Chapter 19 : Excretory Products and their Elimination Flashcards
What are some of the ammonotelic organisms?
bony fish, aquatic amphibians , aquatic insects
What are some of the ureotelic organisms?
mammals, amphibians ,marine fish
What are some fo the uricotelic organisms?
reptiles,birds, land snails, insects , insects
Which organisms have proto nephridia? What is its funciton?
platyhelminthes(flatworm:planaria) , rotifers , soem annelids and cephalochordate (amphioxus)
its funciton is to maintain ionic balance and fluid volume
In which animals are the nephridia prensent?
eartworms and other annelids
it function is to remove netrogenous wastes
In which organisms are malphigian tubules present ?
insects like cockroach
removal of nitrogenous wastes and osmoregulation
What is the excretory organ in the custaceans ? Give some examples of crustaceans?
antennal gland and green gland
one exmaple is prawns
What are the components of the human excretory system?
2 kidney
2 ureter
1 urinary bladder
1 urethra
What are the dimensions of the kidney ? What is its weigt?
10-12 cm
5-7 cm
2-3 cm
120-170 g
What is the opening of the kidney called
the renal hilum
What excretes urine to the ureter?
the renal pelvis
What are the two parts of the nephron?
glomerulus
renal tubule
What is the glomerulus and the bowmans capusle together composed of?
malphigian body or renal corpuscles
Which parts of the nephron is present in the cortical of the kidney ?
malphigian corpuscle( glomerulus and the bowmans capusle ) and PCT, DCT
What are cortilcal nephrons and what is present in it?
extend very little in the cortex
peritubular capillary
What are the medullary nephrons and what is present in it ?
run very deep in the medulla
vasa recta
Where is vasa recta present and what is its shape?
in the juxta medullary nephrons
U
Where is peri tubular capillary present ?
in the cortical nephrons
What are the three main processes of urine formation?
glomerular filtrate
reabsorption
secretion
How much blood is passed from the kidney every minute ?
1100-1200 ml /min
What fraction of ht eblood passes through the glomerulus every minute?
1/5 of the blood pumped by the heart
What causes the blood to pass through the 3 layers of the glomerulus and what are those three layers?
glomerular capillary pressure
endothelium of the glomerular capillary
epithelium of bowmans capsule
the basement membrane between them
What are the epithelial cells of hte bowmans capsule caleld?
PODOCYTE
What are filtration slit?
it is the space between the epithelial cells of the bowmans capsule
Which component of the blood does not pass the epithelium of the bowmans capsule ?
protein
What is GFR? What is its default value?
the amount of filtrate formed by kidney per minute is called Glomelrular filtrattion rate
125ml /min and 180L a day
What regulates the GFR? Describe it ? How does it do it?
the juxta glomerular apparatus (JGA)
JGA : it a special sensitive area formed by cellular modification in the DCT and the AFFERENT ARTERIOLE AT THE LOCATION OF CONTACT
a fall in the GFR can actvate the JG cells to release RENIN (single n) which stimulates the Glomerular blood flow and brings the GFR to normal
How much urine is formed in a day ?
1.5 L
What are the things that are actively absorbed for reabsorption? Which things are passively absorbed?
ACTIVELY : glucose , amino acids , Na+
PASSIVELY : nitrogenous waste , reabsorption of water in a first part
What are the things that are secreted to the tubules and WHY ?
tubular secretion they are important for urine formation as it helps to maintian IONIC and ACID BASE BALANCE
TUBULAR SECRETION: H+ , K+ and NH4 +
What type of epithelium is present in PCT?
brush border cuboidal
What are the things that are absorbed in the PCT ? What are the things that are secreted in the PCT? What is its role ?
ABSORPTION :essential nutrients, electrolytes(70-80% ) and water, HCO3 -
SECREITON : H+ , NH4+, K+
ROLE : maintain the ionic balance and pH of our body
What is the descending and the ascending part of the loop of henle permeable to ?
DESCENDING : water, not to electrolytes
ASCENDING : electrolytes but not to water
How does the filtrate in the Loop get diluted?
due to the passage of the electrolytes to the medullary fluid
What are the things that are absorbed in the DCT ? What are the things that are secreted in the DCT? What is its role ?
