Feedback Loops and Homeostasis

Flashcards covering key vocabulary from the lecture on feedback loops, homeostasis, and cell physiology.

Positive Feedback System

A system where the goal is to remove the stimulus by enhancing the change until the stimulus is removed or destroyed.

Oxytocin

A hormone that causes increased contraction of the uterus and further relaxation of the cervix during childbirth, acting as part of a positive feedback loop.

Antigen

Anything that is capable of inducing an immune response.

Feedforward

A preparatory homeostatic mechanism that anticipates changes about to happen.

Cephalic Phase of Digestion

An example of a feedforward mechanism where the stomach is activated, producing digestive enzymes, mucus, and hydrochloric acid in anticipation of food.

Homeostasis

Maintains life in a state of dynamic equilibrium, involving continuous processes of maintenance.

Cell

The smallest unit capable of life.

Systems Integration

The process by which different body systems (e.g., cardiovascular, urinary) work together to maintain homeostasis for individual cells in multicellular organisms.

Urinary System

The system responsible for maintaining fluid volume and composition by producing filtrate and reabsorbing 99% of it.

Electrical Communication

Requires a difference in ions between the inside and outside of the cell, which must be maintained, exemplified by membrane potential.

Membrane Potential

A measurable difference in electrical charge across the cell membrane, typically around -70 millivolts inside relative to the outside.

Semipermeable Membranes

Membranes whose selective permeability is based on the solubility of the material (water or lipid) and the amount of transport proteins.

Sodium Potassium ATPase

A pump that uses ATP to expel sodium out of the cell and bring potassium in, attaching a phosphate from ATP during the process.

Oxygen in Cellular Respiration

The final electron acceptor in the oxidative phosphorylation pathway, essential for the continuation of cellular respiration and ATP production.

Integumentary System

The body's 'radiator,' the outward-facing system with the capacity to conduct, convect, and radiate heat for thermoregulation.