E-Core Biology
Human Body Vocabulary
1. Homeostasis- The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its physiological processes.
2. Neuron- Any of the impulse-conducting cells that constitute the brain, spinal column, and nerves, consisting of a nucleated cell body with one or more dendrites and a single axon.
3. Nervous system- The system of cells, tissues, and organs that regulates the body's responses to internal and external stimuli.
4. The portion of a nerve cell that contains the nucleus but does not incorporate the dendrites or axon.
5. Dendrite- A branched protoplasmic extension of a nerve cell that conducts impulses from adjacent cells inward toward the cell body. A single nerve may possess many dendrites
6. Axon- The usually long process of a nerve fiber that generally conducts impulses away from the body of the nerve cell.
7. Myelin sheath- The insulating envelope of myelin that surrounds the core of a nerve fiber or axon and facilitates the transmission of nerve impulses
8. Resting potential- The insulating envelope of myelin that surrounds the core of a nerve fiber or axon and facilitates the transmission of nerve impulses.
9. Action potential- A momentary change in electrical potential on the surface of a nerve or muscle cell that takes place when it is stimulated, especially by the transmission of a nerve impulse
10. Threshold- The point that must be exceeded to begin producing a given effect or result or to elicit a response
11. Synapse- The junction across which a nerve impulse passes from an axon terminal to a neuron, muscle cell, or gland cell
12. Neurotransmitter - A chemical substance, such as acetylcholine or dopamine, that transmits nerve impulses across a synapse
13. Meninges- A membrane, especially one of the three membranes enclosing the brain and spinal cord in vertebrates
14. Cerebrospinal fluid - fluid in the space between the meninges that acts as a shock absorber that protects the central nervous system
15. Cerebrum - area of the brain responsible for all voluntary activities of the body
16. Cerebellum - region of the brain that coordinates body movements
17. Brain stem - structure that connects the brain and spinal cord; includes the medulla oblongata and the pons
18. Thalamus - brain structure that receives messages from the sense organs and relays the information to the proper region of the cerebrum for further processing
19. Hypothalamus - brain structure that acts as a control center for recognition and analysis of hunger, thirst, fatigue, anger, and body temperature
20. Reflex - quick automatic response to a stimulus
21. Reflex arc - sensory receptor, sensory neuron, motor neuron, and effector that are involved in a quick response to a stimulus
22. Sensory receptor - neuron that reacts to a specific stimulus, such as light or sound, by sending impulses to other neurons and eventually to the central nervous system
23. Pupil - small opening in the middle of the iris through which light enters the eye
24. Lens - transparent object behind the iris that changes shape to help adjust the eye's focus to see near or distant objects
25. Retina - innermost layer of the eye; contains photoreceptors
26. Rod - photoreceptor in eye that is sensitive to light but not to colors
27. Cone - in gymnosperms, a seed-bearing structure; in the retina of the eye, a photoreceptor that responds to light of different colors, producing color vision
28. Cochlea - fluid-filled part of the inner ear; sends nerve impulses to the brain through the cochlear nerve
29. Semicircular canal - one of three structures within the inner ear that help monitor the position of the body
30. Taste bud - sense organ that detects the flavor of a substance
31. Drug - any substance, other than food, that causes a change in the structure or function of the body
32. Stimulant - drug that speeds up the actions regulated by the nervous system
33. Depressant - drug that decreases the rate of functions regulated by the brain
34. Drug abuse - intentional misuse of any drug for non-medical purposes
35. addiction- uncontrollable dependence on a drug
36. periosteum- tough layer of connective tissue surrounding a bone
37. Haversain canal- one of a network of tubes running through compact bone that contains blood vessels and nerves
38. Bone marrow- soft tissue inside the cavities within bones; two types are tallow marrow and red marrow
39. Cartilage- strong connective tissue that supports the body and is softer and more flexible than bone
40. Ossification- process of bone formation, during which cartilage is replaced by bone
41. joint- place where one bone attaches to another
42. Ligament- strip of tough connective tissue that holds bones together at a joint
43. Myosin- protein that makes up the thick filaments in striations in skeletal muscle cells
44. Actin- protein that mainly makes up the thin filaments in striations in skeletal muscle cells
45. Neurotransmitter junction- point of contact between a motor neuron and a skeletal muscle cell
46. Acetylcholine- neurotransmitter that diffuses across a synapse that diffuses across a synapse and produces an impulse in the cell membrane of a muscle cell
47. Tendon- tough connective tissue that joins skeletal muscles to bones
48. Epidermis- outer layer of the skin
49. Keratin- tough, fibrous protein found in skin
50. Melanin- dark-brown pigment found in skin
51. Dermis- inner layer of skin
52. Hair follicle- tube like pocket of epidermal cells that extends into the dermis; cells at the base of hair follicles produce hair
