Internal Control

Homeostasis

maintenance of a constant, normal internal environment at rest.

Steady state

variable is unchanging but not normal; often reached during submaximal exercise.

Biological control systems

intracellular control systems and organ systems

intracellular control systems

protein breakdown and synthesis, energy production, maintenance of stored nutrients are all examples of what

organ systems

pulmonary and circulatory systems are examples of what

sensor, control center, effector

list the components of biological control systems

detects change

Sensor does what

Control center

assess input and initiates a response

Effector

executes response to restore balance

Gain

strength/precision of a control system. Higher _____= more capable of maintaining homeostasis

High gain systems

pulmonary & cardiovascular systems

Negative feedback

reverses disturbance (e.g., high CO₂ → ↑ ventilation).

Positive feedback

amplifies disturbance (e.g., oxytocin in childbirth).

Exercise & Homeostasis

homeostasis

Exercise disrupts ________via changes in pH, PO₂, PCO₂, and temperature.

fatigue and end of exercise

exercise that is intense or in prolonged in hot/humid environments can exceed ability to maintain steady state and lead to .

Adaptation

structural/functional change improving ability to maintain homeostasis.

Acclimation

adaptation to repeated environmental stress.

Exercise-induced hormesis

low/moderate doses of stress leads to beneficial adaptations.

Cell Signaling

communication btwn cells using chemical messengers, coordinates cellular activities

Intracrine

messenger acts inside the same cell.

Autocrine

messenger secreted, binds to receptors on same cell.

Paracrine

acts on nearby cell (neuromuscular junction)

Endocrine

chemical messenger travel via blood to distant specific receptors

Juxtracrine

direct cell-to-cell contact.

Extracellular Vesicles (EVs)

carry bioactive molecules (RNA, proteins, enzymes) between cells; act via paracrine or endocrine pathways.

contracting muscles

extracellular vesicles are released during exercise via ________ _________

Exercise-induced protein synthesis

what helps improve cells ability to maintain homeostasis

Heat shock proteins

help repair damaged proteins, maintain homeostasis during stress.

Resistance and endurance

what exercise promotes activation of different cell signaling pathways