Excretion

Question 1

Ammonotelic
Requirement of water
Mechanism of excretion
Toxicity
Examples

Answer 1

Very large
By diffusion across body surface or through gill surface ( in fish ) as ammonium ion
Highest
Teleosts ( many bony fishes ),aquatic insects,aquatic amphibians

Question 2

Ureotelic

Requirement of water
Mechanism of excretion
Toxicity
Examples

Answer 2

Less then ammonia
Ammonia produced by metabolism is converted into urea in the liver and released into the blood which is filtered and excreted by kidneys
Less than ammonia
Mammals , marine fishes , many terrestrial amphibian

Question 3

Uricotelic

Requirement of water
Mechanism of excretion
Toxicity
Examples

Answer 3

Least
In form of paste or pellet
Least
Birds, insects ,land snails ,reptiles

Question 4

Protonephridia example

Primarily concerned
Kidneys

Answer 4

Platyhelminthes
Rotifers
Cephalochordate ( amphioxus )
Some annelids
With osmoregulation
All vertebrates

Question 5

Nephridia
Malpighian tubules
Green glands /
Urea is produced in , by

Answer 5

Annelida ( earthworm)
Most of insects ( cockroaches)
Antennal glands eg Crustaceans / prawn
Iiver , urea cycle or ornithine cycle , kerb - Henseleit cycle

Question 6

Homeostatic Father
Homeostatic mechanism
In humans excretory system consists of

Answer 6

Maintenance of steady state ( Walter Cannon
Important for normal life as they maintain condition within a range in which the metabolic processes can occur
A pair of kidneys, one pair of ureters , a urinary bladder , a urethra

Question 7

Kidneys are ( shape , structure, situated b/w , close to
Adult measure length
Width
Thickness , weight

Answer 7

Reddish brown , bean shaped structure, b/w the levels of last thoracic and third lumbar vertebrae close to dorsal inner wall of abdominal cavity
10-12 cm. 5-7 cm ,
2-3 average weight 120-170 kg

Question 8

Hilum , fn
Renal pelvis, with
Retro - peritoneal kidney /
Outer layer of kidney is

Answer 8

Towards the centre of inner concave surface of kidney, through which ureter , blood vessels m nerves enter
Inner to the Hilum is a broad funnel shaped space , with projections called calyces
Extra peritoneal kidney, dorsal attached to dorsal abdominal wall , so only it’s ventral surface is covered by peritoneum
Is a tough capsule

Question 9

Inside the kidney two zones
Medullary pyramids , projecting into
Columns of Bertini

Answer 9

An outer cortex , inner medulla
The medulla is divided into a few conical masses, into calyces
The cortex extends in between the medullary pyramids as renal columns

Question 10

Each nephron of pyramids performs
Major calyx
Minor calyx
Urine passes from pelvis into , both ureters open
Fn

Answer 10

Urine formation which comes in collecting the form here it enters into calyx via a papilla ( tip of pyramid)
Pelvis divides into 3 or 4 branches when enters kidney
Each major calyx further divides into (3 or 4 ) sub branches
Ureter , through separate oblique opening into urinary bladder
The oblique opening prevents the back flow of urine

Question 11

Urinary bladder externally ( nature) , internally lined by
Opening controlled by inner , outer
Urinary bladder opens into a
In females both sphincter are

Answer 11

Detrusor muscle, (involuntary), transitional epithelium or urothelium
By sphincters made up of circular muscles, inner = internal sphincter ( involuntary muscles) outer = external sphincter ( voluntary muscle) during micturition these relax to release urine
A membranous duct called ureters
Are present in membranous urethra

Question 12

Urethra leads to ( males , females )
In males urethra has
Passage of urine

Answer 12

To end of penis , into vulva in females
3 parts , prostatic, membranous, penile urethra .
Nephron ➡️collecting duct ➡️ duct of Bellini ➡️papilla ➡️renal calyx ➡️renal pelvis ➡️ureters ➡️urinary bladder ➡️urethra

Question 13

Nephron is , no . Each nephron has
Glomerulus is
Blood carried from ⬆️
Bowman’s capsule

