Ch. 6 Integumentary System Flashcards
The skin and its accessory structures.
Integumentary System
The outer epithelial layer of the skin.
Epidermis
The thick layer of the skin beneath the epidermis.
Dermis
The layer beneath the skin.
Subcutaneous Layer
The protein in epidermis, hair, and nails.
Keratin
The process by which cells form fibrils of keratin and harden
Keratinization
the older cells that harden during keratinization
Keratinocytes
Dark pigment normally found in skin and hair
Melanin
melanin-producing cell.
Melanocytes
Protective coverings on the ends of fingers and toes.
Nails
Overlies the nail bed.
Nail Plate
This is the surface of the skin that the nail plate overlies.
Nail Bed
whitish, thickened, half-shaped region at the base of a nail plate
Lunula
a group of epidermal cells at the base of a tubelike depression
Hair Follicle
the part of the hair extending from the surface of the dermis
Hair Root
The remains constitute the structure that extends away from the skin surface.
Hairshaft
An inherited condition in which a person has no melanin and has white hair.
Albinism
smooth muscle in the skin associated with a hair follicle
Arrector Pili Muscle
skin glands that secrete sebum
Sebaceous Glands
oily secretion of sebaceous glands
Sebum
sweat glands that maintain body temperature
Eccrine Glands
type of gland whose secretions contain parts of secretory cells
Apocrine Glands
Functions of Skin
Provides a protective covering, helps regulate body temperature, retards water loss from deeper tissues, houses sensory receptors, synthesizes various biochemicals, and excretes small quantities of wastes. Skin cells also help produce vitamin D which is necessary for normal bone and tooth development. Certain skin cells (keratinocytes) assist the immune system by producing hormonelike substances that stimulate the development of certain white blood cells (T lymphocytes).
The structure of the skin. (Be able to label)
The skin has two distinct layers: the epidermis and the dermis. The epidermis, outer layer, is composed of stratified squamous epithelium. The dermis, inner layer, is thicker than the epidermis and includes connective tissue consisting of collagenous and elastic fibers, epithelial tissue, smooth muscle tissue, nervous tissue, and blood. The basement membrane connects the two layers together.
How does your body regulate temperature/why is it important?
The skin plays a key role in the homeostatic mechanism that regulates body temperature.Maintenance of a stable temperature requires that the amount of heat the body loses be balanced by the amount it produced. As body temperature rises, nerve impulses stimulate structures in the skin and other organs to release heat. For example, during physical exercise, active muscles release heat, which the blood carries away. The warmed blood reaches the part of the brain (the hypothalamus) that controls the body’s temperature set point, which signals muscles in the walls of dermal blood vessels to relax. As these vessels dilate (vasodilation), more blood enters them, and some of the heat and the blood carries escapes to the outside. At the same time that the skin loses heat, the nervous system stimulates the eccrine sweat glands to become active and to release sweat onto the skin surface. As this fluid evaporates, it carries heat away from the surface, cooling the body. It is important because even the slight shifts can disrupt the rates of metabolic reactions.
How does the integumentary system heal a wound?
Blood vessels in affected tissues dilate and become more permeable, allowing fluids to leak into the damaged tissues. This provides the tissues with more nutrients and oxygen, which aids healing. If the injury extends into the dermis or subcutaneous layer, blood vessels break, and the escaping blood forms a clot in the wound. The blood clot and dried tissue fluids form a scab that covers and protects underlying tissues. Fibroblasts migrate into the injured region and begin forming new collagenous fibers that bind the edges of the wound together. Blood vessels extend into the area beneath the scab. Phagocytic cells remove dead cells and other debris. Eventually, the damaged tissues are replaced, and the scab sloughs off. In large, open wounds healing may be accompanied by formation of small, rounded masses called granulations that develop in the exposed tissues. The granulation consists of a new branch of a blood vessel and a cluster of collagen-secreting fibroblasts that the vessel nourishes. Some of the blood vessels are resorbed, and the fibroblasts move away, leaving a scar composed of collagenous fibers.
What is the difference between 1st, 2nd, and 3rd-degree burns?
A burn injuring the epidermis alone is 1st degree (superficial partial thickness.)
A burn that destroys the epidermis as well as some underlying dermis is 2nd degree (deep partial-thickness.)
A burn that destroys the epidermis, the dermis, and the accessory structures of the skin is 3rd degree
How is the epidermis formed?
The deepest layer of epidermal cells is called the stratum basale or stratum germinativum, it is close to the dermis and is nourished by dermal blood vessels. When the cells of this layer divide and grow, the older epidermal cells are pushed away from the dermis toward the skin surface. The further the cells move, the poorer their nutrient supply becomes and they die. Other older cells keratinize which means they become tough and tightly packed, forming the epidermis. When dead cells or keratinized cells are shed from the skin regulatory systems begin the process of forming new ones to take their place.
A
Nerve Cell
B
Sweat Gland Duct
C
pore
D
hair shaft
E
Sebaceous Gland
F
Arrector Pili Muscle
G
Stratum Corneum
H
Stratum Basale
I
Dermis
J
Subcutaneous Layer
K
Blood Vessels
L
Sweat Gland
M
Touch Receptor
N
hair follicle
