Chapter 6 : Integumentary System Flashcards
Functions of the Integumentary System
Protective Covering Control Body Temperature Manufactures Vitamin D Major Sense Organ Storage Filter Absorption/Excretion
Protective Covering
Skin provides a protective covering for the body’s underlying tissues from dehydration (retards water loss), injury, and germ invasion
Control Body Temperature
The skin controls body temperature to maintain homeostasis
How it controls body temperature
Acts as an insulator
Shivering
Sweating
Shivering
Contraction of muscles to create heat and pulls skin inward to conserve heat
Sweating
Water loss onto the skin/when evaporates - cools the body
Manufactures Vitamin D
Ultraviolet light from the sun strikes the skin and begins the first steps of vitamin D synthesis
Vitamin D is needed for
Calcium absorption in the small intestine
Calcium is needed for
Muscle contraction, nerve impulses, bone hardening, and proper tooth development
Major Sense Organ
Sense of touch through nerve endings win skin
Storage
The skin has the capability to temporarily store fat, glucose, salts, and water
Filter
The skin filters out harmful ultraviolet rays from the sun
Absorption/Excretion
The skin is very vascular with many capillary beds in the dermis just below the thin epidermis this allows it to absorb certain substances and excrete small amounts of waste through sweat
Epidermis composed of
Stratified squamous epithelial tissue
Stratum Corneum
Outer most layer of epidermis (part we can see)
Stratum Corneum function
Gives skin tough protective barrier and water resistance
Stratum Granulosum
Where Keratinization process begins
Keratinization
The cytoplasm of the outermost cells harden with the protein keratin causing the cells to die
Stratum Spinosum
Contains young cells awaiting keratinization and melanocytes
Melanoctyes
Branching cells within the stratum spinosum that produce melanin (a pigment that give the skin and hair its color)
Melanin
Functions to absorb UV rays to protect the replicating DNA of the cells below (interruption of DNA replication may cause the newly forming cells to become cancerous)
Stratum Basale aka
Germinativum
Stratum Basale
Layer where mitosis happens to replace dead cells lost from the stratum corneum
Basement Membrane
Innermost layer of epidermis that is composed of a series of interconnecting molecules that act as hooks to hold the skin together
Stratum lucidum
Is an additional layer located just below the stratum corneum making the skin thicker only on the palms and soles
Dermis
Inner layer of skin composed of dense connective tissue
Blood vessels of the dermal layer
Supply nourishment and oxygen to the skin cells as well as take away cellular wastes
- lead to capillary beds just below the epidermis
Nerve endings of the dermal layer
Send information to and from the brain to control the sensations of touch and release of secretions from glands
Arrector Pili Muscles of the dermal layer
Smooth muscle that is attached to hair follicles and allowing contraction of the skin and hair for temperature control
Hair Follicles of the dermal layer
Canal containing the growing “alive” area of the hair
Sabaceous Glands of the dermal layer
Produce sebum to moisturize the skin and trap microbes before the enter the skin
Sudoriferous Glands of the dermis
Secrete sweat, a mixture of water, water, salts, and some toxins, to control body temperature
Hair Shaft of the dermal layer
Portion of the hair that project out from hair follicle and the epidermis
Dermal Papillae of the dermal layer
Raised layers of the dermis push the epidermis into permanent ridges creating fingerprints
Fingerprints Function
Used for gripping objects
Creases
Formed from continual folding of skin
Hypodermis (Subcutaneous) Layer
Deepest layer of the integumentary system composed of tissue
Hypodermis contains
about 1/2 of the bodies fat content
Hypodermis provides
a cushion, insulation, and a connection to the muscles under the skin
