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Anterior

Situated toward the front of the body

Deep

Away from the body surface; more internal

Directional Terms

Terms used to explain where one body structure is in relation to another

Distal

Situated away from the point of attachment or origin or a central point; located away from the center of the body

Dorsal

Being or located near, on, or toward the back or posterior part of the human body

Identity

The distinguishing character or personality of an individual

Inferior

Situated below and closer to the feet than another and especially another similar part of an upright body especially of a human being

Lateral

Of or relating to the side; especially of a body part

Medial

Lying or extending in the middle; especially of a body part

Posterior

Situated at or toward the hind part of the body

Proximal

Situated next to or near the point of attachment or origin or a central point

Regional Terms

Anatomical terms that refer to specific visible landmarks on the surface of the body

Superficial

Of, relating to, or located near the surface

Superior

Situated toward the head and further away from the feet than another and especially another similar part of an upright body especially of a human being

System

A group of body organs or structures that together perform one or more vital functions

Ventral

Pertaining to the anterior or front side of the body; opposite of dorsal

Adipose tissue

Connective tissue in which fat is stored and which has the cells distended by droplets of fat

Appendicular Skeleton

Bones of the limbs and limb girdles that are attached to the axial skeleton

Axial Skeleton

The skeleton of the trunk and head

Connective Tissue

Animal tissue that functions mainly to bind and support other tissues, having a sparse population of cells scattered through an extracellular matrix

Epithelial Tissue

Sheets of tightly packed cells that line organs and body cavities

Femur

The proximal bone of the hind or lower limb that is the longest and largest bone in the human body, extends from the hip to the knee

Forensic Anthropology

The branch of physical anthropology in which anthropological data, criteria, and techniques are used to determine the sex, age, genetic population, or parentage of skeletal or biological materials in questions of civil or criminal law

Humerus

The longest bone of the upper arm or forelimb extending from the shoulder to the elbow

Pelvis

A basin-shaped structure in the skeleton of many vertebrates that is formed by the pelvic girdle together with the sacrum and often various coccygeal and caudal vertebrae and that in humans is composed of the two hip bones bounding it on each side and in front while the sacrum and coccyx complete it behind

Skull

The skeleton of the head forming a bony case that encloses and protects the brain and chief sense organs and supports the jaws

Tibia

The inner and usually larger of the two bones of the leg between the knee and ankle that articulates above with the femur and below with the talus -- called also shinbone

Tissue

An integrated group of cells with a common structure and function

Agarose

A polysaccharide obtained from seaweed that is used as the supporting medium in gel electrophoresis.

Biometrics

The measurement and analysis of unique physical or behavioral characteristics (as fingerprint or voice patterns) especially as a means of verifying personal identity.

Deoxyribonucleic acid (DNA)

A double-stranded, helical nucleic acid molecule capable of replicating and determining the inherited structure of a cell's proteins

Gel electrophoresis

The separation of nucleic acids or proteins, on the basis of their size and electrical charge, by measuring their rate of movement through an electrical field in a gel.

Restriction enzyme

A degradative enzyme that recognizes specific nucleotide sequences and cuts up DNA.

Restriction fragment length polymorphisms (RFLPs)

Differences in DNA sequence on homologous chromosomes that can result in different patterns of restriction fragment lengths (DNA segments resulting from treatment with restriction enzymes).

Brain Stem

The part of the brain composed of the midbrain, pons, and medulla oblongata and connecting the spinal cord with the forebrain and cerebrum.

Central nervous system

The part of the nervous system which in vertebrates consists of the brain and spinal cord, to which sensory impulses are transmitted and from which motor impulses pass out, and which supervises and coordinates the activity of the entire nervous system.

Cerebellum

A large dorsally projecting part of the brain concerned especially with the coordination of muscles and the maintenance of bodily equilibrium, situated between the brain stem and the back of the cerebrum and formed in humans of two lateral lobes and a median lobe.

Cerebrum

The dorsal portion, composed of right and left hemispheres, of the vertebrate forebrain; the integrating center for memory, learning, emotions, and other highly complex function of the central nervous system.

