Test#2 Lesson Obejective

What are glands?

Cells or organs that produce and secrete substances such as sweat, oil, or hormones.

What is the difference between exocrine and endocrine glands?

• Exocrine: release secretions through ducts onto a surface or into a cavity.

• Endocrine: release hormones into the blood and have no ducts.

What are the 2 types of glandular ducts?

• Simple = one unbranched duct

• Compound = branched ducts

What are the 3 types of glandular secretions?

Serous, mucous, and mixed (seromucous).
Serous is the most common.

What type of gland is a sebaceous gland?

Holocrine gland.

What do sudoriferous glands do and what type are they?

They produce sweat to help regulate body temperature. They are exocrine glands.

What do sebaceous glands do?

Produce sebum (oil) that lubricates and protects the skin and hair. They are holocrine glands.

What are ceruminous glands and what do they produce?

Apocrine glands in the ear canal that produce cerumen (earwax).

What is the function of cerumen?

Protects and lubricates the ear canal and traps dust, debris, and microorganisms.

What are the main functions of the integumentary system?

Protection, temperature regulation, sensation, vitamin D production, and preventing water loss.

What are the 3 layers associated with the integumentary system?

Epidermis, dermis, and hypodermis.

What are the 2 main layers of the skin?

Epidermis and dermis.

What is found in the hypodermis?

Mainly areolar and adipose connective tissue. It helps insulate, cushion, and anchor the skin.

Which layer of skin is well vascularized?

Dermis

What are the 5 layers of the epidermis from deepest to most superficial?

Basale → Spinosum → Granulosum → Lucidum → Corneum

Does the epidermis have blood vessels?

No. It receives nutrients by diffusion from blood vessels in the dermis.

What makes thick skin different from thin skin?

Thick skin has a much thicker epidermis and contains a stratum lucidum.

Where is thick skin found?

Palms of the hands and soles of the feet.

Is the skin on your back thin or thick?

Thin skin.

What is a keratinocyte?

The main cell type of the epidermis that produces keratin.

What is keratin?

A tough protein that helps make skin strong and waterproof.

What do basal cells do?

hey divide to produce new keratinocytes and replace old epidermal cells.

What 2 important cells are found among basal cells?

Melanocytes and Merkel cells.

What do melanocytes do?

Produce melanin, the pigment that contributes to skin and hair color and helps protect against UV radiation.

What do Merkel cells do?

Help detect light touch.

Do keratinocytes make melanin?

No. Melanocytes make melanin and transfer it to keratinocytes.

What causes hair color?

Melanin produced by melanocytes in the hair follicle.

What layer of the epidermis is replaced about every 4 weeks?

The epidermis.

What are the 2 layers of the dermis?

Papillary layer and reticular layer.

What type of gland is a sebaceous gland?

Holocrine gland.

What type of gland is a sebaceous gland?

Sebum (oil) that lubricates and protects skin and hair.

What do sudoriferous glands do?

Produce sweat, mainly for temperature regulation. They are exocrine glands.

What are ceruminous glands?

Apocrine glands in the ear canal that produce cerumen (earwax).

What does cerumen do?

Protects and lubricates the ear canal and traps dust, debris, and microorganisms.

What is the overall function of the integumentary system?

Protection, immunity, wound healing, vitamin D synthesis, temperature regulation, and sensation.

What are the main components of the integumentary system?

Skin, hair, nails, sweat glands, and sebaceous glands.

What are the 3 layers associated with the integumentary system?

Epidermis, dermis, and hypodermis.

What are the 2 actual layers of the skin?

Epidermis and dermis. The hypodermis is not technically part of the skin.

What is found in the hypodermis?

Areolar and adipose connective tissue. It helps cushion, insulate, and anchor the skin.

Does the epidermis have blood vessels?

No. It gets nutrients by diffusion from blood vessels in the dermis.

What are the 5 epidermal layers from deepest to most superficial?

Basale → Spinosum → Granulosum → Lucidum → Corneum.

What is the stratum basale?

The deepest layer where new epidermal cells are produced.

What is the stratum spinosum?

Provides strength and contains many keratinocytes.

What is the stratum granulosum?

Cells begin to die and fill with keratin.

What is the stratum lucidum?

A clear layer found only in thick skin.

What is the stratum corneum?

