Tag: biology

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Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Consider the following four statements (i) - (iv) and select the correct option.
(i) Fish heart contains only oxygenated blood.
(ii)Closure of A-V valves produces the second heart sound.
(iii) The vascular connection between the digestive tract and kidney is called hepatic portal system.
(iv) Purkinje fibres are nerve fibres present in the heart wall.

  1. i - F, ii - F, iii - T, iv - F

  2. i - F, ii - F, iii - F, iv - T

  3. i - T, ii - T, iii - F, iv - T

  4. i - T, ii - F, iii - T, iv - F
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • The fish heart contains both oxygenate and deoxygenated blood as it has one atrium and one ventricle.
  • Closure of A-V valves produces the first heart sound.
  • The vascular connection between the digestive tract and the liver is called the hepatic portal system.
  • Purkinje fibres are nerve fibres present in the heart wall.
Thus, the correct answer is 'i - F, ii - F, iii - F, iv - T.'

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Which of the following statements is correct regarding neural regulation of cardiac activity?

  1. The cardiac centre lies in medulla oblongata of brain.

  2. Sympathetic nerve fibres accelerate the rate of heart beat and parasympathetic nerve fibres retard the rate of heart beat.

  3. Sensory fibres extend from the receptors present in the walls of aortic arch, carotid sinuses and vena cava to the cardiovascular centre in medulla oblongata.

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

  • The medulla oblongata of the brain controls cardiac activities.
  • The action of sympathetic nerve fibres increases the heart rate, while that of the parasympathetic nerve fibres decrease it.
  • Sensory fibres extend from the receptors present in the walls of the aortic arch, carotid sinuses and vena cava to the cardiovascular centre in the medulla oblongata.
Thus, the correct answer is 'All of these.'

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

The problem of electrical discontinuity caused in the normal heart by the connective tissue separating the atria from the ventricles is solved by

  1. Coordinating electrical activity in the atria with electrical activity in the ventricles by connecting them via the bundle of His

  2. Having the A-V node function as a secondary pacemaker

  3. Having an ectopic pacemaker

  4. Coordinating electrical activity in the atria with electrical activity in the ventricles by connecting them via the vagus nerve.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The fibrous connective tissue skeleton separates the atria from the ventricling, preventing direct electrical propagation between them. This electrical discontinuity is bridged by the atrioventricular bundle, commonly known as the bundle of His, which transmits the action potential from the atria down to the ventricles.

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Cardiac activity could be moderated by the autonomous neural system. Tick the correct answer.

  1. The parasympathetic system stimulates heart rate and stroke volume.

  2. The sympathetic system stimulates heart rate and stroke volume.

  3. The parasympathetic system decreases the heart rate but increase stroke volume.

  4. The sympathetic system decreases the heart rate but increase stroke volume.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cardiac activity could be moderated by the autonomous neural system. The action of sympathetic nerve fibres increases the heart rate and the stroke volume, while that of the parasympathetic nerve fibres decrease these.

Thus, the correct answer is 'The sympathetic system stimulates heart rate and stroke volume.'

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Electric potential of various parts of brain is recorded by an instrument called as

  1. Sphygmomanometer

  2. Electrocardiography

  3. Electroencephalography

  4. CT Scan
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

An electroencephalogram (EEG) is a test that detects electrical activity in the brain using small, flat metal discs (electrodes) attached to scalp. 

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

An Evoked Potential Studies (EPS) enables us to

  1. Evaluate different sensory functions

  2. Detect clinically silent tensions

  3. Study hearing and vision in children

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Evoked potential studies measure electrical activity in the brain in response to stimulation of sight, sound, or touch. Stimuli delivered to the brain through each of these senses evoke minute electrical signals. These signals travel along the nerves and through the spinal cord to specific regions of the brain and are picked up by electrodes, amplified, and displayed for a doctor to interpret. Evoked potentials studies involve three major tests that measure response to visual, auditory, and electrical stimuli. Evoked potential studies may be used to assess hearing or sight, especially in infants and children, to diagnose disorders of the optic nerve, and to detect tumors or other problems affecting the brain and spinal cord. The tests may also be performed to assess brain function during a coma.

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

The weaker magnetic fields of the brain are studied with the help of 

  1. Electro cardiography

  2. SQUID

  3. Prosthesis

  4. Electro encephalography
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A SQUID (superconducting quantum interference device) is a very sensitive magnetometer used to measure extremely subtle magnetic fields, based on superconducting loops containing Josephson junctions. SQUIDs are sensitive enough to measure fields as low as 5 aT (51018 T) within a few days of averaged measurements. Magnetoencephalography (MEG), uses measurements from an array of SQUIDs to make inferences about neural activity inside brains. Because SQUIDs can operate at acquisition rates much higher than the highest temporal frequency of interest in the signals emitted by the brain (kHz), MEG achieves good temporal resolution.

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

A drug called reserpine was discovered by

  1. Jal Vakil

  2. Paul Ehrlich

  3. Hansen

  4. Alexander Wood
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Reserpine is an indole alkaloid, antipsychotic and antihypertensive drug that has been used for the control of high blood pressure.
Rustom Jal Vakil was the first to pioneer the use of resperine to control hypertension.
Thus, the correct answer is option (A), 'Jal Vakil'.

Multiple choice biology transport in mammals regulation of the activity of heart drug, tobacco and alcohol consumption community health and hygiene

Stethoscope was invented by

  1. René Laennec

  2. Wilhelm Roentgen

  3. Edward Jenner

  4. Joseph Lister
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Stethoscope was invented by Rene Laennec. It is a medical device which is mainly used to hear the sound of heart, intestine, blood flow of the arteries and veins.
Wilhelm Roentgen discovered x rays.
Edward Jenner developed the first vaccine for smallpox.
Lister successfully introduced carbolic acid to sterilize surgical instruments and wounds.
So, the correct answer is option A.