Chpt 5 & 6 Multiple Choice VI Created By Day

Nervous tissue is primarily composed of two main cell types: neurons and neuroglia. Neurons are responsible for transmitting electrical signals, while neuroglia, also known as glial cells, provide support and protection to neurons. They help maintain the structural integrity of the nervous system, regulate the extracellular environment, and participate in immune responses. Fibroblasts, chondrocytes, myocytes, and osteocytes are not typically found in nervous tissue.

Skeletal muscle is described as striated because it has a striped or banded appearance due to the arrangement of its muscle fibers. This is in contrast to smooth muscle, which does not have this striped appearance. Skeletal muscle is also described as voluntary because it is under conscious control, meaning we can consciously decide to move our skeletal muscles. Involuntary muscles, on the other hand, are not under conscious control and work automatically, such as the muscles in our digestive system.

Ethnic differences in skin color are primarily caused by differences in the quantity of melanin produced. Melanin is a pigment produced by specialized cells called melanocytes in the skin. It is responsible for determining the color of the skin, hair, and eyes. People with darker skin produce more melanin, while those with lighter skin produce less. This variation in melanin production is influenced by genetic factors and helps protect the skin from the harmful effects of UV radiation. UV radiation exposure can also influence skin color, but it is not the primary cause of ethnic differences in skin color.

A mole is an elevated patch of melanized skin. Moles are commonly found on the skin and are usually brown or black in color. They can vary in size and shape and may appear anywhere on the body. Moles are caused by a cluster of pigmented cells called melanocytes, which produce the pigment melanin. While most moles are harmless, it is important to monitor them for any changes in size, shape, or color, as this could be a sign of skin cancer. Regular skin checks and consultations with a dermatologist are recommended to ensure the health of moles.

The shape of a person's external ear is determined by elastic cartilage. Elastic cartilage is a type of connective tissue that contains elastic fibers, which allows it to be flexible and able to maintain its shape. The external ear needs to be able to bend and move to help capture sound waves, and elastic cartilage provides the necessary flexibility for this function. Dense regular and irregular connective tissues are more involved in providing strength and support to structures, while fibrocartilage is found in areas that require additional support and shock absorption, such as the intervertebral discs. Ligaments are strong bands of connective tissue that connect bones together.

Pallor refers to an unusually pale or white skin color, which is commonly associated with anemia. Anemia is a condition where there is a decrease in the number of red blood cells or a decrease in the amount of hemoglobin in the blood, leading to a reduced oxygen-carrying capacity. This lack of oxygen can cause the skin to appear pale. Therefore, pallor is the most likely skin color to result from anemia.

Jaundice is a condition characterized by a yellowing of the skin and eyes, caused by an excess of bilirubin in the bloodstream. Bilirubin is a yellow pigment produced when red blood cells are broken down. When there is a buildup of bilirubin in the body, it can cause the skin to appear yellow, which is known as jaundice. Erythema refers to redness of the skin, pallor refers to paleness, bronzing refers to a darkening of the skin, and cyanosis refers to a bluish discoloration of the skin due to lack of oxygen.

Goblet cells are specialized cells found in simple columnar and pseudostratified columnar epithelia. These cells produce and secrete mucin, a glycoprotein that forms the protective mucous coating over the mucous membranes. The mucous coating helps to lubricate and protect the underlying tissues from mechanical damage, pathogens, and chemical irritants. Goblet cells are typically found interspersed among the epithelial cells and are characterized by their goblet-like shape, with a narrow base and an expanded apical region where the mucin is stored before secretion.

After six months of lifting weights at the gym, the increase in size of your muscles is due to hypertrophy of muscle cells. Hypertrophy refers to the increase in size or volume of cells, resulting in the enlargement of the muscle tissue. This occurs as a response to the increased demand and stress placed on the muscles during weightlifting exercises. The individual muscle cells grow larger and stronger, leading to an overall increase in muscle size.

Melanoma is the correct answer because it is the most deadly type of skin cancer. While basal cell carcinoma and squamous cell carcinoma are more common, melanoma is more aggressive and has a higher risk of spreading to other parts of the body. Skin lymphoma and skin sarcoma are also types of skin cancer, but they are less common and less deadly compared to melanoma.

