Science for Medicine - Keywords Flashcards
1
Q
Aetiology
A
Causes of disease
2
Q
Pathogenesis
A
How disease develops
3
Q
Symptoms
A
What patients notice
4
Q
Signs
A
What doctors observe
5
Q
Diagnosis
A
The decision reached about a disease
6
Q
Prognosis
A
How the disease is likely to progress
7
Q
Homeostasis
A
The integration of body systems to create an optimum internal environment in which all cells can function
8
Q
Dilution principle
A
volume = mass/conc.
9
Q
Prokryotic cell
A
a primitive cell that makes up unicellular organisms e.g. bacteria. no true nucleus.
10
Q
Eukaryotic cell
A
mostly makes up multicellular organisms. contain many membrane bound intercellular organelles
11
Q
Cytosol
A
The liquid medium of the cytoplasm
12
Q
Ribosome
A
The site of protein synthesis
13
Q
Nucleoid
A
The region of a bacterium that contains the chromosome but has no nuclear membrane
14
Q
Plasmid
A
A circular, double-stranded unit of DNA that replicates within a cell independently of the chromosomal DNA.
15
Q
Smooth Endoplasmic Reticulum
sarcoplasmic reticulum
A
A network of cytoplasmic tubules or flattened sacs, involved in the synthesis of lipids, phospholipids and steroids. in muscle cells, it regulates calcium ion concentration and is called the sarcoplasmic reticulum.
16
Q
Rough endoplasmic reticulum
A
A network of cytoplasmic tubules or flattened sacs with ribosomes on its surface. Protein folding, modification, and assembly takes place in the lumen of the rough ER
17
Q
Golgi apparatus
A
A network of membranous vesicles, that stores and modifies proteins and other macromolecules and transports them within the cell or excretes them from the cell.
18
Q
Secretory vesicle
A
a membrane bound vesicle containing material that is to be excreted from the cell
19
Q
Lysosome
A
a vesicle containing hydrolytic enzymes involved in the digestion of exogenous material
20
Q
peroxisome
A
A cell organelle containing a large number of enzymes, including catalase and oxidase, that break down long-chain fatty acids and other organic molecules.
21
Q
nucleoplasm
A
the contents of the nucleus, similar to the cytoplasm in a cell.
22
Q
substrate-level phosphorylation
A
synthesis of ATP not involving electron transport, used in anaerobic respiration
[glycolysis]
23
Q
oxidative phosphorylation
A
The ATP-generating process in which oxygen serves as the final electron acceptor. The major source of ATP generation in aerobic organisms.
24
Q
phosphodiester bond
A
A covalent chemical bond that links two carbon atoms on the pentose sugars of adjacent nucleotides in RNA and DNA through a phosphate group.
25
Pyrimidine
Cytosine, thymine, uracil
26
Purine
adenine, guanine
27
nucleoside
a pentose sugar and a base
28
nucleotide
a base, a pentose sugar and a (or multiple) phosphate group
29
polysaccharide
a carbohydrate containing a large number of saccharide groups, e.g. starch
30
glycosidic bond
a covalent bond between two monosaccharides forming a disacccharide
31
amphipathic
a molecule with both hydrophobic and hydrophilic properties at different ends.
32
integral membrane proteins
proteins which are permanently attached to the membrane
33
transmembrane proteins
proteins that pass all the way through the membrane
34
peripheral membrane proteins
proteins which only adhere temporarily to the membrane with which they are associated
35
electrochemical gradient
a gradient consisting of both a difference in chemical concentration and a difference in charge
36
carrier mediated transport system
Transport across a membrane via a transmembrane carrier. two forms: active transport and facilitated diffusion
37
facilitated diffusion
movement across a membrane of molecules or ions down their concentration gradient via specific transmembrane proteins. does not require energy from ATP hydrolysis
38
active transport
movement of molecules or ions against their concentration gradient using energy from ATP hydrolysis
39
osmolarity
(penetrating and non-penetrating) solute concentration measured in osmoles per litre
40
Tonicity
concentration of non-penetrating solutes only. measured in osmoles per litre
41
hypo-tonic/osmotic
less than normal tonicity/osmolarity
42
iso-tonic/osmotic
equal tonicity/osmolarity
43
hyper-tonic/osmotic
higher than normal tonicity/osmolarity
44
epithelium
tissue consisting of one or more layers of closely packed cells covering the external and internal surfaces of the body
45
mucosa
a mucus-secreting membrane that lines body cavities or passages that are open to the external environment.
