Homeostasis and Excretion Practice Flashcards

This set of vocabulary flashcards covers concepts from Unit 3 Chapter 10, including excretion, the urinary system, kidney function, dialysis, homeostasis, glucose regulation, osmoregulation, and thermoregulation.

Excretion

The removal of metabolic waste, toxic substances, and excess substances from the body.

Excretory Organs

The Lungs (exhale Carbon Dioxide), Kidneys (produce urine from urea, excess water, and minerals), Skin (sweating), and Liver (breakdown of RBCs to produce bile pigment).

Urinary System

A system comprising two kidneys, two ureters, a urinary bladder, a sphincter muscle, and the urethra.

Nephron

The building unit of the kidney; each kidney is made up of millions of these units.

Nephron Components

The Glomerulus, Bowman’s Capsule, Proximal convoluted tubule, Loop of Henle, Distal convoluted tubule, and Collecting duct.

Ultrafiltration

The process where substances are forced out of the glomerulus under high pressure into Bowman’s capsule.

Selective reabsorption

The process where $100\%$ of glucose is reabsorbed back into the body via active transport to be used in respiration.

Tissue typing

A method used to match a donor kidney with the tissues of a patient to overcome tissue rejection.

Immunosuppressant drugs

Medication given to patients to suppress the immune system so that a new kidney can be accepted by the body.

Dialysis

A treatment for kidney failure where blood from an artery is passed through a machine with a partially permeable membrane to filter urea into dialysis fluid.

Natural concentration gradient (Dialysis)

Maintained by replacing dialysis fluid to ensure urea continues to pass out of the blood.

Homeostasis

Maintaining the internal condition at constant despite changes in the external environment, such as body temperature or blood glucose.

Insulin

A hormone secreted by the pancreas when blood glucose increases; it acts on the liver to promote the conversion of glucose into glycogen.

Glucagon

A hormone secreted by the pancreas when blood glucose decreases; it stimulates the liver to convert glycogen back into glucose.

Osmoregulation

The process of keeping blood concentration constant by regulating water potential.

ADH (Antidiuretic Hormone)

A hormone secreted by the pituitary gland that increases the permeability of the kidney’s collecting duct to reabsorb more water back into the body.

Hypothalamus

The thermoregulatory centre in the brain that acts as the body’s thermostat and detects changes in blood concentration.

Vasodilation

The widening of arterioles to the skin surface to increase blood flow and heat loss via radiation during hot conditions.

Vasoconstriction

The narrowing of arterioles to the skin surface to decrease blood flow and reduce heat loss during cold conditions.

Erector muscles

Muscles that contract in the cold to make body hair stand erect to trap air for insulation, and relax in the heat to flatten hair.

Shivering

The repeated contraction and relaxation of muscles to increase the respiration rate and release more heat.

Epidermis

The outermost layer of the human skin that prevents water loss.

Dermis

The middle layer of skin containing sweat glands, hair follicles, and blood vessels.

Subcutaneous Layer (Hypodermis)

The layer of skin composed of fatty tissues used for insulation.