Hematoma is the correct answer because it is a skin discoloration that occurs due to the accumulation of blood under the skin as a result of trauma or injury. This can be a sign of physical abuse as it suggests that there has been a forceful impact on the skin, causing blood vessels to rupture and blood to pool in the surrounding tissues. Pallor, albinism, erythema, and jaundice are not specifically associated with physical abuse and have different causes.

The four primary tissue types found in adult organs are connective, nervous, epithelial, and muscular. Fibrous tissue is a type of connective tissue, so it is included in the list of primary tissue types. Therefore, the correct answer is fibrous.

Epithelial tissue lines body cavities, covers the body surface, and forms the lining of many organs. This type of tissue is characterized by tightly packed cells that are closely connected to each other, forming a protective barrier. Epithelial tissue plays a crucial role in protecting underlying tissues from mechanical and chemical damage, as well as in regulating the exchange of substances between the body and its environment. It also helps in the absorption, secretion, and excretion processes.

Blood is found in the heart, and one of its functions is to transport nutrients to the tissues.

The stratum basale is the deepest layer of the epidermis and is responsible for the continuous production of new cells through mitosis. This layer contains rapidly dividing cells, which makes it the site of the fastest rate of mitosis. The other layers of the epidermis, such as the stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum, do not exhibit the same level of cell division as the stratum basale. Therefore, the correct answer is stratum basale.

The hypodermis, also known as subcutaneous tissue, is located beneath the dermis and is primarily composed of adipose tissue. Adipose tissue is a type of connective tissue that stores fat and provides insulation and cushioning for the body. It also serves as a source of energy and helps regulate body temperature. Therefore, it is expected to find an abundance of adipose tissue in the hypodermis.

The given statement implies that the tissue has multiple layers of cells, but all the cells reach the basement membrane. This indicates that the tissue appears stratified but is actually pseudostratified. Additionally, the statement mentions that only cells reaching the free surface have cilia, which is a characteristic feature of pseudostratified columnar epithelium. Therefore, the correct answer is pseudostratified columnar.

Simple squamous epithelium is associated with rapid transport of substances through a membrane because it consists of a single layer of flat cells that allow for efficient diffusion and filtration. On the other hand, stratified squamous epithelium is associated with resistance to abrasion because it is composed of multiple layers of cells that provide protection against mechanical stress and friction.

Hyaline cartilage is not considered a type of fibrous connective tissue. Fibrous connective tissues are characterized by having a dense arrangement of collagen fibers. Reticular tissue is a type of fibrous connective tissue that forms a network of reticular fibers. Dense regular connective tissue consists of collagen fibers arranged in parallel, providing strength and flexibility to tendons and ligaments. Dense irregular connective tissue has collagen fibers arranged in a random pattern, providing strength and support to organs and joints. Areolar tissue is a loose connective tissue that contains a variety of cells and fibers, providing support and elasticity.

The correct answer is mesoderm; mesenchyme. The mesoderm is the middle germ layer in embryonic development, and it gives rise to a gelatinous material called mesenchyme. This mesenchyme then differentiates into various types of connective tissue, including bone, muscle, and blood.

The stratum lucidum is absent from most epidermis. The stratum lucidum is a thin, translucent layer of the epidermis found only in thick skin, such as the palms of the hands and soles of the feet. It is composed of dead keratinocytes and provides additional protection to these areas. In contrast, the other layers mentioned (stratum basale, stratum spinosum, stratum granulosum, and stratum corneum) are present in most areas of the epidermis.

The reddish color of the skin of the lips is primarily due to hemoglobin. Hemoglobin is a protein found in red blood cells that carries oxygen throughout the body. When blood vessels near the surface of the lips dilate or become engorged with blood, it gives the lips a reddish hue. Hemoglobin has a red pigment, which is why it contributes to the color of the lips.

The correct answer is eponychium (cuticle). The eponychium, also known as the cuticle, refers to the narrow zone of dead skin that overhangs the proximal end of a nail. It acts as a protective barrier, sealing the area between the nail plate and the skin, preventing infection and debris from entering the nail bed.

The nail matrix is responsible for the growth of the nail. It is located at the base of the nail, just below the cuticle. The cells in the nail matrix divide and multiply through the process of mitosis, which leads to the production of new cells. These new cells then push the existing nail plate forward, resulting in nail growth. Therefore, the correct answer is nail matrix.