Answer 13

Each kidney has nearly 1 million complex tubular structures . Glomerulus & renal tubule
Tuft of capillaries formed by afferent arteriole - a fine branch of renal artery
Is carried away by efferent arteriole
The renal tubule begins with a double walled cup like structure, which encloses glomerulus

Question 14

Malpighian body/
PCT
A _______ shaped Henle loop
DCT
Cortical region
Medulla

Answer 14

Renal corpuscle = glomerulus along with bowman’s capsule
Proximal convoluted tubule = the tubule continues to form a highly coiled network
Hairpin , which has a descending and an ascending limb
Distal convoluted tubule = The ascending limb continues as another highly coiled tubular region
Malpighian corpuscle , PCT , DCT
Loop of henle

Question 15

Collecting duct, many which “””””””” and open
Cortical nephron
Juxta medullary nephron

Answer 15

DCTs of many nephron open into a straight tube many of converge and open into renal pelvis through medullary pyramids in calyces
( majority) the loop of henle is too short and extends only very little into medulla (80-85%)
The loop of henle is very long and runs deep into medulla

Question 16

Peritubular capillaries
Vasa recta ,,,,,,,,,, shape
Absent or

Answer 16

Efferent arteriole emerging from glomerulus forms a fine capillary network around the renal tubule
A minute vessel of this network runs parallel to henles loop forming a ‘ U’ shaped
Or highly reduced in cortical nephrons

Question 17

Juxtaglomerular apparatus consists
Is a special
Built in location for

Answer 17

Juxtaglomerular cells ( cells of walls of afferent modified) + macula dense ( modified DCT wall ) + lacis / polkissen / mesangial cell
Sensitive region formed by cellular modifications in DCT and afferent arteriole at location of contact
Regulation of GFR

Question 18

Fall in gfr can activate the
Oxygenated blood
Deoxygenated

Answer 18

JG cells to release renin which can stimulate glomerular blood flow and thereby gfr back to Normal
Heart ➡️ dorsal aorta.➡️ Renal arteries➡️. Afferent arteriole ➡️ glomerulus➡️ Efferent➡️. Vasa recta
Vasa recta ➡️ venules ➡️ renal vein ➡️ inferior vena cava

Question 19

Urine formation process
On average blood filtered (constitute)
—- pressure causes filtration

Answer 19

Glomerular / ultra filtration Selective reabsorption , tubular secretion
1100-1200, which constitute roughly 1/5th of blood pumped out by each ventricle of heart
The glomerular capillary blood pressure

Question 20

Glomerular capillary blood pressure 3 layers
Podocytes , slit pores / filtration

Answer 20

Endothelium of glomerular blood vessels
The epithelium of bowman’s capsule
A basement membrane between them
Epithelial cells of bowman’s capsule are arranged In an intricate manner so as to leave some minute spaces called

Question 21

Filtration plasma exception
Glomerular filtration rate , value
Efficient mechanism for regulation of GFR

Answer 21

The proteins pass onto lumen of bowmen’s capsule
The amount of filtrate formed by kidneys per minute , 125ml/minute i.e 180 litres per day
Juxta glomerular apparatus is a special sensitive region formed by cellular modifications in DCT and afferent arteriole at location of their contact

Question 22

Volume of filtrate,urine released ____ suggest
Who perform this (reabsorption ) and by how
Eg active
Passively reabsorption

Answer 22

1.5 litres , that nearly 99 % of filtrate has to be reabsorbed by renal tubules
Tubular epithelial cells in different segments of nephron perform, active / passive mechanisms
Glucose,amino acids, na +
Nitrogenous waste , also occurs in initial segments of nephron

Question 23

During urine formation tubular cell secrete
Also imp cause
Filtration fraction
The effective filtration pressure that causes ultrafiltration is determined by - pressure

Answer 23

Substance like H+,K+ and ammonia into filtrate
It’ helps in maintenance of ionic and acid base balance of body fluids
GFR/RPF=125 (ml/min)/650 (ml/min) = 1/5
Glomerular hydrostatic pressure
Blood colloid osmotic pressure of blood
Capsular hydrostatic pressure

Question 24

Glomerular hydrostatic pressure , due to , is the ( value )

