Urinary lecture 1 Flashcards
maintaining the balance of these is critical for survival
fluid, electrolyte, and acid-base balance
the human body is composed of
solid and liquid components
body water composition differs between men and women, and according to age and relative body fat. what are the rough guidelines for given populations?
infants: 73%
healthy young men: 60%
healthy young women: 50%
elderly: 45%
this tissue is the least hydrated
adipose tissue
>20% water
water content for skeletal tissue
75%
these 2 things make up most solid components of the body:
proteins and lipids
what are the 2 main fluid components in the human body?
intracellular fluid & extracellular fluid (plasma and interstitial fluid)
intercellular fluid (ICF)
compartment (2/3)
all fluid within the body’s cells
extracellular fluid:
compartment 1/3
plasma- liquid part of blood
interstitial fluid- in spaces between cells (lymph, csf, synovial fluid, aqueous and vitreous humors)
water serves as:
the universal solvent in which all solvents are dissolved
all body fluid consists of:
solvents and solutes
solutes:
electrolytes: dissociate into ions in water
nonelectrolytes: usually formed by cobalent bonds, so don’t dissociate
the bulk of dissolved molecules are
large proteins called nonelectrolytes such as phospholipids, cholesterol, and triglycerides
fluid movement between compartments is constant and depends on
osmotic and hydrostatic pressures
hydrostatic pressure:
pressure of fluid in a system (like a capillary)
osmotic pressure:
measure of the tendency of a solvent to move into a more concentrated solution
anything that changes solute concentration in compartment leads to water movement
water follows solutes! almost always
osmosis occurs in most cells because
they have an abundance of aquaporins in their plasma membrane
water (solvent) mover freely between compartments of cells, however solutes:
depend on transport proteins
exchange between plasma and IF occurs where
across capillaries
(balance of hydrostatic pressure and osmotic pressure)
exchange between IF and ICF occurs across cell membranes and depends on
membrane permeability (channels and transporters)
water balance is maintained by:
- thirst mechanism
- blood volume/pressure
- antidiuretic hormone
- electrolyte balance
- renin-angeitensin-aldosterone mechanism
- atrial natriuretic peptide
dehydration:
leads to increased osmolaty in ECF, dry mount
stimulates thrist and activates hormonal systems working at the kidney to conserve water
chain of events : dehydration
- excessive loss of H2- from ECF
- ECF osmotic pressure rises
- cells lose h2O to ECF by osmosis; cells shrink
overhydration:
decreases input to thirst center
overhydration : chain of events
- excessive h2O enters the ECF
- ECF osmotic pressure falls
- H2O moves into cells by osmosis, cells swell
regulation of sodium balance
- sodium is most abundant cation in ECF
- only cation exerting significant osmotic pressure
- controls ECF volume and water distribution because water follows salt.
Changes in Na+ levels affect plasma volume, blood pressure, and ICF and IF volumes!
Regulating dietary sodium intake is a major strategy in control of blood pressure
T/F regulating dietary sodium is a strategy for controlling blood pressure
true
blood and tissue pH is maintained over a very small range:
normal arterial pH 7.35-7.45
each digit jump in pH represents this change in hydrogen ion concentration
10-fold change in hydrogen ion concentration
higher number on the pH scale have
lower hydrogen concentration (H+)
this system is the bodies purification plant
urinary system
what are the 6 major functions of the kidneys?
- regulate total volume of water in the body and the total concentration of solutes (osmolality)
- regulate the concentration of ions in the extracellular fluids
- regulate long term acid-base balance
- excrete metabolic wastes and foreigns substances (drugs and toxins)
- producing hormones (erythropoietin, renin)
- converting vitamin d to its active form
define urinary:
organ system responsible for water, electrolyte, and acid-base balance, removals of nitrogenous wastes, urine production and excretion.
ex. urinary tract infection
renal
of or related to the kidneys
ex. renal pyramids
nephro-
of or related to the kidneys
ex. nephrology
urinary organs & functions
- kidneys: filter blood and form urine
- ureter: long muscular tubes that transport urine from kidneys to urinary bladder
- urinary bladder: muscular organ that stores urine
- urethra- tube that transmits urine from bladder to exterior
renal hilium:
at medial edge, is connection point for ureters, renal artery, and renal vein, lympthatic, and nerves
the kidneys are supported by 3 layers of tissue
- fibrous capsule: thin layer of dense regular connective tissue surrounding the kidney
- renal fascia: outer dense fibrous connective tissue anchoring kidney to surrounding structures
- perirenal fat capsule: fatty mass that protects kidney
the internal structure of kidney includes:
outer cortex & inner medulla
renal cortex
superficial layer with granular appearance
Renal Medulla
Medullary (renal) pyramids – cone-
shaped tissue that appear striped due to parallel bundles of urine collecting tubes and capillaries
* Renal Columns – inward extensions of cortex separating pyramids
* Lobes – pyramid surrounded by cortical tissue
The Kidneys have a rich blood supply
- receive one-fourth of total cardiac output (about 1200 ml/min)
- Renal artery is a branch of abdominal aorta: branches to every lobe
- Branches into cortex send an Afferent Arteriole to each nephron
- Venous blood collected into renal vein and sent to inferior vena cava
nephron:
basic structural and functional unit of the kidney
what are the 2 parts of the nephron
- renal copuscle : responsible for filtering the blood and forming pre urine
- renal tuble: adjusts contents of pre-urine to form urine.
functions of the renal tube:
- removes 99% of water from preurine and returns it to the blood
- concentrates urine
- adjusts ion levels
- adjusts pH
collecting duct:
multiple nephrons empty here and each renal pyramid will have many ducts
calyces:
funnel final urine from collecting ducts toward renal pelvis
chain of events: renal pelvis
Urine drains continuously from papilla of renal pyramids and empties into a minor calyx
* Several minor calyces drain into a major calyx
* 3-5 major calyces drain into the renal pelvis
* Urine leaves the kidney at the point where the renal pelvis becomes the ureter
urine passes through urinary system: order of events.
- Kidneys form urine continuously – collected by renal pelvis which drains into ureter
- Ureters deliver urine to urinary bladder
- Urinary bladder stores urine until time for urination
- During urination, urine leaves bladder through urethra and out of body
ureters:
deliver urine to urinary bladder
urinary bladder:
stores urine until time for urination