The outermost layer, made mostly of dead, keratinized cells that protect the body.

What makes thick skin different from thin skin?

Thick skin has a thicker epidermis and stratum lucidum.

Where is thick skin found?

Palms of the hands and soles of the feet.

Is the skin on your back thin or thick?

Thin skin.

What is a keratinocyte?

The main cell of the epidermis that produces keratin.

What is keratin?

A tough protein that makes skin strong and water-resistant.

What 2 important cells are found among basal cells?

Melanocytes and Merkel cells.

What do melanocytes do?

Produce melanin, which contributes to skin and hair color and helps protect against UV radiation.

What do Merkel cells do?

Detect light touch.

Do keratinocytes make melanin?

No. Melanocytes make melanin and transfer it to keratinocytes.

Where do basal cell carcinomas come from?

Basal cells in the stratum basale.

Which layer of skin is well vascularized?

Dermis.

What are the 2 layers of the dermis?

Papillary and reticular layers.

What is the papillary layer?

The superficial dermis, made mostly of areolar connective tissue. It contains blood vessels and sensory receptors

What is a dermal papilla?

A projection of the dermis into the epidermis that helps anchor the two layers and contains blood vessels/sensory receptors.

What is the reticular layer?

The deeper, thicker dermal layer that provides strength and elasticity.

What do collagen and elastic fibers do?

Collagen = strength. Elastic fibers = stretch and recoil.

What is the hypodermis?

A layer under the skin, made mainly of areolar and adipose connective tissue.

What 3 pigments influence skin color?

Melanin, carotene, and hemoglobin.

Do darker-skinned people have more melanocytes?

No. The number of melanocytes is generally similar; differences mainly involve the amount, type, and distribution of melanin.

Why can lighter skin burn more easily?

It generally has less protective melanin, allowing more UV radiation to affect the skin.

How does skin provide physical protection?

Keratinized cells create a tough barrier that protects against injury, chemicals, and water loss.

How does skin provide immunity?

It acts as a physical and chemical barrier against pathogens.

How does skin help with wound healing?

Skin cells repair damaged tissue and replace lost cells.

How does skin make vitamin D?

UV light triggers vitamin D production in the skin.

ow does skin regulate body temperature?

Sweating cools the body, while blood vessels dilate or constrict to control heat loss.

How does skin provide sensation?

Nerve endings detect touch, pressure, temperature, and pain.

How does the integumentary system work with the nervous system?

Skin nerve endings send information about touch, pressure, temperature, and pain to the brain.

How does it work with the cardiovascular system?

Skin blood vessels dilate or constrict to help regulate body temperature.

How does it work with the lymphatic/immune system?

Skin acts as the body's first line of defense against pathogens.

How does it work with the urinary system?

Sweat can remove small amounts of waste, and the kidneys help activate vitamin D.

How does it work with the skeletal system?

Vitamin D helps the body absorb calcium and phosphorus, which are needed for healthy bones.

What is hair?

A keratinized structure that grows from a hair follicle.

Where does hair grow from?

The hair matrix inside the hair bulb.

Are the cells in the hair shaft living?

No. The hair shaft is made of dead, keratinized cells

What is a hair follicle?

A tube-like structure in the skin from which hair grows.

What is the hair shaft?

The portion of hair above the skin's surface.

What is the hair root?

The portion of hair below the skin.

What is the hair bulb?

The enlarged base of the follicle where hair growth begins.

What is the hair matrix?

Rapidly dividing cells that produce new hair

What are the 3 phases of hair growth?

Anagen = growth → Catagen = transition → Telogen = resting.

What causes goosebumps?

Arrector pili muscles contract, causing the hairs to stand up.

Where do nails grow from?

The nail matrix, which contains dividing cells.

What is the nail bed made of?

Epidermis lying over the dermis

How are nails, hair, and skin related?

They are all integumentary structures and contain keratin.

What is basal cell carcinoma?

A type of skin cancer arising from basal cells, usually growing slowly.

What is squamous cell carcinoma?

A skin cancer arising from squamous cells of the epidermis.

What is melanoma?

A serious skin cancer that develops from melanocytes.

What is eczema?

A condition causing inflamed, itchy, irritated skin.

What is acne?

A skin condition involving hair follicles and sebaceous glands, often causing pimples and inflammation.