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Human Body
Term | Definition |
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Homeostasis | the tendency of a system owing to the coordinated response of its parts to any situation or stimulus that would tend to disturb its normal condition or function. |
joint | a place in the body where two bones come together |
spongy bone | layer of bone tissue having many small spaces and found just in the layer of the compact bone |
compact bone | hard,dense bone tissue that is beneath the outer membrane of a bone |
cartilage | a connective tissue that is more flexible than than bone and that protects the ends of bones and keeps them from rubbing them together |
ligament | strong connective tissue that holds bones together in movable joints |
tendon | strong connective tissue that connects muscle to bone |
red marrow | bone marrow of children and some adult bones that is required for the formation of red blood cells |
yellow marrow | bone marrow that is yellow with fat; found at the ends of long bones in adults |
skeletal muscle | a muscle that is connected to the skeleton to form part of the mechanical system that moves the limbs and other parts of the body. |
striated muscle | A muscle that is made up of long fibers characterized by transverse or oblique striations, or alternating light and dark bands under the microscope. |
smooth muscle | Smooth muscle is an involuntary non-striated muscle. It is divided into two subgroups; the single-unit (unitary) and multiunit smooth muscle. |
cardiac muscle | Cardiac muscle (heart muscle) is involuntary striated muscle that is found in the walls and histological foundation of the heart, specifically the myocardium. |
The integumentary system | The integumentary system is the organ system that protects the body from various kinds of damage, such as loss of water or abrasion from outside. |
epidermis | the outer layer of cells covering an organism, in particular. |
dermis | The dermis is a layer of skin between the epidermis (with which it makes up the cutis) and subcutaneous tissues, that consists of connective tissue and cushions the body from stress and strain. |
melanin | Melanin is a broad term for a group of natural pigments found in most organisms (arachnids are one of the few groups in which it has not been detected). |
follicle | a small secretory cavity, sac, or gland, in particular. |
mechanical digestion | Mechanical digestion is the actual physical break down of food into smaller pieces. |
chemical digestion | the act or process of converting food into chemical substances that can be absorbed and assimilated. |
epiglottis | The epiglottis is a flap that is made of elastic cartilage tissue covered with a mucous membrane, attached to the entrance of the larynx. |
peristalsis | Peristalsis is a radially symmetrical contraction and relaxation of muscles that propagates in a wave down a tube, in an anterograde direction. |
esophagus | the part of the alimentary canal that connects the throat to the stomach; the gullet. In humans and other vertebrates it is a muscular tube lined with mucous membrane. |
absorption | the process or action by which one thing absorbs or is absorbed by another: |
villus | any of numerous minute elongated projections set closely together on a surface, typically increasing its surface area for the absorption of substances, in particular. |
pacemaker | an artificial device for stimulating the heart muscle and regulating its contractions. |
artery | any of the muscular-walled tubes forming part of the circulation system by which blood (mainly that which has been oxygenated) is conveyed from the heart to all parts of the body. |
capillary | any of the muscular-walled tubes forming part of the circulation system by which blood (mainly that which has been oxygenated) is conveyed from the heart to all parts of the body. |
vein | any of the tubes forming part of the blood circulation system of the body, carrying in most cases oxygen-depleted blood toward the heart. |
plasma | Plasma is one of the four fundamental states of matter, the others being solid, liquid, and gas. A plasma has properties unlike those of the other states. |
red blood cell | Physiology. one of the cells of the blood, which in mammals are enucleate disks concave on both sides, contain hemoglobin, and carry oxygen to the cells and tissues and carbon dioxide back to the respiratory organs. |
hemoglobin | Hemoglobin; also spelled haemoglobin and abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates |
white blood cell | any of various nearly colorless cells of the immune system that circulate mainly in the blood |
platelet | Platelets, also called "thrombocytes", are blood cells whose function (along with the coagulation factors) is to stop bleeding. |
lymph | a colorless fluid containing white blood cells, that bathes the tissues and drains through the lymphatic system into the bloodstream. |
