Lecture 8,9,10

What are the components of the integumentary system?

Skin, hair, nails, sweat, oil, and mammary glands.

Which of the following is a primary function of the integumentary system?

Protecting underlying tissues from injury and fluid loss.

The integumentary system is composed of two major divisions: the physical barrier and the accessory organs. The physical barrier is also known as the:

Cutaneous membrane.

What are the two major components of the cutaneous membrane?

Epidermis and dermis.

Which layer of the cutaneous membrane is described as hardened keratinized stratified squamous epithelium?

Epidermis.

Fingerprints are a result of the unique pattern of:

Epidermal ridges.

Which epidermal layer contains stem cells that divide to produce new skin cells, as well as Merkel cells that respond to touch, and melanocytes?

Stratum basale.

The "spiny layer" of the epidermis, composed of 8-10 layers of keratinocytes bound by desmosomes, and containing Langerhans cells for defense, is known as the:

Stratum spinosum.

Which epidermal layer is known as the "grainy layer" and is responsible for waterproofing the skin?

Stratum granulosum.

The stratum lucidum, a clear or glassy layer that makes the skin strong, is found only in which type of skin?

Thick skin.

What is the outermost protective region of the epidermis, consisting of 15-30 layers of keratinized cells that are shed?

Stratum corneum.

How do epidermal cells primarily receive oxygen and nutrients?

From the dermis.

How long does it typically take for cells to move from the deepest stratum to the most superficial layer of the epidermis?

About 7-10 days.

Which type of skin covers most of the body, is typically hairy, and lacks the stratum lucidum?

Thin skin.

Which cells are the most abundant in the epidermis and secrete a waterproofing protein to protect the body surface from dehydration?

Keratinocytes.

What is the primary function of melanocytes?

Making brown pigment around the nucleus to protect DNA from UV damage.

Which cells in the epidermis are sensory cells that detect small changes in pressure on the surface of the skin?

Merkel cells.

What type of cells are fixed macrophages that fight infectious problems in the skin?

Langerhans cells.

Which of the following factors influences skin color?

Epidermal pigmentation.

Skin color depends on the amount and type of melanin in the skin. What type of melanin is responsible for brown color?

Eumelanin.

The dermis is located between which two layers?

Epidermis and hypodermis.

The dermis contains two layers: the papillary layer and the:

Reticular layer.

The reticular layer of the dermis is primarily composed of:

Dense, irregular connective tissue with collagen and elastic fibers.

Which of the following sensory receptors found extensively in the dermis detect deep pressure and vibration?

Pacinian corpuscles.

What type of sensory receptors in the dermis are sensitive to pressure and stretching of the skin?

Ruffini corpuscles.

As a person ages, what change occurs regarding melanocytes in light-skinned individuals?

Fewer melanocytes, leading to very pale skin and increased sun sensitivity.

A common age-related change affecting the integumentary system is drier epidermis, caused by:

Decreased sebaceous gland activity.

What is a consequence of reduced Vitamin D3 production due to aging?

Muscle weakness and brittle bones.

Thinning of the dermis with age primarily results in:

Sagging and wrinkling.

Blister repair that takes 3–4 weeks in a young adult takes approximately how long in a 65- to 75-year-old?

6-8 weeks.

What is the primary cause of dandruff?

C. Fungal infection

Which of the following is a characteristic of albinism?

C. Genetic failure to produce melanin

Vitiligo is a condition where:

B. Melanocytes stop functioning in patches.

When there is more blood flow to the skin, its color tends to appear:

C. Redder

Cyanosis, which indicates poor tissue perfusion, is most obviously seen in which areas of the body?

C. Lips and fingernails

Which type of skin cancer is identified as the most common?

B. Basal Cell Carcinoma

The greatest risk factor for skin cancers like Basal Cell Carcinoma is:

C. Exposure to UV rays of the sun

Basal Cell Carcinoma originates in which layer of the skin?

B. Stratum basale

Why is Basal Cell Carcinoma generally considered less dangerous than Malignant Melanoma?

C. It virtually has no metastasis and rarely spreads.

Malignant Melanoma is particularly dangerous because cancerous melanocytes:

B. Grow rapidly and metastasize through the lymphatic system.

What is the 5-year survival rate for Malignant Melanoma if it is detected early and removed surgically?

