the body, which occurs at the end of the digestive process, not during absorption.

B. Passage of foods and liquids from one digestive organ to the next

This describes propulsion, specifically peristalsis, which moves food along the gastrointestinal (GI) tract. While essential to digestion, it does not involve the uptake of nutrients into the bloodstream.

D. Reactions that break chemical bonds of food particles

This describes digestion, particularly chemical digestion, where enzymes break down complex molecules into absorbable units. Absorption, in contrast, is the process after digestion, where these smaller molecules are taken into the body.

Correct Answer:

Foot

Explanation:

The calcaneus is the largest bone in the foot and forms the heel. It is a tarsal bone and plays a vital role in weight-bearing and walking by providing support and structure for the foot. It also serves as the attachment point for the Achilles tendon.

Why Other Options are Wrong:

Mouth

The mouth contains bones such as the mandible and maxilla, but not the calcaneus. The calcaneus is not involved in oral structure or function.

Hand

Bones in the hand include carpals, metacarpals, and phalanges—not the calcaneus. The calcaneus is part of the foot, not the upper limb.

Head

The bones of the head include the skull bones (like the frontal, parietal, and occipital bones), but the calcaneus has no connection to the head or cranial structures.

Correct Answer:

Head

Explanation:

The pituitary gland is located at the base of the brain, within a bony structure called the sella turcica of the sphenoid bone. It is part of the endocrine system and regulates numerous hormones. A pituitary tumor, therefore, is found within the cranial cavity—specifically in the head.

Why Other Options are Wrong:

Trunk

The trunk refers to the central part of the body, including the chest and abdomen. The pituitary gland is not located in the trunk, so a tumor here would not affect that gland.

Neck

The thyroid and parathyroid glands are located in the neck, not the pituitary gland. A tumor in the neck area would not be considered a pituitary tumor.

Abdomen

The abdominal cavity houses organs such as the liver, stomach, intestines, and kidneys, but not the pituitary gland. Therefore, a pituitary tumor would not be found here.

Correct Answer: D. Humoral stimulation

Explanation of the Correct Answer:

D. Humoral stimulation

Glucagon secretion is regulated through humoral stimulation, which refers to changes in the composition of the blood—particularly blood glucose levels. When blood glucose drops (hypoglycemia), the alpha cells of the pancreas detect this decrease and respond by secreting glucagon. Glucagon then stimulates the liver to break down glycogen into glucose (glycogenolysis) and to form new glucose (gluconeogenesis), both of which raise blood glucose levels. This process is a classic example of humoral regulation, where the chemical makeup of body fluids directly triggers hormone release.

Why the Other Options Are Incorrect:

A. Neural stimulation

Neural stimulation involves direct innervation by nerves, such as sympathetic stimulation triggering the adrenal medulla to release epinephrine. Glucagon release is not primarily triggered this way.

B. Hormonal stimulation

This involves one hormone triggering the release of another, like ACTH stimulating cortisol release. Glucagon is not secreted in response to another hormone.

C. Neurohormonal stimulation

This refers to hormones released by neurons into the bloodstream (e.g., oxytocin from the posterior pituitary). Glucagon is secreted by endocrine cells, not neurosecretory cells.

Correct Answer:

Ear wax

Explanation:

Ceruminous glands are modified apocrine sweat glands located in the external auditory canal. They secrete cerumen, commonly known as earwax. Cerumen protects the ear canal by trapping dust and microorganisms, preventing infection, and providing lubrication. It also has antibacterial properties and helps maintain ear health.

Why Other Options are Wrong:

Keratin

Keratin is a structural protein produced by keratinocytes in the skin, hair, and nails. Ceruminous glands do not produce keratin.

Oily sebum

Sebum is secreted by sebaceous glands, not ceruminous glands. Though both are part of the integumentary system, they serve different purposes and are located in different regions.

Mucus

Mucus is secreted by mucous membranes in areas like the respiratory and digestive tracts. Ceruminous glands do not produce mucus.

Correct Answer: B. Trachea

Explanation of the Correct Answer:

B. Trachea

The trachea, also known as the windpipe, is part of the lower respiratory tract, not the upper respiratory tract. It begins at the larynx and extends down into the chest, where it branches into the left and right bronchi leading to the lungs. The trachea is responsible for carrying air from the upper respiratory structures into the lungs, but it is anatomically part of the lower respiratory tract.

Why the Other Options Are Correct:

A. Larynx

The larynx (voice box) is located at the junction of the pharynx and the trachea and is considered part of the upper respiratory tract. It plays a critical role in voice production, as well as protecting the trachea from food aspiration through the epiglottis.

C. Pharynx

The pharynx, also known as the throat, is part of the upper respiratory tract. It connects the nasal and oral cavities to the larynx and esophagus. It serves as a passageway for both air (to the lungs) and food (to the esophagus).

D. Nose

The nose is the entry point for air and is also part of the upper respiratory tract. It filters, warms, and humidifies the air before it enters the lungs, and it plays an important role in the sense of smell.

Correct Answer: C. ATP

Explanation of the Correct Answer:

C. ATP

The ultimate product of carbohydrate metabolism is ATP (adenosine triphosphate). Carbohydrates, particularly glucose, are broken down through a series of metabolic processes like glycolysis, the Krebs cycle, and oxidative phosphorylation. This breakdown releases energy, which is used to produce ATP. ATP is the primary energy currency of the cell, used to power a wide variety of cellular processes, including muscle contraction, protein synthesis, and active transport across cell membranes.

Why the Other Options Are Incorrect:

A. Radiation

Radiation is not a product of carbohydrate metabolism. Carbohydrate metabolism involves biochemical processes that produce energy, not radiation.

B. Glucose

While glucose is the starting point for carbohydrate metabolism, it is not the ultimate product. Glucose is broken down into pyruvate in glycolysis, and eventually, through other metabolic pathways, it contributes to the production of ATP. Therefore, glucose is a precursor, not the final product.

D. None of these

This option is incorrect because ATP is indeed the final product of carbohydrate metabolism.