CBSE Questions for Class 11 Medical Biology Breathing And Exchange Of Gases Quiz 7 - MCQExams.com

$$\textbf{Correct Option C}$$

$$\textbf{Solution}$$

$$\bullet$$ There are various forms of respiratory disease that occurs due to various reasons.

$$\bullet$$ $$\textbf{Option B}$$ Arthritis is a disease which is associated with joint pain and can cause swelling and stiffness in the joints.

$$\bullet$$ $$\textbf{Option C}$$ Asthma is a respiratory disease which occurs because of the production of extra mucus in the narrow trachea which makes the person difficult to breathe.

$$\bullet$$ $$\textbf{Option D}$$ Cancer is a disease in which the abnormal cells divide uncontrollably by destroying the tissue of the body.

So, the correct option is C.

$$\textbf{Correct option:B}$$ 

$$\textbf{Solution:}$$

$$\textbf{Inspiration:}$$

$$\bullet$$ During inspiration,there is influx of air from the atmosphere into the lungs,which occurs due to the combined movement of diaphragm and external intercostal muscles due to which the size of thoracic cavity increases .

$$\bullet$$ The inhaled air is composed of approximately 21%oxygen,78%nitrogenand 0.04% carbon dioxide.

$$\textbf{Expiration:}$$

$$\bullet$$ Expiration is the process in which the foul air which consists of waste by products such as  carbon dioxide ,produced during cellular respiration is removed from the  lungs to the outside of the body.

$$\textbf{Hence, the correct option is (B)}$$

•  In a tracheotomy, the tube is inserted through a cut in the neck below the vocal cords this allows air to enter the lungs. 
• Breathing is then done through the tube, bypassing the mouth, nose, and throat. Air from your nose and mouth passes down through your throat to the larynx and into the trachea.
•  The trachea is the big air tube leading to the lungs. When you breathe out, air leaves your lungs through this tube. Hence, During tracheotomy (a tube inserted directly into the trachea), colder and drier air enters the lungs than normal which can cause lung crusting and infection. The primary cause for this is air does not flow through the nasal passageways.

The digestive system includes alimentary canal and associated glands to carry out the digestion of food and release the energy stored in these food substances. The primary function of the respiratory system is to allow atmospheric oxygen from the air to enter the blood and carbon dioxide from the blood to exit into the air. The endocrine system includes endocrine glands and maintains the homeostasis of the body through hormonal actions. Nervous system serves in the reception of sensory input followed by their integration in the brain and spinal cord and generation of motor output to produce the response. Thus, the correct answer is B.

• The process of breathing ) is divided into two distinct phases, inspiration and expiration occur simultaneously.
  
• Inspiration can occur if the pressure within the lungs (intra-pulmonary pressure) is less than the atmospheric pressure,
•  Inspiration is initiated by the contraction of a diaphragm which increases the volume of the thoracic chamber in the anteroposterior axis. The contraction of external inter-costal muscles lifts up the ribs and the sternum causing an increase in the volume of the thoracic chamber in the dorsoventral axis.
• The overall increase in the thoracic volume causes a similar increase in pulmonary volume. An increase in pulmonary volume decreases the intrapulmonary pressure to less than the atmospheric pressure which forces the air from outside to move into the lungs. Hence, When the pressure of air within the lungs is less than the atmospheric pressure, air will not flow out of the lungs.
  

• Carbon dioxide is the waste gas that is produced when carbon is combined with oxygen as part of the body's energy-making processes.
• The lungs and respiratory system allow oxygen in the air to be taken into the body, it also helps the body to get rid of carbon dioxide in the air breathed out.
• When the blood from the heart flows through the capillaries and collects oxygen from the alveoli. At the same time, carbon dioxide passes out of the capillaries and into the alveoli. These blood brings oxygen to the body cells and takes away their carbon dioxide.  Hence, the circulatory system and respiratory system eliminates carbon dioxide from the body.

$$\textbf{Correct answer: D}$$ 

$$\textbf{Option (A):}$$ 

$$\bullet$$ The eardrum helps in passing the sound vibrations to the middle ear. It helps in the reception of sound and not producing it.

$$\textbf{Option (B):}$$ 

$$\bullet$$ The auditory nerves carry the impulse for the audition of sound. This is not responsible for the generation of sound

$$\textbf{Option (C):}$$ 

$$\bullet$$ The optic nerve is responsible for carrying the signal of visual impulse from the retina to the brain.

$$\bullet$$ Optical cortex is the region where the visual impulse reaches the brain.

$$\textbf{Option (D):}$$ 

$$\bullet$$ The vocal cords in the larynx are responsible for producing the sound.

$$\bullet$$ Due to the presence of these vocal cords, the larynx is also called the voice box.

$$\bullet$$ The vibration of the vocal cords is responsible for producing sounds that come out through the mouth. Voicebox helps in speaking.

Hence, the correct answer is option (D).

• Exhalation is the flow of the breath out of an organism. In humans, it is the movement of air from the lungs out of the airways, to the external environment during breathing.
• During exhalation, the diaphragm relaxes and moves upward into the chest cavity. The intercostal muscles between the ribs also relax to reduce the space in the chest cavity. As they relax they position the rib cage downwards and inwards.
  
• As the space in the chest cavity gets smaller, the air rich in Carbon dioxide is forced out of the lungs and windpipe and then out of the nose or mouth.
• Hence, during exhalation, the ribs move downwards.

• Blood enters the right atrium and passes through the right ventricle.
• The right ventricle pumps the blood to the lungs where it becomes oxygenated.
  
• The oxygenated blood is brought back to the heart by the pulmonary veins which enter the left atrium.
  

• The Adam's apple is also called the laryngeal prominence.
  
• It is a feature of the human neck and is referred to as the lump or protrusion that is formed by the angle of the thyroid cartilage surrounding the larynx.

1. The relaxation and contraction of the diaphragm,
2. and the movement of the intercostal muscles present in the thorax of an individual are responsible for the ventilation movements of the lungs that facilitate respiration.