CONDITIONAL ABSORPTION : Na+ and water
REABSORPTION : HCO3 -
SECRETION : H + ,K+ and NH3
ROLE: miantain the PH AND Na/ K BALANCE in the body
What are the roles of the collecting duct?
large amount of water could be absorbed form this region
it allows the passage of UREA into the medullary interstitium to keep the osmolarity
maintain the pH and ionic balance of the blood by selective SECRETION of K+ , H+ ION
What are the things that play an important role in the concentration of the urne?
HENLE’S LOOP and VASA RECTA
Why is the mechanism of concentration called the countrer current concentraiton?
because the flow of stuff in Loop of Henle and the vasa recta are in oppsite direction
What is the concentration gradient in in the inner and outer medulla?
300 in the outer
1200 in the outer
What helps in the increasing the osmolarity towards the inner part of the medulla?
the proximity of hte vasa recta and the loop of henle
What are the chemicals that causes the concentration gradient in the medulla?
urea and NaCl
How does the counter current mechanism help in the concentrating the urine?
by creating the high conc gradient in the kidney the water is absorbed from the collecting tubule to concentrate the urine
By how many times does the double ciculation concentrate the urine?
4 time more concentrated
What are the things that help regulate the urine formation?
HYPOTHALAMUS
JGA
HEART
How does HYPOTHALAMUS control the fluid loss?
loos of fluid trigger this
HYPOTHALAMUS stimulates the neurohypophysis
neurohypophysis releases ADH( vasopressin)
ADH - helps in the reabsorption of water in the DCT
increase in the body fluid switched it off
How does HYPOTHALAMUS control the fluid loss?
loos of fluid trigger this
HYPOTHALAMUS stimulates the neurohypophysis
neurohypophysis releases ADH( vasopressin)
ADH - helps in the reabsorption of WATER in the DCT
increase in the body fluid switched it off
What is the affect of Angiotensin II and how does it do it ?
it is a powerful vasoconstrictor and can increase the blood pressure thus the GFR
it can also activate the adrenal cortex to release aldosterone
What is the function of aldosterone?
it causes absorption of Na+ and water from the DCT
How deos ANF control the urine flow? What triggers it?
ANF can cause the vasodilation and thereby decrease the blood pressure
it is triggered by INCREASE IN THE FLOW OF BLOOD IN THE HEART
What is the renin and angiotensin mechanism ?
it the process started by the JGA cells
When is the urine released?
when the urinary bladde is filled with urine
the stretch receptor on the wall of the urinary bladder sends signals to the CNS
the CNS sends signals to initiate the contraction of the smooth muscles of the blader and simultaneous relaxation of the urethral spinchter
causing relsease of urine
What is micturation ?
the process of release of urine is called micturaiton
What is the neural mechanism of release of urine called?
it is called micturaiton relfex
How much urine is relseased per day ?
1 -15 L of urine
What is the pH of urine
pH = 6.0 `
How much urea is excreted in a day by humans?
25 - 30 gm of urea
What does the presence of glucose in urine indicate?
glycosuria
What does the presence of ketone body int he urine represent?
diabetes mellitus
What are the other organs tha t paly a role in excretion?
LUNGS
LIVER
SKIN
How does the LUNGS carry out excretion?
CO2
What excretion does the liver carry out ?
bilirubin , biliverdin m cholesterol , degraded steroid hormone, vitamins and drugs
What are the things excreted by sweat gland?
NaCl, urea , lactic acid
their primary function of sweat is to cool it
What are the things that are secreted by sebaceos gland?
sterols , hydrocarbons and waxes through sebum
Can saliva excrete nitrogenous excretion>
yes
What happens if ketone body is present in urine?
ketone bodies
What is uremia ?
accumulation of urea in the blood is called uremia
What can uremia lead to ?
it can lead to kidney failure
What is haemodyalysis ?
using an artificial kidney to clean the blood
What is the use heparin during dialysis ?
it is use as an anti coagulant
What is the membrane used in dialysis ?
cellophane
What happens in renal calculi?
stone or insoluble mass of crystallized salts formed withhin the kidney
What is glomerulonephritis ?
inflammation of glomeruli in the kidney
it can lead to ureamia and kidney failure
From where to where does the collecting duct extend?
cortex to the inner medulla
What are the cells of JGA apparatus?
JG cells
macula densa cells
mesengial cells/lacis/pokisen cell