Tag: biology

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Questions Related to biology

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

The ion that always keeps the cardiac muscle unit in contracting state is

  1. Sodium

  2. Potassium

  3. Calcium

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

The calcium ions are responsible for muscle contraction by generating the action potential in the muscle cells. More influx of calcium ions may contract the heart muscle to a prolonged state of contraction, which will lead to abnormal increase in the heart rate. 

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

EEG can help in diagnosing certain conditions like

  1. Epilepsy

  2. Encephalitis

  3. Dementia

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

An electroencephalogram (EEG) is a test that measures and records the electrical activity of your brain by using sensors (electrodes). EEG is most often used to diagnose epilepsy, which causes abnormalities in EEG readings. It is also used to diagnose sleep disorders, coma, encephalopathies, and brain death. EEG used to be a first line method of diagnosis for tumors, stroke and other focal brain disorders.

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

MEG is

  1. Magnetoencephalography

  2. Magnetoelectron transport

  3. Metallic emission tantrum

  4. Mixed electronic tachycardia
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Magnetoencephalography (MEG) is a non-invasive neurophysiological technique that measures the magnetic fields generated by neuronal activity of the brain. The spatial distributions of the magnetic fields are analyzed to localize the sources of the activity within the brain, and the locations of the sources are superimposed on anatomical images, such as MRI, to provide information about both the structure and function of the brain. 

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

Who was first to record EEG of man?

  1. Hans Berger

  2. Galileo Galilei

  3. Willem Einthoven

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

Electroencephalography (EEG) is the recording of electrical activity along the scalp. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain. German physiologist and psychiatrist Hans Berger recorded the first human EEG in 1924. 

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

Heart beat is accelerated by

  1. Sympathetic nerves and acetylcholine

  2. Cranial nerves and adrenaline

  3. Cranial nerves and acetylcholine

  4. Sympathetic nerves and epinephrine.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sympathetic nerves release norepinephrine and stimulate the adrenal medulla to release epinephrine, both of which accelerate the heart rate. Acetylcholine is a parasympathetic neurotransmitter that slows the heart rate.

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

Which term does not apply to human heart?

  1. Neurogenic

  2. Pacemaker

  3. Few chambered

  4. Mitral valve
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
A neurogenic heart is the one in which impulses are originated by nerves. This type of heart is present in cockroach and some invertebrates. Human heart is myogenic which means that impulses are originated by muscles. 
The SA node in human heart is called pacemaker as it initiates and maintains the rhythmic contraction of heart. 
Human heart is four chambered consisting of 2 auricles and 2 ventricles. 
Mitral valve is also known as bicuspid valve and present between left atrium and left ventricle. 
Hence, neurogenic heart does not apply to human heart.
So, the correct answer is 'Neurogenic'.
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 not true?

  1. Regulation of blood vessel diameter originates from the vasomotor centre of the pons

  2. Baroreceptors may stimulate the vasomotor center

  3. Chemoreceptors are particularly sensitive to blood levels

  4. Cerebral cortex can play a role in regulating blood pressure
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The vasomotor center is a portion of the medulla oblongata, that together with the cardiovascular & respiratory centers regulates blood pressure too.

So, the correct option is 'Regulation of blood vessel diameter originates from the vasomotor center of the pons'.

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

Regarding circulatory adjustments during exercise which of the following is correct?

  1. The cardiac output increases more than tenfold in severe exercise.

  2. The increase in cardiac output during exercise is mainly due to an increase in stroke volume.

  3. The increase in stroke volume seen in exercise occurs despite a smaller and end - diastolic volume.

  4. In sever exercise the mean arterial pressure is unchanged because diastolic pressure.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cardiac output is the product of heart rate and stroke volume. During exercise, both increase significantly to meet oxygen demand, with the increase in stroke volume being a primary contributor to the rise in cardiac output.

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

Read the following statements and select the correct ones.


(i) Nodal tissue is specialised cardiac musculature in human heart which has the ability to generate action potential.
(ii) Position of SA Node - right corner of right atrium
(iii) Position of AV Node - right corner of ventricle
(iv) AV bundle continues from AV Node
(v) Purkinje fibres are modified cardiac muscle fibres that originate from the atrioventricular node and spread into the two ventricles.

  1. (i) and (ii)

  2. (i), (ii) and (iv)

  3. (ii), (iv) and (v)

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

Statement (i) is correct because nodal tissue generates action potentials. Statement (ii) is correct because the SA node is located in the upper right corner of the right atrium. Statement (iv) is correct as the AV bundle continues from the AV node. Statement (iii) is incorrect because the AV node is located in the lower left corner of the right atrium near the AV septum, not in the ventricle. Statement (v) is incorrect because Purkinje fibers emerge from the bundle of His, not directly as the sole origin from the AV node without the bundle.