Human Circulatory and Respiratory Systems

Flashcards covering the human circulatory and respiratory systems, including the heart, blood vessels, blood components, and the mechanics of breathing.

Closed Circulatory System

A system where blood is contained within vessels, including a four-chambered heart, arteries, veins, and capillaries.

Atria

The two upper chambers of the heart that receive blood from the body.

Ventricles

The two lower chambers of the heart that pump blood out to the body.

Pericardium

The membrane that protects the human heart.

Septum

The structure that separates the right and left sides of the heart.

AV Valves

Valves that prevent the backflow of blood from the ventricles into the atria.

SA Node

Controls the rate of the heartbeat.

Myocardium

The type of muscle found in the heart.

Arteries

Vessels that carry blood away from the heart and have thick, elastic walls.

Aorta

The largest artery in the body.

Arterioles

The smallest arteries.

Pulse

The contraction of heart muscle felt in arteries.

Capillaries

Microscopic vessels with walls one cell thick that connect arterioles with venules for material exchange.

Veins

Vessels that carry blood to the heart and contain valves to prevent backflow.

Coronary Circulation

Provides the heart muscle with oxygen and nutrients via the coronary arteries.

Blood

A liquid tissue composed of plasma and solid components (red blood cells, white blood cells, and platelets) for transport and protection.

Red Blood Cells (Erythrocytes)

Disk-shaped cells without a nucleus that transport oxygen using hemoglobin.

Hemoglobin

Respiratory pigment in red blood cells that increases oxygen-carrying capacity.

White Blood Cells

Ameba-like cells with a nucleus that fight infections by phagocytosis or producing antibodies.

Platelets

Cell fragments that initiate blood clotting.

Thromboplastin

Released by platelets to convert prothrombin to thrombin, initiating clot formation.

Fibrin

An insoluble protein that forms a meshwork to trap blood cells and form a clot.

Agglutinogens

Proteins on the surface of red blood cells that determine blood type.

Agglutinins

Proteins in plasma that react with agglutinogens, causing blood cells to clump.

Rh Factor

A protein on red blood cells; its presence determines Rh-positive status.

Lungs

Organs of respiration containing tubes and sacs for gas exchange.

Epiglottis

A flap of tissue that blocks the trachea during swallowing.

Bronchi

Two branches of the trachea that enter the lungs.

Bronchioles

Smaller tubes branching from the bronchi in the lungs.

Alveoli

Air sacs in the lungs where gas exchange occurs.

Diaphragm

A large muscle separating the thoracic and abdominal cavities, essential for breathing.

Inhalation

The process by which air moves into the lungs; diaphragm moves down, chest cavity volume increases, pressure decreases.

Exhalation

The process by which air moves out of the lungs; diaphragm relaxes, chest cavity volume decreases, pressure increases.

External Respiration

The exchange of gases between the lungs and the blood.

Internal Respiration

The exchange of respiratory gases between the blood and the cells.

Oxyhemoglobin

Formed when oxygen combines with hemoglobin in the lungs.

What are the principal organs of the respiratory system?

The nasal cavity, pharynx, larynx, trachea, bronchi, and lungs.

Pleura

A double-layered serous membrane surrounding the lungs.

Tidal Volume

The volume of air inhaled or exhaled during normal breathing.

Vital Capacity

The maximum amount of air that can be exhaled after a maximum inhalation.

Residual Volume

The amount of air remaining in the lungs after a maximal exhalation.

Functional Residual Capacity

The volume of air remaining in the lungs after a normal exhalation.

Total Lung Capacity

The total volume of air the lungs can hold.

Minute Ventilation

The amount of air moved into or out of the lungs per minute.

Respiratory Control Center

Located in the medulla oblongata and pons; controls the rate and depth of breathing.

Acidosis

A decrease in blood pH (more acidic).

Alkalosis

An increase in blood pH (more alkaline).