Human Biology and Metabolic Systems Flashcards

This set of vocabulary flashcards covers concepts from the respiratory, circulatory, excretory, and digestive systems, as well as cell division, specialized cells, and enzymes.

Alveoli

The end of the bronchiole where gas exchange occurs; they feature single-cell walls, a moist surface with surfactant, and a large $\text{SA:V ratio}$ for efficient diffusion.

Surfactant

A layer on the surface of the alveoli that keeps them moist to facilitate gas exchange.

Artery

A blood vessel with a thick outer wall, a thick layer of muscle and elastic fibres, and a small lumen that carries blood away from the Heart (oxygenated except for the pulmonary artery).

Vein

A blood vessel with fairly thin walls, a large lumen, and valves to stop backflow; it carries blood to the Heart (deoxygenated except for the pulmonary vein).

Capillary

Extremely small vessels with walls $1$ cell thick that connect veins and arteries, featuring a lumen size that fits $1$ RBC to improve the efficiency of $O_2$ and $CO_2$ diffusion.

Nitrogenous Wastes

Metabolic wastes such as Ammonia and Urea produced from the breakdown of excess proteins and Amino Acids.

Glomerulus

The structure in the nephron responsible for filtration of the blood.

Bowmans Capsule

The part of the nephron that receives filtered fluid from the glomerulus.

Loop of Henle

A part of the nephron where the counter-current diffusion of water and ions occurs for reabsorption.

Enzymes

Biomolecules that speed up reactions by lowering activation energy; they work best under optimal conditions and can denature if temperature or pH is too high or low.

Urea Cycle

A process in the liver where toxic ammonia is converted into non-toxic urea by combining it with carbon dioxide.

Amylase

An enzyme responsible for breaking down polymer carbohydrates like Starch, Glycogen, and Cellulose into the monomer Glucose.

Protease

The enzyme that breaks down Proteins and Polypeptides into Amino Acids.

Lipase

An enzyme that breaks down Lipids (Triglycerides, Phospholipids, and Steroids) into Glycerol and Fatty acids.

Mitosis

Cell division for growth and repair where $1$ parent cell with $46$ Chromosomes produces $2$ identical daughter cells.

Meiosis

Cell division for sexual reproduction where $1$ parent cell results in $4$ daughter cells containing half the information ($23$ chromosomes).

Stem cells

Unspecialised cells that have not developed a specific function and can divide and develop into many different cell types; found mainly in embryos and some adult tissue like bone marrow.

Cell Hierarchy

The organizational levels of biology: Groups of CELLS that perform the same function form TISSUES, which form ORGANS, which form SYSTEMS.

Villi

Finger-like projections on the inside surface of the small intestine that improve absorption.

Oesophis

A structure in the digestive system where peristic movement occurs.

Peristic

The mechanical movement or process mentioned in the context of the Oesophis within the digestive system.