Tag: excretion in living organisms

Questions Related to excretion in living organisms

Choose the correct answers from the following given.
The mammalian excretory system involves all of the following except

evs - i excretion in living organisms other systems in the body excretory system in human human excretory organs

  1. reabsorption of high molecular weight proteins from the glomerular filtrate

  2. active transport of chloride ions from the filtrate into the peritubular tissues

  3. release of nitrogenous wastes into the intestines

  4. hormonal control of permeability of walls in various excretory tubules

Show answer
Correct Option: C
Explanation:

The excretory system in the mammals deals with the absorption on the basis of the permeability of the system , among all the options given the option other than the function of the excretory system is releasing nitrogenous wastes.

Hence the correct answer is C .

The primary threshold substance are............... .

evs - i excretion in living organisms other systems in the body excretory system in human human excretory organs

  1. Urea and uric acid

  2. Potassium and calcium

  3. Glucose and amino acids

  4. Plasma proteins

Show answer
Correct Option: A
Explanation:

A substance present in blood is filtered through kidneys. Depending on the concentration they are divided as follows, High threshold substances(such as chlorides or glucose), Low threshold substances (such as phosphates or urea). No-threshold substances (such as creatinine sulfate). The primary threshold substance is Urea and uric acid.

So the correct option is 'Urea and uric acid.'

In mammals, the urinary bladder opens into

evs excretion in living organisms other systems in the body excretory system in human human excretory organs

  1. Uterus

  2. Urethra

  3. Vestibule

  4. Ureter

Show answer
Correct Option: B
Explanation:

The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. Urine enters the bladder via the ureters and exits via the urethra. 

So, the correct answer is option B.

The interior of the urinary bladder is lined by

evs - i excretion in living organisms other systems in the body excretory system in human human excretory organs

  1. Columnar epithelium

  2. Squamous epithelium

  3. Transitional epithelium

  4. Goblet cells

Show answer
Correct Option: C
Explanation:

The urinary bladder is lined with transitional epithelium. It does not produce mucus.

Kidneys, skin and lungs are

evs excretion in living organisms other systems in the body excretory system in human human excretory organs

  1. Excretory organs

  2. Digestive organs

  3. Reproductive organs

  4. None of the above.

Show answer
Correct Option: A
Explanation:

The lungs, kidneys, and skin are excretory organs. Excess carbon dioxide is removed from the body through the lungs. Excess urea, water, and salts are removed by the kidneys and leave the body as urine. Excess water and salts also leave the body through the skin through sweat.

So, the correct answer is option A.

Which one is an accessory excretory organ?

evs excretion in living organisms other systems in the body excretory system in human human excretory organs

  1. Liver

  2. Stomach

  3. Intestine

  4. Heart

Show answer
Correct Option: A
Explanation:
An organ that helps in a process but is not part of the tract related to that biological process is called as accessory organ.
For instance, salivary glands, liver, gallbladder, and pancreas are not part of the digestive tract, but they have a role in digestive activities. The accessory digestive organs are the tongue, salivary glands, pancreas, liver, and gallbladder.
Hence, the answer is 'Liver'

The urinary bladder is muscular and is under ............ control.

evs excretion in living organisms other systems in the body excretory system in human human excretory organs

  1. Muscular

  2. Mechanical

  3. Nervous

  4. Hormonal

Show answer
Correct Option: C
Explanation:

The urinary bladder is made up of several detrusor muscles which mainly expands and contracts by the signals received by the autonomic nervous system. Parasympathetic nerves from the S2, S3 and S4 levels of spinal cord cause the upper part of the bladder to contract and bladder neck to relax, assisting in the process of micturition (urination). Sympathetic nerves from the $T _{11}$-$L _2$ levels of spinal cord do the opposite, causing the upper section of the bladder to relax and the bladder neck to contract, ensuring urine storage.

So, the correct answer is option C.

Which one is not supplied exclusively with involuntary muscles?

evs excretion in living organisms other systems in the body excretory system in human human excretory organs

  1. Iris

  2. Gland ducts

  3. Urethra

  4. Coats of blood vessels

Show answer
Correct Option: C
Explanation:

Iris is supplied by involuntary muscles which contract or relax in response to photo stimuli. Gland ducts have muscles in their walls and in the form of sphincters which are involuntary. Coats of blood vessels also have a muscle layer sandwiched between two other layers. Urethra has two sphincters of which one is involuntary and one is voluntary. Hence, urethra is not exclusively supplied with involuntary muscles.

The wall of urinary bladder has a thick layer of smooth muscle called

evs excretion in living organisms other systems in the body excretory system in human human excretory organs

  1. Dartos

  2. Detrusor

  3. Deltoid

  4. Depressor

Show answer
Correct Option: B
Explanation:

a) Dartos muscle is a muscle present in the scrotal sac. 

b) Deltoid muscle is a muscle of the upper arm. 
c) Depressor muscle is a facial muscle. 
d) Detrusor smooth muscle present in the wall of the urinary bladder is detrusor muscle. It helps in contraction of the urinary bladder during micturition.
So, the correct answer is 'Detrusor'.