Vocabulary 8-9 Flashcards
1
Q
ABO system
A
The commonly used blood classification system, based on the antigens present or absent in the blood
2
Q
Accessory muscles
A
The muscles not normally used during quiet breathing
Ex. Sternocleidomastoid, pectoralis major, abdominal muscles
3
Q
Accommodation
A
The ability of the lens of the eye to change its shape to focus on a close object
4
Q
Acetabulum
A
The socket formed by the coxal (hip) bone into which the ball-shaped femoral head fits snugly
5
Q
ACh
A
Acetylcholine
A neurotransmitter released at synapses within the autonomic nervous system and by motor neurons to stimulate skeletal muscle contraction
6
Q
Acetylcholinesterase
A
An enzyme found in the central nervous system, in red blood cells, and in motor endplates of skeletal muscle that causes the decomposition of acetylcholine
7
Q
Acid
A
Any molecule that can give up a hydrogen ion, and therefore increases the concentration of hydrogen ions in a water solution
8
Q
Acidosis
A
A pathological condition resulting from the accumulation of acids in the body (blood pH less than 7.35)
9
Q
Acromion process
A
The tip of the shoulder and the site of attachment for the clavicle and various shoulder muscles
10
Q
Action potential
A
Sequence of changes in the membrane potential that occurs when an excitable cell (neuron or muscle) is stimulated
11
Q
Actin
A
A contractile protein found in the thin filaments of skeletal muscle cells
12
Q
Active transport
A
A method used to move compounds across a cell membrane to create or maintain an imbalance of charges, usually against a concentration gradient and requiring the expenditure of energy
13
Q
Adaptation
A
The temporary or permanent reduction of sensitivity to a particular stimulus
14
Q
ATP
A
Adenosine triphosphate
The nucleotide formed from the metabolism of nutrients in the cell; involved in energy metabolism; used to store energy
15
Q
Adrenal cortex
A
The outer layer of the adrenal gland; it produces hormones that are important in regulating the water and salt balance of the body
16
Q
Adrenal glands
A
Paired endocrine glands located on top of the kidneys that release epinephrine and norepinephrine when stimulated by the sympathetic nervous system; each adrenal gland consists of an inner adrenal medulla and an adrenal cortex
17
Q
Adrenergic
A
Having the characteristics of the sympathetic division of the autonomic nervous system
18
Q
ACTH
A
Adrenocorticotropic hormone
Hormone that targets the adrenal cortex to secrete cortisol (a glucocorticoid)
19
Q
Aerobic metabolism
A
Metabolism that can proceed only in the presence of oxygen
20
Q
Afterimage
A
The perception that a stimulus is still present after the stimulus has been removed
21
Q
Afterload
A
The pressure in the aorta against which the left ventricle must pump blood
22
Q
Albumins
A
The smallest of plasma proteins; they make up around 60% of the plasma proteins and are responsible for the oncotic pressure in the vasculature, thereby controlling the movement of water into and out of the circulation
23
Q
Aldosterone
A
A hormone responsible for the reabsorption of sodium and water from the kidney tubules
24
Q
Alkalosis
A
A pathologic condition resulting from the accumulation of bases in the body (blood pH greater than 7.45)
25
Alleles
Variant forms of a gene, which can be identical or slightly different in a sequence of deoxyribonucleic acid
26
Alveoli
The air sacs of the lungs in which the exchange of oxygen and carbon dioxide takes place; also, the bony sockets for the teeth that reside in the mandible and maxilla
27
Anabolism
The building of larger substances from smaller substances, such as the building of proteins from amino acids
28
Anaerobic metabolism
Metabolism that occurs in the absence of oxygen
29
Anatomy
The study of the structure of an organism and its parts
30
Angle of Louis
A prominence of the sternum that indicates the point where the second rib joins the sternum; also called the sternal angle or manubriosternal junction
31
Antagonist
A molecule that blocks the ability of a given chemical to bind to its receptor, preventing a biologic response
32
Antigens
Proteins, polysaccharides, glycoproteins, or glycolipids commonly found on the surfaces of red blood cells that stimulate an immune system response and cause formation of antibodies; cells learn to recognize antigens as either “self” or “nonself” (foreign)
33
Aorta
The principal artery leaving the left side of the heart and carrying freshly oxygenated blood to the body; the largest artery in the body
34
Aortic valve
The semilunar valve that regulates blood flow from the left ventricle to the aorta
35
Apneustic center
A portion of the pons that is thought to work with the pontine respiratory group to regulate the length and depth of inspiration
36
Appendicular skeleton
The portion of the skeletal system made up of the upper extremities, shoulder girdle, pelvic girdle, and lower extremities
37
Aqueous humor
Watery fluid filling the anterior eye cavity; the quantity determines the intraocular pressure, which is critical to sight
38
Areolar tissue
A type of loose connective tissue that binds skin to underlying organs and fills in spaces between muscles
39
Arytenoid cartilages
Six paired cartilages stacked on top of each other in the larynx
40
Astigmatism
Condition where parts of the image are out of focus and others are in focus; caused by irregularities in the shape of the eye lens
41
Atlas
The first cervical vertebra (C1), which provides support for the head
42
Atria
Two upper chambers of the heart
43
Atrial natriuretic peptide
A hormone produced by the atria when they are distended by increased blood volume; it inhibits the absorption of water and sodium in the renal tubules, thereby increasing the elimination of water
44
Atrioventricular (AV) node
A group of cells that conduct an electrical impulse through the heart; located in the floor of the right atrium immediately behind the tricuspid valve and near the opening of the coronary sinus
45
Atrioventricular (AV) valves
The mitral and tricuspid valves through which blood flows from the atria to the ventricles
46
Automaticity
Ability of cardiac pacemaker cells to initiate an electrical impulse spontaneously without being stimulated from another source (such as a nerve)
47
ANS
Autonomic Nervous System
A subdivision of the nervous system that controls primarily involuntary body functions; comprised of the sympathetic and parasympathetic nervous systems
48
Autosomes
The chromosomes that do not carry genes that determine sex
49
Axial skeleton
The portion of the skeleton made up of the skull, thoracic cage, and vertebral column
50
Axis
Imaginary line joining the positive and negative electrodes of a lead; also the second cervical vertebra
51
Axon
Long, slender extension of a neuron (nerve cell) that conducts electrical impulses away from the nerve cell body to adjacent cells
52
B lymphocytes
Lymphocytes that exist in the blood, and are abundant in the lymph nodes, bone marrow, intestinal lining, and spleen; also called B cells
53
Baroreceptors
Nerve endings that are stimulated by pressure changes, including increased arterial blood pressure; they are located in the aortic arch and carotid sinuses
54
Basal ganglia
Structures located deep within the cerebrum, diencephalon, and midbrain that have an important role in coordination of motor movements and posture
55
Basal metabolic rate
The rate at which nutrients are consumed in the body
56
Basophils
White blood cells that contain histamine granules and other substances that are released during inflammatory and allergic responses
57
Bilirubin
A waste product of red blood cell destruction that undergoes further metabolism in the liver
58
Binocular vision
The merging of two images into one
59
Blood-brain barrier
A layer of tightly-adhered cells that protects the brain and spinal cord from exposure to medications, toxins, and infectious particles
60
Bone marrow
Soft tissue that fills the inside of bones and is the site of production of red blood cells, platelets, and most white blood cells
61
Bony labyrinth
The collection of hollows in the bone of the inner ear that provide protection to the structures of the inner ear from damage and from extraneous stimulation
62
Boyle’s law
Gas law that demonstrates that as a pressure increases, volume decreases; at a constant temperature, the volume of a gas is inversely proportional to its pressure; written as PV = K
63
Brain
The part of the central nervous system located within the cranium; contains billions of neurons that serve a variety of functions including consciousness, perception, control of reactions to the environment, emotional responses, and judgment
64
Brainstem
The area of the brain between the spinal cord and cerebrum that contains the midbrain, pons, and medulla; controls functions that are necessary for life, such as breathing
65
Bruit
Abnormal whooshing sounds indicating turbulent blood flow within a narrowed blood vessel, usually heard in the carotid arteries
66
Buffer system
