Human bio

Nose/Nasal Cavity

The externally visible part of the respiratory system where air enters through the nostrils, lined with mucous membranes to warm and humidify the air, while trapping debris.

Pharynx

The muscular passageway that connects the nasal cavity to the larynx, serving as a pathway for both air and food.

Epiglottis

A flap of elastic cartilage that protects the superior opening of the larynx and routes food to the esophagus and air towards the trachea.

Larynx

A cartilage structure that joins the pharynx to the trachea, routing air and food, and housing the vocal cords.

Trachea

A 4-inch long tube connecting the larynx to the bronchi, reinforced by C-shaped hyaline cartilage for structural support.

Bronchi

Air passages formed by the division of the trachea, leading into the lungs, with the right bronchus being wider and straighter than the left.

Bronchioles

The smaller branches of the bronchi that divide until the terminal bronchioles, made of smooth muscle and elastin for controlling air flow.

Lungs

Organs that occupy most of the thoracic cavity, divided into lobes and responsible for gas exchange between air and blood.

Alveoli

Small air sacs with thin walls in the lungs surrounded by blood capillaries, facilitating gas exchange.

Diaphragm

A muscle that separates the chest cavity from the lungs and plays a crucial role in breathing by increasing lung volume during inhalation.

Inspiration

The process of taking air into the lungs, which occurs when lung pressure decreases in relation to atmospheric pressure.

Expiration

The process of breathing out, occurring when lung pressure exceeds atmospheric pressure due to the relaxation of respiratory muscles.

Cardiac Output

The volume of blood ejected from a ventricle per minute, influenced by heart rate and stroke volume.

Homeostasis

The maintenance of stable internal conditions in the body despite external changes.

Metabolism

All chemical reactions that occur in cells of organisms, attempting to balance energy release and utilization.

Glycolysis

The first phase in the breakdown of glucose occurring in the cytosol, converting glucose into pyruvate without requiring oxygen.

Aerobic Respiration

The process of breaking down glucose completely in the presence of oxygen to produce carbon dioxide, water, and ATP.

Anaerobic Respiration

The conversion of pyruvate to lactic acid in the absence of oxygen, allowing cells to produce energy.

Blood Plasma

The liquid part of blood that carries cells and platelets, consisting mainly of water and dissolved substances.

Red Blood Cells (Erythrocytes)

Cells that transport oxygen from the lungs to body tissues and carry carbon dioxide back to the lungs.

White Blood Cells (Leukocytes)

Cells responsible for immune defense by removing dead or injured cells and engulfing pathogens.

Platelets (Thrombocytes)

Small cell fragments involved in blood clotting to prevent blood loss from damaged vessels.

Nephron

The functional unit of the kidney where urine formation occurs through glomerular filtration, selective reabsorption, and tubular secretion.

Glomerular Filtration

The process of filtering blood in the glomerulus to form filtrate, collecting components smaller than proteins.

Selective Reabsorption

The process in the nephron where certain substances from the filtrate are returned to the bloodstream.

Joints

Connections between bones that facilitate movement; classified into fibrous, cartilaginous, and synovial types.

Synovial Joint

Joints characterized by a joint cavity filled with synovial fluid, allowing for a wide range of movement.

Antigen

A substance that can stimulate the formation of antibodies in the immune response.

Antibody

A protein produced by the immune system in response to a specific antigen.

Blood Transfusion

The transfer of blood or blood components from one person to another, requiring blood type matching.