Exam 3 - Integumentary

Question 1

Integumentary System

Answer 1

The integumentary system includes the skin (the largest organ in the body), hair, nails, and glands. It serves as the body’s first line of defense against external damage, regulates temperature, prevents water loss, and assists in sensation and vitamin D production.

Question 2

Epidermis

Answer 2

The epidermis is the top layer of skin, composed of avascular keratinized stratified squamous epithelial cells. It consists of thin layers, including the stratum corneum, lucidum, granulosum, spinosum, and basale. Cells replicate in the stratum basale, moving upward as older cells are pushed to the surface and eventually die. The hair shaft extends through the epidermis.
1. Protection: Acts as a barrier against pathogens and physical damage.
2. Sensation: Contains nerve endings that respond to touch and pain.
3. Vitamin D Production: Synthesizes vitamin D when exposed to UV radiation.
4. Waterproofing: Prevents excessive water loss.
5. Absorption: Allows for the absorption of topical medications.

Question 3

Dermis

Answer 3

The dermis lies beneath the epidermis and is composed of dense irregular connective tissue. It contains fibroblast cells that produce collagen, elastin, and the extracellular matrix. The dermis consists of two layers: the papillary layer (loose connective tissue with dermal papillae) and the reticular layer (dense irregular connective tissue). It contains blood vessels, nerve endings, and hair follicles, providing strength, elasticity, and support to the skin, as well as housing sensory receptors and regulating temperature.

Question 4

Hypodermis (Subcutaneous layer) (not part of integumentary system)

Answer 4

The hypodermis, located beneath the dermis, is made of loose connective tissue, including adipose (tissue insulates the body, helps regulate temperature, and serves as an energy reserve by storing fat.) and areolar tissue. This layer, also known as superficial fascia, connects the skin to deeper fascia and contains numerous blood vessels and nerve endings. It varies in thickness across different body areas, provides insulation and cushioning for underlying structures, stores energy as fat, and does not contain glands.

Question 5

Dermis Structures

Answer 5

1. Papillary Layer: The top layer of the dermis, made of loose connective tissue. It contains dermal papillae, which form fingerprints and enhance grip and sensitivity.
2. Reticular Layer: Located below the papillary layer, this layer is composed of dense irregular connective tissue. It provides strength and elasticity and contains collagen, elastin, blood vessels, nerves, and glands.

Question 6

Hair

Answer 6

Hair covers most of the body and is made of keratin. It consists of a root (below the skin) and a shaft (above the skin). Hair grows from hair follicles, which anchor the hair and connect to sebaceous (oil) glands and arrector pili muscles. Hair follicles play a key role in hair growth and regeneration. Hair protects the body, conserves heat, and secretes sebum for lubrication.

Question 7

Nails

Answer 7

Nails cover the distal ends of fingers and toes and are composed of keratin. They grow from the proximal end and consist of a root and a nail plate. The visible half-moon shape at the base is called the lunula. Nails protect the digits and assist in grasping items, providing both structural integrity and functionality.

Question 8

Functions of Integumentary System

Answer 8

The skin serves multiple vital functions: it provides protection against pathogens and physical injuries, regulates body temperature through sweating and blood flow adjustments, and allows for sensation via various nerve endings. Additionally, the skin aids in excretion by eliminating waste through sweat, synthesizes vitamin D when exposed to UV radiation, and maintains water resistance to prevent excessive dehydration. It also plays a role in immune function through Langerhans cells, stores lipids and electrolytes, contributes to aesthetic appearance and communication, and can absorb certain substances, facilitating topical medication delivery.

Question 9

Stages of Healing

Answer 9

1. Hemostasis: Stops bleeding immediately after injury.
2. Inflammation: Brings healing cells to the site.
3. Angiogenesis: Forms new blood vessels to supply nutrients.
4. Epithelial Repair: New tissue grows to close the wound.

Question 10

Skin Cancer

Answer 10

1. Basal Cell Carcinoma (BCC): Arises from the epidermis; usually less dangerous and grows slowly.
2. Squamous Cell Carcinoma (SCC): Also originates in the epidermis; generally less aggressive but can be more serious than BCC if not treated.
3. Melanoma: Develops from melanocytes; this type is the most serious as it spreads quickly and can be life-threatening.

Question 10

Burns

Answer 10

1. Superficial Damage: Affects only the epidermis, usually resulting in minor injuries like abrasions or first-degree burns.
2. Partial Thickness Damage: Involves the epidermis and part of the dermis, seen in second-degree burns.
3. Full Thickness Damage: Extends through the epidermis and dermis into the hypodermis, potentially affecting underlying muscle or bone, often seen in third-degree burns.

