Effect of Air Temperature on Heat Conductance and Frostbite Risk

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What action can help increase body temperature according to the text?

Seeking a cooler environment

Drinking hot fluids (correct)

Wearing light-colored, loose clothing

Reducing physical activity

How do monocytes, macrophages, and Kupffer cells contribute to an increase in body temperature?

By reducing activity

By seeking a cooler environment

By resetting the hypothalamic thermostat

By producing cytokines like IL-1 and IL-6 (correct)

Which of the following is NOT mentioned as a way to decrease body temperature in the text?

Seeking a cooler environment

Increasing physical activity (correct)

Wearing light-colored, loose clothing

Reducing physical activity

What is the role of the hypothalamic 'thermostat' in body temperature regulation?

Resetting to a new set point above 37°C during fever Signup and view all the answers

Which cells produce cytokines that act as endogenous pyrogens in the body?

Monocytes, macrophages, and Kupffer cells Signup and view all the answers

What is the purpose of light-colored, loose clothing according to the text?

To restrict heat loss Signup and view all the answers

What is the major factor that determines how rapidly heat is conducted from the body core to the skin?

The speed at which heat can be conducted to the skin Signup and view all the answers

Which body system contributes to resting metabolism primarily through the thermogenic effect of food?

Digestive system Signup and view all the answers

Which method is responsible for around half of the body heat loss under normal conditions?

Radiation Signup and view all the answers

What role does sympathetic stimulation play in metabolic rate?

Leads to extra metabolism through hormonal effects on cells Signup and view all the answers

In the context of heat transfer from the body to the environment, what is the primary method involved in heat loss without contact?

Radiation Signup and view all the answers

Which of the following contributes most significantly to resting metabolism during exercise according to the text?

Extra metabolism needed for digestion, absorption, and food storage Signup and view all the answers

What is the main effect of fully vasoconstricted state on the conductance of heat from the core to the skin surface?

4 fold increase in heat conductance Signup and view all the answers

What happens to skin cells if blood flow to the skin is restricted for an extended period?

They begin to die due to lack of oxygen and nutrients Signup and view all the answers

Which nerve fibers innervate sweat glands?

Cholinergic nerve fibers Signup and view all the answers

What is one of the mechanisms that cause excess heat production which is inhibited when the body is too hot?

Shivering Signup and view all the answers

What is the main effect of skin vasoconstriction when the body is too cold?

Vasodilation of skin blood vessels Signup and view all the answers

What is the role of sympathetic stimulation in arrector pili muscles?

Contraction for standing hairs upright Signup and view all the answers

What is the primary reason for the fever induced by cytokines?

Local synthesis and release of prostaglandins in the hypothalamus Signup and view all the answers

What can happen as body core temperature reaches 41°C?

Confusion and loss of consciousness Signup and view all the answers

How does excessive hyperthermia (>41°C) affect the body?

Can cause disseminated intravascular coagulation Signup and view all the answers

What is the effect of acetylsalicylic acid (aspirin) on the hypothalamus?

Inhibits prostaglandin synthesis Signup and view all the answers

What does a very high body temperature (>41°C) cause?

Disseminated intravascular coagulation Signup and view all the answers

What condition arises from overexposure to a hot and humid environment?

Heat stroke Signup and view all the answers

What controls the vasoconstriction of the arterioles and arteriovenous anastomoses supplying blood to the venous plexus of the skin?

Sympathetic nervous system Signup and view all the answers

Which part of the hypothalamus is responsible for mediating temperature increasing mechanisms?

Posterior region Signup and view all the answers

What provides the main medium for transporting heat from the core to the skin regions?

Blood Signup and view all the answers

Where are blood vessels distributed profusely in relation to heat regulation?

Beneath the skin Signup and view all the answers

Which areas are directly supplied with blood to the venous plexus from small arteries through arteriovenous anastomoses?

Hands, feet, and ears Signup and view all the answers

Which nervous system is primarily responsible for controlling vasoconstriction in response to changes in body core temperature?