Integumentary System Flashcards
Of what are the organs of the integumentary system made?
Cutaneous Membrane
Give the name and location of the four different kinds of membranes
- Serous membranes:line body cavities that don’t open to the outside; secrete serous fluid
- Mucous membranes: line cavities and tubes opening to the outside; secrete mucus (note: “mucous” is an adjective and “mucus” is a noun)
- Synovial membranes: line joint cavities; secrete synovial fluid
- Cutaneous membranes: cover the body as skin
What is the largest organ by weight?
The skin
Name the major functions of the integumentary system
- Protects the body from invading microorganism (unless the skin is broken)
- Prevents water loss from the body
- Helps to regulate body temperature
- Important in the synthesis of vitamin D
- Has sensory receptors for touch, pain, pressure, and temperature
- Excretes small quantities of wastes
The integumentary system is composed of two distinct tissue layers. Name and describe them
- Epidermis:The outermost layer of the skin; composed of stratified squamous epithelial tissue; avascular (has no blood vessels)
- Dermis: the innermost layer of the skin; composed of connective tissue (collagen, elastin, adipose, blood), smooth muscle tissue, and nervous tissue
How does the function of the epidermis differ from that of the dermis?
The epidermis protects the body, and the dermis nourishes the epidermis with its blood vessels
What are the accessory structures of the integumentary system or skin?
- Hair follicles
- Nails
- Sweat glands (eccrine and apocrine)
- Sebaceous gland
Where is the subcutaneous layer found? Is it a part of the skin?
- The subcutaneous layer is located below the dermis another name for it it’s hypodermis
- The subcutaneous layer is not considered to be a part of the sin
What is the function of the subcutaneous layer?
- Insulates the body since it is composed of adipose tissue (fat)
- Adheres the dermis to the muscular layer
What are characteristics of the epidermis
- Composed of stratified squamous epithelium
- Has no blood vessels (is avascular)
- Its outer layers become keratinized (hardened) and ‘’slough’’ or fall off
- Its innermost layer of cells rests on a basement membrane
- It is thickest on the palms of the hands and soles of the feet
What are the layers (strata) of the epidermis, from the outside to the inside?
- Stratum corneum-outermost, keratinized part of the epidermis
- Stratum lucidum-appears as a clear layer on the palms and the soles
- Stratum granulosum-cells underneath the stratum lucidum
- Stratum spinosum- cells located within dermal papillae
- Stratum basale-layer of cells attached to the basement membrane: contains melanin containing cells called melanocytes
Why is the boundary between the epidermis and dermis uneven?
The epidermis has ridges. The dermis has dermal papillae which extend up into the spaces between epidermal ridges, carrying blood vessels to nourish the epidermis. This unevenness leads to unique fingerprints for individuals
What are characteristics of the dermis?
- Contains the accessory structures of the skin: hair follicles, nails, sweat glands, and sebaceous glands
- Has blood vessels
- Binds the epidermis to underlying tissue( the subcutaneous layer)
- Has fibrous connective tissue (collagen and elastin) which provide resilience and elasticity
- Has smooth muscle fibers attached to hair follicles; when they contract they cause your hair to stand on end
- Has nerve fibers
- Has sensory receptors like Meissner’s corpuscles and pacinian corpuscles
Can severely burned or injured dermis tissue always regenerate?
No. If accessory structures(hair follicles, nails, sebaceous glands, sweat glands) do not survive, the dermis cannot regenerate. If accessory structures survive, the dermis can regenerate
What is the meaning of these terms associated with hair: hair follicle, hair root, hair shaft, hair papillae, and arrector pili muscle?
- Hair Root-portion of the hair from the scalp down
- Hair follicle-tube-like depression of epidermal cells extending down into the dermis; completely surrounds the root of the hair and hair papillae
- Hair Shaft-portion of the hair from the scalp
- Hair papillae-projection of connective tissue extending up into the hair follicle; enables blood vessels to get to rapidly growing cells in the hair root and nourish them
- Arrector pili muscle-smooth muscle associated with the hair follicle; when it contracts is causes “goose bumps” and hair to stand on end
What are nails?
Protective covering on the ends of fingers and toes
Differentiate among nail plate, nail bed, lunula
- Nail bed-produced from epidermal cells; is continuous with the skin
- Nail plate-portion lying over the nail bed
- Lunula-most actively growing potion of the nail; shaped like a half moon;located at the base of the nail plate; when it grows, it pushes the nail plate over the nail bed
What are some characteristics of sebaceous glands?
- Coiled glandular tissues made up of epidermal cells specialized to form secretions
- Sebum is the name for the secretions of sebaceous glands
- Sebum is composed of oily substance plus the cells that secrete them
- Sebum acts to keep hair and skin soft, pliable, and waterproof
- Sebaceous glands are always associated with hair follicles
- Sebaceous glands are absent on the palms and the soles
Sebaceous glands are holocrine glands. WHat does this mean?
They secrete both their secretions plus the cell that secreted them. This means that sebum contains both the cell secretions (oil) and the cells themselves
What are two types of sweat glands? How do they compare?
