Chapter 6 part 3-chat study guide

4 main functions of skin

protection, sensation, vitamin D production, temperature regulation

Protection and what it does

prevents injury, infection, water loss, and UV damage

Sensation and what it does

detects touch, pressure, pain, and temp

Vitamin D production and what it does

begins the process of making vitamin D

Temperature regulation and what it does

helps keep body temperature normal

Protection protects the body in four important ways

Keratin; melanin; sweat; sebum

Keratin

makes outer layer tough and helps prevent pathogens from entering and water from escaping

Melanin

Absorbs UV radiation and helps protect DNA from damage

Sweat

Is slightly acidic, which helps prevent microorganisms from growing

Sebum

produces an oily coating that reduces water loss and contains antibacterial substances

Different sensation receptors

Lamellated corpuscles, Tactile corpuscles, Tactile dice, Free nerve endings, Root hair plexus

Lamallated and what it detects

Deep/heavy pressure

Tactile corpuscles and what it detects

light touch and texture

Tactile discs and what it detects

Light touch and pressure

Free nerve endings and what it detects

Pain and temperature

Root hair plexus and what it detects

Hair movement

Vitamin D production 3 steps

Uv light converts a cholesterol-derived precursor into D3 (cholecalciferol); Cholecalciferol travels through the blood to liver and is converted to calcidiol; calcidiol is converted to calcitriol (active form of vitamin D)

Body temp regulation

the skin helps maintain normal body temperature through negative feedback

When you’re HOT

body temp increases; blood vessels in skin vasodilate; more blood flows near surface of skin; heat escapes from body; sweat glands release sweat; sweat evaporates and cools body

4 ways to lose body heat

radiation; conduction; convection; evaporation

Radiation meaning and example

heat transfers through electromagnetic waves; your body releases heat into cooler surroundings without touching them

Conduction meaning and examples

heat transfers through direct contact; a chair becomes warm after you sit on it

Convection meaning and example

moving air or fluid carriers heat away; a fan blows cooler air across skin

Evaporation meaning and example

sweat changes from liquid to gas, removing heat; sweating during exercise

When you’re COLD

body temp decreases; skin blood vessels vasoconstrict; less blood reaches skin surface; less heat is lost; body keeps more heat near core

The body can also produce heat through?

shivering which is caused by repeated skeletal muscle contractions

Hyperthermia

TOO HOT; causes hot or flushed skin; dizziness; weakness; nausea; headache; rapid pulse

Hypothermia

TOO COLD; causes confusion; lethargy; loss of reflexes; unconsciousness; heart rhythm problems; organ failure

Who is at more risk for hypothermia?

older adults, who have less muscle mass or insulation; very thin individuals with less insulating fat; very young children who have difficulty regulating body temp; people without adequate shelter or protection from cold weather

Inflammation

body’s normal response to injury, infection, or tissue damage

4 main signs of inflammation

redness (more blood flow to area); swelling (fluid leaks into tissues); warmth (increased blood flow); pain (swelling and inflammatory chemicals stimulate nerves)

How inflammation works

tissue becomes damaged; damaged cells/nearby cells release chemicals; blood vessels dilate and become more permeable; more blood and fluid enter damaged area; white blood cells help remove dead cells and pathogens; oxygen and nutrients support healing

Why is inflammation helpful?

Delivers oxygen and nutrients; brings white blood cells to area; helps remove dead cells and debris; supports tissue repair

Healing of wounds

break in skin that can damage the epidermis, dermis, or both

2 wound types

Epidermis only; epidermis and dermis

Epidermis only healing process

stratum basale cells divide and migrate to replace damaged cells

Epidermis & dermis healing process

blood clot forms, epithelial cells divide, fibroblasts repair connective tissue, blood vessels grow into area, and tissue heals

Key cells involved in wound healing

Platelets, keratinocytes, fibroblasts, white blood cells

Platelets

help form blood clots

Keratinocytes

replace damaged epidermal cells

fibroblasts

produce new connective tissue and collagen

white blood cells

remove pathogens, dead cells, and debris

what organ activates vitamin D in its final step?

kidneys produce calcitriol which is the active form of vitamin D

What temperature indicates hypothermia?

34 degrees C

What happens in wound healing

all stages overlap