The Excretory System

Question 1

Define excretion

Answer 1

the process of removal of harmful and unwanted nitrogenous wastes, from the body

Question 2

substances eliminated from body

Answer 2

1. CO2 and water vapour (respiratory)
2. nitrogenous metabolic wastes (kidneys)
3. excess salts (kidneys)
4. water
5. bile pigments

Question 3

pigment in urine

Answer 3

urochrome

Question 4

function of liver

Answer 4

detoxifies ammonia by converting it to urea
breaks down bad cholesterol, alcohol, nicotine, and drugs

Question 5

location of kidney

Answer 5

located on either side of the backbone and protected by the last two ribs. right one is lower than left one

Question 6

location of hilum

Answer 6

a notch present in the median surface of each kidney

Question 7

location of urinary bladder

Answer 7

lower part of the abdomen

Question 8

urination also known as

Answer 8

micturition

Question 9

internal structure of kidney

Answer 9

1. outer dark cortex and inner light medulla
2. medulla consists of finely striped materials arranged in conical pyramids
3. apex of each pyramid is papilla and projects into the pelvis of kidney
4. cortical tissues extend between adjacent renal pyramids to form renal columns

Question 10

structural and functional unit of kidneys

Answer 10

uriniferous tubules/ nephrons/ kidney tubules/ renal tubules

Question 11

Bowman’s capsule

Answer 11

thin-walled cup. Its hollow internal space continues into tubule.

Question 12

glomerulus

Answer 12

on the outer concavity of bowman’s capsule, there is a knot-like mass of capillaries

Question 13

malpighian capsule/ renal capsule

Answer 13

bowman’s capsule and glomerulus together

Question 14

why is there a dotted appearance in cortex of kidney in sectional view

Answer 14

both bowman’s capsule and PCT lie in the cortex

Question 15

loop of Henle

Answer 15

Middle U-shaped part, that is not convoluted. it runs in medulla to turn back and re-enter cortex to continue into the next convoluted region of tubule

Question 16

afferent arteriole

Answer 16

renal artery has rebranched into afferent arterioles, which breaks into capillaries and forms glomerulus

Question 17

efferent arteriole

Answer 17

reuniting capillaries of the glomerulus. after running a short distance, breaks up into a secondary capillary network (VASA RECTA), which surrounds renal tubule, rejoins to form a vein

Question 18

major steps of urine formation

Answer 18

1. glomerular ultrafiltration
2. reabsorption
3. tubular secretion

Question 19

glomerular ultrafiltration

Answer 19

blood flows through glomerulus in great pressure, because efferent arteriole is narrower. liquid part of the blood filters out from glomerulus and into renal tubule

Question 20

parts of blood that come out during ultrafiltration

Answer 20

plasma, its organic and inorganic substances, urea, glucose, amino acids

Question 21

define glomerular filtrate

Answer 21

fluid entering the renal tubule after ultrafiltration

Question 22

what does glomerular filtrate consist of

Answer 22

water, urea, salts, glucose, and other plasma

Question 23

reabsorption

Answer 23

glomerular filtrate passes down the renal tubule, water and useful substances are reabsorbed

Question 24

define selective absorption

Answer 24

during reabsorption, useful substances are absorbed only to the extent that the normal concentration of blood is not disturbed

Question 25

tubular secretion

Answer 25

potassium ions in normal course, and foreign chemicals like drugs and penicillin are passed into the forming urine in DCT. the passage involves the activity of cell in tubular wall

Question 26

define urine

Answer 26

the filtrate left after reabsorption and tubular secretion

Question 27

function of bowman’s capsule

Answer 27

receives glomerular filtrate\

Question 28

function of PCT

Answer 28

reabsorbs most water, glucose, sodium and chlorine ions

Question 29

function of loop of Henle

Answer 29

absorption of water and sodium ions

Question 30

function of DCT

Answer 30

1. reabsorption of remaining chlorides and some water
2. walls secrete potassium and foreign drugs into forming urine

Question 31

define micturition

Answer 31

urine is expelled from the urinary bladder on relaxation of sphincter muscles located at the opening of urinary bladder into the urethra, on impulse sent from nervous system

Question 32

pH of urine

Answer 32

5-8

Question 33

specific gravity of urine

Answer 33

1.003- 1.035

Question 34

organic constituents of urine

Answer 34

1. urea
2. creatinine
3. uric acid
4. others

Question 35

inorganic constituents of urine

Answer 35

1. sodium chloride
2. potassium chloride
3. ammonia

Question 36

define haematuria

Answer 36

blood passes with urine due to some infection in urinary tract, kidney stones, or some tumour

Question 37

define glycosuria

Answer 37

excess glucose passes out with urine due to diabetes mellitus

Question 38

define albuminuria

Answer 38

due to high BP, or increased permeability of bowman’s capsule membrane due to infection, albumin passes out in urine

Question 39

why does urine contain bile pigments

Answer 39

anaemia, hepatitis, jaundice, liver cirrhosis

Question 40

define diuresis

Answer 40

increased production of urine

Question 41

concentration of urine by water reabsorption is controlled by what hormone

Answer 41

antidiuretic hormone (ADH)

Question 42

where is ADH secreted

Answer 42

posterior lobe of pituitary gland of brain

Question 43

if ADH secretion reduces…

Answer 43

more urine is produced (diuresis)

Question 44

examples of diuretics

Answer 44

liquid diets, tea, coffee, alcohole

Question 45

define osmoregulation

Answer 45

regulation of osmotic pressure of the blood

Question 46

define uremia

Answer 46

overaccumulation of poisonous urea in body