53. Myocardium- thick middle muscle layer of the heart; pumps blood through the circulatory system
54. Atrium- upper chamber of the heart that receives and holds blood that is about to enter the ventricle.
55. Ventricle- lower chamber of the heart that pumps blood out of the heart
56. Pulmonary circulation- pathway of circulation between the heart and lungs
57. Systemic circulation- pathway of circulation between the heart and the rest of the body except the lungs
58. Valve- flap of connective tissue between an atrium and a ventricle, or in a vein, that prevents backflow of blood
59. Pacemaker- small group of cardiac muscle cells in the right atrium that �set the pace� for the heart as a whole; also known as the sinoatrial node
60. Aorta- large blood vessel in mammals through which blood travels from the left ventricle to all parts of the body except the lungs
61. Artery- large blood vessel that carries blood from the heart to the tissues of the body
62. Capillary- smallest blood vessel; brings nutrients and oxygen to the tissues and absorbs carbon dioxide and waste products
63. Vein- in plants, a cluster of vascular tissues in leaves; in animals, a blood vessel that returns blood to the heart
64. Atherosclerosis- condition in which fatty deposits called plaque build up on the inner walls of the arteries
65. Plasma- straw-colored fluid that makes up about 55% of blood; consists of about 90% water, and about 10% dissolved gasses, salts, nutrients, enzymes, hormones, waste products, and plasma proteins
66. Hemoglobin- iron-containing protein in red blood cells that transport oxygen from the lungs to the tissues of the body
67. Lymphocyte- type of white blood cell that produces antibodies that help destroy pathogens
68. Platelet- cell fragment released by bone marrow that helps in blood clotting
69. Lymph- fluid lost by the blood into surrounding tissue
70. Pharynx- muscular tube at the end of the gastrovascular cavity, or throat, that connects the mouth with the rest of the digestive tract and serves as a passageway for air and food
71. Trachea- windpipe; tube through which air moves
72. Larynx- structure in the throat containing the vocal chords
73. Bronchus- passageway leading from the trachea to a lung
74. Alveolus- tiny air sac at the end of a bronchiole in the lungs that provides surface area for gas exchange to occur
75. Diaphragm- large, flat muscle at the bottom of the chest cavity that helps with breathing.
76. Calorie-term used by scientists to measure the energy stored in foods; 1000 calories
77. Carbohydrate-compound made up of carbon, hydrogen, and oxygen atoms; major source of energy for the human body
78. Fat-lipid; made up of fatty acids and glycerol; protects body organs, insulates body, and stores energy in the body
79. Protein-macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair and to make up enzymes
80. Vitamin-organic molecule that helps regulate body processes
81. Mineral-inorganic nutrient the body needs, usually in small amounts
82. Amylase-enzyme in saliva that breaks the chemical bonds between the sugar monomers in starches
83. Esophagus-food tube connecting the mouth to the stomach
84. Peristalsis-rhythmic muscular contractions that squeeze food through the esophagus into the stomach
85. Stomach-large muscular sac that continues the mechanical and chemical digestion of food
86. Chyme-mixture of stomach fluids and food produced in the stomach by contracting stomach muscles
87. Small intestine-digestive organ in which most chemical digestion takes place
88. Pancreas-gland that produces hormones that regulate blood sugar; produces enzymes that break down carbohydrates, proteins, lipids, and nucleic acids; and produces sodium bicarbonate, a base that neutralizes stomach acid
89. Liver-large organ just above the stomach that produces bile, a fluid loaded with lipids and salts
90. Villus-folded projection that increases the surface area of the walls of the small intestine
91. Large intestine-colon; organ that removes water from the undigested materials that pass through it
92. Kidney-organ that removes urea, excess water, and other waste products from the blood and passes them to the ureter
93. Ureter-tube that carries urine from the kidney to the urinary bladder
94. Urinary bladder-saclike organ in which urine is stored before being excreted
95. Nephron-blood-filtering unit in the renal cortex of the kidney
96. Filtration-process by which a liquid or gas passes through a filter to remove wastes
97. Glomerulus-small network of capillaries encased in the upper end of a nephron; where the filtration of blood takes place
98. Bowman�s capsule-cup-shaped structure in the upper end of a nephron that encases the glomerulus
99. Loop of Henle-section of the nephron tubule that conserves water and minimizes the volume of urine
100. Urethra-tube that carries urine from the bladder and releases it from the body; in males, tube through which semen is released from the body
101. Hormone-substance produced in one part of an organism that affects another part of the same organism
102. Target Cell-cell that has a receptor for a particular hormone
103. Exocrine gland-gland that releases its secretions through tubelike structures called ducts
104. Endocrine gland-gland that releases its secretions directly into the bloodstream
105. Prostaglandin-hormonelike modified fatty acid produced by a wide range of cells; generally affects only nearby cells and tissues