46
exocrine
secreting externally
47
endocrine
secreting internally
48
epidermis
The outer, protective, nonvascular layer of the skin. Composed of stratified epithelial tissue
49
dermis
The connective tissue layer of the skin, containing nerve endings, sweat and sebaceous glands, blood and lymph vessels.
50
hypodermis
A subcutaneous layer of loose connective tissue containing fat cells that attaches to the upper layers of skin.
51
keratinisation
process by which keratin is deposited in cells and they become horny
52
osteoblast
a bone forming cell
53
osteoclast
a cell involved in the breakdown and re-absorption of bone
54
osteocyte
a mature bone cell
55
trabecular bone
spongy bone with gaps willed with bone marrow
56
cortical bone
thin outer layer of compact bone
57
lipoprotein
a protein in which one of the components is a lipid
58
metalloprotein
a protein bound to a metal ion, e.g. haemoglobin
59
glycoprotein
a protein with a carbohydrate group
60
elastins
proteins capable of stretch
61
collagens
inelastic proteins which compose a major part of connective tissue
62
keratins
fibrous proteins whose fibers are a component of the horny layer of the epidermis, hair and nails.
63
cofactor
A specific substance required for the activity of an enzyme, such as a coenzyme or metal ion.
64
coenzymes
organic molecules required for the catalytic function of certain enzymes, e.g ATP
65
isoenzyme
enzymes that differ in amino acid sequence but catalyze the same chemical reaction.
66
Vmax
maximum rate of calalysed reaction
67
Km
the concentration of substrate when the reaction takes place at half its maximum rate
68
competitive inhibition
an inhibitor binds to the active site of an enzyme, preventing the substrate from binding
69
non-competitive inhibition
the inhibitor reduces the activity of the enzyme and binds equally well to the enzyme whether or not it has already bound the substrate.
70
enzyme assays
laboratory methods for measuring enzymatic activity
71
oligosacchardie
a saccharide polymer containing a small number (3-10) monosaccharides. often found in beans, peas, lentils etc.
72
monosaccharides
Glucose, Fructose, Galactose
73
disaccharides
Sucrose, Lactose, Maltose
74
Digestive glycosidases
hydrolytic enzymes that act on glycosides
75
Glucokinase
phosphorylates glucose in the liver
76
Hexokinase
phosphorylates glucose in tissues other than the liver
77
lactate dehydrogenase
converts pyruvate to lactate
78
pyruvate dehydrogenase
converts pyruvate to Acetyl CoA
79
Cori cycle
glycolysis in skeletal muscle, lactate transported to liver, gluconeogenesis to form glucose transported back to skeletal muscle
80
galactokinase
converts galactose to galactose-1-phosphate by adding a phosphate from the hydrolysis of ATP
81
fructokinase
converts fructose to fructose-6-phosphate by adding a phosphate from the hydrolysis of ATP
82
glycosoaminoglycan
long, unbranched polysaccharides
83
proteoglycan
a glycosaminoglycan bound to a protein chain
84
proton motive force (chemiosmosis)
energy that is generated by the transfer of protons or electrons across a membrane
85
Triacylglycerol
Glycerol esterified at each of its three hydroxyl groups by a fatty acid
86
phospholipid
any lipid that contains phosphorus, the major lipids in cell membranes.
87
fatty acid
a straight chain monocarboxylic acid
88
lipases
any enzyme that catalyzes the hydrolysis of fats (a subclass of esterases)
89
Chylomicron
lipoproteins that transport dietary fats from the intestines through the blood to other tissues
90
albumin
a water soluble plasma protein that adheres to various substances in the blood during transport
91
fatty acid synthase
a multi-enzyme protein that catalyzes fatty acid synthesis
92
prostaglandins
fatty acids with hormone like effects
93
Thromboxanes
Substances similar to the prostaglandins that promote blood clotting.