Question 11

Skin Infections

Answer 11

1. Impetigo: A bacterial skin infection caused by staphylococcal or streptococcal bacteria, characterized by red sores that can rupture and ooze.
2. Herpes Simplex: Causes cold sores or genital herpes.
3. Herpes Zoster (Shingles): Reactivates the chickenpox virus, resulting in painful rashes and blisters.

Question 12

Skin disorders

Answer 12

Skin Disorders: A variety of conditions affecting the skin include bacterial infections (e.g., impetigo), viral infections (e.g., herpes simplex, shingles), autoimmune diseases (e.g., pemphigus, lupus erythematosus, systemic sclerosis), chronic conditions (e.g., psoriasis, eczema), and infections (e.g., acne, ringworm, contact dermatitis, warts). Each condition has distinct symptoms and requires specific treatments.

Question 13

Accessory Organ Disorders

Answer 13

These disorders, often linked to autoimmune diseases like scleroderma and lupus or drug reactions, affect skin-related glands, leading to symptoms such as skin lesions, dryness, and gland dysfunction.

Question 14

Rule of Nines

Answer 14

1. Purpose of the Rule of Nines - The Rule of Nines estimates the total body surface area (TBSA) affected by burns in adults, helping healthcare providers assess burn severity and treatment needs.
2. Body Area Percentages
   Head and neck: 9%
   Each arm: 9%
   Each leg: 18%
   Anterior trunk: 18%
   Posterior trunk: 18%
   Perineum: 1%

Question 15

Integumentary System Functions and Changes with Age

Answer 15

1. Loss of Elasticity - Decreased collagen and elastin lead to sagging and wrinkles; hearing loss can also occur.
   2: Thinning - The epidermis and dermis are thin, making skin more fragile and prone to injury.
   3: Dryness - Reduced oil and moisture retention cause dry, rough skin.
   4: Pigmentation Changes - Age spots and uneven skin tone result from sun exposure and decreased melanin production.
   5: Hair Changes - Graying occurs from reduced melanin; hair may thin or fall out, leading to alopecia.
   6: Nail Changes - Nails grow slower and can become thicker and more brittle.
   7: Sweat Gland Changes - Decreased sweat production leads to feeling cold, increases the risk of heatstroke, and makes infections more likely, with potential electrolyte imbalances.

Question 16

Types of Skin Lesions

Answer 16

1: Macule - Flat spot, less than 1 cm in diameter.
2: Papule - Firm raised bump, less than 1 cm in diameter.
3: Ulcer - Skin lesion that appears where the body rests on skin over bony projections.
4: Fissure - Cracks in the skin, such as those observed with athlete’s foot.
5: Vesicle - Blister or fluid-filled sac, less than 5 mm in diameter.
6: Pustule - A raised, solid bump on the skin filled with pus.

Question 17

Stratum layers

Answer 17

1. The Stratum Corneum, the outermost layer made of dead, flattened keratinized cells that provides a protective barrier
2. The Stratum Lucidum, found only in thick skin (like palms and soles) for added protection
3. The Stratum Granulosum, where keratinocytes begin to die and accumulate keratin and lipids, contributing to water resistance
4. The Stratum Spinosum, which provides strength and flexibility and contains immune-functioning Langerhans cells
5. The Stratum Basale is the deepest layer where new cells are generated. Exfoliation occurs in the Stratum Corneum, removing dead skin cells to promote renewal and improve skin texture.

Question 18

Glands

Answer 18

1. Sebaceous Glands: Secrete sebum, an oily substance that lubricates and protects the skin and hair, preventing dryness and forming a barrier against bacteria. Excess sebum can lead to oily skin and clogged pores. Vernix caseosa is a secretion from sebaceous glands that cover newborns.
2. Sudoriferous Glands:
   A. Eccrine Glands: Found throughout the body; they help regulate temperature by secreting sweat and are active throughout life.
   B. Apocrine Glands: Located in specific areas (armpits, groin); they secrete a thicker sweat in response to puberty and stress and are associated with body odor.
3. Ceruminous Glands: Produce earwax (cerumen) in the ear canal, helping to trap debris and prevent infections
4. The Meibomian glands are a type of gland associated with the eyes. They secrete an oily substance that helps prevent the evaporation of the eye’s tear film, keeping the eyes lubricated.