Fast-acting defenses for acid-base changes, providing almost immediate protection against changes in the hydrogen ion concentration of extracellular fluid
67
Bundle of His
The portion of the conduction system of the heart located in the upper portion of the interventricular septum that conducts an electrical impulse from the atrioventricular junction to the right and left bundle branches
68
Bursa
A small, padlike sac or cavity filled with a small amount of synovial fluid that helps reduce the amount of friction between a tendon and a bone or between a tendon and a ligament, usually located near a joint
69
Calcaneus
The heel bone; the largest of the tarsal bones
70
Calorie
The amount of heat needed to raise the temperature of a gram of water by 33°F (1°C); the amount of energy that can be obtained from the nutrients you eat; also called a kilocalorie
71
Carbohydrates
Substances (including sugars and starches) that provide much of the energy required by the body’s cells, as well as helping to build cell structures
72
Cardiac cycle
The repetitive pumping process that begins with the onset of cardiac muscle contraction and ends just before the beginning of the next contraction; each one consists of ventricular contraction (systole) and relaxation (diastole)
73
Carina
The point of bifurcation of the right and left primary (mainstem) bronchi
74
Carpal bones
The eight small bones of the wrist
75
Cartilaginous joints
Those connected by hyaline cartilage, or fibrocartilage, such as the joints that separate the vertebrae
76
Catabolism
The breakdown of larger molecules into smaller ones
77
Cataract
Clouding of the lens of the eye or its surrounding transparent membrane
78
Catecholamines
Amine substances such as dopamine, epinephrine, and norepinephrine that function as neurotransmitters, hormones, or both
79
Cell membrane
A selectively permeable layer of cells that surround intracellular contents and control movement of substances into and out of the cell; also called the cytoplasmic membrane or plasma membrane
80
Cellular respiration
A biochemical process resulting in the production of energy in the form of adenosine triphosphate
81
CNS
Central Nervous System
The brain and spinal cord
82
Cerebellum
Area of the brain involved in fine and gross muscle coordination; responsible for interpretation of actual movement and correction of any movements that interfere with coordination and the body’s position
83
Cerebral cortex
The outer covering of gray matter that covers the cerebral hemispheres; regulates voluntary skeletal movement and plays an important role in one’s level of awareness
84
CPP
Cerebral perfusion pressure
Pressure inside the cerebral arteries and an indicator of brain perfusion; calculated by subtracting intracranial pressure from mean arterial pressure
85
CSF
Cerebrospinal fluid
Fluid produced in the ventricles of the brain that flows in the subarachnoid space and bathes the meninges
86
Cerebrum
The largest part of the brain; made up of several lobes that control movement, hearing, balance, speech, visual perception, emotions, and personality; divided into right and left hemispheres; also called gray matter
87
Chemoreceptors
Sense organs that monitor the levels of oxygen and carbon dioxide and the pH of cerebrospinal fluid and blood and provide feedback to the respiratory centers to modify the rate and depth of breathing based on the body’s needs at any given time
88
Cholinergic
Having the characteristics of the parasympathetic division of the autonomic nervous system; also refers to other structures or functions that are related to acetylcholine
89
Chordae tendineae
Thin bands of fibrous tissue that attach to the atrioventricular valves in the heart and prevent them from inverting
90
Choroid
The vascular, pigmented middle layer of the eye wall
91
Choroid plexus
Group of specialized cells in the ventricles of the brain; filters blood through cerebral capillaries to create cerebrospinal fluid
92
Chromosomes
Structures formed from condensed fibers and protein of deoxyribonucleic acid; they are threadlike, and are contained within the nucleus of the cells
93
Chronotropic effect
Related to the effect of the rate of contraction of the heart
94
Ciliary body
The structure associated with the choroid layer of the eye that secretes aqueous humor and contains the ciliary muscle
95
Circulatory system
The complex arrangement of connected tubes, including the arteries, arterioles, capillaries, venules, and veins, that moves blood, oxygen, nutrients, carbon dioxide, and cellular waste throughout the body
96
Circumflex coronary artery
One of two branches of the left main coronary artery
97
Citric acid cycle
A sequence of enzymatic reactions involving the metabolism of carbon chains of glucose, fatty acids, and amino acids to yield carbon dioxide, water, and high-energy phosphate bonds; also known as the Krebs cycle or tricarboxylic acid cycle
98
Clotting cascade
A set of interactions that lead to the formation of a fibrin clot; also called the coagulation cascade
99
Cochlea
The portion of the inner ear that has hearing receptors
100
Compound
A substance that can be broken down into the two or more elements contained within it
101
Conductivity
The property that allows a cardiac cell to receive an electrical impulse and pass it on to an adjoining cardiac cell
102
Cones
One of two photoreceptors of the retina that can distinguish colors, but requires a greater amount of light to activate and create an image
103
Conjunctiva
The membranous covering on the anterior surface of the eye that also lines the eyelids
104
Conjunctivitis
Inflammation of the conjunctiva
105
Connective tissues
Tissues that bind, support, protect, frame, and fill body structures; they also store fat, produce blood cells, repair tissues, and protect against infection
106
Contractility
The ability of myocardial cells to shorten in response to an impulse, which results in contraction
107
Cornea
The transparent tissue layer in front of the pupil and iris of the eye
108
Coronary sinus
Venous drain for the coronary circulation into the right atrium
109
Corpus callosum
A deep bridge of nerve fibers connecting the brain hemispheres
110
Corticosteroids
Any of several steroids secreted by the adrenal gland
111
Cortisol
A glucocorticoid of the middle adrenal cortex that influences protein and fat metabolism and stimulates glucose to be synthesized from noncarbohydrates
112
Cranial nerves
The 12 pairs of nerves that arise from the base of the brain
113
Cranial vault
The bones that encase and protect the brain, including the parietal, temporal, frontal, occipital, sphenoid, and ethmoid bones; the roof of the skull (cranium)
114
Cranium
The area of the head above the ears and eyes; the part of the skull that houses the brain
115
Cribriform plate
A horizontal bone perforated with numerous openings for the passage of the olfactory nerve filaments from the nasal cavity
116
Cricoid cartilage
A firm ridge of cartilage that forms the lower part of the larynx; the first ring of the trachea and the only upper airway structure that forms a complete ring; also called the cricoid ring
117
Cricothyroid membrane
A thin sheet of fascia located between the thyroid and cricoid cartilage that is relatively avascular and contains few nerves; the site for emergency access to the airway
118
Cytoplasm
The gel-like material that fills out a cell; it makes up most of the volume of the cell, and suspends the organelles of the cell
119
Deep fascia
A dense layer of fibrous tissue below the subcutaneous tissue; composed of tough bands of tissue that surround muscles and other internal structures
120
Dendrites
Branchlike projections of nerve cells that receive impulses or sensory information from nearby cells and conduct impulses toward the nerve cell body
121
DNA
Deoxyribonucleic acid
Specialized structure within the cell that carries genetic material for reproduction
122
Depolarization
In response to an action potential, the rapid movement of electrolytes across a cell membrane that changes overall charge of the cell; this rapid shifting of electrolytes and cellular charges is the main catalyst for muscle contractions and neural transmissions
123
Dermatome
The area of the skin supplied by a specific sensory spinal nerve
124
Descending aorta
The portion of the aorta that extends through the thorax and abdomen into the pelvis
125
Diapedesis
A process whereby leukocytes move through the wall of a capillary and out to the tissues where they are needed most
126
Diaphragm
Large skeletal muscle that plays a major role in breathing and separates the chest cavity from the abdominal cavity
127
Diaphysis
The shaft of a long bone
128
Diastole
Phase of the cardiac cycle in which the atria and ventricles relax between contractions and blood enters these chambers
129
Diencephalon
Portion of the brain between the brainstem and cerebrum; contains the epithalamus, the thalamus, the hypothalamus, and the subthalamus
130
Differentiation
The process of specialization of a cell
131
Diffusion
