All Definitions Flashcards
acidosis
lower than normal pH level, i.e. accumulation of acid in the body
ADH
antidiuretic hormone, hypothalamic hormone, released from the neurohypophysis – increases water permeability in the collecting duct, thus decreasing urine volume
aldosteron
steroid hormone of the adrenal gland – increases Na+ reabsorption in the kidney and at other places
alkalosis
higher than normal pH level, i.e. accumulation of base in the body
ANP
atrial natriuretic peptid – secreted in the atrium of the heart, it increases Na+ and urine discharge decreasing blood volume
bilirubin
yellowish bile pigment produced by breakdown of heme
clearance
a functional measure of the kidney function – the plasma volume that is (theoretically) fully cleared of a certain material per a unit of time in the kidneys
cortical nephron
the most frequent nephron type located in the cortex of the kidney with short Henle’s loop
diuresis
discharge of urine from the urinary bladder
diuretics
drugs that increase the amount of urine and urination
facultative reabsorption
controlled reuptake of certain elements of the primary urine (ultrafiltrate) in the distal kidney tubules and collecting duct according to the need of the organism
GFR
(glomerular filtration rate) the amount of fluid filtrated per unit of time in the glomeruli of the kidneys
glomerulus
the functional unit of the kidneys consisting of the Bowman-capsule and of a coiled capillary system
Henle’s loop
a tubule connecting the proximal and the distal tubules in the kidneys
juxtaglomerular apparatus (JGA)
cell-group located in the angular area of the glomerulus and the tubules in the nephrons that produces renin (to regulate ionic milieu and fluid balance through the renin-angiotensin system)
juxtamedullary nephron
nephron located close to the corticomedullary border in the kidney, with long Henle’s loop descending deep in the renal medulla
nephron
functional and anatomical unit of the kidneys; its parts are the glomerulus, proximal- and distal tubules, Henle’s loop and collecting duct
obligate reabsorption
the compulsory reabsorption under any circumstances of a portion of some materials (e.g. water, sodium, glucose) in the proximal tubule of the nephron
podocyte
epithelial cell type in the Bowman’s capsule attached to the basal membrane of the glomerulus – filtrate passes between its footlike processes into the tubules of the nephron
RBF
(renal blood flow), the amount of blood flowing through the kidneys per unit of time
reabsorption
backward transport of some ultrafiltrated materials from the tubules to the blood vessels in the kidneys
renin
peptid hormone (protease) released by the juxtaglomerular apparatus – transforms angiotensinogen into angiotensin I
RPF
(renal plasma flow), the amount of blood plasma flowing through the kidneys per unit of time
tubular maximum
a rate limit of transport proteins (maximal transport capacity) in the kidney tubules above which only a portion of the given material is reabsorbed (e.g. glucose in the proximal tubule)
tubule (proximal, distal)
small tubes leading from the glomerulus to the collecting duct in the nephron
ultrafiltration
filtration in the glomeruli of the kidneys in which water and small organic and inorganic compounds pass the membranes from the plasma to the proximal tubule whereas colloid particles and cells remain unfiltered
urea
nitrogen containing compound actively eliminated by the kidneys; the main way to eliminate excess nitrogen
absorption
transport of the digested nutrients (amino-acids, sugars, fatty-acids) from the lumen of the intestine to the blood vessels across the intestinal wall
amylases
enzymes that digest carbohydrates (in the saliva or pancreatic juice)
cardiac sphincter
ring of muscles separating the esophagus from the stomach
CCK
cholecystokinin – produced in the small intestine in response to lipids and proteins, it induces emptying of the gallbladder, increases enzyme production in the pancreas and inhibits emptying of the stomach
chief cells
pepsinogen producing cells in the stomach
digestion
chemical break-down of the nutritive macromolecular polymers (proteins, carbohydrates, lipids, nucleic acids) into oligomers, dimers and finally monomers.
