Structure and Function of The Main Body Organs

Vocabulary flashcards covering the location, tissue structure, and primary functions of the main organs in the human body.

Organ

A structure formed by a group of tissues working together to perform specific functions in the body.

Heart

An organ situated between the lungs in the chest with its apex to the left, composed of cardiac muscle and epithelial linings, that pumps blood to the lungs and around the body.

Lungs

Two organs located on either side of the heart that fill the chest cavity, composed of simple epithelia and elastic fibres, that facilitate the inhalation and exhalation of gases linked to respiration.

Brain

The nervous centre inside the skull composed of nervous tissue consisting of neurons and neuroglia, which receives and sends nervous impulses as a means of communication and controls all life functions.

Stomach

An organ in the abdomen on the left side beneath the diaphragm, composed of three layers of non-striated muscle, epithelium, and gastric glands, which churns and mixes food into chyme and begins digestion.

Liver

An organ in the upper right abdomen beneath the diaphragm, composed of cuboid epithelial cells in lobules, involved in digestion, metabolism, excretion of waste products, storing glycogen, and secreting bile and salts.

Pancreas

An organ lying behind the stomach between the stomach and duodenum on the left side of the abdomen, composed of glandular epithelium, which secretes vital digestive juices down ducts to the small intestine and secretes insulin and glucagon.

Duodenum

The C-shaped part of the small intestine lying beyond the stomach, composed of two coats of non-striated muscle lined by columnar epithelium, which passes chyme to the ileum and secretes major digestive secretions.

Ileum

The long coiled part of the small intestine joined to the duodenum, composed of two coats of non-striated muscle and villi lined by columnar epithelium, which passes undigested chyme to the colon and absorbs nutrients into the bloodstream.

Colon

Part of the large intestine joining the ileum in the right-hand side of the abdomen, running up to the liver, across in front of the stomach, and down the left side to join with the rectum, which absorbs water to produce semi-solid faeces.

Kidneys

Two organs located on either side of the back wall of the abdomen below the diaphragm (the left kidney being higher than the right due to the liver), composed of nephrons, which secrete urine, eliminate waste products and water, and maintain homeostasis.

Urinary Bladder

An organ lying centrally at the front of the lower pelvis, composed of non-striated muscle lined by epithelium, which collects and stores urine ready for excretion.

Ovaries

Female reproductive organs located on each side of the pelvis below the kidneys, composed of connective tissues, blood vessels, and epithelial cells forming follicles, which produce ova or eggs and secrete hormones.

Testes

Male reproductive organs located in the groin in a skin sac called the scrotum outside the body cavity, composed of connective tissues, blood vessels, and epithelial cells forming convoluted seminiferous tubules, which produce spermatozoa and secrete testosterone.

Uterus

A female reproductive organ situated centrally in the pelvis connected to the ovaries by Fallopian tubes, composed of non-striated muscle lined by special epithelium, which produces new epithelium monthly, supports and protects the foetus, and contracts powerfully during birth.

Skin

A protective layer covering the whole body, composed of keratinised, compound epithelium above a dermis of areolar tissue, which provides a water- and bacteria-proof covering and assists in body temperature regulation and homeostasis.

Major Body Organs Overview

An anatomical diagram illustrating the anatomical positions of key body organs, including the brain, skin, heart, lungs, liver, pancreas, stomach, large intestine, small intestine, kidneys, bladder, uterus, ovaries, and testes.