The process of particles moving from an area of higher concentration to an area of lower concentration along a concentration gradient until equilibrium is achieved
132
Digestion
The chemical breakdown of food material into smaller fragments that can be absorbed into the circulatory system
133
Diploid cells
Cells that carry two of each of the 23 chromosomes- one from the father and one from the mother
134
DRG
Dorsal respiratory group
A portion of the medulla oblongata that functions as a respiratory integration center; it receives input from several sources including the pontine respiratory group, sensory input through the glossopharyngeal and vagus nerves, central chemoreceptors in the medulla, and peripheral chemoreceptors
135
Dura mater
The outermost of the three meninges that enclose the brain and spinal cord; it is the toughest meningeal layer
136
Electrolytes
Salt or acid substances that become ionic conductors when dissolved in a solvent (such as water); chemicals dissolved in the blood
137
Endocardium
The thin membrane lining the inside of the heart
138
Endocrine glands
Glands that have no ducts and secrete directly into tissue fluid or blood
139
Endocrine system
The complex message and control system that integrates many body functions, including the release of hormones
140
Endolymph
The fluid containing nerve receptors that resides inside the membranous labyrinth; sound waves converted into pressure waves are transmitted through this fluid to the auditory nerves
141
ENS
Enteric nervous system
A subdivision of the autonomic nervous system that controls the digestive system
142
Enzymes
Substances designed to speed up the rate of specific biochemical reactions
143
Eosinophil
A leukocyte that may play a role following infection in various areas in the body
144
Epicardium
The layer of the serous pericardium that lies closely against the heart; also called the visceral pericardium
145
Epiglottis
A thin, flaplike structure that allows air to pass into the trachea but prevents food and liquid from entering
146
Epinephrine
A hormone produced by the adrenal medulla that has a vital role in the function of the sympathetic division of the autonomic nervous system; mediates the fight-or-flight response; also called adrenaline
147
Epiphyseal plate
The growth plate of a long bone; a major site of bone development during childhood; also called the physis
148
Epithelial tissues
Body tissues that cover organs, form the inner lining of cavities, and line hollow organs
149
Estrogen
A hormone released from the ovaries that stimulates the uterine lining during the menstrual cycle
150
Eustachian tube
A branch of the internal auditory canal that connects the middle ear to the oropharynx
151
Excitability
The ability of cardiac muscle cells to respond to an electrical, chemical, or mechanical stimulus
152
Exhalation
The passive part of the breathing process in which the diaphragm and the intercostal muscles relax, forcing air out of the lungs
153
Exocrine glands
Glands that secrete chemicals into ducts that open onto a surface for elimination
154
Expiratory reserve volume
The amount of air that can be exhaled following a normal exhalation; average volume is about 1,200 mL
155
ECF
Extracellular fluid
Fluid outside of the cell, in which most of the body’s supply of sodium is contained; accounts for 15%-20% of body weight
156
Extrinsic muscles
Referring to the eye; six muscles that attach to the exterior of the globe and are controlled by the cranial nerves
157
Fascia
A sheet or band of tough fibrous connective tissue that covers, supports, and separates muscles, and which also covers arteries, veins, tendons, and ligaments
158
Fibrin
A white, insoluble protein formed by the action of thrombin on fibrinogen during the blood clotting process; forms the matrix of a blood clot
159
Fibrinogen
A plasma protein that is important for blood clotting
160
Fibrous joints
Joints that lie between bones that closely contact each other, joined by thin, dense connective tissue
161
Filtration
The movement of fluid from intravascular fluid under high pressure to interstitial fluid, which is generally under lower pressure
162
Fluid balance
The process of maintaining homeostasis through equal intake (water taken into the body) and output (water excreted from the body) of fluids
163
Fontanelles
The soft spots in the skull of a newborn and infant where the sutures of the skull have not yet grown together
164
FIO2
Fraction of inspired oxygen
The percentage of oxygen in inhaled air
165
Gag reflex
A normal neural reflex elicited by touching the soft palate or posterior pharynx; the responses are symmetric elevation of the palate, retraction of the tongue, and contraction of the pharyngeal muscles
166
General senses
Sensations monitored throughout the body by receptors scattered throughout many different tissues
167
Genotype
The arrangement of a person’s genes and their characteristics is based on the combination of alleles, for one gene or many
168
Glaucoma
A disease of the eye caused by an increase in intraocular pressure; when severe enough, this may damage the optic nerve and potentially cause permanent loss of vision
169
Globulins
Antibodies made by the liver or lymphatic tissues that make up around 36% of the plasma proteins
170
Glottis
The true vocal cords and the opening between them
171
Gluconeogenesis
A process that stimulates both the liver and the kidneys to produce glucose from noncarbohydrate molecules
172
Glycogen
A long polymer from which glucose is converted in the liver (animal starch)
173
Glycogenolysis
The breakdown of glycogen to glucose
174
Glycolysis
Process by which glucose and other sugars are broken down to yield lactic acid (anaerobic glycolysis) or pyruvic acid (aerobic glycolysis); the breakdown releases energy in the form of adenosine triphosphate
175
Haploid cells
Cells that carry genetic instructions via 23 individual chromosomes
176
Hard palate
The anterior portion of the palate that is supported by bone (primarily the maxillary bone)
177
Hematocrit
A measure of the relative percentage of blood cells (mainly erythrocytes) in a given volume of whole blood
178
Hematopoietic system
The blood components and the organs involved in their development and production
179
Hemoglobin
An iron-containing pigment found in red blood cells that carries oxygen to the cells from the lungs and carbon dioxide away from the cells to the lungs
180
Hemostasis
The stoppage of bleeding; involves the steps of blood vessel spasm, platelet plug formation, and blood clotting
181
Henry’s law
A law of gas that states that the amount of gas in a solution varies directly with the partial pressure of a gas over a solution
182
Hepatic portal system
A specialized part of the venous system that carries blood from the digestive tract to the liver and then to the inferior vena cava
183
Hering-Breuer reflex
A protective mechanism that terminates inhalation, thus preventing overexpansion of the lungs
184
Histamine
A vasoactive amine found in large amounts in basophils that increases tissue inflammation; increases vascular permeability and causes vasodilation
185
Homeostasis
A tendency to constancy or stability in the body’s internal environment; processes that balance the supply and demand of the body’s needs
186
Homologous chromosome
A chromosome of the same numbered pair from the opposite parent
187
Hormone
A substance that is produced in one tissue or organ and is released into the blood and carried to other (target) organs, where it acts to produce a specific response
188
Hydrostatic pressure
The pressure of water against the walls of its container
189
Hyoid bone
A small, horseshoe-shaped bone to which the jaw, tongue, epiglottis, and thyroid cartilage attach
190
Hyperopia
Farsighted; the ability to see distant objects with difficulty focusing on objects close
191
Hypertonic
Concentration of solute is higher compared with another solution
192
Hypothalamus
An area of the diencephalon that is the primary link between the endocrine system and the nervous system; responsible for control of many body functions, including heart rate, digestion, sexual development, temperature regulation, emotion, hunger, thirst, and regulation of the sleep cycle
193
Hypotonic
Concentration of solute is lower compared with another solution
194
Hypoxic drive
A situation in which a person’s stimulus to breathe comes from a decrease in PaO2 rather than the normal stimulus, an increase in PaCO2
195
Immunity
The body’s ability to protect itself from acquiring a disease
196
Inhalation
The active process of moving air into the lungs; also called inspiration; also a route of medication delivery
197
Inotropic effect
The effect on the contractility of muscle tissue, especially cardiac muscle
198
Insertion
A moveable part of the body to which a skeletal muscle is fastened at a moveable joint; its action opposed that of an origin
199
Inspiratory reserve volume
The additional amount of air that can be inhaled after the normal tidal volume has been reached
200
Integumentary system
The largest organ system in the body, consisting of the skin and accessory structures (eg. hair, nails, glands)