Blood colloid osmotic pressure is ,due to ,resists ( value )

Answer 24

Bp in glomerular capillaries , difference in diameter of afferent and efferent arteriole ,main driving force to cause filtration ( 60 to 75 mm hg)
Is osmotic pressure created in blood of glomerular capillaries due to plasma proteins , the filtration of fluid from capillaries ( 30 to 32 mg )

Question 25

Capsular hydrostatic pressure ,resists Net filtration pressure

Answer 25

Pressure caused by fluid (filtrate) that reaches into bowmen’s capsule , filtration NGP = GHP -[ BCOP + CHP] =(75 or 60) - (32-18) mm of hg = 10 to 25 mm of hg

Question 26

Proximal convoluted tubule lined by (fn Reabsorbed , fn By

Answer 26

Simple cuboidal brush border epithelium , increases the surface are for reabsorption Nearly all the essential nutrients, 70-80% of electrolytes , water , Maintain. The ph and ionic balance of body fluids by selective selection of h ions ,ammonia , potassium ions into filtrate and by absorption of HCO3 from it

Question 27

Henles loop ascending limb reabsorption,fn Descending limb permeable/ impermeable fn , Ascending limb ——- So

Answer 27

Minimum, in maintenance of high osmolarity of medullary interstitial fluid Permeable to water but almost impermeable to electrolytes. This concentrates the filtrate as it moves down Is impermeable to water but allows transport of electrolytes actively or passively Concentrated fluid pass upward , it get diluted due to passage of electrolytes to medullary fluid

Question 28

Distal convolutions tube ———- reabsorption Selective reabsorption , fn Collecting tube extends , reabsorbed to what

Answer 28

Conditional reabsorption of Na + , water , HCO3 Of hydrogen and potassium ions , NH3 to maintain the pH and sodium potassium balance in blood This long duct extends frm cortex of kidney to inner part of medulla , large amounts of water could be reabsorbed to produce a concentrated urine

Question 29

Collecting duct allows Also plays a role Chemical composition of urine, water Salts Urea. Other materials

Answer 29

Passage of small amounts of urea into medullary interstitium to keep the osmolarity In maintenance of pH and ionic balance of blood by selective reabsorption of H+ , K+ 95% 2 2.7 0.3 % ( Durgs , hippuric acid , uric acid , vitamin-C ,dyes

Question 30

Urine pigment , formed due to Ph of urine , specific gravity Ions excreted out through urine Ions removed out through High threshold substances

Answer 30

Pale yellow colour of urine due to urochrome pigment , reduction of Hb 6 , = 1.01to 1.05 Monovolent ions = Na+,K+,Cl-,HCO3,H3O Faecal matter are mainly divalent and trivalent ions eg Ca2+,mg2+,CO-2 3, Po-3 4 Substance which are completely reabsorbed eg glucose , amino acid

Question 31

Athreshold substance Water electrolyte are examples of what Low threshold substances Human excrete value urea Diuretic substance

Answer 31

Substance which are not reabsorbed at all eg Inulin,sulphates,para amino hippuric acids (PAHA ) Substance which are reabsorbed the body are demand of variable threshold substances Less reabsorbed eg urea 25 gm urea / day Substance which increases the urine formation eg tea , coffee , alcohol

Question 32

Glycosuria , diseases Disease due to deficiency of ADH , characterised Urine formation , elimination Blood vessel with maximum urea is , minimum Average urine excrete Amount of urea in urine

Answer 32

If glucose remains unreabsorbed from PCT than comes out through urine , diabetes mellitus ADH or vasopressin = diabetes insipidus , by more dilute urine In liver , kidney Hepatic vein , renal vein 1-1.5 liters per day Alpha protein diet

Question 33

—- plays a significant role in counter current mechanisms Forms a counter current What helps in maintaining an increasing osmolarity towards the Gradient is mainly caused by

Answer 33

Henles loop and vasa recta The flow of filtrate in two limbs of henles loop is in opposite direction The flow of blood through two limbs of vasa recta The proximity between henles loop and vasa recta as well as the counter current mechanism in them The inner medullary inetrstitium i,e from 300 mOsmolL-1 in cortex to about 1200 mOsmolL-1 in inner medulla NaCl and urea