Question 19

Factors Affecting Skin Colors

Answer 19

1. Melanin: A pigment produced by melanocytes, which are specialized skin cells located in the basal layer of the epidermis. Melanin gives color to skin, hair, and eyes and plays a crucial role in protecting the skin from UV radiation.
2. Hemoglobin: An oxygen-carrying protein in red blood cells that imparts a pinkish hue to the skin, especially noticeable in fair-skinned individuals.
3. Bilirubin: A yellow pigment produced during the breakdown of red blood cells. Elevated levels can cause jaundice, resulting in a yellowish tint to the skin.
4. Carotene: A yellow-orange pigment found in certain foods, such as carrots. It can accumulate in the stratum corneum, giving the skin a slightly orange tint.
5. Erythema: Redness of the skin caused by increased blood flow to the superficial capillaries. It can result from inflammation, sunburn, infection, or allergic reactions, and typically fades when the underlying cause is resolved.
6. Jaundice: Characterized by yellowing of the skin, eyes, and mucous membranes due to elevated levels of bilirubin in the blood, often indicating liver dysfunction or other health issues.
7. Cyanosis: A bluish or purplish discoloration of the skin, lips, or nails caused by a lack of oxygen in the blood. It can result from respiratory or circulatory problems and often indicates underlying medical conditions requiring immediate attention.

Question 20

Wound Healing - Skin Changes

Answer 20

1. Scar: A mark left on the skin after a wound or injury has healed. It forms when the body produces collagen to repair damaged tissue, often resulting in a different texture or color compared to the surrounding skin. Scars can fade over time but may remain permanently.
2. Fibroblasts: Specialized cells that produce new connective tissue and secrete collagen to close wounds, playing a crucial role in the healing process.

Question 21

Proteins in Skin

Answer 21

1. Keratin: A fibrous protein that forms the primary structural component of hair, nails, and the outer layer of skin. It provides strength, durability, and protection against environmental damage and water loss, contributing to the skin’s barrier function.
2. Collagen: A protein found in the dermis that provides structure, thickness, and strength to the skin, helping to protect it from damage and maintain its elasticity.

Question 22

Blood Vessels

Answer 22

Blood vessels in the skin regulate temperature through vasodilation and vasoconstriction, supply essential nutrients and oxygen, and assist in removing metabolic waste from skin cells.

Question 23

Nerves

Answer 23

Nerves contain sensory endings that detect touch, pain, pressure, and temperature, with specialized receptors like Meissner corpuscles for light touch and Pacinian corpuscles for deep pressure.

Question 24

Elastic Fibers

Answer 24

Elastic fibers provide support and flexibility to the skin, enabling it to return to its original shape after stretching while maintaining structural integrity.

Question 25

Arrector Pili Muscle

Answer 25

Arrector pili are small muscles attached to hair follicles that cause goosebumps. When contracted, they make the hair stand upright, a response triggered by cold or emotional stimuli, helping to trap heat or signal a fight-or-flight response.

Question 26

Alopecia

Answer 26

Alopecia is the loss of hair on the scalp or body. Types include:
1. Alopecia Areata: Patchy hair loss (autoimmune).
2. Androgenetic Alopecia: Genetic baldness.
3. Traction Alopecia: Hair loss from pulling. Causes can include genetics, stress, and medical conditions.

Question 27

Factors Affecting healing

Answer 27

1. Proper nutrition is essential for repair.
2. A good blood supply is necessary for nutrient delivery.
3. Infection must be avoided for effective healing.
4. Younger individuals typically heal faster than older adults.

Question 28

Wound Care

Answer 28

1. Protect the area with a dressing.
2. Clean the wound with water or saline.
3. Use wet or dry dressings to maintain moisture.
4. Keep the dressing clean and monitor for infection; apply antibacterial ointments as needed.

Question 29

Skin Assessment Techniques

Answer 29

The assessment involves inspection to observe color, texture, and lesions; palpation to evaluate temperature, moisture, and turgor; and assessing hair and nails for abnormalities, including capillary refill to check circulation by observing the time for color to return after pressing the nail bed.

Question 30

Regenerative Processes

Answer 30

The body’s ability to repair and regenerate tissue involves hemostasis to stop bleeding, inflammation to remove debris and recruit healing cells, proliferation where new cells are generated, and remodeling to restore tissue structure and function, allowing for recovery from injuries or wounds.

Question 31

UV Exposure

Answer 31

UV exposure causes various skin-related changes, including DNA damage that increases the risk of skin cancer, premature aging through the breakdown of collagen and elastin, and hyperpigmentation resulting in dark spots. It can lead to sunburn, characterized by inflammation and redness, and suppress local immune responses, making the skin more susceptible to infections. Additionally, prolonged UV exposure results in rough, leathery skin texture, the formation of actinic keratosis (rough patches that can progress to cancer), and an increased likelihood of developing skin cancers such as basal cell carcinoma, squamous cell carcinoma, and melanoma.