[Anaphy Lec] LQ2

Skin

Largest organ by surface area and weight

Skin

Plays a crucial role in protection, sensation, and thermoregulation

Epidermis

The superficial layer of the skin

Dermis

The deeper layer of the skin

Subcutaneous layer

Otherwise known as the hypodermis that lies beneath the dermis that provides insulation and cushioning

Keratinocytes

Produces a particular protein that provides strength and waterproofing to the skin

Keratinocytes

Makes up 90% of the epidermis, and produces the lamellar granules

Lamellar granules

Releases lipid-rich secretion that acts as a water-repellent sealant, retarding loss of body fluids and entry of foreign materials

Melanocytes

Makes up 8% of the epidermis, produces a black pigment, and is particularly susceptible to damage by exposure to UV light

Langerhans cells

Also known as intraepidermal macrophages, they participate in immune responses mounted against microbes that invade the skin. They also assist other cells in identifying an antigen

Tactile epithelial cells

Detects touch sensations with the help of a tactile disc

Stratum basale

The deepest layer of the epidermis

Stratum spinosum

This layer of the skin provides strength and flexibility to the skin.

Stratum granulosum

Cells in this layer are flattened keratinocytes that are undergoing apoptosis; moreover, present in lamellar granules

Stratum corneum

These cells are continuously shed and replaced by cells from the deeper strata. Due to friction, this can stimulate the growth of callus

Thin skin

This skin generally has four layers: stratum basale, stratum spinosum, stratum granulosum, and stratum corneum. The skin in our entire body

Thick skin

This skin generally has five layers, similar to those of the four-layered ones but with stratum lucidum. This is normally the skin on our hands (palms) and feet (soles)

cubodial or columnar keratinocytes

The stratum basale is composed of ____

Stratum lucidum

This layer can only be found on the soles, fingers, and palms. It consists of three to five layers of flattened, clear, dead keratinocytes that contain large amounts of keratin

Callus

An abnormal thickening of the stratum corneum

Keratinization

The movement of cells from one epidermal layer to the next; hence, they accumulate more and more keratin

Dermis

Part of the skin that is composed mainly of connective tissue containing collagen and elastic fibers

dermal papillae

The surface area of the superficial layer of the dermis that consists of areolar connective tissue

Corpuscles of touch

Also known as Meissner corpuscles, are nerve endings that are sensitive to touch

Deeper reticular region

Region of the dermis that consists of dense irregular connective tissue

Extensibility

Ability to stretch

Elasticity

Its ability to return to the original shape after stretching

Striae

Commonly known as stretch marks, caused by extreme stretching that produces small tears in the dermis

Melanin

Primay determinant of skin color out of the three pigments

Melanin

The amount of this pigment causes the skin's color to vary from pale yellow to reddish-brown to black.

Freckles

An example of melanin accumulation around the face

Nevus

More commonly known as a mole, and is a benign localized overgrowth of melanocytes and usually develops in childhood or adolescence

Albinism

An inherited inability of an individual to produce melanin

Vitiligo

The partial or complete loss of melanocytes from patches of skin produces irregular white spots

Hemoglobin

Anya, who lives in Korea is considerably paler and yellow-ish and pinkish. She likely has a little amount of melanin because of where she lives. But what causes the pink-ish tone?

Carotene

The pigment of yellow-orange and is a vitamin A precursor

Pili

Commonly known as hair, and is an accessory structure of the skin present in most skin surfaces except the palms, soles, and plantar surfaces.

Hair shaft

The superficial portion that projects above the surface of the skin

Hair root

The portion below the surface that penetrates into the dermis and sometimes into the subcutaneous layer.

Hair follicle

Is composed of two layers of epidermal cells (external and internal root sheaths) and therefore surrounds the hair root

Arrector pili

Contracts under stress or cold temperatures (commonly known as goosebumps); hence, pulls the hair shafts perpendicular to the skin surface.

Hirutism

A condition of excessive body hair

Androgenic alopecia

Commonly known as male-pattern baldness and happens in genetically predisposed adults where androgens inhibit hair growth

Melanin

Is responsible for an individual's hair color

Yellow to red

Allison is blonde, and Abigail is a redhead. This means there is a presence of iron and more sulfur caused by what variants of melanin?

Decline

Gray hair occurs when there is a ____ in the synthesis of melanin.

White hair

This color of hair results from accumulation of air bubbles in the hair shaft.

Sebaceous glands

Commonly known as oil glands and their secreting portions lie in the dermis and open into the hair follicles or directly onto a skin surface.