lymph node | A lymph node is an oval-shaped organ of the lymphatic system, distributed widely throughout the body including the armpit and stomach and linked by lymphatic vessels. |
cilia | Cilia are slender protuberances that project from the much larger cell body. |
pharynx | The pharynx (plural: pharynges) is an organ found in vertebrates and invertebrates, though the structure is not universally the same across the species. |
trachea | a large membranous tube reinforced by rings of cartilage, extending from the larynx to the bronchial tubes and conveying air to and from the lungs; the windpipe. |
alveoli | a small cavity, pit, or hollow, in particular. |
diaphragm | a dome-shaped, muscular partition separating the thorax from the abdomen in mammals. It plays a major role in breathing, as its contraction increases the volume of the thorax and so inflates the lungs. |
larynx | the voice box |
excretion | Excretion is the process by which waste products of metabolism and other non-useful materials are eliminated from an organism. |
urea | a colorless crystalline compound that is the main nitrogenous breakdown product of protein metabolism in mammals and is excreted in urine. |
kidney | each of a pair of organs in the abdominal cavity of mammals, birds, and reptiles, excreting urine. |
ureter | the duct by which urine passes from the kidney to the bladder or cloaca. |
urinary bladder | The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. |
urethra | In anatomy, the urethra is a tube that connects the urinary bladder to the urinary meatus for the removal of fluids from the body |
nephron | Nephron is the basic structural and functional unit of the kidney. |
pathogen | A pathogen in the oldest and broadest sense is anything that can produce disease. |
inflammatory response | a tissue reaction to injury or an antigen that may include pain, swelling, itching, redness, heat, and loss of function. The response may involve dilation of blood vessels and consequent leakage of fluid, |
immune response | the reaction of the cells and fluids of the body to the presence of a substance that is not recognized as a constituent of the body itself. |
antibody | An antibody (Ab), also known as an immunoglobulin (Ig), is a large Y-shape protein produced by plasma cells that is used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. |
stimulus | a thing or event that evokes a specific functional reaction in an organ or tissue: |
response | A reaction, as that of an organism or a mechanism, to a specific stimulus. |
neuron | A neuron is an electrically excitable cell that processes and transmits information through electrical and chemical signals. |
dendrite | Dendrites are the branched projections of a neuron that act to propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project. |
axon | An axon, also known as a nerve fibre, is a long, slender projection of a nerve cell, or neuron, that typically conducts electrical impulses away from the neuron's cell body. |
nerve | (in the body) a whitish fiber or bundle of fibers that transmits impulses of sensation to the brain or spinal cord, and impulses from these to the muscles and organs: "the optic nerve" |
sensory neuron | Sensory neurons are nerve cells that transmit sensory information (sight, sound, feeling, etc.). |
interneuron | An interneuron (also called relay neuron, association neuron, connector neuron or local circuit neuron) is a neuron that forms a connection between other neurons. |
motor neuron | A motor neuron (or motoneuron) is a nerve cell (neuron) that originates in the motor region of the cerebral cortex or the brain stem |
synapse | a junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter. |
central nervous system | The central nervous system (CNS) is the part of the nervous system consisting of the brain and spinal cord. |
peripheral nervous system | The peripheral nervous system (or PNS), is composed of nerves leading to and from the CNS, often through junctions known as ganglia. |
somatic nervous system | The somatic nervous system (SoNS or voluntary nervous system) is the part of the peripheral nervous system associated with the voluntary control of body movements via skeletal muscles. |
autonomic nervous system | The autonomic nervous system (ANS), also known as the visceral nervous system and involuntary nervous system — is a division of the peripheral nervous system that functions as a control system |
reflex | A reflex action, differently known as a reflex, is an involuntary and nearly instantaneous movement in response to a stimulus. |
hormone | A hormone is a class of signaling molecules produced by glands in multicellular organisms that are transported by the circulatory system to target distant organs to regulate physiology and behavior. |
endocrine gland | any gland of the body that secretes hormones directly into the blood or lymph, e.g. the thyroid, pituitary, pineal, and adrenal glands |
target cell | a cell that is acted on selectively by a specific agent (as a virus, drug, or hormone) |