Anatomy & Physiology Unit 2

The first arrow is pointing at the thickest layer, which is the dermis. The dermis is the middle layer of the skin, located between the epidermis (outer layer) and the hypodermis (innermost layer). It is composed of connective tissue, blood vessels, nerves, and various structures such as hair follicles and sweat glands. The dermis provides strength, elasticity, and support to the skin, and plays a crucial role in regulating body temperature and protecting underlying tissues.

The deepest purple arrow is pointing to the hypodermis. The hypodermis is the deepest layer of the skin, located below the dermis. It is composed of fat cells and connective tissue, and its main function is to insulate and cushion the body.

The epidermis is the outermost layer of the skin. It acts as a protective barrier against environmental factors and helps regulate body temperature. It is composed of multiple layers of cells, including the outermost layer of dead skin cells called the stratum corneum. The epidermis also contains melanocytes, which produce the pigment melanin responsible for skin color. Overall, the epidermis plays a vital role in maintaining the integrity and function of the skin.

Langerhans cells are specialized macrophages that are found in the epidermis of the skin. They play a crucial role in the immune system by phagocytizing pathogens and presenting antigens to T cells. Therefore, Langerhans cells are the correct answer for this question.

The center "beige coloured" part is called the medulla. Its function is to provide structural support to the hair shaft. The medulla is composed of loosely arranged cells and can contain air or fluid. It is made up of soft keratin and is pigmented.

Laminitis, also known as founder, is a painful condition that affects the hooves of horses and other hoofed animals. It is characterized by inflammation and damage to the laminae, which are the sensitive tissues that connect the hoof wall to the underlying structures. The term "founder" is commonly used to describe this condition, as it refers to the sinking or rotation of the coffin bone within the hoof. This can lead to severe lameness and potentially life-threatening complications if not treated promptly.

The integument is the largest organ in the body and it covers external surfaces. It also has varying thickness depending on the location, meaning that it can be thicker in some areas and thinner in others. The integument is continuous with the mucous membranes of body cavities, allowing for the exchange of substances between the external environment and the internal body. Additionally, the integument has great regeneration abilities, meaning it can heal and repair itself when damaged.

Hair loss is commonly referred to as alopecia. Alopecia is a medical term used to describe the condition where a person experiences partial or complete hair loss. It can occur on the scalp or other parts of the body, and it can be temporary or permanent. Alopecia can be caused by various factors such as genetics, hormonal changes, autoimmune disorders, or certain medical treatments.

The dermis is the second layer of the skin and is composed of two main layers: the papillary layer and the reticular layer. The papillary layer is the upper layer of the dermis and is responsible for providing nutrients to the epidermis. The reticular layer is the lower layer of the dermis and is responsible for providing strength and elasticity to the skin. Therefore, the correct answer is reticular and papillary.

The statement is false because there is no distinct boundary between the papillary and reticular layers in the dermis. The papillary layer is the outermost layer of the dermis, composed of loose connective tissue, while the reticular layer is the deeper layer, consisting of dense irregular connective tissue. However, the transition between these two layers is not clearly demarcated, and they blend together rather than having a distinct boundary.

The skin is composed of three main layers: the dermis, hypodermis, and epidermis. The dermis is the middle layer of the skin, containing blood vessels, nerves, and connective tissues. The hypodermis, also known as the subcutaneous tissue, is the deepest layer of the skin, consisting of fat cells that provide insulation and cushioning. The epidermis is the outermost layer of the skin, serving as a protective barrier against external factors. The options "Hippopotamus" and "Epicdermis" are not valid layers of the skin.

Keratinization is a process in which cells lose their nucleus and organelles, and then flatten and die. This process occurs in the outermost layer of the skin, known as the epidermis. The cells in this layer, called keratinocytes, undergo keratinization to produce a tough, protective protein called keratin. As the keratinocytes move towards the surface of the skin, they lose their nucleus and organelles, becoming filled with keratin. Eventually, these flattened, keratin-filled cells slough off and are replaced by new cells from below. This process helps to strengthen and protect the skin.

Laminitis is the inflammation of the lamina, which are tissues that connect the hoof wall to the coffin bone. This inflammation prevents the tissues from expanding beyond the hoof wall, leading to compression of the lamina. This condition is often painful for the horse and can cause lameness.