201
Interstitial fluid
The fluid located outside of the blood vessels in the spaces between the body’s cells
202
Interstitial space
The space in between the cells
203
ICF
Intracellular fluid
Fluid within the cells in which most of the body’s supply of potassium is contained; accounts for 40%-45% of body weight
204
Intravascular fluid
Fluid outside cells but inside the circulatory system; the majority of it is plasma, which is the fluid component of blood
205
Ionic bond
A chemical bond where oppositely charged ions attract each other
206
Ions
Atoms that have become positively or negatively charged, either by giving up or acquiring an electron
207
Islets of Langerhans
Groups of cells located in the pancreas that produce insulin, glucagon, somatostatin, and pancreatic polypeptide
208
Isotonic solution
A solution in which there is an equal concentration of solutes and water on either side of a semipermeable membrane; in this case, water does not shift, and no change in cell shape occurs
209
Joint capsule
A saclike envelope that encloses the cavity of a synovial joint
210
Kilocalorie
The amount of heat needed to raise the temperature of a gram of water by 33°F (1°C); the amount of energy that can be obtained from the nutrients you eat; also known as a calorie
211
Lacrimal glands
The glands that produce fluids to keep the eye moist; also called tear glands
212
Lactic acid
A metabolic end product of the breakdown of glucose that accumulates when metabolism proceeds in the absence of oxygen
213
Larynx
A complete structure formed by the epiglottis, thyroid cartilage, cricoid cartilage, arytenoid cartilage, corniculate cartilage, and cuneiform cartilage; also called the voice box
214
Left anterior descending artery
One of the two branches of the left main coronary artery that supplies blood to the left ventricle and other areas of the heart
215
Lens
The transparent disc within the eye that refracts light to focus images on the retina
216
Lipids
Fats, fatlike substances (cholesterol and phospholipids), and oils that supply energy for body processes and building of certain structures
217
Lymph
A thin liquid formed from interstitial fluid that flows through the lymphatic vessels and lymph nodes and aids in immune response and debris removal
218
Lymph nodes
Round or bean-shaped structures interspersed along the course of the lymph vessels, which filter the lymph and serve as a source of lymphocytes
219
Lymph vessels
Unidirectional, thin-walled vessels through which lymph circulates through the body; they travel close to the major veins
220
Lymphatic system
A network of capillaries, vessels, ducts, nodes, and organs that helps to maintain the fluid environment of the body by producing lymph and transporting it through the body
221
Lymphocytes
A type of white blood cell that has an important role in immunity
222
Macrophages
Large cells, usually derived from monocytes, that are specialized for phagocytosis; they kill pathogens, absorb foreign materials, and slow infections and infectious agents
223
Macula
A yellow depression in the retina where acute vision arises; also known as the macula lutea
224
Mast cells
Cells located in connective tissues to which antibodies, formed in response to allergens, attach, bursting the cells and releasing chemical mediators in response to an antigen-antibody reaction
225
Mediastinum
The space between the lungs, in the center of the chest, that contains the heart, great vessels, part of the esophagus, lymphatic channels, trachea, primary bronchi, and paired vagus and phrenic nerves
226
Medulla oblongata
Inferior part of the brainstem that is continuous inferiorly with the spinal cord; serves as a conduction pathway for ascending and descending nerve tracts; responsible for maintenance of basic life functions, such as heart rate and breathing
227
Meiosis
A type of cell division that occurs in the production of eggs and sperm
228
Melanin
The pigment that gives skin its color
229
Meninges
A set of three tough membranes, the dura mater, arachnoid, and pia mater, that enclose the entire brain and spinal cord
230
Metacarpals
The five bones that form the palm and back of the hand
231
Midbrain
The most superior portion of the brainstem; it works with the pons to route information from higher within the brain to the spinal cord and vice versa
232
Mineral
An inorganic element essential for human metabolism
233
Minute volume
The amount of air that moves in and out of the lungs per minute minus the dead space; also called minute ventilation
234
Mitosis
The division of the chromosomes in a cell nucleus
235
Mitral valve
The atrioventricular valve in the heart that separates the left atrium from the left ventricle
236
Monocytes
White blood cells that mature in the blood and then travel to the tissues, where they differentiate into macrophages; these function primarily as scavengers for the tissues
237
Monosaccharides
The simplest carbohydrate molecule
238
Motor nerve
Nerve that carries information from the central nervous system to the muscles of the body
239
Motor neurons
Nerve cells that transmit instructions from the central nervous system to the end organs; also known as efferent neurons
240
Mucous membranes
The lining of body cavities and passages that communicate directly or indirectly with the environment outside the body
241
Mucus
The opaque, sticky secretion of the mucous membranes that lubricates the body openings
242
Murmur
An abnormal heart sound, heard as a “whooshing,” indicating turbulent blood flow within the heart
243
Muscle tissue
Contractile tissue consisting of filaments of actin and myosin, which slide past each other, shortening cells
244
Musculoskeletal
The bones and voluntary muscles of the body
245
Myocardium
The middle and thickest layer of the heart; it contains the cardiac muscle fibers that cause contraction of the heart, as well as the conduction system and blood supply
246
Myoglobin
A pigment synthesized in the muscles to give skeletal muscles their red-brown color
247
Myopia
Nearsighted; the ability to see objects close with difficulty seeing objects far away
248
Myosin
A contractile protein found in the thick filaments of skeletal muscle cells
249
Nasopharynx
The part of the pharynx that lies above the level of the palate
250
Negative feedback
The concept that once the desired effect of a process has been achieved, further action is inhibited until it is needed again; also called feedback inhibition
251
Negative pressure ventilation
Drawing of air into the lungs; airflow from a region of higher pressure (outside the body) to a region of lower pressure (the lungs); occurs during normal breathing
252
Neoplasm
A mass of tissue produced by abnormal cell growth and division that may be malignant (cancerous) or benign
253
Nephrons
The functional (urine-producing) units of the kidneys
254
Nervous system
The system that controls virtually all activities of the body, both voluntary and involuntary
255
Nervous tissue
Composed of neurons and neuroglia
256
Neuroglia
Supporting cells that provide a supporting skeleton for neural tissue, isolate and protect the cell membranes of neurons, regulate the composition of interstitial fluid, defend neural tissue from pathogens, and aid in the repair of injury
257
Neuromuscular junction
The connection between a motor neuron and a muscle fiber
258
Neurons
The basic nerve cells of the nervous system, containing a nucleus within a cell body and extending one or more processes; they exist in masses to form nervous tissue
259
Neurotransmitter
A chemical released from one nerve that crosses the synaptic cleft to reach a receptor
260
Neutrophils
One of the three types of granulocytes; they have multi-lobed nuclei that resemble a string of baseballs held together by a thin strand of thread; they destroy bacteria, antigen-antibody complexes, and foreign matter
261
Norepinephrine
A naturally occurring catecholamine that functions as a neurotransmitter and adrenal hormone; it is synthesized by the adrenal medulla, the peripheral sympathetic nerves, and the central nervous system; it is also available as a drug sometimes used in the treatment of severe hypotension; produces vasoconstriction though its alpha-stimulator properties
262
Nucleic acids
Large organic molecules, or macromolecules, that carry genetic information or form structures within cells, and include deoxyribonucleic acid and ribonucleic acid
263
Nucleus
In the context of a cell, a cellular organelle that contains the genetic information; controls the function and structure of a cell; in the context of an atom, the central portion of an atom that contains protons and neutrons
264
Nutrients
Substances that provide nourishment for growth such as carbohydrates, lipids, proteins, vitamins, minerals, and water
265
Oligosaccharide
A simple sugar composed of 2 to 10 monosaccharides
266
Oncotic pressure
The pressure of water to move, typically into the capillary, as the result of the presence of plasma proteins
267
Oocyte
Immature female sex cell produced in the ovary that may develop by meiosis into an ovum (egg)