Sebum

This oily substance keeps hair from drying out, prevents excessive evaporation of water from skin, keeps the skin soft, and inhibits the growth of certain bacteria.

Melanin

The color of blackheads is due to _, and oxidized oil, not dirt

Sudoriferous glands

Commonly known as sweat glands as they release perspiration into hair follicles or onto the skin surface through pores.

Eccrine sweat glands

Type of sweat glands that is more commonly distributed throughout the body especially in the forehead, palms, and soles.

Eccrine sweat glands

The main function of this sweat gland is to regulate the body's temperature through evaporation. They also function in emotional sweating (cold sweat) as response to fear or embarrassment

Apocrine sweat glands

Type of sweat glands found mainly in the skin of the axilla (armpit), groin, areolae (pigmented areas around the nipples) of the breasts, and beard

Subcutaneous layer

The secretory portion of the sweat glands is located mostly in the _

Apocrine sweat glands

Generally, sweat from this area is odorless however once it iinteracts with bacteria on the surface of the skin for example, the bacteria metabolizes its components causing this to create a musky odor (our body odor)

Eccrine sweat glands

These sweat glands function soon after birth

Apocrcine sweat glands

These sweat glands does not function until puberty

Ceruminous glands

Commonly known as earwax

Cerumen

A yellow-ish combined secretion of the ceruminous and sebaceous glands

Nails

Composed of hard, dead, keratinized cells that protect the tips of fingers and toes

Nail body

The visible part of the nail.

Free Edge

The part that extends beyond the fingertip

Nail root

The part that is embedded in the skin

Lunula

The visible part of the nail matrix, often seen as the white cresent

Cuticle

A tissue that overlaps the nail plate at the. base

Nail matrix

The area where cell division occurs; hence, leads to nail growth

UV exposure

Activates vitamin D synthesis that is essential for calcium and phosphorus absorption in the inestines

Epidermal Wound Healing

This skin healing only involves the epidermis (ex. paper cut) and basal cells migrate to cover the wound and proliferate to form new layers; hence, healing is done in about 2-3 days

Deep Wound Healing

This skim healing happens when injury extends into the dermis. This will cause fibroblasts to produce collagen that forms a scar tissue, while epithelial tissues replace the scab,

Basal Cell Carcinoma

A skin cancer that arises from the stratum basale; rarely metastasizes

Squamous Cell Carinoma

Originates from the stratum spinosum; has a variable tendency to metastasize.

Malignant Melanoma

Develops from melanocytes; accounts for about 2% of skin cancers but is more aggressive

UVB

These sun rays are responsible for sunburn and can contribute to skin aging and cancer risk.

First-Degree Burns

Affect only the epidermis; cause redness and mild pain without blisters

Second-Degree Burns

Involve the epidermis and part of the dermis; cause blisters and significant pain

Third-Degree Burns

Damage all skin layers and may destroy skin functions; often require medical intervention.

Pressure Ulcers

Results from prologed pressure on the skin; hence, leads to reduced blood flow.

Skeletal system

Consists of the entirety of bones and their cartilage

Calcium and phosphorus

The skeletal system functions in mineral homeostasis as bone tissue stores several minerals, especially ___ and ____

Long bones

Type of bone that has a greater length than width and consist of a shaft and a variable number of ends

Long bones

Femur is what type of bone?

Long bones

Tibia and fibula is what type of bone?

Long bones

Humerus is what type of bone?

Long bones

Ulna is what type of bone?

Long bones

Radius is what type of bone?

Long bones

Phalenges is what type of bone?

Short bones

Type of bone that are somewhat cube-shaped and nearly equal in length and width

Short bones

Wrist and ankle bones are under what type of bone?

Flat bones

Type of bones that are thin and afford considerable protection, and provide extensive surfaces for muscle attachment

Flat bones

Cranial bones is what type of bone?

Flat bones

Sternum is what type of bone?

Flat bones

Scapulae is what type of bone?

Irregular bones

These bones have complex shapes and cannot be grouped

Irregular bones

The vertebrae and some facial bones are classified as what kind of bones?

Diaphysis

The bone's shaft or body

Epiphyses

The distal and proximal ends of the bone

Metaphyses

Regions where the diaphysis joins the epiphyses

Articular cartilage

A thin layer of hyaline cartilage covering the regions of the epiphyses where the bone articulates with other bones

Periosteum

A sheath of dense irregular connective tissue and blood vessels that surround the parts of the bone outside of the articular cartilage