1.
Histology is best defined as the study of ___.
Correct Answer
B. Tissues and how they are arranged into organs
Explanation
Histology is the study of tissues and how they are arranged into organs. It involves examining the microscopic structure of tissues and understanding their functions within the context of organ systems. By studying histology, scientists and medical professionals can gain insights into the organization and composition of different tissues, which can help in diagnosing diseases and understanding the normal functioning of the human body.
2.
The tough superficial layer of the epidermis is known as the
Correct Answer
D. Stratum corneum
Explanation
The tough superficial layer of the epidermis is known as the stratum corneum. This layer is composed of dead skin cells that have become flattened and filled with keratin, a tough protein. The stratum corneum serves as a protective barrier for the underlying layers of the skin, preventing water loss and protecting against external factors such as UV radiation, chemicals, and pathogens.
3.
Each of the following is a possible function of the integumentary system, except
Correct Answer
C. Synthesis of vitamin C
Explanation
The skin synthesizes vitamnin D.
4.
Glands that discharge an oily secretion into hair follicles are ____ glands.
Correct Answer
C. Sebaceous
Explanation
Sebaceous glands are the glands that discharge an oily secretion into hair follicles. This oily secretion, known as sebum, helps to lubricate and waterproof the skin and hair. Sebaceous glands are found all over the body, except for the palms of the hands and soles of the feet. They are most abundant on the face and scalp. The sebum produced by sebaceous glands plays a crucial role in maintaining healthy skin and hair.
5.
All of the following are true of the pigment melanin, except that it
Correct Answer
A. Decreases in concentration within cells during exposure to the sun
Explanation
Our melanocytes would produce more to protect us from the sun (Thats how we tan)
6.
Glands that secrete hormones into the interstitial fluid are
Correct Answer
A. Endocrine glands
Explanation
Endocrine glands are the correct answer because they are responsible for secreting hormones directly into the interstitial fluid. These hormones are then transported through the bloodstream to target cells or organs, where they regulate various physiological processes. Unlike exocrine glands, which secrete their products through ducts, endocrine glands release their hormones directly into the surrounding fluid. Merocrine, interstitial, and holocrine glands are not involved in hormone secretion into the interstitial fluid, making them incorrect options.
7.
The type of cells that form the strata in the epidermis are
Correct Answer
C. Keratinocytes
Explanation
Keratinocytes are the type of cells that form the strata in the epidermis. These cells are responsible for producing keratin, a tough protein that provides strength and protection to the skin. Keratinocytes undergo a process called keratinization, where they become filled with keratin and eventually form the outermost layer of the skin. This layer helps to prevent water loss, protect against UV radiation, and provide a barrier against pathogens. Therefore, keratinocytes play a crucial role in maintaining the integrity and function of the epidermis.
8.
An albino individual lacks the ability to produce
Correct Answer
C. Melanin
Explanation
Melanin is a pigment produced by specialized cells called melanocytes in the skin, hair, and eyes. It is responsible for giving color to these tissues. Albino individuals have a genetic condition that causes a lack or reduction in the production of melanin. As a result, they have very pale or white skin, hair, and eyes. This lack of melanin also makes them more susceptible to sunburn and increases their risk of developing skin cancer.
9.
Which of the following connective tissue cells produces collagen?
Correct Answer
E. Fibroblasts
Explanation
Fibroblasts are the connective tissue cells that produce collagen. Collagen is the main structural protein in the extracellular matrix of connective tissues, providing strength and support. Adipocytes are fat cells, dendritic cells are immune cells involved in antigen presentation, mast cells are involved in allergic reactions, and macrophages are immune cells involved in phagocytosis. Only fibroblasts are responsible for collagen production.
10.
Which layer of dividing cells is at the base of the epidermis?
Correct Answer
B. Stratum basale
Explanation
The correct answer is "stratum basale." The stratum basale is the bottom layer of dividing cells in the epidermis. It is responsible for the continuous production of new skin cells, which eventually move up to the upper layers of the epidermis and replace old cells that are shed from the surface of the skin. This layer also contains melanocytes, which produce the pigment melanin that gives color to the skin.
