NORMAL STRUCTURE AND FUNCTION OF THE INTEGUMENTARY SYSTEM

OVERVIEW (FUNCTION)

Major Structures

Primary Functions

Skin

Intact skin is the first line of defense for the immune system. Skin waterproofs the body and is the major receptor for the sense of touch.

Sebaceous Glands

Secrete sebum (oil) to lubricate the skin and discourage the growth of bacteria on the skin.

Sweat Glands

Secrete sweat to regulate body temperature and water content and excrete some metabolic waste.

Hair

Aids in controlling the loss of body heat.

Nails

Protect the dorsal surface of the last bone of each finger and toe.

EPIDERMIS

OUTERMOST LAYER OF THE SKIN


BASAL LAYER

  • LOWEST level of the Epidermis

  • NEW CELLS are produced and pushed upward; when they reach the top they DIE: These cells are called SQUAMOUS CELLS

  • Also Contains Melanocyte (Melanin Cells)—Produce the Pigment that determines skin color

KERATIN

  • Fibrous, Water-Repellent PROTEIN

  • Soft = Primary component of Epidermis

  • Hard = Found in the Nails and Hair

BASAL LAYER, KERATIN CELLS, MELANIN CELLSADDITIONAL IMAGE INCLUDING MACRO VIEW

DERMIS (AKA CORIUM)

CONTAINS CONNECTIVE TISSUE, BLOOD VESSEL, LYMPH VESSELS, NERVE, AND EXOCRINE GLANDS (Sweat, Sebaceous)

SENSORY NERVE ENDINGS

  • The receptors that allow for stimuli such as touch, temperature, pain, and pressure


TISSUES

  • COLLAGEN

    • Tough flexible protein material [THINK GLUE]

    • Also found in Bones, Cartilage, Tendons, and Ligaments

MAST CELLS

  • HEPARIN

    • Anticoagulant (Blood thinner) | Prevents blood clotting

  • HISTAMINE

    • Allergy Response | Causes symptoms like itching and increased mucus secretion

SWEAT GLANDS

  • APOCRINE (Found at the Hair follicles)

  • Eccrine (Found almost everywhere else)

    • Knees weak, Palms are sweaty

OTHER SWEAT GLAND TERMINOLOGY

  • Pores

  • Perspiration

    • Sweat (99% Water, 1% Salt and Metabolic waste)

    • Sweat + Bacteria = Body Odor (S T I N K Y)

  • Hidrosis

    • Production and excretion of Sweat

  • Fun Fact

    • Mammary glands (Milk-producing) are modified sweat glands (Therefore, these glands are apart of both the integumentary and reproductive systems.

SEBACEOUS GLANDS

  • Closely associated with Hair Follicles

  • Produces Sebum

    • Oily substance that lubricates the skin and prevents/discourages bacteria Growth on the skin

HAIR

  • Tightly fused, Dead Proteins Cells filled with HARD Keratin

  • Melanin at the base of the follicle determine color

SUB-DERMIS (Subcutaneous Layer)

CONNECTS SKIN TO MUSCLE SURFACES

ADIPOSE TISSUE

  • Fat

LIPOCYTES

  • Fat Cells

  • Manufacture and stores large quantities of fat