1.1 Intro to cell compounds

A set of vocabulary flashcards covering the components of homeostatic control systems, negative feedback examples, and the positive feedback mechanism of childbirth.

Homeostasis

The process of keeping internal and external cell environments within tightly regulated physiological tolerance limits rather than keeping conditions static.

Homeostatic mechanisms

Self-regulating control systems through which the body maintains homeostasis.

Change (stimuli)

Anything that requires a cell to react, such as a change in temperature, pressure, or chemical composition inside or surrounding the cell.

Receptors

Sensory components that detect stimuli and alert the proper control center to counteract the change and return the system to a balanced state.

Control center

A component that includes a set point, receives impulses from remote receptors, and sends commands via the efferent pathway to effectors.

Set point

A specific value in the control center that defines what a particular physiological value should be, such as body temperature at $37ºC$.

Effectors

The physical change agents and workhorses of homeostasis, such as muscles, glands, and fluids, that elicit responses to counteract changes.

Afferent pathway

The route through which input is sent from the receptor to the control center after a change is detected.

Efferent pathway

The route through which output is sent from the control center to the effector to initiate a response.

Negative Feedback

A control mechanism that maintains normalcy by counteracting changes in conditions such as body temperature, $CO_2$ levels, blood sugar, and blood pH.

Baroreceptors

Sensors that detect the pressure of the blood going through the arteries while the heart is pumping.

Glossopharyngeal nerve

The nerve that carries chemical signals regarding blood pressure from sensors to the pressure control center in the brain.

Hypothalamus

The control center that receives messages from nerve endings during high body temperature and causes sweating to return the body to normal temperature.

Medulla Oblongata

The control center that receives messages from receptors regarding high $CO_2$ levels and causes breathing to return levels to normal.

Positive Feedback

A cycle in which the adaptive response further stimulates the regulatory center, causing the body to move into an increasingly unstable state until a specific outcome is achieved.

Oxytocin

A hormone released during childbirth that intensifies and speeds up contractions as part of a positive feedback cycle.

Cervix

The tissue that, when contacted by the head of the fetus, initiates the release of oxytocin and the positive feedback mechanism of childbirth.