94
Leukotrienes
products of thromboxane metabolism that produce allergic and inflammatory reactions similar to those of histamine.
95
cholesterol
a precursor of bile acids and steroid hormones and a key constituent of cell membranes.
96
bile salts
the salt form of bile acids that contributes to the emulsification of fats in the intestine and their absorption from the GI tract.
97
glia
the supporting structure of nervous tissue, consisting of astrocytes, oligodendrocytes, and microglia.
98
resting membrane potential
The voltage difference between the inside and the outside of a cell when no stimulus is applied.
99
refractory period
The period following effective stimulation, during which excitable tissue fails to respond to a stimulus of threshold intensity
100
conduction velocity
the speed with which an electrical impulse can be transmitted through excitable tissue
101
saltatory conduction
conduction in which the nerve impulse jumps from one node of Ranvier to the next.
102
nAChR
nicotinic acetylcholine receptor
103
reuptake
The reabsorption of a neurotransmitter by a neuron following transmission across a synapse.
104
temporal summation
the additive effect of sequential potentials from the same presynaptic neuron
105
spatial summation
the additive effect of simultaneous potentials from different presynaptic neurons
106
troponin
a complex of muscle proteins which, when combined with Ca2+, influences tropomyosin to initiate contraction.
107
tropomyosin
a muscle protein that inhibits contraction by blocking the interaction of actin and myosin, except when influenced by troponin.
108
isotonic contraction/twitch
muscle tension remains constant but muscle length changes
109
isometric contraction/twitch
muscle length remains constant but muscle tension changes
110
latent period
the time between a stimulus to the nerve and the contraction of the muscle
111
tetanus
a state of sustained muscular contraction without periods of relaxation caused by repetitive stimulation
112
fatigue
loss of the ability of a muscle to respond to stimuli.
113
gap-junctions
regions of high ionic permeability between closely apposed cells
114
intercalated disc
site of intercellular passage of ions and electrical impulses between two cardiac muscle cells
115
autorhythmicity
the property of cardiac muscle cells generating their own rhythm
116
functional refractory period
the minimum interval possible between successive responses to stimulation of a tissue
117
relative refractory period
period after the functional refractory period during which a neuron cannot respond to a normal stimulus but will do so if a stronger than usual stimulus is applied.
118
pacemaker potentials
a graded potential in pacemaker cells that fires action potentials when a threshold is reached
119
molecular recognition
the specific interaction between two or more molecules through non-covalent bonding
120
G-proteins
intracellular membrane-associated proteins activated by receptors
121
exteroceptors
receptors that respond to external stimuli; located in the skin, oral cavity, eyes, ears, and nose.
122
enteroceptors
any receptor that responds to stimuli inside the body
123
proprioceptors
a receptor that detects the motion or position of the body or a limb
124
chemoceptors
a receptor that responds to chemical stimuli
125
thermoreceptors
a nerve ending sensitive to stimulation by heat.
126
mechanoreceptors
A mechanoreceptor is a sensory receptor that responds to mechanical pressure or distortion
127
nociceptors
Nerve endings selectively responding to painful stimuli
128
generator potential
local depolarization of the membrane potential at the end of a sensory neuron in graded response to the strength of a stimulus
129
pacinian corpuscle
An encapsulated receptor found in deep layers of the skin that senses vibratory pressure and touch.
130
muscle spindle
A sensory receptor in a muscle that responds to the stretching of tissue.
131
intrafusal fibres
muscle fibres within a muscle spindle containing afferent nerve endings that detect length changes in the extrafusal muscle fibres
132
nuclear chain fibres
intrafusal fibres containing a single row of centrally positioned nuclei.
133
nuclear bag fibres
intrafusal fibres containing a central mass of nuclei
134
gamma efferent fibres
motor nerve fibers that transmit impulses from the central nervous system to the intrafusal fibers of the muscle spindle
135
golgi tendon organ
a proprioceptive sensory nerve ending in tendons activated by any increase of the tendon's tension
136
receptive field
an area of the body surface over which a single sensory receptor is capable of sensing stimuli. (smaller in more sensitive areas)
137
reciprocal innervation
Innervation of muscles, in which contraction of one set of muscles leads to the relaxation of opposing muscles.