11.
Lanugo is found
Correct Answer
B. On a fetus
Explanation
Lanugo refers to the fine, downy hair that covers the body of a fetus. It is typically present on the scalp, palms of the hands, and soles of the feet. This hair serves as insulation for the developing baby and helps regulate their body temperature. Once the fetus reaches a certain stage of development, the lanugo hair is usually shed and replaced by coarser hair. Therefore, the correct answer is "on a fetus."
12.
Transitional epithelium is found
Correct Answer
B. Lining the urinary bladder
Explanation
This type of tissue is made to stretch and then recoil back. Our bladder can greatly increase in size, so this type of tissue allows stretching without causing damage.
13.
Thin skin contains ___ layer(s) or keratinocytes, and thick skin contains ____ layers.
Correct Answer
D. 4;5
Explanation
Thin skin contains 4 layers of keratinocytes, while thick skin contains 5 layers. The number of layers in the skin varies depending on its thickness. Thin skin, which is found in most areas of the body, has a thinner epidermis with only 4 layers of keratinocytes. Thick skin, on the other hand, is found in areas that experience more wear and tear, such as the palms of the hands and soles of the feet. It has a thicker epidermis with 5 layers of keratinocytes, providing extra protection and durability.
14.
Cyanosis signifies that a patient
Correct Answer
D. Has oxygen-starved skin
Explanation
Cyanosis is a condition characterized by the bluish discoloration of the skin, lips, or nails due to a lack of oxygen in the blood. When the blood is not adequately oxygenated, it appears bluish instead of its normal red color. This can occur due to various reasons such as respiratory problems, heart conditions, or circulatory issues. Therefore, cyanosis signifies that a patient has oxygen-starved skin.
15.
If a fair-skinned person is sunburned, why does his or her skin turn red?
Correct Answer
B. The blood flow to the skin increases
Explanation
When a fair-skinned person gets sunburned, their skin turns red due to the increase in blood flow to the affected area. Sunburn is a result of excessive exposure to ultraviolet (UV) radiation, which damages the skin cells. In response to this damage, the body increases blood flow to the affected area to promote healing. This increased blood flow brings more oxygen and nutrients to the damaged skin, causing it to appear red. Additionally, the increased blood flow may also be a result of inflammation in the skin, as the body's immune response is triggered to repair the damaged cells.
16.
This type of tissue always has a top and a bottom.
Correct Answer
A. Epithelial tissue
Explanation
The basement membrane is at the bottom, and the surface farthest from the basement membrane is the top or apical surface.
17.
The junction type that lets neighboring cells exchanage small molecules is the
Correct Answer
E. Gap junctions
Explanation
Gap junctions are the correct answer because they are specialized intercellular connections that allow neighboring cells to communicate and exchange small molecules. These junctions consist of protein channels called connexons, which form channels between adjacent cells, allowing for the direct transfer of ions, nutrients, and signaling molecules. Gap junctions are found in various tissues and play a crucial role in coordinating cellular activities and maintaining tissue homeostasis.
18.
Which of the following is not one of the four main tissue categories?
Correct Answer
A. Osseous tissue
Explanation
osseous tissue (bone tissue) is a type of connective tissue.
19.
_____ are cells in the epidermis that are part of the immune system.
Correct Answer
B. Dendritic cells
Explanation
Dendritic cells, also known as Langerhans are macrophages that guard against toxins, microbes, and other pathogens.
20.
The protein that permits stretching and recoiling of the skin is
Correct Answer
C. Elastin
Explanation
Elastin is the protein that allows the skin to stretch and recoil. It is a highly elastic protein that provides flexibility and resilience to tissues in the body, including the skin. Collagen, on the other hand, provides structural support and strength to the skin, but it is not directly responsible for its ability to stretch and recoil. Melanin is responsible for skin pigmentation, carotene is a pigment found in fruits and vegetables, and keratin is a protein found in the hair, nails, and outer layer of the skin.