Test: Human Physiology: Respiratory System - 1

Pleurisy involves inflammation of the tissue layers (pleura) lining the lungs and inner chest wall. Pleurisy is often associated with the accumulation of fluid between the two layers of pleura, known as pleural effusion. Symptoms of pleurisy include pain in the chest, which is aggravated by breathing in, shortness of breath, and local tenderness. The diagnosis of pleurisy is made by the characteristic chest pain and physical findings on examination of the chest. The pleural accumulation of fluid (pleural effusion) can be seen by imaging studies.

Mucus helps to moisten and protect the airways. Mucus lines the ciliated cells of the trachea to trap inhaled foreign particles that the cilia then waft upward toward the larynx and then the pharynx where it can be either swallowed into the stomach or expelled as phlegm.

'Motile' (or moving) cilia are found in the lungs, respiratory tract and middle ear. These cilia have a rhythmic waving or beating motion. They work, for instance, to keep the airways clear of mucus and dirt, allowing us to breathe easily and without irritation. They also help propel sperm.

Chloride shift also known as the Hamburger phenomenon is a process which occurs in a cardiovascular system and refers to the exchange of bicarbonate (HCO₃⁻) and chloride (Cl⁻) across the membrane of red blood cells (RBCs).

Oxygen haemoglobin dissociation curve gives the relationship between the saturation of haemoglobin and oxygen tension.
The curve obtained by plotting percent saturation of Hb against time is sigmoid, at 30°C and pH7.4. Dissociation of oxyhaemoglobin can be promoted by rise in the body temperature and low pH (high CO₂).

The oxygen-carrying capacity of hemoglobin determines how much oxygen is carried in the blood.

In addition, other environmental factors and diseases can also affect oxygen-carrying capacity and delivery; the same is true for carbon dioxide levels, blood pH, and body temperature.

When carbon dioxide is in the blood, it reacts with water to form bicarbonate (HCO^{3 −}) and hydrogen ions (H⁺). As the level of carbon dioxide in the blood increases, more H+ is produced and the pH decreases.

The increase in carbon dioxide and subsequent decrease in pH reduce the affinity of hemoglobin for oxygen. The oxygen dissociates from the Hb molecule, shifting the oxygen dissociation curve to the right.

Therefore, more oxygen is needed to reach the same hemoglobin saturation level as when the pH was higher.

An increase in blood CO₂ concentration, which leads to a decrease in blood pH. This will result in haemoglobin proteins releasing their load of oxygen. Conversely, a decrease in carbon dioxide provokes an increase in pH, which results in haemoglobin picking up more oxygen. Since carbon dioxide reacts with water to form carbonic acid, an increase in CO₂ results in a decrease in blood pH.

The correct option is Option C.

In emphysema, the inner walls of the lungs' air sacs (alveoli) are damaged, causing them to eventually rupture. This creates one larger air space instead of many small ones and reduces the surface area available for gas exchange. Emphysema is a lung condition that causes shortness of breath.

Oxygenation literally means the addition of oxygen to a chemical substance or physical system. Thus binding of oxygen with haemoglobin can also be reffered as oxygenation. Oxyhemoglobin is formed when oxygen binds to the heme component of the protein hemoglobin in red blood cells, during physiological respiration.
Whereas oxidation is a loss of electron, which can be either in the form of gaining of oxygen or loss of hydrogen and reduction is a gain of electron, which can be either in the form of loss of oxygen or gaining of hydrogen.

The cartilage rings in the trachea prevent the trachea from collapsing during the absence of air and also protect it. These cartilaginous rings are C-shaped.
So, the correct answer is option D.

The lungs are surrounded by two membranes, the pleurae. The outer pleura is attached to the chest wall and is known as the parietal pleura; the inner one is attached to the lung and other visceral tissues and is known as the visceral pleura.
So, the correct answer is option C.

Chloride shift is a process which occurs in a cardiovascular system and refers to the exchange of bicarbonate and chloride across the membrane of red blood cells.

The tracheae, primary, secondary and tertiary bronchi, and initial bronchioles are supported by incomplete cartilaginous rings. The rings are incomplete on the dorsal side. Each terminal bronchiole gives rise to a number of very thin, irregular walled and vascularised bag-like structures called alveoli.

The important derivatives of the three germ layers are given below :

A. Endoderm : 1) Gut tube epithelium 2) Liver 3) Respiratory system 4) Pancreas

B. Mesoderm : 1) Connective tissue 2) Bone 3) Muscles 4) Cardiovascular system 5) Lymphatics 6) Urogenital structure

C. Ectoderm : 1) Epidermis 2) Nervous system 3) Adrenal medulla

In mammals like humans inspiration and expiration are carried out by creating pressure gradients between the atmosphere and the alveoli with the help of specialised muscles -intercostals and diaphragm. Diaphragm is dome shaped muscular separation between abdominal and thoracic cavities. It is characteristic of mammals. 

The epiglottis moves back and forth to prevent the passage of food and liquids into the lungs. The usual upright position of the epiglottis allows air to flow into the lungs and the larynx. When you swallow, the epiglottis flattens backward to cover the entrance to your larynx and prevent food from entering the lungs and windpipe. The epiglottis returns to its usual position after swallowing. 
Thus, the correct answer is option D.

Injury-related pneumothorax: A puncture wound to the chest, such as a gunshot, etc. A one-way valve mechanism prevents air from escaping the pleural cavity. If the patient is not treated immediately, death can result.

The corniculate cartilages (cartilages of Santorini) are two small conical nodules consisting of elastic cartilage, which articulate with the summits of the arytenoid cartilages and serve to prolong them posteriorly and medially.

Larynx generally called the voice box or GLOTTIS, it's a pathway for air between the pharynx above and the trachea below next see the path of air in human.
External nostrils --->vestibule ---->nasal chamber--->internal nares--->naso pharynx--->pharynx--->**GLOTTIS**-->larynx.

The alveolar membrane is the gas-exchange surface. Carbon dioxide rich blood is pumped from the rest of the body into the alveolar blood vessels where, through diffusion, it releases its carbon dioxide and absorbs oxygen.

In frogs the process of respiration takes place through three respiratory surfaces - skin, lungs and lining of the mouth. However, when submerged in water, the frog respires through its cutaneous membranes on the skin as it is quite permeable to water and contains a large network of blood vessels. The cutaneous membrane allows the respiratory gases to readily diffuse directly. Even when out of water, mucus glands present in the skin help in the cutaneous respiration.

Therefore, the correct answer is option D.

Oxyhemoglobin is formed during physiological respiration when oxygen binds to the heme component of the protein hemoglobin in red blood cells. This process occurs in the pulmonary capillaries adjacent to the alveoli of the lungs.