Homeostasis in A-Level Biology

Flashcards covering essential concepts related to homeostasis, glucose regulation, and nephron function in A-Level Biology.

Homeostasis

The process of maintaining the internal environment within restricted limits for optimal survival.

Negative Feedback

A control mechanism that restores any change back to original levels.

Receptor Cells

Cells that detect changing conditions inside or outside the body.

Coordinating System

A system, such as the nervous system or endocrine system, that communicates changes to effectors.

Physiological Control Systems

Systems ensuring that internal conditions within the body do not stray beyond required limits.

Glucose Regulation

The process by which blood glucose levels are maintained, involving hormones such as insulin and glucagon.

Glycogenesis

The synthesis of glycogen from glucose, reducing blood glucose concentration.

Glycogenolysis

The breakdown of glycogen to glucose, increasing blood glucose concentration.

Glucagon

A hormone secreted by alpha cells in the pancreas that increases blood glucose levels.

Adrenaline

A hormone that can increase blood glucose concentration by activating enzymes to convert glycogen to glucose.

Osmoregulation

The control of the water potential of body fluids, an example of homeostasis.

ADH (Antidiuretic Hormone)

A hormone that increases the permeability of the collecting ducts to water, thus regulating blood water content.

Selectivereabsorption

The process by which useful molecules are reabsorbed from the filtrate back into the blood.

Nephron

The functional unit of the kidney responsible for urine formation.

Ultrafiltration

The process where small molecules are filtered out of the blood into the Bowman's capsule, forming glomerular filtrate.

Glomerulus

A knot of capillaries in the nephron where ultrafiltration takes place.

Podocytes

Epithelial cells in the Bowman's capsule with extensions that help facilitate filtration.

Type I Diabetes

A condition where the pancreas fails to produce insulin, often treated with insulin injections.

Type II Diabetes

A condition where insulin receptors fail to respond to insulin, often linked to obesity and lifestyle.

Calibration Curve

A graph used to determine the concentration of an unknown sample by comparing it to known concentrations.