268
Optic chiasm
Location where approximately half of the nerve fibers from each eye cross over to the opposite side of the brain
269
Orbit
An eye socket of the skull
270
Organ of Corti
The organ that is the primary receptor for sound, and is made up of thousands of individual cilia, each with their own associated nerve
271
Organelles
Structures within cells that have specialized functions
272
Origin
A relatively immovable part of the body where a skeletal muscle is fastened at a moveable joint; its action opposes that of an insertion
273
Oropharynx
A tubular structure that extends vertically from the back of the mouth to the esophagus and trachea
274
Osmosis
The movement of a solvent, such as water, from an area of low solute concentration to one of high concentration through a selectively permeable membrane to equalize concentrations of a solute on both sides of the membrane
275
Osmotic pressure
The pressure exerted by the concentration of the solutes in a given space to stop the flow of solvent across a semipermeable membrane
276
Ossification
The formation of bone by osteoblasts
277
Osteoblasts
Cells involved in the formation of bony tissue
278
Osteoclasts
Macrophages of the bone surface that dissolve the matrix and return minerals to the extracellular fluid
279
Osteocytes
Mature bone cells
280
Otoliths
A pair of fluid-filled sacs within the inner ear that are used by the central nervous system to collect information about movement and orientation in space
281
Oval window
The opening between the stapes and inner ear
282
Ovaries
Female glands that produce sex hormones and ova (eggs)
283
Oxygenation
The process of loading oxygen molecules onto hemoglobin molecules in the bloodstream
284
Oxyhemoglobin
Hemoglobin that has oxygen molecules bound to it
285
Palate
The roof of the oral cavity; it separates the nasal cavity from the oral cavity
286
Pancreas
An organ with both endocrine and exocrine functions; it is a major source of digestive enzymes and produces the hormone insulin
287
Papillary muscles
Muscles attached to the chordae tendineae of the atrioventricular heart valves and the ventricular muscle of the heart
288
Paranasal sinuses
The sinuses, or hollowed sections of bone in the front of the head, which are lined with mucous membrane and drain into the nasal cavity; the frontal, ethmoid, sphenoid, and maxillary sinuses
289
Parathyroid glands
Four glands that are embedded in the posterior portion of each lobe of the thyroid; they produce and secrete parathyroid hormone
290
PTH
Parathyroid hormone
Hormone produced and secreted by the parathyroid glands; it maintains normal levels of calcium in the blood and normal neuromuscular function
291
Parietal pleura
The lining of the pleural cavity attached tightly to the interior of the chest cage
292
Partial pressure
The pressure exerted by an individual gas in a mixture
293
Pelvis
The attachment of the lower extremities to the body, consisting of the sacrum and two pelvic bones
294
Peptide
Protein molecule consisting of amino acids held together by peptide bonds
295
Perception
Becoming aware of or understanding something using the senses
296
Perfusion
The circulation of oxygenated blood within an organ or tissue in adequate amounts to meet the cells’ current needs; also involves the removal of wastes
297
Pericardium
A thin, double-layered membrane made up of the fibrous pericardium and serous pericardium
298
Perilymph
Fluid within the bony labyrinth that surrounds and protects the membranous labyrinth while allowing transmission of pressure waves caused by sound
299
PNS
Peripheral nervous system
The part of the nervous system that consists of 31 pairs of spinal nerves and 12 pairs of cranial nerves that are responsible for communication between the central nervous system and the rest of the body; these may be sensory nerves, motor nerves, or connecting nerves
300
Peristalsis
The wavelike contraction of smooth muscle by which the ureters or other tubular organs propel their contents
301
Peritoneum
Double-layered serous membrane that lines the abdominal cavity and covers the organs located in the abdominopelvic cavity
302
pH
The measure of acidity or alkalinity of a solution
303
Phagocytosis
A form of endocytosis in which a cell surrounds a foreign particle and engulfs it
304
Phantom pain
A sensation of pain in a part of the body that is no longer present
305
Pharynx
The area between the nasal cavity and the larynx and posterior to the oral cavity; the throat
306
Phenotype
The appearance, health condition, or other characteristics associated with a particular genotype
307
Phospholipid
A type of lipid molecule that comprises the cell membrane
308
Physiology
The study of processes and functions of the living organism
309
Pia mater
The innermost of the three meninges that enclose the brain and spinal cord; it rests directly on the brain and spinal cord
310
Pineal gland
A gland in the brain that synthesizes and secretes melatonin, a hormone that affects patterns of sleep and wakefulness
311
Pinna
A formation of cartilage of the outer ear that protects the ear and collects sounds onto the ear canal, while allowing some perception of the direction from which the sound comes; also called the auricle
312
Pinocytosis
A form of endocytosis in which the cell membrane sinks inward and ingests droplets of extracellular fluid
313
Pituitary gland
An endocrine gland responsible for directly or indirectly affecting all body functions; also called the hypophysis
314
Plasma
A watery, yellow fluid that carries the blood cells and nutrients and transports cellular waste material to the organs of excretion
315
Plasma cells
Cells that produce antibodies (immunoglobulins) to destroy antigens or antigen-containing particles; formed from divided and differentiated B cells
316
Plasmin
A naturally occurring enzyme that dissolves the fibrin fibers in blood clots; usually present in the body in its inactive form, plasminogen
317
Platelets
Formed elements of the blood that function in blood clotting; also called thrombocytes
318
Pleura
The serous membranes covering the lungs and lining the thoracic cavity
319
Pleural space
The potential space between the parietal pleura and the visceral pleura
320
Plexus
A cluster of nerve roots that permits peripheral nerve roots to rejoin and function as a group
321
Polarized
When a cell is at rest, ions are actively transported into and out of the cell to create an electrochemical gradient across the cell membrane
322
Polypeptide
Formed from many amino acids bound into a chain; when this has more than 100 molecules, it is considered to be a protein; certain protein molecules have more than one
323
Polysaccharides
Complex carbohydrates that contain many simple joined sugar units, such as plant starch; some, such as cellulose, cannot be broken down for nutrition in humans but play important roles in digestion
324
Pons
Area of the brainstem that contains the sleep and respiratory centers for the body, which along with the medulla, control breathing
325
PRG
Pontine respiratory group
A portion of the pons that communicates information to both the ventral and dorsal respiratory groups; it is thought to smooth the transition between each phase of the ventilatory cycle and alter breathing by making each breath shorter and shallower or longer and deeper, depending on the body’s needs
326
Precapillary sphincters
Smooth muscle located at the entrances to the capillaries; responsive to local tissue needs
327
Preload
The volume of blood in the ventricle at the end of diastole; it is primarily a reflection of venous return (the blood that is returned to the heart)
328
Presbyopia
The increased difficulty in focusing on objects that occurs with aging
329
Progesterone
A female hormone released from the ovaries that promotes changes in the uterus during the reproductive cycle, affects the mammary glands, and helps regulate gonadotropin secretion
330
Proprioception
The awareness of motion and position of a body part
331
Prostaglandins
Lipids made from arachidonic acid that usually act more locally than hormones, are very potent, stimulate hormone secretions, and help to regulate blood pressure
332
Proteins
Created from amino acids, they include enzymes, plasma proteins, muscle components (actin and myosin), hormones, and antibodies
333
Prothrombin
A protein made in the liver and released into the blood where it is converted into thrombin during the process of blood clotting
334
Pulmonary artery
One of two arteries that carry deoxygenated blood from the right ventricle to the lungs
335
Pulmonary circulation
The flow of blood from the right ventricle through the pulmonary arteries and all of their branches and capillaries in the lungs and back to the left atrium through the venules and pulmonary veins; also called the lesser circulation
336
Pulmonary veins
The four veins that return oxygenated blood from the lungs to the left atrium of the heart
337
Pulmonic valve
The semilunar valve that regulates blood flow between the right ventricle and the pulmonary artery; also called the pulmonary semilunar valve