D. 99 percent

The dermis is located between which two layers of the integument?

C. Epidermis and hypodermis

The two primary fiber types found within the dermis are:

C. Collagen and elastic fibers

Which of the following factors is listed as contributing to skin wrinkles?

C. Collagen losses in the dermal layer

Tension (cleavage) lines in the skin are formed by the arrangement of:

C. Collagen and elastic fibers in the skin.

From a clinical perspective, a cut made parallel to dermal cleavage lines will generally:

C. Heal better and with less scarring.

Keloids are described as:

C. Raised, thickened masses of scar tissue that grow into surrounding dermis.

The hypodermis, also known as the subcutaneous layer, is primarily dominated by what type of tissue?

C. Adipose tissue

Cellulite is caused by:

C. Uneven accumulation of adipose into the dermis.

Botox injections are typically given:

D. Into muscles to paralyze them.

Where are SQ (subcutaneous) injections administered?

B. Into the fatty layer under the skin

A TB test, which involves a dermal injection, is administered into the:

C. Thick connective tissue dermal layer

The first phase of integumentary system repair is:

D. Inflammation

During the inflammation phase of wound healing, what do mast cells stimulate?

D. Swelling, redness, heat, and pain

In which phase of wound repair does a blood clot (scab) form at the surface, and cells of the stratum basale divide and migrate along wound edges?

B. Migratory phase

A first-degree burn is characterized by:

D. Only the surface of the epidermis being affected, causing redness.

What is a defining characteristic of a second-degree burn?

B. Blistering, pain, and swelling occur, affecting the entire epidermis and possibly some dermis.

Third-degree burns are also known as:

B. Full-thickness burns

A burn that destroys the epidermis and dermis and extends into the subcutaneous layer is classified as a:

C. Third-degree burn

Which type of burn usually requires skin grafting because it cannot repair itself extensively?

C. Third-degree burns

From which layer of the skin do hair, glands, and nails all arise?

C) Epidermis

Hair is primarily composed of what type of nonliving material?

C) Keratin

What describes terminal hairs?

C) Large, coarse, darkly pigmented

Where are vellus hairs typically found?

C) On the general body surface

The cells that make up hair are described as being:

B) Dead and keratinized

What structure is responsible for producing a single hair?

C) Hair follicle

The portion of the hair that anchors it into the skin is known as the:

B) Hair root

What is the function of the root hair plexus?

C) To provide sensory nerves surrounding the follicle

Contraction of the arrector pili muscle causes what action?

C) Pulling hair erect

Actively dividing basal cells that form hair are found in which structure?

C) Hair matrix

The medulla of the hair contains what type of keratin?

C) Flexible, soft keratin

What characteristic is attributed to the cortex of the hair?

C) It gives hair stiffness

Describe the cuticle of the hair.

C) It is thin but very tough

Pattern hair loss (balding) is influenced by what two main factors?

B) Genetics and hormones

What is a characteristic of eumelanin?

C) It produces deeper brown to black hair

What contributes to the appearance of grey hair?

C) Loss of melanin producing cells in the medulla

What is the shape of a straight hair shaft?

C) Completely round

What characteristic of the cuticle leads to more frizz resistance?

B) Flatter cuticle

How is the shape of curly hair described?

D) Alternating between round and flat

Chemical treatments like permanents and relaxers primarily impact what aspect of hair?

B) The hair follicle protein structure

Sebaceous glands discharge their oily lipid secretion using what method?

C) Holocrine

Sebum is a mixture that includes which of the following?

B) Proteins and electrolytes (also triglycerides, cholesterol)

What primarily stimulates sebaceous (oil) glands?

B) Hormones

When sebaceous glands get clogged, they can form what?

A) Comedomes (blackheads)

Sweat glands produce watery secretion primarily by what method?

C) Merocrine

The sweat glands found in the armpits and groin that produce odorous secretions after puberty are what type?

D) Apocrine

A primary function of eccrine (merocrine) sweat glands is:

C) Thermoregulation

The nail body is composed of dead cells packed with what?

C) Keratin

Where does nail production occur?

C) Nail root

The eponychium is also known as what common term?

B) Cuticle