When a horse has laminitis, the lamina, which is a sensitive structure that connects the hoof wall to the coffin bone (P3), deteriorates and dies. As a result, P3 starts to separate or pull away from the hoof wall. This separation causes extreme pain and discomfort for the horse and can lead to further complications and lameness.

The correct answer is Apocrine sweat gland. Apocrine sweat glands are a type of sweat gland found in the skin. They are located in specific areas such as the armpits and groin region. These glands produce a thicker, odorless secretion that is then broken down by bacteria on the skin, resulting in body odor. Apocrine sweat glands are different from eccrine sweat glands, which produce a watery sweat to regulate body temperature.

The given statement "Hair is a trait shared by all animals" is incorrect. Hair is not a trait shared by all animals. While hair is a mammalian trait, not all animals have hair. Other animals, such as reptiles, birds, and fish, have different types of coverings like scales, feathers, or fins. Therefore, the statement contradicts the fact that hair is not a trait shared by all animals.

The epidermis is the outermost layer of the skin, and it serves as a protective barrier for the underlying tissues. Stratified squamous epithelial tissue is the correct answer because it is the type of tissue that makes up the epidermis. This type of tissue consists of multiple layers of flattened cells, which provides strength and protection against mechanical stress and abrasion. The stratified nature of this tissue allows for the constant renewal of cells from the deeper layers to the surface, ensuring the maintenance of a healthy and functional epidermis.

The statement "The epidermis is avascular" is true. The epidermis is the outermost layer of the skin and it does not contain any blood vessels. It is primarily composed of layers of cells that provide protection to the underlying tissues. The lack of blood vessels in the epidermis means that it relies on diffusion of nutrients and oxygen from the underlying dermis for its metabolic needs. This avascular nature of the epidermis is important for maintaining its function as a barrier against external factors.

Pacinian Corpuscles are specialized sensory receptors that are responsible for detecting and responding to mechanical pressure and vibration stimuli. These receptors are found throughout the body, particularly in areas such as the skin, joints, and internal organs. When pressure is applied to the Pacinian Corpuscles, they generate electrical signals that are transmitted to the brain, allowing us to perceive and interpret the sensation of pressure.

Malignant melanoma, basal cell carcinoma, and squamous cell carcinoma are the three most common types of carcinoma. Malignant melanoma is a type of skin cancer that develops from melanocytes, the cells that produce pigment in the skin. Basal cell carcinoma is a type of skin cancer that starts in the basal cells of the skin's outermost layer. Squamous cell carcinoma is another type of skin cancer that arises from the squamous cells, which are flat cells in the outermost layer of the skin. These three types of carcinoma are frequently diagnosed and account for the majority of skin cancer cases.

Carcinoma is the correct answer because it is a type of cancer that originates from epithelial cells. Epithelial cells are the cells that line the surfaces and cavities of the body, and carcinoma specifically refers to cancer that develops in these cells. Carcinomas can occur in various organs such as the skin, lungs, breast, prostate, and colon. They are the most common type of cancer and can spread to nearby tissues if not detected and treated early.

Malignant melanoma is a type of skin cancer that arises from the pigment-producing cells called melanocytes. It typically presents with symptoms such as changes in the size, shape, or color of existing moles, the appearance of new moles, asymmetry of moles, irregular borders, and uneven coloration. It may also be accompanied by symptoms like itching, bleeding, or ulceration. Malignant melanoma is an aggressive form of skin cancer that can metastasize to other parts of the body if not detected and treated early.

Squamous carcinoma is the correct answer because it is listed as the first option and is the only type of carcinoma mentioned in the given options. The other two options, Basal Carcinoma and Malignant melanoma, are not relevant to the question and can be disregarded.

The image provided shows symptoms of basal carcinoma. Basal cell carcinoma is a type of skin cancer that usually appears as a small, shiny bump or a red, scaly patch on the skin. It is the most common type of skin cancer and is typically caused by long-term exposure to the sun's ultraviolet (UV) rays. The image shows characteristics such as a raised, pearly bump with visible blood vessels, which are typical signs of basal cell carcinoma.