338
Pulse pressure
The difference between systolic and diastolic pressures
339
Purkinje fibers
A system of fibers in the ventricles that conducts the excitation impulse from the bundle branches to the myocardium
340
Referred pain
Pain that feels as if it is originating from a body part other than the site being stimulated
341
Reflex arc
A sensory message that reaches the spinal cord and meets with a motor nerve to cause an action; the reflex action occurs without the message first having to reach the brain to voluntarily cause the action
342
Refracting system
A series of transparent structures within the eye that redirect light as it passes through mediums of different densities
343
Renal corpuscle
The initial blood-filtering component of the nephron
344
Renal cortex
The outer portion of each kidney; it forms renal columns and has tiny tubules associated with the nephrons
345
Renal medulla
The inner portion of each kidney; it is made of conical renal pyramids, and has striations
346
Renal pelvis
A cone-shaped collecting area that connects the ureter and the kidney
347
Renal tubule
The portion of the nephron containing the tubular fluid filtered through the glomerulus
348
Renin
A hormone produced by cells in the juxtaglomerular apparatus when the blood pressure is low
349
Repolarization
The process by which ions are moved across the cell membrane to return to a polarized state
350
Reproductive system
The system in males and females that controls the reproductive processes via organs and glands that create sex cells and transport them to areas where fertilization can occur
351
Residual volume
The amount of air remaining in the lungs and airway passages that is unable to be expelled after a maximal forced exhalation
352
Respiration
The exchange of gases between a living organism and its environment
353
Respiratory membrane
Where gas exchange takes place; oxygen is picked up in the bloodstream and carbon dioxide is eliminated through the lungs
354
Respiratory system
All the structures of the body that contribute to the process of breathing, consisting of the upper and lower airways and their component parts
355
RAS
Reticular activating system
Group of specialized neurons in the brainstem; involved in sleep and wake cycles; maintains consciousness
356
Retina
The inner layer of the eye wall, including the visual receptors
357
Rh factor
An antigen found on the red blood cells of most people; when a woman without this protein is impregnated by a man with this protein, the woman’s body can create antibodies against the protein and attack future pregnancies
358
Right coronary artery
Blood vessel that provides oxygenated blood to the right side of the heart muscle
359
Rods
One of two photoreceptors of the retina sensitive to light, but does not discriminate colors, producing a picture that is somewhat less focused and essentially black and white
360
Sacroiliac joint
The point of attachment of the ilium to the sacrum
361
Saddle joint
Two saddle-shaped articulating surfaces oriented at right angles to each other so that complementary surfaces articulate with each other, such as is the case with the thumb
362
Schwann cells
Neuroglial cells in the peripheral nervous system that form a myelin sheath around axons
363
Sclera
The white, fibrous outer layer of the eyeball
364
Scrotum
A pouch of skin and subcutaneous tissue hanging from the lower abdominal region, posterior to the penis
365
Sebaceous glands
Glands that produce an oily substance called sebum, which discharges along the shafts of the hairs
366
Semilunar (SL) valves
The two valves, the aortic and pulmonic valves, that are shaped like half-moons and separate the heart from the aorta and pulmonary arteries
367
Semipermeable
Property of the cell membrane that describes the ability to allow certain elements to pass through while not allowing others to do so
368
Sensory nerves
The nerves that carry sensations of touch, taste, heat, cold, pain, and other modalities from the body to the central nervous system
369
Sensory receptors
Structures located in the dermis that initiate nerve impulses that can reach one’s conscious awareness
370
Sex chromosomes
The X and Y chromosomes, which determine sex
371
Sinoatrial (SA) node
The normal site of the origin of electrical impulses; located high in the right atrium, it is the natural pacemaker of the heart
372
Sinuses
Cavities formed by the cranial bones that trap contaminants from entering the respiratory tract and act as tributaries for fluid to and from the eustachian tubes and tear ducts
373
Skeletal muscle tissue
Voluntary muscle tissue attached to bones and composed of long, threadlike cells that have light and dark striations
374
Sliding filament theory
A method of action of muscle contraction involving how sarcomeres shorten, with thick and thin filaments sliding past each other toward the center of the sarcomere from both ends
375
Sodium-potassium pump
The mechanism by which the cell brings in two potassium ions and releases three sodium ions
376
Soft palate
The posterior portion of the palate that is made up of mucous membrane, muscular fibers, and mucous glands; it is so named because it has no bony support
377
Solute
The dissolved particles contained in a solvent
378
Solution
A mixture of a solvent and a solute
379
Solvent
The fluid that dissolves a solute, or the substance in which a solute is dissolved or mixed
380
Somatic nervous system
The part of the nervous system that regulates activities over which there is voluntary control
381
Somatic pain
Pain caused by the activation of pain receptors in the body’s superficial tissues, such as the skin, bones, muscles, and joints; in contrast to visceral pain, this is generally more intense and more precisely localized
382
Sphincters
Muscles arranged in circles that are able to decrease the diameter of tubes; examples are found within the rectum, bladder, and blood vessels
383
Spinal nerves
31 pairs of nerves that originate from the spinal cord and exit the spine on either side between vertebrae; each has a sensory root and a motor root and is responsible for sending and receiving sensory and motor messages to and from the central nervous system from a portion of the body
384
Stem cells
Cells that retain the ability to divide repeatedly without specializing, and that allow for continual growth and renewal
385
Strabismus
Loss of perception of depth and overlapping or doubled images
386
Stratum corneum
The outermost or dead layer of the skin
387
Stroke volume (SV)
The volume of blood pumped forward with each ventricular contraction
388
Subarachnoid space
The space located between the pia mater and the arachnoid membrane
389
Suprasternal notch
The indentation formed by the superior border of the manubrium and the clavicles, often used as a landmark for procedures such as subclavian vein access; also known as the jugular notch
390
Surfactant
A liquid protein substance that coats the alveoli in the lungs, decreases alveolar surface tension, and keeps the alveoli expanded; a low level in a premature infant contributes to respiratory distress syndrome
391
Sutures
Seams that occur only between the bones of the skull; they are a type of fibrous joint
392
Sweat glands
The glands that secrete sweat, located in the dermal layer of the skin
393
Synapse
A functional connection where neurons communicate with other cells
394
Synaptic cleft
The space between neurons; also called the synaptic gap
395
Synaptic vesicles
Small sacs that contain neurotransmitters
396
Synovial fluid
The fluid secreted by synovial membranes that lubricates synovial joints
397
Synovial joints
Complex joints that allow free movement of the component bones and are lubricated with synovial fluid
398
Synovial membrane
The lining of a joint that secretes synovial fluid into the joint space
399
Systematic vascular resistance
The resistance that blood must overcome to be able to move within the blood vessels; related to the amount of dilation or constriction in the blood vessel
400
T lymphocytes
Lymphocytes that interact directly with antigens, producing the cellular immune response; they also stimulate the B lymphocytes to produce antibodies; also called T cells
401
Tentorium
A horizontal projection of the dura that separates the cerebellum from the cerebrum
402
Testosterone
The most important male sex hormone (androgen)
403
Thalamus
Structure of the diencephalon that is the sensory switchboard of the brain, through which almost all signals travel on their way in or out of the brain
404
Thermoregulation
The process by which the body maintains temperature through a combination of heat gain by metabolic processes and muscular movement and heat loss through breathing, evaporation, conduction, convection, and perspiration
405
Thoracic duct
One of two great lymph vessels; it empties into the superior vena cava
406
Thrombin
An enzyme that causes the conversion of fibrinogen to fibrin, which binds to a platelet plug, forming a final mature clot
407
Thromboplastin
A chemical that stimulates blood clotting
