Membranes and the Integumentary System

Membranes

Tissues that surround and protect body surfaces and line body cavities.

Epithelial Membranes

Membranes composed of epithelial tissue and underlying connective tissue; includes mucous

Connective Tissue Membranes

Membranes composed solely of connective tissue; includes synovial membranes.

Mucous Membranes

Epithelial membranes that line body cavities open to the outside (e.g.

Lamina Propria

The layer of loose connective tissue underneath the epithelium in mucous membranes.

Serous Membranes

Epithelial membranes that line body cavities closed to the outside; secrete serous fluid to reduce friction.

Parietal Layer

The outer layer of a serous membrane

Visceral Layer

The inner layer of a serous membrane

Pleura

Serous membrane surrounding the lungs.

Pericardium

Serous membrane surrounding the heart.

Peritoneum

Serous membrane lining the abdominal cavity and covering abdominal organs.

Cutaneous Membrane

The skin; a keratinizing stratified squamous epithelium over dense connective tissue.

Synovial Membranes

Connective tissue membranes that line joint cavities

Bursae

Small connective tissue sacs filled with synovial fluid that cushion tendons and ligaments around joints.

Integumentary System

Body system consisting of skin

Keratin

Tough

Melanocytes

Cells in the epidermis that produce melanin

Epidermis

The outermost layer of the skin; avascular (no blood supply).

Dermis

The deep layer of the skin; composed of dense connective tissue; "true skin".

Hypodermis

Subcutaneous layer of fat and connective tissue beneath the dermis; also called subcutaneous fascia.

Epidermal Dendritic Cells

Cells in the epidermis that initiate immune responses against bacteria and viruses.

Merkel Cells

Touch receptor cells located in the stratum basale of the epidermis; attached to nerve endings.

Stratum Corneum

Outermost layer of the epidermis; composed of dead

Stratum Lucidum

Clear layer of thick skin found in palms

Stratum Granulosum

Epidermal layer where cells become flat and fill with keratin; becomes tough and water-resistant.

Stratum Spinosum

Epidermal layer where keratin production increases; cells appear spiny under a microscope.

Stratum Basale

Deepest layer of the epidermis; contains melanocytes and continuously produces new cells.

Papillary Layer

The outer layer of the dermis; contains dermal papillae with capillaries and nerve endings.

Reticular Layer

The deep layer of the dermis; contains blood vessels

Dermal Papillae

Finger-like projections of the papillary dermis that extend into the epidermis; contain capillaries or nerve endings.

Sudoriferous Glands

Sweat glands found all over the body.

Eccrine Glands

Most common type of sweat gland; secrete watery sweat for thermoregulation.

Apocrine Glands

Sweat glands found in armpits and groin; secrete a thicker sweat associated with body odor.

Sebaceous Glands

Oil glands found all over except palms and soles; secrete sebum to moisturize skin and hair.

Sebum

Oily secretion from sebaceous glands that softens skin and hair and has antibacterial properties.

Hair Follicle

Structure in the dermis from which hair grows.

Hair Papilla

Structure at the base of the hair follicle containing capillaries that nourish the hair.

Matrix

The base of the hair follicle where new hair cells are produced.