Human Respiratory and Circulatory Systems

These flashcards cover key vocabulary and concepts related to the human respiratory and circulatory systems, including definitions of important terms and physiological functions.

Alveoli

Air sacs in the lungs that facilitate gas exchange.

Trachea

The windpipe; a tube that carries air to the bronchi.

Diaphragm

A sheet of muscle that contracts to help with breathing.

Atherosclerosis

A disease characterized by the hardening of arteries due to fatty deposits.

Blood Plasma

The liquid component of blood that carries cells and nutrients.

Sinoatrial Node

The natural pacemaker of the heart that regulates heartbeat.

Cardiac Cycle

The sequence of contraction and relaxation in the heart.

Capillaries

Microscopic blood vessels where gas exchange occurs.

Closed Circulatory System

A system where blood is confined to vessels.

Open Circulatory System

A system where the circulatory fluid bathes organs.

Hemoglobin

An iron-containing protein in red blood cells that transports oxygen.

Erythrocytes

Red blood cells responsible for carrying oxygen.

Leukocytes

White blood cells involved in fighting infections.

Obesity

An excessive accumulation of body fat.

Villi

Finger-like projections in the small intestine that increase surface area for absorption.