Human and Social Biology: Homeostasis, Excretion, and Cardiovascular Health

Comprehensive vocabulary flashcards covering heart attack causes and symptoms, skin histology, osmoregulation and kidney function, negative feedback mechanisms, homeostatic balance systems, and excretion.

Atherosclerosis

A condition occurring when fatty deposits containing cholesterol build up on the inside wall of the coronary arteries, restricting oxygenated blood flow to the heart muscle.

Coronary Thrombosis

A blood clot that forms inside a narrowed coronary artery, which can partially or completely block blood flow and lead to a heart attack.

Cardiac Arrest

The abrupt cessation of normal heart function where the heart stops beating.

Hypertension

High blood pressure, which elevates the risk of experiencing a heart attack.

Epidermis

The outermost layer of the skin that protects the body against pathogens, water loss, harmful ultraviolet rays, and harmful chemicals.

Dermis

The layer of connective tissue located directly beneath the epidermis.

Subcutaneous Layer

The innermost layer of the skin composed primarily of fat; it acts as padding against damage and protects against heat loss in low environmental temperatures.

Sebaceous Glands

Exocrine glands in the skin that secrete sebum, an oily substance that keeps the skin soft, supple, and waterproof while inhibiting bacterial growth.

Hair Erector Muscles

Muscles that contract to make hairs stand upright, causing goose bumps in humans and trapping a layer of air next to the skin for thermal insulation.

Sweat Glands

Skin structures that absorb water, urea, and salts from the blood to produce sweat, cooling the body via evaporation through pores on the skin surface.

Cornified Layer

A waterproof surface layer of the epidermis composed of dead cells rich in keratin.

Osmoregulation

The physiological process of maintaining and regulating the water content of blood plasma and body fluids.

Hypothalamus

The region of the brain responsible for detecting changes in the concentration of blood plasma.

Antidiuretic Hormone (ADH)

A hormone produced by the pituitary gland at the base of the brain that travels via blood to the kidneys to regulate the permeability of kidney tubules and collecting ducts to water.

Selective Reabsorption

The process in the kidneys where essential amounts of water and solutes are reabsorbed into the blood plasma, regulating the volume and concentration of urine produced.

Homeostasis

The maintenance of a constant internal environment in the body to ensure enzymes operate and control metabolic reactions efficiently.

Negative Feedback Mechanism

A self-regulating control loop where receptors detect deviations from a normal level and trigger effectors to exert an opposite corrective action, restoring the system to its set point.

Effectors

Muscles, glands, or organs that carry out corrective responses in response to regulatory control signals to adjust internal body levels.

Nervous System

A fast-acting body coordination system that transmits electrical impulses via nerves to control processes such as temperature and $CO_2$ levels through respiratory rate.

Hormonal System

A slower, long-lasting coordination system that uses chemical messengers called hormones secreted by endocrine glands into the bloodstream to regulate functions such as blood glucose.

Excretion

The removal of metabolic waste products from the body that would otherwise accumulate and cause cellular damage.