Desmosomes are cell junctions that provide strong adhesion between cells, particularly in tissues that experience mechanical stress. In the stratum spinosum, desmosomes play a crucial role in giving the layer its spiny appearance and holding it together. These specialized structures consist of proteins that form strong connections between neighboring cells, allowing them to resist separation and maintain the integrity of the tissue. Therefore, desmosomes are responsible for the spiny appearance and cohesion of the stratum spinosum.

Conical Papillae in the stratum corneum of foot pads provide traction. These structures, found in the foot pads of animals like cats and dogs, help improve grip and prevent slipping. The conical shape of the papillae increases the surface area in contact with the ground, enhancing friction and allowing for better traction. This is particularly important for animals that need to navigate various terrains or engage in activities that require stability and grip, such as running, jumping, or climbing.

The correct answer is Distal Phalanx P3. The distal phalanx is the third and smallest bone in the horse's digit, commonly known as the hoof. It is located at the very bottom of the digit and is covered by the hoof capsule. The proximal phalanx (P1) is the bone located above the distal phalanx, the middle phalanx (P2) is the bone located between the proximal and distal phalanx, and the fetlock is the joint above the proximal phalanx.

The cutaneous pouches in sheep that secrete lanolin are located infraorbitally, interdigitally, and inguinally. This means that the pouches are found below the eye sockets, between the digits of the hooves, and in the groin area. These specific locations are where the sheep produce and store lanolin, a waxy substance that helps to protect their skin and wool.

The statement is incorrect because sheep do not have sebaceous glands in cutaneous pouches. Sebaceous glands are found in the skin of mammals, including humans, but sheep do not possess these glands in pouches on their skin. Therefore, the correct answer is False.

The correct answer is "Distal phalanx P3." Claws are keratinized coverings that protect the distal phalanx P3, which is the bone at the tip of the digit. The keratinized covering provides strength and durability to the distal phalanx P3, allowing it to effectively perform its functions such as gripping, scratching, and hunting. The other options listed, proximal phalanx P1, metacarpus, and dewclaw, are not directly related to the keratinized covering of claws.

The correct answer is sebaceous gland. Sebaceous glands are small oil-producing glands found in the skin. They secrete an oily substance called sebum, which helps to lubricate and waterproof the skin and hair. Sebaceous glands are most abundant on the face, scalp, and upper back. They can become overactive, leading to oily skin and acne, or they can become blocked, resulting in the formation of a sebaceous cyst.

The epidermis is separated from the dermis by the basement membrane. The basement membrane is a thin, specialized extracellular matrix that acts as a barrier between the two layers of the skin. It provides structural support and helps to anchor the epidermis to the dermis. The basement membrane also plays a crucial role in regulating the movement of cells and molecules between the epidermis and dermis, contributing to the overall function and integrity of the skin.

The dog is exhibiting the behavior of scooting, which involves dragging its rear end along the floor. This behavior is commonly seen in dogs with clogged anal glands, as they try to relieve the discomfort or itchiness caused by the blockage. The terms "scooting on floor" and "scoot" are alternative ways to describe this action.

Hooved mammals are commonly referred to as ungulates. This term encompasses a wide range of animals, including horses, cows, deer, and other related species. The name "ungulate" comes from the Latin word "ungula," meaning hoof. These animals have evolved to have specialized feet with hooves, which allow them to move efficiently and adapt to various habitats. The term "ungulates" is widely used in the field of zoology to categorize and study this diverse group of mammals.

The outermost white "scaley" part is called the cuticle. Its function is to provide a protective covering for the underlying layers of the structure. It consists of a single layer of keratinized squamous cells, which are hardened and flattened. This layer helps to prevent damage to the underlying cells and tissues, and also helps to reduce water loss and maintain hydration. The cuticle acts as a barrier against external factors such as UV radiation, chemicals, and physical abrasion.

Squamous cell carcinoma is a type of skin cancer that is characterized by its aggressive nature, forming ulcerated lesions. It also has the ability to spread rapidly to nearby lymph nodes. Furthermore, it is commonly found in areas of the skin that are most exposed to ultraviolet (UV) radiation, such as the face, neck, and hands.