The oil of your scalp is secreted by sebaceous glands associated with the hair follicles. Sebaceous glands are responsible for producing sebum, an oily substance that helps to moisturize and protect the hair and scalp. These glands are found throughout the skin, including the scalp, and are most abundant on the face and scalp. The sebum produced by the sebaceous glands helps to keep the hair and scalp healthy and lubricated.

Third-degree burns involve the epidermis, all of the dermis, and often some deeper tissue. This means that all layers of the skin are affected, including the outermost layer (epidermis) and the layer beneath it (dermis). These burns are the most severe and can cause significant damage to the skin and underlying tissues. They often result in the loss of sensation and can require extensive medical treatment, including skin grafts.

The basement membrane is a thin, fibrous layer that separates the epithelium, which is a type of tissue that covers the body's surfaces and lines its cavities, from the underlying connective tissue. It provides support and anchors the epithelium to the connective tissue, helping to maintain the structural integrity of organs and tissues. The basement membrane also acts as a barrier, regulating the movement of substances between the epithelium and connective tissue.

The correct answer is Transitional; stratified squamous. Transitional epithelium is found in the bladder and it is characterized by the ability to stretch and accommodate changes in volume. It is made up of multiple layers of cells that can change shape from squamous when the bladder is empty to cuboidal or columnar when the bladder is full. Stratified squamous epithelium, on the other hand, is a type of epithelium found in areas subject to wear and tear, such as the skin. In this type of epithelium, the apical cells are flattened, not rounded. Therefore, the correct answer is Transitional; stratified squamous.

Nonkeratinized epithelium provides a moist and slippery surface and is well suited to resist stress, as in the vagina. This type of epithelium does not contain keratin, a tough protein that provides protection and prevents water loss. The vagina is a moist environment that requires protection against friction and stress, and nonkeratinized epithelium is better able to fulfill this function compared to keratinized epithelium, which is found in the skin and provides a tougher, more protective barrier.

Triglycerides are constantly synthesized and stored in adipose tissue, which is the primary site of triglyceride storage in the body. Adipose tissue consists of adipocytes, specialized cells that store fat in the form of triglycerides. When the body needs energy, triglycerides are hydrolyzed and released into circulation from adipose tissue. Therefore, adipose tissue is responsible for the synthesis, storage, and release of triglycerides into the bloodstream.

Macrophages play a crucial role in the healing of a skin wound by phagocytizing and digesting tissue debris. When a wound occurs, macrophages are attracted to the site and engulf any dead cells, bacteria, or foreign particles present. By removing this debris, macrophages help to clean and prepare the wound for the next stages of healing. This process promotes tissue regeneration and reduces the risk of infection, ultimately aiding in the overall healing process.

Fibrosis is the correct answer because it refers to the replacement of damaged tissue with scar tissue. Necrosis refers to the death of cells or tissues, apoptosis is programmed cell death, gangrene is the death of body tissue due to lack of blood supply, and regeneration is the process of renewal and regrowth of tissues.

Tactile (Merkel) cells are associated with the sense of touch. These specialized cells are found in the skin's epidermis and are responsible for detecting tactile sensations such as pressure and texture. They form connections with nerve fibers, allowing them to transmit signals to the brain, which then interprets the sensation. The other options listed, fibroblasts, melanocytes, keratinocytes, and dendritic (Langerhans) cells, are not directly involved in the sense of touch.

Dendritic (Langerhans) cells are specialized immune cells found in the skin and mucous membranes. They play a crucial role in the body's immune response by recognizing and capturing pathogens, toxins, and microbes that may enter the body through the skin. They then present these captured antigens to other immune cells, such as T cells, to initiate an immune response. Therefore, dendritic cells act as a first line of defense against potential threats to the body, making them the correct answer in this case.

The variations in hair color arise from the relative amounts of eumelanin and pheomelanin. Eumelanin is responsible for dark brown to black hair colors, while pheomelanin is responsible for red and blonde hair colors. The different ratios of these two pigments determine the different shades and colors of hair.

Merocrine glands are the cutaneous glands that are responsible for cooling the body. These glands secrete sweat onto the surface of the skin, which then evaporates and helps to lower the body temperature. Sebaceous glands produce oil to lubricate the skin and hair, ceruminous glands produce earwax, and apocrine glands are responsible for producing sweat with a strong odor. Exothermic glands are not a type of cutaneous gland and do not play a role in cooling the body.