408
Thymus
A lymphatic organ located in the thorax that is important in early immunity; it shrinks with age and is eventually replaced by other types of tissue
409
Thyroid cartilage
A firm prominence of cartilage that forms the upper part of the larynx; the Adam’s apple
410
Thyroid gland
A large endocrine gland that is located at the base of the neck and produces and excretes hormones that influence growth, development, and metabolism
411
Tidal volume
The amount of air moved in and out of the lungs in one relaxed breath; about 500 mL for an adult
412
Tissue
A group of cells that are similar in structure and function
413
Titin
A noncontractile protein found in sarcomeres of cardiac and skeletal muscle
414
TBW
Total body water
Total amount of fluid in the human body; accounts for about 60% of the weight of a healthy adult male; divided into various compartments
415
Transcellular fluid
Fluid classified as extracellular but distinct because it is formed from the transport activities of the cells; examples include cerebrospinal fluid, bladder urine, the aqueous humor, and the synovial fluid of the joints
416
Tricuspid valve
The atrioventricular valve that separates the right atrium from the right ventricle
417
Tropomyosin
An actin-binding protein that regulates muscle contraction and other actin-related mechanical functions of the body
418
Troponin
A regulatory protein in the actin filaments of skeletal and cardiac muscle that attaches to tropomyosin
419
Tubular reabsorption
The process that moves substances from the tubular fluid into the blood, within the peritubular capillary
420
Tubular secretion
The process that moves substances from the blood in the peritubular capillary into the renal tubule
421
Tunica adventitia
The outer layer of tissue of a blood vessel wall, composed of elastic and fibrous connective tissue
422
Tunica intima
The smooth, thin, inner lining of a blood vessel
423
Tunica media
The middle and thickest layer of tissue of a blood vessel wall, composed of elastic tissue and smooth muscle cells that allow the vessel to expand or contract in response to changes in blood pressure and tissue demand
424
Ureter
A small, hollow tube that carries urine from the kidneys to the bladder
425
Urethra
The canal that conveys urine from the bladder to outside the body
426
Urinary bladder
A sac behind the pubic symphysis made of smooth muscle that collects and stores urine
427
Urinary system
The organs that control the discharge of certain waste materials filtered from the blood and excreted as urine
428
Uterus
A muscular, inverted pear-shaped organ that lies situated between the urinary bladder and the rectum
429
Ventilation
The mechanical process of moving air into and out of the lungs in two separate phases: inhalation (inspiration) and exhalation (expiration)
430
VRG
Ventral respiratory group
An area of the medulla oblongata that can cause inspiration or expiration depending on which motor neurons are stimulated
431
Vestibule
The structure into which the vagina opens posteriorly, and the female urethra opens into in the midline; also the central part of the labyrinth of the ear, behind the cochlea and in front of the semicircular canals
432
Visceral pain
Deep pain caused by activation of pain receptors in internal areas of the body that are enclosed within a cavity, such as the chest, abdomen, or pelvis
433
Visceral pleura
Lining of the pleural cavity that adheres tightly to the surface of the lung
434
Vital capacity
The amount of air moved in and out of the lungs with maximum inspiration and exhalation
435
Vitamins
Organic compounds required for normal metabolism
436
Vitreous humor
A jellylike fluid filling the posterior eye cavity that helps the globe maintain its shape without distorting light
437
White matter
Bundles of myelinated nerves
438
Acquired immunity
The immunity that occurs when the body is exposed to a foreign substance or disease and produces antibodies to the invader
439
Activation
Mediators of inflammation trigger the appearance of molecules known as selectins and integrins on the surfaces of endothelial cells and polymorphonuclear neutrophils, respectively
440
Adhesion
The attachment of polymorphonuclear neutrophils to endothelial cells, mediated by selectins and integrins
441
Alcoholic ketoacidosis
The metabolic acidotic state that manifests because of the inadequate nutritional habits associated with chronic alcohol abuse; the liver and body experience inadequate fuel reserves of glycogen and, thus, have to switch to fatty acid metabolism
442
Allergen
Any substance that causes a hypersensitivity reaction
443
Allergy
A hypersensitivity reaction to the presence of an agent (allergen) that is intrinsically harmless
444
Anaphylactic shock
A severe hypersensitivity reaction that involves bronchoconstriction and cardiovascular collapse
445
Angiogenesis
The growth of new blood vessels
446
Antibody
A protein secreted by certain immune cells that bind antigens to make them more visible to the immune system
447
Apoptosis
Normal, genetically programmed cell death
448
Asthma
A chronic inflammatory lower airway condition resulting in intermittent wheezing and excess mucus production
449
Atopic
An allergic tendency
450
Atrophy
A decrease in cell size due to a loss of subcellular components
451
Autoantibodies
Antibodies directed against the person’s own proteins
452
Autoimmunity
The production of antibodies or T cells that work against the tissues of a person’s body, producing autoimmune disease or a hypersensitivity reaction
453
Autosomal dominant
A pattern of inheritance that involves genes that are located on autosomes or the nonsex chromosomes; inheritance of only one copy of a particular form of a gene is needed to show the trait
454
Autosomal recessive
A pattern of inheritance that involves genes that are located on autosomes or the nonsex chromosomes; inheritance of two copies of a particular form of a gene is needed to show the trait
455
Bradypnea
A slow respiratory rate
456
Capillary refill time
A test performed on the fingernails or toenails that involves briefly squeezing the toenail or fingernail and evaluating the time it takes for the color to return
457
Cardiogenic shock
A condition caused by loss of 40% or more of the functioning myocardium; the heart is no longer able to circulate sufficient blood to maintain adequate oxygen delivery
458
Carpopedal spasm
A contorted position of the hand or foot in which the fingers or toes flex in a clawlike manner; may result from hyperventilation or hypocalcemia
459
Cell-mediated immunity
The immune process by which T-cell lymphocytes recognize antigens and then secrete cytokines (specifically lymphokines) that attract other cells or stimulate the production of cytotoxic cells that kill the infected cells
460
Central shock
A type of shock caused by central pump failure, including cardiogenic shock and obstructive shock
461
Chemotaxins
Components of the activated complement system that attract leukocytes from the circulation to help fight infections
462
Chemotaxis
The movement of additional white blood cells to an area of inflammation in response to the release of chemical mediators, such as neutrophils, injured tissue, and monocytes
463
Coagulation system
The system that forms blood clots in the body and facilitates repairs to the vascular tree
464
Complement system
A group of plasma proteins whose function is to do one of three things: attract leukocytes to sites of inflammation, activate leukocytes, and directly destroy cells
465
Cytokines
The products of cells that affect the function of other cells
466
Distributive shock
The type of shock caused by widespread dilation of the resistance vessels (small arterioles), the capacitance vessels (small venules), or both
467
Dysplasia
An alteration in the size, shape, and organization of cells
468
Edema
Swelling caused by excessive fluid trapped in the body tissues
469
Fibrinolysis cascade
The breakdown of fibrin in blood clots and the prevention of the polymerization of fibrin into new clots
470
Free radicals
A molecule that is missing one electron in its outer shell
471
General adaptation syndrome
A three-stage description of the body’s short- and long-term reactions to stress
472
Gram-negative
A reaction of bacteria to a Gram stain in which the bacteria do not retain the dark purple stain; this type of bacteria has cell walls that consist largely of lipids, and have pathogenic qualities that make them especially problematic for humans
473
Gram-positive
A reaction of bacteria to a Gram stain in which the bacteria retain the dark purple stain; this type of bacteria has thick cell walls composed of many layers
474
Hapten
A substance that normally does not stimulate an immune response but can be combined with an antigen and at a later point initiate an antibody response
475
Helper T cells
A type of T lymphocyte that is involved in cell-mediated and antibody-mediated immune responses; it secretes cytokines that stimulate the B cells and other T cells
476
Hemochromatosis
