Integumentary System Flashcards
Do all organs have all 4 types of tissues?
YES
What is the structure of the skin?
- 21 sq ft of skin
- loosely attached
Epidermis
-Outermost layer
- made up of stratified, squamous epithelial cells
- lacks a direct blood supply
has layers within it
Stratum Basale
- Deepest layer of epithelial tissue
- composed of living cells
- cells are produced by mitosis
Langerhans Cells
Produced in bone marrow, and migrate to the stratum basale / attacking and destroying (white blood cells) / found in deepest level of epidermis
Melanocytes
Produces the protein melanin which is responsible for skin color / sunlight, and UV light stimulates production of melanin
Albinism
Genetic defect that causes the production of nonfunctional melanin and leads to a lack of pigmentation in the body
Freckles
Clusters of melanocytes, produces dark pigment in small areas and tends to fade with age
Stratum Corenum
- Uppermost layer of the epidermis (exposed)
- Dead cells are coated with a protein called keratin which makes them waterproof
- The last thing a living cell does it produce keratin
- Constantly losing dead cells from this layer
- They are replaced by living cells in the stratum basale
- Prevents mechanical damage and the invasion by bacteria
Dermis
- Middle layer
- Mainly connective tissue
- Contains the blood supply
Subcutaneous
- Made up of Adipose tissue (fatty layer)
- Provides insulation
- Gives cushioning (long term energy)
- Females typically have a thicker layer
- Older people have a thinner layer
Hair
- Produced by cells in the epidermis
- Located in the dermis
- Keratin cells produce the hair
- Hair follicle / root / shaft
- Eyelashes last 3-4 months
- Scalp hair lasts 3-4 years
- Hair has a blood supply
Nails
- Produced by cells of the epidermis
- Made of keratin
Sweat Glands
- 90-40 per cm
- Has the same chemical makeup as urine
Apocrine Glands
- Opens into the hair follicles
- May contain sexual attractants
- Discharge is due to stress
Endocrine Glands
- Opens into the skin surface
- Excrete water, salt, and urea
- Controls body temp through the release of sweat
- Ex. Earwax
Sebaceous Gland
- Found only in hair follicles
- Secrets sebum (keeps hair pliable, good food source for bacteria)
- Blocked glands (produces blackheads, infected glands = pimple)
- Becomes active at puberty
- Decreases as you age
- Every hair has glands attached to it
Mammary Glands
- Modified sweat glands
- Produces milk after childbirth
- Stops producing after nursing
Protection
- Physical trauma - elasticity
- Bacterial infection - compact cells
- Waterproof - keratin/sebum
Synthesis of Vitamin D
- Exposure to UV light
- Regulates calcium, phosphorus in the blood
- Muscle contrations
- Nerve impulses
- Lack of vitamin D may cause Rickets (Bone Deformation)
Sensory Reception
- Pain
- Pressure
- Temp
- Itching
Regulation of Body Temp
- Subcutaneous Layer
- Sweat Glands
- Blood Flow
- When body temp increases, blood versicles open up in the dermis allowing more blood to the surface, above the subcutaneous layer
Hyperthermia
Above normal body temp
Heat Exhaustion
100-105 temp
- Headache
- Tired
- Vomiting
- Low BP
- Sweating
Heat Stroke
100+
- Dizzy
- Confused
- Delusions
Fever
- Infection
- Pyrogens released in the body that goes to the brain
- Effects the hypothalamus
- White blood cells are more effective
Hypothermia
90-95
- Below normal body temp
- Shivering
- Lack of coordination
80-90
- Slow pulse
- Hallucinations
- Loss of consciousness
- 50% mortality
1st degree burn
Redness, pain (epidermis only)
2nd degree burn
Redness, pain, blisters (epidermis and dermis)
3rd degree burn
Full thickness burns, no pain (epidermis, dermis, and subcutaneous)
Rule of Nines
The front and back of the head and neck equal 9% of the body’s surface area. The front and back of each arm and hand equal 9% of the body’s surface area
Wound Healing
- Clotting
- New epidermis grows in the wound
- New dermis grows under epidermis
Skin Cancer
- UV exposure as a child
- Moles and sun exposure (shoulders and face)
- Fair skinned people should be more cautious
- Dark, irregular shaped
- Gray skin around the mole
- Itching
Effects of Aging
- Decrease in elastic tissue of the dermis
- Wrinkles
- Thinning of the subcutaneous layer
- Sagging skin