Question 34

______ maintains the interstitial gradient of NaCL, Nacl returned to interstituim by NaCl is transported by , exchanged by Urea is added to interstitial medullary fluid Urea re enter

Answer 34

Loop of henles , ascending part of vasa recta Ascending limb of henles loop , descending limb of vasa recta In small amount by diffusing out of collecting duct In ascending thin segment of loop of henle by diffusion

Question 35

Counter current mechanism helps How filtrate makes blood hypertonic Final — initial filtrate Osmoreceptors in body are activated by

Answer 35

To maintain a concentration gradient in medullary interstitium As filtrate flow down in CD more and more water moves out of tubule by osmosis >>> 4 more times Changes in blood volume, body fluid volume and ionic concentration

Question 36

What activates the osmoreceptors , stimulates the How ADH prevents diuresis Switch off ADH

Answer 36

An excessive loss of fluid from the body , the hypothalamus to release anti diuretic hormone ( ADH) or vasopressin from neurohypophysis It facial water reabsorption from latter part of tubule Increase in body fluid volume

Question 37

ADH also affects This causes an increase in A fall in glomerular blood flow / , to release, which converts Angiotensin fn

Answer 37

Kidney function by its constrictory effects on blood vessels In blood pressure-> increase the glomerular blood flow , thereby the GfR Glomerular blood pressure/ GFR can activate the JG cells to release renin which converts angiotensinogen in blood to angiotensin 1 and further angiotensin 2 A powerful vasoconstrictor increases the glomerular blood pressure and then GFR

Question 38

Angiotensin 2 also activates It causes Also leads to What can cause release of atrial natriuretic factor

Answer 38

The adrenal cortex to release Aldosterone Reabsorption of Na+ and water from distal parts of tubule An increase in Bp and GFR An increase in blood flow to atria of heart

Question 39

ANF can cause Acts as Urine is stored in , till a In response

Answer 39

Vasodilation (dilation of blood vessels) and thereby decrease blood pressure A check on renin angiotensin mechanism Urinary bladder , a voluntary signal is sent to CNS The stretch receptors on walls of bladder send signal to CNS

Question 40

CNS passes message to Average urine , urea Indicatives of diabetes mellitus

Answer 40

Initiate the contraction of smooth muscles of bladder and simultaneous relaxation of urethral sphincter causing the release of urine 1 to 1. 5 liters , 25-30 gm Glycosuria. , ketonuria

Question 41

Lungs eliminate Co2 Water Skin glands 1 contains Primary fn

Answer 41

200 ml/min 400 ml/min Sweat , sebaceous gland 99.5% water, NaCl , lactic acid, small amount of urea , amino acid , glucose Is to facilitate a cooling effect on body surface

Question 42

Sebum contains , secretion provides Liver is main site for elimination of Bole carries these materials to

Answer 42

Waxes , sterols , other hydrocarbons , fatty acids ,,,,, a protective oily covering for skin Cholesterol, bile pigments ( bilirubin, biliverdin) , degraded steroids hormones , some vitamins, drugs Intestine from where they are excreted with faeces

Question 43

Uraemia Blood drained from convenient _____ , is pumped into The units contain , fluid same composition as The ______ _______ mem of tube allows

Answer 43

Malfunctioning of kidneys can lead to accumulation of urea in blood Artery , into a dialysing unit after adding an anticoagulant like heparin A coiled cellophane tube surrounded by a fluid , plasma except nitrogenous waste Porous cellophane , allows the passage of molecules based on concentrations gradient

Question 44

The cleared blood is pumped through Renal failure syndrome characteristed by Glomerulonephritis

Answer 44

Vein Renal dysfunction,oliguria, anuria , sudden rise in metabolic waste products like urea & creatine ( n2 waste ) in blood (uremia) Disease where due to infection/ injury in the basement membrane, the inflammation of glomerulus leads to renal failure & death

Question 45

Renal calculi / Calculi made up of

Answer 45

Urolithiasis = formation of stone within kidney , Calcium phosphate, uric acid , cystine / calcium oxalate