Gyrus

A convoluted ridge between anatomical grooves.

Limbic System

A group of subcortical structures (as the hypothalamus, the hippocampus, and the amygdala) of the brain that are concerned especially with emotion and motivation.

Lobe

A division of a body organ (as the brain, lungs, or liver) marked off by a fissure on the surface.

Peripheral nervous system

The part of the nervous system that is outside the central nervous system and comprises the cranial nerves excepting the optic nerve, the spinal nerves, and the autonomic nervous system.

Phrenology

The study of the conformation of the skull based on the belief that it is indicative of mental faculties and character.

Sulcus

A shallow furrow on the surface of the brain separating adjacent gyri.

Action Potential

A momentary reversal in electrical potential across a plasma membrane (as of a nerve cell or muscle fiber) that occurs when a cell has been activated by a stimulus.

Axon

A long nerve cell process that usually conducts impulses away from the cell body.

Dendrite

Any of the usually branching protoplasmic processes that conduct impulses toward the body of a neuron.

Ion

An atom or group of atoms that carries a positive or negative electric charge as a result of having lost or gained one or more electrons.

Myelin sheath

In a neuron, an insulating coat of cell membrane from Schwann cells that is interrupted by nodes of Ranvier

Neuron

A nerve cell; the fundamental unit of the nervous system, having structure and properties that allow it to conduct signals by taking advantage of the electrical charge across its cell membrane.

Neurotransmitter

A substance (as norepinephrine or acetylcholine) that transmits nerve impulses across a synapse.

Reaction Time

The time elapsing between the beginning of the application of a stimulus and the beginning of an organism's reaction to it.

Reflex

An automatic and often inborn response to a stimulus that involves a nerve impulse passing inward from a receptor to the spinal cord and thence outward to an effector (as a muscle or gland) without reaching the level of consciousness and often without passing to the brain.

Synapse

The place at which a nervous impulse passes from one neuron to another.

Endocrine Gland

A gland (as the thyroid or the pituitary) that produces an endocrine secretion -- called also ductless gland, gland of internal secretion.

Endocrine System

The glands and parts of glands that produce endocrine secretions, help to integrate and control bodily metabolic activity, and include especially the pituitary, thyroid, parathyroid, adrenals, islets of Langerhans, ovaries, and testes.

Exocrine Gland

A gland (as a sweat gland, a salivary gland, or a kidney) that releases a secretion external to or at the surface of an organ by means of a canal or duct.

Gland

A cell, group of cells, or organ of endothelial origin that selectively removes materials from the blood, concentrates or alters them, and secretes them for further use in the body or for elimination from the body

Glucagon

A protein hormone that is produced especially by the pancreatic islets of Langerhans and that promotes an increase in the sugar content of the blood by increasing the rate of breakdown of glycogen in the liver.

Hormone

Any one of the many circulating chemical signals found in all multicellular organisms that are formed in specialized cells, travel in body fluids, and coordinate the various parts of the organism by interacting with target cells.

Hypothalamus

The ventral part of the vertebrate forebrain; functions in maintaining homeostasis, especially in coordinating the endocrine and nervous systems; secretes hormones of the posterior pituitary and releasing factors, which regulate the anterior pituitary.

Insulin

A vertebrate hormone that lowers blood glucose levels by promoting the uptake of glucose by most body cells and the synthesis and storage of glycogen in the liver

Pituitary gland

An endocrine gland at the base of the hypothalamus; consists of a posterior lobe, which stores and releases two hormones produced by the hypothalamus, and an anterior lobe, which produces and secretes many hormones that regulate diverse body functions.

Accommodation

The automatic adjustment of the eye for seeing at different distances affected chiefly by changes in the convexity of the crystalline lens.

Astigmatism

A defect of an optical system (as a lens) causing rays from a point to fail to meet in a focal point resulting in a blurred and imperfect image.

Blind spot

The small circular area in the retina where the optic nerve enters the eye that is devoid of rods and cones and is insensitive to light.

