Anatomy & Physiology

Branch of biology concerned with the study of body structure of various organisms, including humans.

The abdomen is tightly packed with a number of organs that are involved in the nutrition of the body. These are kept in their relative positions by the muscles of the abdominal wall and the bands of the visceral peritoneum.

Either of a pair of flattened endocrine glands, situated one above each kidney, that secrete adrenaline and various steroid hormones, including sex hormones.

Blood vessel that carries blood from the heart to any part of the body.

The largest part of the brain, occupying most of the cranial cavity within the skull. It is separated into right and left halves (the right and left cerebral hemispheres), connected by a body of nerve fibres known as the corpus callosum.

The supervisory center of the nervous system in all vertebrates. It also serves as the site of emotions, memory, self-awareness, and thought.

System of vessels in an animal's body that transports essential substances (blood or other circulatory fluid) to and from the different parts of the body.

Supportive tissue widely distributed in the body, characterized by large amounts of intercellular substance and relatively few cells. The intercellular material, or matrix, is produced by the cells and gives the tissue its particular character.

Organ of hearing and equilibrium. The human ear consists of outer, middle, and inner parts.

Organ of vision and light perception. In humans the eye is of the camera type, with an iris diaphragm and variable focusing, or accommodation.

Muscular hoselike portion of the gastrointestinal tract extending from the lower end of the stomach (pylorus) to the anal opening.

Organ of voice in mammals. Commonly known as the voice box, the larynx is a tubular chamber about 2 in. (5 cm) high, consisting of walls of cartilage bound by ligaments and membranes, and moved by muscles.

Small oval endocrine gland that lies at the base of the brain. It is sometimes called the master gland of the body because all the other endocrine glands depend on its secretions for stimulation.

In most female mammals, hollow muscular organ in which the fetus develops and from which it is delivered at the end of pregnancy.

Framework of bones that supports and gives form to the body, protects its internal organs, and provides anchorage points for its muscles. It is composed of about 200 bones.

From The Human Body Book
Muscles are the body’s “flesh”. They bulge and ripple just under the skin, and are arranged in criss-crossing layers down to the bones. Their job is to contract and pull the bones to which they are anchored. Rarely working alone, they usually contract in groups, moving bones at accurate angles and by precise distances.

From The Human Body Book
The heart is a powerful organ about the size of a clenched fist. Located just to the left of centre in between the lungs, it operates as two coordinated pumps that send blood around the body.

From The Human Body Book
The brain, in conjunction with the spinal cord, regulates both non-conscious processes and coordinates most voluntary movement. Furthermore, the brain is the site of consciousness, allowing humans to think and learn.

From The Human Body Book
The respiratory system, in close conjunction with the circulatory system, is responsible for supplying all body cells with essential oxygen and removing potentially harmful carbon dioxide from the body.

From The Human Body Book
The digestive system consists of a long passageway, known as the alimentary canal or digestive tract, and associated organs, including the liver, gallbladder, and pancreas.

Basic biological unit of which all plant and animal tissues are composed.

Structures in a cell nucleus that carry the many thousands of genes, in sequence, that determine the characteristics of an organism.

Often referred to as the molecule of life, DNA (deoxyribonucleic acid) is found in almost all living things. It acts as a type of chemical code that contains instructions, known as genes, for how the body and all its different parts grow, develop, function, and maintain themselves.

Molecular unit of inherited material in a living organism.

Process of nuclear division in a living cell by which the number of chromosomes is reduced to half the original number. Meiosis occurs only in the process of gametogenesis, i.e., when the gametes, or sex cells (ovum and sperm), are being formed.

A semi-autonomous intracellular organelle, one or more (usually many) of which occur in most types of eukaryotic cell.

Process of nuclear division in a living cell by which the carriers of hereditary information, or the chromosomes, are exactly replicated and the two copies distributed to identical daughter nuclei.

System of vessels in an animal's body that transports essential substances (blood or other circulatory fluid) to and from the different parts of the body.

In the body, all the organs and tissues involved in the digestion of food.

Body control system composed of a group of glands that maintain a stable internal environment by producing chemical regulatory substances called hormones.

The adaptable system of body defenses centers on specialized white blood cells called lymphocytes. These respond to invasion by varied microorganisms.

Network of vessels carrying lymph, or tissue-cleansing fluid, from the tissues into the veins of the circulatory system. The lymphatic system functions along with the circulatory system in absorbing nutrients from the small intestines.

From The human body book: An illustrated guide to its structure, function and disorders
Muscle tissue creates bodily movements and it also powers internal processes, from the heartbeat and the movement of food through the intestines to the adjustment of artery diameter and focusing the eye.

Network of specialized tissue that controls actions and reactions of the body and its adjustment to the environment.

In animals, the anatomical organs concerned with production of offspring.

From Britannica Concise EncyclopediaOrgan system involved in respiration. In humans, the diaphragm and, to a lesser extent, the muscles between the ribs generate a pumping action, moving air in and out of the lungs through a system of pipes (conducting airways), divided into upper and lower airway systems.

Group of organs of the body concerned with excretion of urine, that is, water and the waste products of metabolism.

Soft tissue filling the spongy interiors of animal bones. Red marrow is the principal organ that forms blood cells in mammals, including humans. As the skeleton matures, fat-storing yellow marrow displaces red marrow in the shafts of the long bones of the limbs.

The supervisory center of the nervous system in all vertebrates. It also serves as the site of emotions, memory, self-awareness, and thought.

Muscular organ that rhythmically contracts to force blood around the body of an animal with a circulatory system.

Muscular hoselike portion of the gastrointestinal tract extending from the lower end of the stomach (pylorus) to the anal opening.

Either of a pair of organs at the back of the abdomen whose function is the removal of waste pro-ducts from the blood, and the excretion of such compounds from the body, usually in the form of urine.

Largest glandular organ of the body, weighing about 3 lb (1.36 kg).

In mammals, large cavity of the body, used for gas exchange.

Glandular organ that secretes digestive enzymes and hormones.

Saclike dilation in the gastrointestinal tract between the esophagus and the intestines, forming an organ of digestion.

From Black's Medical Dictionary
An organ deeply placed in the abdomen and a major constituent of the RETICULO-ENDOTHELIAL SYSTEM.

Organ of hearing and equilibrium. The human ear consists of outer, middle, and inner parts.

Organ of vision and light perception. In humans the eye is of the camera type, with an iris diaphragm and variable focusing, or accommodation.

From the The Hutchinson Unabridged Encyclopedia
The organs of smell are confined to a small area in the roof of the nasal cavity. The olfactory cells are stimulated when certain molecules reach them.

The flexible tissue (integument) enclosing the body of vertebrate animals. In humans and other mammals, the skin operates a complex organ of numerous structures (sometimes called the integumentary system) serving vital protective and metabolic functions.

From Black's Medical Dictionary, 43rd Edition
The tongue consists of a free part known as the tip, a body, and a hinder fixed part or root. The under-surface lies upon the floor of the mouth, whilst the upper surface is curved from side to side, and still more from before backwards so as to adapt it to the roof of the mouth.