Eccrine sweat glands
- Consist of tiny tube originating as a ball-shaped coil lined with sweat secreting epithelial cells
- Are not associated with hair follicles
- Release sweat to the outside of the body through a pore
- When body temperature increases, eccrine sweat glands respond by secreting sweat
- Sweat functions to cool the body and to rid it of some wastes
What are two types of sweat glands? How do they compare?
Apocrine sweat glands
- Consist of tiny tribe originating as a ball-shaped coil lined with sweat-secreting epithelial cells
- Are associated with hair follicles
- Sweat is released to outside of body through the hair follicle
- When you are emotionally upset or sexually aroused, apocrine sweat glands respond by secreting sweat
- This sweat develops a scent as it is metabolized by bacteria on the skin
- Apocrine sweat glands become active at puberty and are most numerous in the inguinal (groin) area
Name and describe some common disorders of the integumentary
- Acute sunburn-occurs when too much ultraviolet (UV) radiation reaches the skin and causes an inflammation or reddening due to dilation of peripheral blood vessels
- Skin cancer-begins when ultraviolet radiation mutates the DNA of a skin cell
- Contact dermatitis-Superficial skin inflammation or irritation resulting from either an immune response or exposure to an irritant
- Acne-inflammation of sebaceous gland caused by hormones signaling an increased release of sebum
Why do some individuals have darker skin than others?
People with dark skin have 1. More melanin pigment and 2. Larger pigment granules
How does the body react to acute sunburn?
- Melanocytes in the stratum basale produce more melanin pigment
- The stratum corneum sheds cells which might be damaged by UV radiation
How does the body normally react to mutated skin cells?
-DNA repair enzymes repair the mutated DNA before cells divide
There are two types of skin cancers: cutaneous carcinomas and cutaneous melanomas. How do they differ? Carcinoma
- More common
- Develop from non pigmented epithelial cells
- Slow to spread
- Have a good cure rate
There are two types of skin cancers: cutaneous carcinomas and cutaneous melanomas. How do they differ? Melanoma
- Less common
- Develop from pigmented epithelial cells so appear dark
- Spread quickly
- Have a poor cure rate
Distinguish between the two types of contact dermatitis
Allergic contact dermatitis
- Caused by an immune system reaction to an allergen
- Examples include poison ivy, shrimp,and metal jewelry
Distinguish between the two types of contact dermatitis Irritant contact dermatitis
- Caused by irritating substance
- Examples include diaper rash, dishpan hands
What causes acne?
- Overactive sebaceous glands brought about by hormonal changes
- Sebum is trapped within the hair follicle before it can be released to the outside of the skin
- Bacteria live in and eat the blocked sebum
Why does a pimple appear inflamed?
Bacteria thrive in oil-clogged hair follicles and trigger an immune reaction
What is a whitehead?
Dead bacteria plus the neutrophils (white blood cells) which destroy them
How does the integumentary system regulate temperature? Why is the important?
- Eccrine sweat glands secrete sweat which covers the skin
- Sweat evaporates from the skin, carrying heat with it and thus cooling the body
- It is important for homeostasis, or a steady range of body temperature, to be maintained so that enzymes catalyzing chemical reactions are not denatured (broken down) by extreme heat
What are some things that cause body temperature to increase?
- Increases in air temperature
- Cellular metabolism is skeletal muscles
- Infections
How does the body lose heat?
- Through radiation
- Through conduction
- Through evaporation
How does hypothermia differ from hyperthermia?
- Hypothermia-decrease in body temperature brought about by exposure to the cold or too little subcutaneous fat
- Hyperthermia-increase in body temperature brought about by increased air temperature, decrease evaporative cooling of the skin due to the high humidity, increased exercise, infection
Genetic, environmental, and physiological factors influence skin color. Give an example of each
Genetic factors
- Lack of the pigment melanin which results in albinism
- Lots of pigment because of more melanin pigment and/or larger pigment granules
Genetic, environmental, and physiological factors influence skin color. Give an example of each
Environmental Factors
Sunlight darkens existing melanin and stimulates melanocytes to produce more pigment this darkening the skin
Genetic, environmental, and physiological factors influence skin color. Give an example of each
Physiological Factors
- Cyanosis (bluish coloration of skin caused by heart or respiratory problems)
- Jaundice (yellowish coloration of skin caused by liver problems)
How does a shallow cut heal?
Epithelial cells are stimulated to divide more rapidly and fill in the gap
What steps are involved in the healing of a deep cut?
- Escaping blood forms a clot
- Tissue fluid leaks into the clot
- A scab is formed as the tissue fluid and blood dries
- Fibroblasts from fibers which bind the wound edges together
- Connective tissue stimulates cell division which fill in the gap
What is the rule of nines? Why is it important?
- The way healthcare professionals determine the amount of skin surface area that is affected by a burn
- Need to know the amount of surface area damaged so will know (1) how much skin might be required for a graft and (2) how much fluid will be needed to replace lost fluids
What are some life span changes affecting the integumentary system?
Scaly skin Age spots Thinning epidermis Reduced dermis Fat loss Wrinkling skin Sagging skin Less oil secretion by sebaceous glands Decreased melanin production Thinning hair Decreased number of hair follicles Impaired nail growth Declining sensory receptors Hard to control body temperature Diminished ability to active vitamin D
