functions of the skin/regulation of body temperature.

what are the functions of the skin?

• It maintains homeostasis by regulating body temperature

• protective covering

• retards water loss/prevents water loss

• houses sensory receptors (pacinian & meissner’s corpuscles.)

• contains immune system cells (epidernmal or langerhans cells)

• excretes small amounts of waste 

  • Sweat

• help produce vitamin D needed for normal bone and tooth development

how does skin maintain homeostasis?

By regulating body temperature

what kind of covering does the skin provide?

a protective covering

how does the skin prevent dehydration?

By retarding (slowing) water loss

what sensory receptors does the skin house?

Pain and touch/press receptors (meissner’s corpuscles). 

what immune function does the skin provide?

Contains immune system cells (like epidermal or langerhans cells).

what does the skin excrete?

small amounts of wastes.

what vitamin does the skin help produce?

Vitamin D for normal bone and tooth development.

why is the skin important for homeostasis?

It helps maintain stable internal conditions through protection, temperature regulation, and waste removal. 

what monitors the body’s temperature set point?

The Hypothalamus

what is the normal deep body temperature?

Around 37 degree celsius or 98.6 degree fahrenheit. 

what happens when body temperature becomes extremely high?

Enzymes and proteins can be destroyed, which disrupts metabolic functions and can lead to cell damage or death. 

what role does the skin play in temperature regulation?

The skin plays a key role in homeostatic mechanisms by helping regulate heat loss and retention through blood vessel activity and sweat glands.

Where does most of our body heat come from?

It comes from cellular metabolism, especially in active body cells like skeletal muscle, cardiac muscle, and liver cells. 

how is heat connected to metabolism and CO2 production.?

During cellular metabolism, cells produce Co2 and release heat as a byproduct. (about 60% of the energy from metabolism is converted into heat.

How does the body respond when it becomes too warm?

• Vasodilation of dermal blood vessels. 

  • blood vessels widen → more blood flow → releases heat → helps cool the body down

• Vasoconstriction of deeper blood vessels. 

  • blood vessels narrow → less blood flow → conserves heat → helps keep the body warm.

• Heat escapes through the skin. 

What are the four methods of heat loss?

1. Radiation: Primary method: infrared heat rays escape from the body to cooler surroundings.

2. Conduction: Heat moves from skin to cooler objects by direct contact.

3. Convection: Heat loss into circulating air currents.

4. Evaporation: Sweat changes into gas, carrying heat away from the body. 

What happens to sweat during evaporation?

Sweat changes from a liquid into a gas, this phase change carries heat away, cooling the body. 

What happens when our body temperature rises above normal? (hot)

• Thermoreceptors detect the change and signal the hypothalamus. 

• The hypothalamus triggers vasodilation of dermal blood vessels, increasing blood flow to the skin. 

• Sweat glands are activated to increase evaporative cooling. 

• These actions lower the body temperature back to the set point. 

What happens when body temperature falls below normal? (cold)

• Thermoreceptors signal the hypothalamus of the drop.

• The hypothalamus triggers vasoconstriction of dermal blood vessels, reducing heat loss. 

• Sweat glands become inactive 

• Muscles contract involuntarily (shivering) to generate more heat through muscle activity. 

• These actions raise body temp back to normal 

what is the feedback type involved in body temperature regulation?

• Negative feedback: when temperature deviates from the set point, corrective responses are activated to bring it back to normal. 

How do thermoreceptors and the hypothalamus work together in temperature regulation?

Thermoreceptors detect changes in body temperature and send signals to the hypothalamus, which acts as the control center to trigger heat loss or heat conservation mechanisms. 

What is hyperthermia?

Its abnormally high body temperature that occurs when the body produces or absorbs more heat than it can release. 

What can cause hyperthermia?

• Hot, humid air where sweat cannot evaporate. 

  • sweat cannot evaporate cuz there’s 2 much water in the air.

• High air temperature makes heat radiation less effective. 

• Prolonged exposure to heat or heavy exercise in hot conditions. 

What are symptoms of hyperthermia?

• Skin becomes dry. 

• Person feels weak, dizzy, and nauseated. 

• May experience headache and a rapid pulse. 

• Body may gain heat from hotter air instead of losing it. 

• Can lead to heat stroke if untreated. 

What is hypothermia?

Abnormally low body temperature that occurs when heat loss exceeds heat production. 

What can cause hypothermia?

• Prolonged exposure to cold or illness that interferes with heat production. 

• Older adults and thin people are at greater risk because they have less fat in the hypodermis, which means less insulation. 

What happens to the body during hypothermia?

• Shivering occurs — involuntary skeletal muscle contraction triggered by the hypothalamus. 

• Progresses to confusion, lethargy, loss of reflexes and consciousness. 

• Without treatment, organs begin to shut down and death may occur. 

What happens when homeostatic temperature control mechanisms fail in an extremely hot environment?

The body can no longer effectively regulate temperature, leading to hyperthermia — a dangerous overheating of the body. 

How does hyperthermia occur?

• Exposure to high heat overwhelms body’s control mechanisms. 

• Heat builds up faster than it can be lost. 

• Even when the hypothalamic set point is normal, body temperature continues to rise. 

• Extreme vasodilation can collapse the cardiovascular system and it can be fatal. 

what is a fever, and how is it different from hyperthermia?

• Fever: is a controlled rise in body temperature 

• The hypothalamus raises the set point in response to infection. 

• helps fight infection by slowing pathogen growth and enhancing immune response. 

What causes the hypothalamus to raise the body’s temperature during a fever?

• Phagocytes release pyrogens when they detect bacteria or viruses.

• These pyrogens signal the hypothalamus to increase the set point, elevating temperature to help destroy pathogens.