ASC101 Organ Systems Vocabulary Flashcards

Vocabulary practice flashcards covering general organ structures, as well as the respiratory, renal, and hepatic organ systems from ASC101 lecture notes.

Organ

A single structural unit composed of a collection of tissues with a common function, whose primary tissues most often originate from a single germ layer.

Tubular Organs

Hollow organs with a common layered architecture consisting of a lumen, mucosa, submucosa, muscularis, and serosa.

Lumen

The open pathway or interior space within a tubular organ, derived from the Latin word for 'light'.

Mucosa

The innermost epithelial lining of a tubular organ that comes into direct contact with external substances.

Submucosa

A supportive connective tissue layer in hollow organs that contains blood vessels, lymphatics, and nerves.

Muscularis

The muscle tissue layer of a tubular organ responsible for pushing contents through its pathway or moving the organ.

Serosa

The protective external coating layer surrounding a tubular organ.

Capsule

The outer protective and supporting connective tissue shell of a solid organ.

Cortex

The outer functional zone (shell or bark) of a solid organ that contains its primary functional units.

Medulla

The interior middle zone of a solid organ containing collection channels, ducts, or drainage pathways.

Stroma

The internal structural framework of a solid organ, including trabeculae (septa) and reticula.

Trabeculae

Connective tissue extensions (also called septa) projecting inward from the capsule to form part of a solid organ's framework.

Reticula

A network mesh of fibers holding the functional units of a solid organ together.

Hilum

An attachment point on a solid organ where primary blood vessels, nerves, and lymphatics enter and exit the tissue.

Upper Respiratory Tract

The section of the respiratory system consisting of the mouth and nasal passage that functions to filter, warm, and humidify air.

Lower Respiratory Tract

The section of the respiratory system comprising the trachea, bronchi, bronchioles, and pulmonary lungs responsible for gas exchange.

Pulmonary Circulation

Vascular route that carries deoxygenated blood from the right ventricle of the heart through the pulmonary artery to the lungs.

Bronchial Circulation

Vascular route that supplies nutrient-rich blood from the systemic aorta directly to lung tissue.

Pulmonary Alveoli

Microscopic, grape-like air sacs located at the ends of the respiratory tree that serve as the functional units for gas exchange.

Type I Pneumocytes

Squamous alveolar cells specialized for gas exchange, accounting for approximately $40\%$ of alveolar cells and $90\text{--}95\%$ of the internal surface area.

Type II Pneumocytes

Secretory alveolar cells that produce surfactant, composed of $80\%$ phospholipids, $10\%$ cholesterol, and $10\%$ protein.

Trachea

Windpipe lined with pseudostratified epithelia and C-shaped cartilage rings that prevent airway collapse under negative pressure.

Bronchioles

Small airway passages with a diameter of $<1\,\text{mm}$ containing thick smooth muscle and simple cuboidal epithelia, but lacking cartilage.

Renal Cortex

The light-colored outer region of the kidney that houses renal columns and initial tubular structures.

Renal Medulla

The darker inner region of the kidney containing renal pyramids.

Minor Calyces

Cup-like urine collection structures in the kidney that wrap around each individual renal papilla.

Renal Pelvis

A large, flat, funnel-shaped cavity in the kidney formed by merged major calyces that drains urine directly into the ureter.

Nephron

The functional filtration unit of the kidney, consisting of a renal corpuscle and a renal tubule system.

Glomerulus

A fenestrated capillary cluster within the renal corpuscle where blood plasma filtration occurs under a pressure gradient of approximately $10\,\text{mm\,Hg}$.

Detrusor

The muscular wall of the urinary bladder that exhibits receptive relaxation to allow expansion without rising internal pressure.

Hepatic Portal Vein

Blood vessel carrying nutrient-rich, deoxygenated blood from the digestive tract directly to the liver, providing $75\text{--}80\%$ of its blood supply.

Hepatic Artery

Blood vessel delivering oxygenated blood from systemic circulation to supply $20\text{--}25\%$ of the liver's blood and sustain liver tissue.

Hepatic Lobule

The hexagonal functional unit of the liver consisting of hepatocytes organized around a central vein and bounded by portal triads.

Portal Triad

A functional triplet structure found at the vertices of a hepatic lobule, consisting of a portal vein branch, a hepatic artery branch, and a bile duct.