Homeostasis

What is homeostasis?

process by which organisms maintain a relatively stable internal environment

What is the difference between homeostasis and steady state?

homeostasis is the body's normal stable environment, while steady state is the ability of the body to maintain new steadiness in response to stimulus such as exercise

How does ATP production affect the body?

body temperature increases, as well as friction and metabolism

What is the master regulator of the body?

hypothalamus

How does the body conserve heat?

capillaries vasoconstrict and sweat secretion ceases in order to trap the insulating air layer

How does the body release heat?

capillaries vasodilate and sweat secretion begins in order to lose heat via evaporation

What is normal body temperature?

37 degrees C (98.6 degrees F)

What is the body's regulating center for heart rate and blood pressure?

medulla oblongata

What is mean arterial pressure?

average pressure in the arteries that propels blood into the tissues

What is the role of baroreceptors on the carotid/aorta?

they send information to the medulla when there is a disruption to homeostasis

What is the function of the vagal nerve?

connected to the heart, decreases heart rate

What is the function of the cardiac sympathetic nerve?

connected to the heart, increases heart rate

What is the function of the vasomotor nerve?

sends information to the medulla to enable vasoconstriction and vasodilation of the blood vessels in order to increase/decrease blood pressure

Why does blood pressure increase during exercise?

cardiac output increases and the body requires more oxygen

In general, how is homeostasis maintained?

homeostasis is disrupted by a stimulus, causing a change in internal conditions. This change in sensed and communicated to the control center, which enables the proper effectors to return the body to homeostasis (negative feedback loop)

What is normal blood sugar in a fasting state?

70-100 mg/dL

How is blood sugar regulated?

via a negative feedback loop in which insulin is released by the pancreas for glucose uptake into storage from the bloodstream and glucagon is released by the pancreas to signal the liver to release stored glucose

What happens to blood sugar after eating?

it rises initially, but returns to normal levels about 2 hours after eating

What happens to insulin and glucagon during exercise?

insulin decreases and glucagon increases because we are using glucose stores in the body and breaking down glycogen

How does glucose enter body stores during exercise?

insulin binds to a receptor, triggering a signal cascade that activates GLUT4, whose excitement is increased with exercise, GLUT4 then goes through exocytosis and travels to the cell membrane to allow the entry of glucose molecules from bloodstream into storage

How are testosterone levels affected during exercise?

because exercise breaks down muscle fibers, testosterone levels increase to repair and build new muscle

How are steroids different from other hormones?

they enter the cell nucleus in order to directly alter genetic transcription

What is the function of satellite cells?

they are dormant at the cell edge and fuse with muscle fibers in order to increase the amount of nuclei and therefore the muscle size

What is glycogen synthase?

enzyme that joins together chains of glucose molecules to make glycogen (levels increase with testosterone)