CHAPTER 44 - Human Body Systems and Homeostasis

Flashcards based on key concepts related to the human body and regulation of systems.

Thermoregulation

Maintaining the body temperature within a range that allows cells to function efficiently.

Negative Pressure Breathing

A mechanism where the diaphragm contracts to increase lung volume and decrease pressure, allowing air to flow in.

Ectotherm

Organisms (also known as poikilotherms) whose body heat comes from the environment, resulting in body temperature being equal to the environment's temperature.

Endotherm

Organisms (also known as homeotherms) that generate body heat from metabolism, maintaining a consistent internal temperature.

Oxygen pathway

The route taken by O₂ from the external environment through the nasal cavity, lungs, bloodstream, heart, and finally into muscle cells for cellular respiration.

Gas Exchange

The process occurring in the alveoli where oxygen diffuses into the bloodstream and binds to hemoglobin in red blood cells.

Filtrate

A liquid that has passed through a filter, in this context referring to the fluid in the nephron that has been filtered from blood in the kidneys.

Hemoglobin

A protein in red blood cells that binds to oxygen for transport throughout the body.

Bowman's Capsule

The structure in the nephron of the kidney that receives filtrate from the blood.

Vasopressin

Also known as antidiuretic hormone (ADH), it controls the volume of urine by increasing the permeability of water, allowing more water to be reabsorbed into the body.

Aldosterone

A hormone that stimulates sodium reabsorption in the kidneys, which in turn increases water reabsorption.

Nephridia

Excretory tubules in simpler animals like earthworms that facilitate waste removal.

Malpighian tubules

Excretory structures in insects that help manage waste and conserve water.

Homeostasis

The maintenance of stable internal conditions in an organism despite changes in the external environment.

Mitochondria

Cellular organelles where cellular respiration occurs and ATP is produced.

Capillaries

Small blood vessels that allow for the exchange of gases, nutrients, and wastes between blood and tissues.