Cone

Any of the conical photosensitive receptor cells of the vertebrate retina that function in color vision

Cornea

The transparent part of the coat of the eyeball that covers the iris and pupil and admits light to the interior.

Depth Perception

The ability to judge the distance of objects and the spatial relationship of objects at different distances.

Hyperopia

A condition in which visual images come to a focus behind the retina of the eye and vision is better for distant than for near objects -- called also farsightedness

Iris

The opaque muscular contractile diaphragm that is suspended in the aqueous humor in front of the lens of the eye, is perforated by the pupil and is continuous peripherally with the ciliary body, has a deeply pigmented posterior surface which excludes the entrance of light except through the pupil and a colored anterior surface which determines the color of the eyes.

Lens

A curved piece of glass or plastic used singly or combined in eyeglasses or an optical instrument (as a microscope) for forming an image by focusing rays of light

Myopia

A condition in which the visual images come to a focus in front of the retina of the eye because of defects in the refractive media of the eye or of abnormal length of the eyeball resulting especially in defective vision of distant objects -- called also nearsightedness.

Optic nerve

Either of the pair of sensory nerves that comprise the second pair of cranial nerves, arise from the ventral part of the diencephalon, form an optic chiasma before passing to the eye and spreading over the anterior surface of the retina, and conduct visual stimuli to the brain.

Pupil

The opening in the iris, which admits light into the interior of the vertebrate eye; muscles in the iris regulate its size.

Refraction

The deflection from a straight path undergone by a light ray or a wave of energy in passing obliquely from one medium (as air) into another (as water or glass) in which its velocity is different.

Retina

The sensory membrane that lines most of the large posterior chamber of the vertebrate eye, is composed of several layers including one containing the rods and cones, and functions as the immediate instrument of vision by receiving the image formed by the lens and converting it into chemical and nervous signals which reach the brain by way of the optic nerve.

Rod

Any of the long rod-shaped photosensitive receptors in the retina responsive to faint light

Homeostasis

The maintenance of relatively stable internal physiological conditions (as body temperature or the pH of blood) in higher animals under fluctuating environmental conditions

Macromolecule

A very large molecule (as of a protein, nucleic acid, or carbohydrate) built up from smaller chemical structures

Resource

A very large molecule (as of a protein, nucleic acid, or carbohydrate) built up from smaller chemical structures

Adenosine triphosphate (ATP)

An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in the cell.

Anabolism

Synthetic, energy-requiring reactions whereby small molecules are built up into larger ones.

Basal metabolic rate (BMR)

The rate at which heat is given off by an organism at complete rest.

Body mass index (BMI)

A measure of body fat that is the ratio of the weight of the body in kilograms to the square of its height in meters.

Bolus

A soft mass of chewed food.

Calorie

The amount of heat energy required to raise the temperature of 1 g of water by 1°C. The Calorie (with a capital C), usually used to indicate the energy content of food, is a kilocalorie

Catabolism

Chemical reactions that break down complex organic compounds into simple ones, with the net release of energy.

Digestion

The process of making food absorbable by mechanically and enzymatically breaking it down into simpler chemical compounds in the alimentary canal.

Digestive system

The bodily system concerned with the ingestion, digestion, and absorption of food.

Enzyme

A protein serving as a catalyst, a chemical agent that changes the rate of reaction without being consumed by the reaction

Esophagus

A muscular tube that in adult humans is about nine inches (23 centimeters) long and passes from the pharynx down the neck between the trachea and the spinal column and behind the left bronchus where it pierces the diaphragm slightly to the left of the middle line and joins the cardiac end of the stomach.

Gallbladder

A membranous muscular sac in which bile from the liver is stored.

Gastrointestinal tract

The stomach and intestine as a functional unit

Large intestine

The more terminal division of the vertebrate intestine that is wider and shorter than the small intestine, typically divided into cecum, colon, and rectum, and concerned especially with the resorption of water and the formation of feces.

Liver

The largest internal organ in the vertebrate body; performs diverse functions such as producing bile, preparing nitrogenous wastes for disposal, and detoxifying poisonous chemicals in the blood.