endopeptidase
protease that cuts internal peptide bonds in a peptid chain
exopeptidase
protease that cuts amino acids from the end of peptide chains
fermentation
anaerobic enzymatic conversion of organic compounds, especially carbohydrates, to simpler compounds usually by bacteria (e.g. fermentation of cellulose in the alimentary canal)
gastrin
hormone produced in the stomach – increases HCl secretion
GIP
glucose-dependent insulinotropic hormone – produced in the small intestine in response to carbohydrates, it induces insulin secretion and inhibits emptying of the stomach
intrinsic factor
protein secreted in the stomach, needed for the absorption of B12 vitamin (extrinsic factor)
lactose intolerance
lactose contained by milk and some diary products is not metabolized in the gut due to the lack of the enzyme lactase
lipases
enzymes in the pancreatic juice that digest lipids (fat)
lipogenesis
synthesis of neutral fat from fatty-acids and glycerol
mass peristalsis
a fast and powerful peristaltic wave in the large intestine initiated by the sudden distension of the (usually empty) duodenum (frequently results in defecation)
nucleases
enzymes digesting nucleic-acids (e.g. DNA, RNA)
parietal cells
HCl producing cells in the stomach
peristalsis
wormlike movement by which the alimentary canal or other tubular organs having both longitudinal and circular muscle fibers propel their contents
proteases
enzymes digesting proteins and polypeptides
pyloric sphincter
ring of muscles separating the stomach from the duodenum
reflux
backward flow of stomach content into the esophagus due mainly to weakness of the cardiac sphincter
secretin
produced in the small intestine in response to acid, it increases HCO3- production in the pancreas and inhibits emptying of the stomach
villus, villi
small, finger-like, vascular processes found densely packed on the inner wall of the gut increasing the absorptive surface
lipoprotein lipase
enzyme in the capillary wall catalyzing cleavage of fatty acids from lipids in lipoproteins (LDL, VLDL, etc.)
polyuria
the excretion of an abnormally large quantity of urine
polydipsia
excessive thirst and water consumption
ketoacidosis
acidosis caused by the increased production of acidic ketone bodies (e.g. in diabetes mellitus)
direct calorimetry
measurement of heat actually produced by an organism confined in a sealed chamber or calorimeter
indirect calorimetry
estimation of the heat produced by an organism by measuring oxygen consumption and respiratory differences of oxygen and carbon dioxide in the inspired and expired air
incretins
intestinal hormones increasing insulin secretion
endogenous hyperglycemia
blood sugar level is abnormally high without carbohydrate consumption
exogenous hyperglycemia
blood sugar level increases abnormally following carbohydrate consumption
anabolism
a part of the intermediary metabolism, syntheses of materials, building up the organism’s own materials
catabolism
part of the intermediary metabolism, breaking down the absorbed compounds (usually for producing or storing of energy)
citric-acid cycle
(Szentgyörgyi-Krebs cycle) – final break-down of the two-carbonic compound acetyl-group that comes from either the glycolysis or the fatty-acid metabolism (beta-oxidation); the end-products are carbon-dioxide and reduced co-enzymes
Cori-cycle
a procedure in which the lactic-acid produced in the muscles under anaerobic conditions is remetabolised to sugar in the liver on the expense of the break-down of its 1/3 amount
diabetes mellitus
disease due to the lack or ineffectiveness of the insulin hormone; symptoms are sugar in the urine, excess urination and overdrinking, acetone in the saliva, metabolic disturbances, sometimes coma
pentose-phosphate cycle
an alternative route to the glycolysis in which 5 C-atom sugars (e.g. ribose, etc.) are formed; NADPH, a co-enzyme necessary for fatty-acid synthesis is also produced here
fatty-acid synthesis
enzymatic production of long-chained fatty-acids from acetyl-Coenzyme-A (requires NADPH).
glucogenic amino-acids
amino-acids that can enter into the sugar-metabolic pathways
gluconeogenesis
a procedure in which the liver synthesizes de novo sugars from lactic acid and amino-acids (mainly from blood proteins)
glycolysis
break-down procedure of 6-C sugars into acetyl (-Coenzyme-A)-group
hyperglycemia
elevated blood-sugar level
hypoglycemia
decreased blood-sugar level
ketogenic amino-acids
amino-acids with ketone-like derivatives that cannot enter into the sugar-metabolism
NAD- (and NADH)
co-enzyme that binds hydrogen in the glycolysis and in the citric-acid cycle and carries it to the oxidative phosphorylation
Langerhans’ islets
hormone producing (endocrine) cell-groups of the pancreas
lipolysis
breaking down neutral fats into fatty-acids and glycerol
oxidative phosphorylation
final phase of the energy metabolism in the mitochondrion; hydrogen is moved from reduced co-enzymes (FADH2, NADH) to oxygen forming water, while released energy is stored in the form of ATP
respiratory quotient
the carbon dioxide output divided by the oxygen uptake
ejaculation
the forceful removal (ejection) of the sebum through the urethra in the males
emission
the release of the semen from it stores (vesicula seminalis) to the urethra before ejaculation
erection
the solidification of the penis by being filled up with blood before a sexual act
gametogenesis
production of reproductive cells (gametes) in the reproductive organs (oogenesis, spermatogenesis)
gonads
organs producing reproductive cells (gametes) (testis, ovary)