Chapter 1: Major Themes of Anatomy and Physiology - Homeostasis and Gradients

Vocabulary flashcards covering core concepts of homeostasis, feedback loops, components of homeostatic control systems, and physiological gradients from Chapter 1.

Homeostasis

The maintenance of a stable internal environment within the body through coordinated physiological processes.

Homeostatic imbalance

Disturbances in the body's internal environment that can lead to disease or death if uncorrected.

Feedback loop

A physiological mechanism that alters the original change that triggered it.

Negative feedback

A primary mechanism of homeostasis where a system senses a change and activates mechanisms to reverse or negate that change.

Vasodilation

The widening of blood vessels in the skin that acts as a heat-losing mechanism when body temperature is too warm.

Vasoconstriction

The narrowing of blood vessels in the skin that acts as a heat-gaining mechanism when body temperature is too cold.

Receptor

A body structure that senses a change in physiological conditions, such as stretch receptors monitoring blood pressure.

Baroreceptors

Pressure-sensitive receptors located above the heart that respond to changes in blood pressure, such as drops caused by postural changes.

Integrating center

A control center, such as the cardiac center of the brainstem, that processes sensory information, makes a decision, and directs the physiological response.

Effector

A cell or organ, such as the heart, that carries out the final corrective action to restore homeostasis.

Positive feedback

A self-amplifying physiological cycle where a change leads to greater change in the same direction to produce rapid changes.

Oxytocin

A hormone secreted by the pituitary gland that stimulates uterine contractions during childbirth in response to nerve impulses from the cervix.

Gradient

A difference in chemical concentration, charge, temperature, or pressure between two points.

Down gradient

The movement of matter or energy from a region of higher value to a lower value without requiring metabolic energy.

Up gradient

The movement of matter or energy from a region of lower value to a higher value, which requires spending metabolic energy.

Concentration gradient

A difference in chemical concentration between two points, driving movement such as dietary glucose through cell membrane channels.

Electrical gradient

A difference in electrical charge between two points, driving the flow of charged particles like sodium ions.

Thermal gradient

A difference in temperature between two points, driving heat transfer from warm blood through the skin to cool air.

Pressure gradient

A difference in pressure between two points, driving fluid flow such as blood moving from higher pressure to lower pressure.