An inherited disease in which the body absorbs more iron than it needs and stores it in the liver, kidneys, and pancreas
477
Hemolytic anemia
A disease characterized by increased destruction of the red blood cells; it can occur from an Rh factor reaction (primarily in Rh-positive neonates born to sensitized Rh-negative mothers), exposure to chemicals, or a disorder of the immune system
478
Hemophilia
An inherited sex-linked disorder characterized by excessive bleeding
479
Humoral immunity
A type of immunity in which B-cell lymphocytes produce antibodies called immunoglobulins which recognize a specific antigen and then react with it
480
Hypercalcemia
An elevated blood calcium level
481
Hypercholesterolemia
An elevated blood cholesterol level
482
Hyperkalemia
An elevated serum potassium level
483
Hypermagnesemia
An increased serum magnesium level
484
Hypernatremia
A serum sodium level greater than or equal to 143 mEq/L
485
Hyperphosphatemia
An elevated serum phosphate level
486
Hyperplasia
An increase in the actual number of cells in an organ or tissue, usually resulting in an increase in the size of the organ or tissue
487
Hypersensitivity
A generic term for responses of the body to a substance to which a patient has increased sensitivity
488
Hypertrophy
An increase in the size of the cells due to synthesis of more subcellular components, leading to an increase in tissue and organ size
489
Hypocalcemia
A decreased serum calcium level
490
Hypokalemia
A decreased serum potassium level
491
Hypomagnesemia
A decreased serum magnesium level
492
Hyponatremia
A serum sodium level that is less than or equal to 135 mEq/L
493
Hypoperfusion
A condition that occurs when the level of tissue perfusion decreases below that needed to maintain normal cellular functions
494
Hypophosphatemia
A decreased serum phosphate level
495
Hypothalamic-pituitary-adrenal axis
A major part of the neuroendocrine system that controls reactions to stress; it is the mechanism for a set of interactions among glands, hormones, and parts of the midbrain that mediate the general adaptation syndrome
496
Hypovolemic shock
A condition that occurs when the circulating blood volume is inadequate to deliver adequate oxygen and nutrients to the body
497
Immune response
The body’s defense reaction to any substance that is recognized as foreign
498
Immune system
The body system that includes all of the structures and processes designed to mount a defense against foreign substances and disease-causing agents
499
Immunodeficiency
An abnormal condition in which some part of the body’s immune system is inadequate, and, consequently, resistance to infectious disease is decreased
500
Immunogen
An antigen that is capable of generating an immune response
501
Immunoglobulins
Antibodies secreted by the B cells
502
Incidence
The number of new cases of a disease in a population
503
Inflammatory response
A reaction by tissues of the body to irritation or injury, characterized by pain, swelling, redness, and heat
504
Interferon
A protein produced by cells in response to viral invasion that is released into the bloodstream or intercellular fluid to induce healthy cells to manufacture an enzyme that counters the infection
505
Interleukins
Chemical substances that attract white blood cells to the sites of injury and bacterial invasions
506
Isoimmunity
The formation of antibodies or T cells that are directed against antigens or another person’s cells
507
Ketoacidosis
An acidotic state created by the production of ketones via fat metabolism
508
Ketones
Acidic by-products of fat metabolism
509
Killer T cells
The cells released during a type IV allergic reaction that kill antigen-bearing target cells
510
Kinin system
A group of polypeptides that mediate inflammatory responses by stimulating visceral smooth muscle and relaxing vascular smooth muscle to produce vasodilation
511
Lactic acidosis
Anaerobic cellular respiration due to hypoperfusion of tissues and organs
512
Leukocytosis
An elevated white blood cell count, often due to inflammation
513
Leukotrienes
Arachidonic acid metabolites that function as chemical mediators of inflammation; also known as slow-reacting substances of anaphylaxis
514
Lymphokines
Cytokines released by lymphocytes, including many of the interleukins, gamma interferon, tumor necrosis factor beta, and chemokines
515
Margination
The loss of fluid from the blood vessels into the tissue, causing the blood left in the vessels to have increased viscosity, which in turn slows the flow of blood and produces stasis
516
Membrane attack complex
Molecules that insert themselves into the bacterial membrane, leading to weakened areas in the membrane
517
Metabolic acidosis
A pathologic condition characterized by a blood pH of less than 7.35 and caused by an accumulation of acids in the body from a metabolic cause
518
Metabolic alkalosis
A pathologic condition characterized by a blood pH of greater than 7.45 and caused by an accumulation of bases in the body from a metabolic cause
519
Metaplasia
A reversible, cellular adaptation in which one adult cell type is replaced by another adult cell type
520
Morbidity
Number of nonfatally injured or disabled people; usually expressed as a rate, meaning the number of nonfatal injuries in a certain population in a given time period divided by the size of the population
521
Morbid obesity
An excessively unhealthy accumulation of body fat, defined as a body mass index of greater than or equal to 40 kg/m2
522
Mortality
The quality of being mortal; number of deaths from a disease in a given population
523
MODS
Multiple organ dysfunction syndrome
A grave but sometimes reversible condition in an acutely ill patient characterized by the progressive dysfunction of two or more organs or organ systems not affected by the patient’s initial illness or injury
524
Natural immunity
A nonspecific cellular and humoral response that operates as the body’s first line of defense against pathogens; also called native immunity
525
Necrosis
The death of tissue, usually caused by a cessation of the blood supply
526
Neurogenic shock
A type of shock that usually results from spinal cord injury; loss of normal sympathetic nervous system tone and vasodilation occur
527
Obesity
An unhealthy accumulation of body fat, defined as a body mass index of greater than or equal to 30 kg/m2
528
Obstructive shock
The type of shock that occurs when blood flow to the heart or great vessels is obstructed
529
Oliguria
Decreased urine output
530
Opsonization
The process by which an antibody coats an antigen to facilitate its recognition by immune cells
531
Overweight
An unhealthy accumulation of body fat, defined as a body mass index of 25 to 29.9 kg/m2
532
Pathophysiology
The study of physiology of altered functioning in the presence of disease
533
Pericardial tamponade
The impairment of diastolic filling of the right ventricle due to significant amounts of fluid in the pericardial sac surrounding the heart, leading to a decrease in the cardiac output
534
Peripheral shock
Shock caused by peripheral circulatory abnormalities; includes hypovolemic shock and distributive shock
535
Phagocytes
The cells that engulf and consume foreign material such as microorganisms and debris
536
PMNs
Polymorphonuclear neutrophils
The type of white blood cells formed by bone marrow tissue that have a nucleus consisting of several parts or lobes connected by fine strands
537
Polyuria
Frequent and plentiful urination
538
Prevalence
The number of cases of a disease in a specific population within a given period
539
Pyrogens
Chemicals or proteins that travel to the brain and affect the hypothalamus and stimulate a rise in the body’s core temperature
540
Receptor
A specialized area in tissue that initiates certain actions after specific stimulation
541
Respiratory acidosis
A pathologic condition characterized by a blood pH of less than 7.35 and caused by an accumulation of acids in the body from a respiratory cause
542
Respiratory alkalosis
A pathologic condition characterized by a blood pH of more than 7.45 and caused by an accumulation of bases in the body from a respiratory cause
543
Septic shock
The type of shock that occurs as a result of widespread infection, usually bacterial; untreated, the result is multiple organ dysfunction syndrome and often death
544
Serotonin
A vasoactive amine that increases vascular permeability to cause vasodilation
545
Serum sickness
A condition in which antigen-antibody complexes formed in the bloodstream deposit in sites around the body, most notably the kidneys, with resultant inflammatory reactions
546
Transmigration (diapedesis)
The polymorphonuclear neutrophils permeate through the vessel wall, moving into the interstitial space
547
Urticaria
Multiple small, raised areas on the skin that may be one of the warning signs of impending anaphylaxis; also known as hives
548
Vasculitis
An inflammation of the blood vessels
549
Vasoactive amines
Substances such as histamine and serotonin that increase vascular permeability
550
Virulence
A measure of the disease-causing ability of a microorganism