Fingerprints left on things we touch are associated with dermal papillae. Dermal papillae are small, raised structures found in the dermis layer of the skin. They play a role in the formation of fingerprints by projecting into the epidermis and creating ridges on the surface of the skin. These ridges, along with sweat glands and oil glands, contribute to the unique pattern of fingerprints that can be used for identification purposes. Epidermal ridges, stratum basale, subcutaneous tissue, and subcutaneous fat are not directly involved in the formation of fingerprints.

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Collagenous fibers are a major component of tendons, ligaments, and the deeper portion of the skin. Tendons connect muscles to bones, providing strength and stability for movement. Ligaments connect bones to other bones, providing stability and support for joints. The deeper portion of the skin, known as the dermis, contains collagenous fibers that give the skin its strength and elasticity. Therefore, collagenous fibers are most abundant in tendons, ligaments, and the deeper portion of the skin.

The hypodermis is the correct answer because it is not a part of the skin. The skin is composed of three layers: the epidermis, the dermis, and the hypodermis. The epidermis is the outermost layer of the skin, the dermis is the middle layer, and the hypodermis is the innermost layer. Therefore, the hypodermis is not included in the skin.

The correct answer is "a hair." A pilus refers to a hair on the body. It is a small, slender filament-like structure that grows from the skin and is composed of keratin. It can be found on various parts of the body, including the scalp, face, arms, legs, and pubic area. The primary function of hair is to provide insulation, protection, and sensory perception.

The contraction of the piloerector muscles (pilomotor muscle or arrector pili) in humans causes hairs to stand on end with no apparent function. This physiological response, known as piloerection, is a vestigial reflex that humans have inherited from our evolutionary ancestors. In animals, piloerection can serve various purposes such as making the individual appear bigger to intimidate predators or to trap an insulating layer of warm air next to the skin. However, in humans, this response does not have a significant function and is considered to be a remnant of our evolutionary past.

An epithelium with all cells tall and narrow and with every cell touching the basement membrane is called simple columnar. This type of epithelium consists of a single layer of tall and narrow cells that are closely packed together, with each cell extending from the basement membrane to the apical surface. This arrangement allows for efficient absorption and secretion, making simple columnar epithelium commonly found in areas such as the lining of the digestive tract.

The stratum corneum is the outermost layer of the epidermis and is composed of up to 30 layers of dead cells. These cells are flat and filled with keratin, a protein that provides strength and protection to the skin. The stratum corneum acts as a barrier, preventing the entry of harmful substances and excessive water loss from the body. It also helps to maintain skin hydration and plays a role in the shedding of dead skin cells.

Fibroblasts are cells that produce and maintain the extracellular matrix in connective tissues. They are responsible for synthesizing and organizing the protein fibers, such as collagen and elastin, which provide structural support and flexibility to the tissues. Dense regular and dense irregular connective tissues both contain fibroblasts and protein fibers. Dense regular connective tissue is found in tendons and ligaments, where the collagen fibers are arranged in parallel bundles, providing strength and resistance to tension. Dense irregular connective tissue is found in the dermis of the skin and forms a meshwork of collagen fibers that provide strength and support in multiple directions.

The dermal papilla is a small, cone-shaped projection at the base of the hair follicle. It contains a network of blood vessels that supply nutrients and oxygen to the hair bulb, which is responsible for hair growth. Without this blood supply, the hair would not receive the necessary nutrition to grow and thrive. Therefore, the dermal papilla is the sole source of nutrition for the hair.

A connective tissue fiber refers to a complex of macromolecules, a nerve fiber refers to a part of a cell, and a muscle fiber refers to an entire cell.

Stratified squamous epithelium is the most widespread epithelium in the body because it is found in areas that experience a lot of wear and tear, such as the skin and the lining of the mouth and esophagus. On the other hand, stratified columnar epithelium is rare because it is only found in a few specific locations in the body, such as the male urethra and parts of the conjunctiva in the eye.

The question asks for the types of cells found in the epidermis, excluding one option. Melanocytes, stem cells, keratinocytes, and tactile (Merkel) cells are all types of cells found in the epidermis. However, fibroblasts are not typically found in the epidermis. They are a type of cell found in the dermis, which is the layer of skin beneath the epidermis.

The ectoderm is the outermost layer of cells in the early embryo. It gives rise to the nervous system, which includes the brain and spinal cord, as well as the epidermis, which is the outermost layer of the skin.