138
interneuron
a neuron between the primary afferent neuron and the final motor neuron
139
ipsilateral reflex
a reflex in which the response occurs on the same side of the body that is stimulated.
140
contralateral reflex
a reflex in which the response occurs on the opposite side of the body that is stimulated.
141
autonomic nervous system
that part of the nervous system that controls the (involuntary) motor innervation of smooth muscle
142
sympathetic nervous system
the thoracolumbar part of the autonomic nervous system (fight or flight)
143
parasympathetic nervous system
the cranio-sacral part of the autonomic nervous system (rest and digest)
144
paravertebral ganglia
sympathetic ganglia in the sympathetic trunk
145
prevertebral ganglia
sympathetic ganglia which lie between the sympathetic trunk and the target organ
146
nitrogen fixation
the conversion of atmospheric nitrogen into products such as ammonia by nitrogen fixing bacteria in soil
147
protein turnover
the balance between protein synthesis and protein degradation.
148
negative nitrogen balance
state where nitrogen output exceeds nitrogen intake
149
positive nitrogen balance
state where nitrogen intake exceeds nitrogen output
150
kwashiorkor
severe dietary protein deficiency in children, characterised by anemia, edema, pot belly, depigmentation of the skin and loss of hair
151
carboxypeptidase
An exopeptidase that removes the amino acid at the free carboxyl end of a polypeptide chain
152
aminopeptidase
An exopeptidase that removes the amino acid at the free amino group end of a polypeptide chain
153
transamination
a reaction where an amino group is transferred from an amino acid to an alpha-keto acid
154
aminotransferase
Enzyme that transfers amino groups from an amino acid to a keto acid
155
hyperammonaemia
elevated levels of ammonia or its compounds in the blood.
156
glucogenic amino acids
an amino acid whose carbon skeleton yields either pyruvate or oxaloacetate so can be converted to glucose through gluconeogenesis
157
ketogenic amino acids
an amino acid whose carbon skeleton yields ketone bodies that can be converted into acetyl CoA
158
phenylketonuria
a disease caused by a lack of PAH enzyme, leading to a build up of phenylalanine which causes irreversible abnormalities in brain structure and function
159
oncotic pressure
the osmotic pressure exerted by plasma proteins on the capillary wall, it pulls water into the circulatory system
160
erythrocyte
a mature red blood cell
161
leukocyte
a white blood cell
162
neutrophil
an abundant type of granular, phagocytotic white blood cell
163
eosinophils
a granular WBC, attacks pathogens too large for neutrophils
164
basophils
granular leukocytes, release histamine and herapin which trigger inflammation
165
monocytes
largest WBCs, migrate to connective tissue where thay mature into macrophages
166
macrophage
mature monocytes, usually immobile but become mobile during inflammation when they phagocytose pathogens to present to lymphocytes
167
platelet
a small, nonnucleated disc-like body found in plasma that promotes blood clotting
168
erythropoietin
a hormone which stimulates red blood cell production
169
haematocrit
Percentage of the volume of a blood sample occupied by cells.
170
natural killer cells
large granular lymphocytes that kill target cells using antibody-dependent cell-mediated cytotoxicity using perforin. they can also use perforin to kill cells in the absence of antibody
171
dendritic cells
a cell that captures antigens and migrates to the lymph nodes and spleen, where it presents the processed antigens to T cells.
172
complement system
A complex system of proteins found in normal blood plasma that combines with antibodies to destroy pathogenic bacteria and other foreign cells
173
major histocompatibility (MHC)
cell surface proteins that bind to antigens derived from pathogens and display them on the cell surface for recognition by lymphocytes
174
tolerance
specific nonreactivity of lymphocytes to a particular antigen
175
chemokines
cytokines that are chemokinetic and chemotactic, stimulating leukocyte movement and attraction.
176
cytokines
Chemicals that act on cells to stimulate or inhibit their function
177
endergonic
requires energy
178
exergonic
releases energy
179
buffer
a mixture of a weak acid and its conjugate base or vice versa. resists change in pH
180
haemopoiesis
formation of blood cells
