Respiration Test 1

Short Hint:

• Plasma is responsible for a minimal amount of oxygen transport, with the given options indicating this value lies between 2^% and 6^%.
• Most oxygen, approximately 97%, is transported by red blood cells in the form of oxyhemoglobin (Hb₄O₂).

According to the provided explanation, the correct answer is A, "2^%".

Short Hint:

• The human respiratory system consists of various parts, some of which contain cartilage, including the trachea and bronchi, which are fortified with cartilage rings.
• The larynx also contains cartilage which is essential for voice production.
• The bronchioles, however, are devoid of cartilage and consist of ciliated cuboidal epithelium.

Therefore, out of the given options, the correct answer is D, "Bronchioles".

Short Hint:

• Oxygen transport in human cells is facilitated by hemoglobin.
• The release of oxygen from hemoglobin in cells or tissues is dependent on the pressure measured in mm of Hg.
• The given options denote a range of pressure values, and according to the information provided, oxygen is released from hemoglobin under resting conditions at 40 mm of Hg and under exercise conditions at 18 mm of Hg.

Hence, the closest correct answer to these values is D, "50 mm of Hg".

Short Hint:

• The human respiratory system comprises different sections, each having unique structural attributes.
• Cartilage plates are typically found in certain regions of the air passage way, including the trachea and both proximal and distal regions of the bronchi.
• The bronchioles, however, lack these cartilage plates.

Given the information provided, the correct answer is C, "Proximal region of bronchi", as the distal end, which is close to the bronchioles, does not contain cartilage plates.

Short Hint:

• The bronchioles, part of the human respiratory system, are characterized by their small size and specific diameter.
• These respiratory passages vary in diameter, with the given options ranging from 1 mm to 2 mm.
• The bronchioles, lined with ciliated cuboidal epithelium, have a diameter specified as 1 mm, making the correct answer B, "1 mm".

Short Hint:

• The amount of oxygen present in arterial blood is a vital measurement in understanding the oxygen-carrying capacity of the blood.
• In 100ml of arterial blood, the quantity of oxygen present can vary. The given options range between 17.4 ml O₂ and 20.4 ml O₂.
• Under normal resting conditions, 100ml of arterial blood is said to carry 19.4ml of O₂ at a pressure of 95mm of Hg and saturation of 97%.

Therefore, the correct answer is A, "19.4 ml O₂".

Short Hint:

• The amount of oxygen carried in blood plasma is significant in understanding the body's overall oxygen transportation.
• According to the given options, oxygen volume in 100ml of arterial blood plasma can vary from 0.29 ml O₂ to 0.59 ml O₂.
• The information reveals that 100ml of arterial blood plasma typically carries 0.29 ml of O₂ at a pressure of 95mm of Hg.

Therefore, the correct answer is A, "0.29 ml O₂".

Short Hint:

• Alveoli, tiny air sacs in the lungs, have walls of a certain thickness.
• The given options range from 0.1 μm to 10 μm.
• To ensure optimal gas exchange, alveolar walls are extremely thin, marked at approximately 0.1 μm, which fits the correct answer B, "0.1 μm".

Detailed Hints:

• Carbonic anhydrase is an enzyme located in various parts of the body.
• This enzyme is particularly present in the given options: white blood cells, red blood cells, platelets, and lungs.
• However, red blood cells are identified as the primary source of carbonic anhydrase, leading to the correct answer B, "Red blood cells".

Detailed Hints:

• Hemoglobin, a protein in red blood cells, carries oxygen. Its concentration in blood is crucial for oxygen transport.
• The given options for the amount of hemoglobin in 100ml of blood range from 5 g to 20 g.
• According to the information, 100ml of blood contains approximately 15g of hemoglobin, marking the correct answer as C, "15 g".

Detailed Hints:

• Hemoglobin's ability to bind with oxygen is a crucial element for assessing the body's oxygen carrying capacity.
• The given options suggest that 1 gm of hemoglobin can bind with a volume of oxygen ranging from 1.24 ml to 2.34 ml.
• Hafner’s constant, which is 1.34 ml of O₂ per gm of hemoglobin, is the accepted value, making the correct answer B, "1.34 ml of O₂".

Detailed Hints:

• The release of oxygen from blood to tissues is a crucial process that ensures the proper functioning of the body.
• The options suggest the volume of oxygen delivered by 100ml of blood to tissues at rest ranges from 5 ml to 20.4 ml.
• Based on arterial and venous blood oxygen differences (19.4 mlO₂ - 14.4 mlO₂), it is widely accepted that 100ml of blood releases 5ml of oxygen to resting tissues, hence the correct answer is A, "5 ml".

Detailed Hints:

• The oxygen content in venous blood is a critical measure of the body's oxygen utilization.
• According to the given options, 100ml of resting venous blood contains oxygen volumes ranging from 5 ml O₂ to 20 ml O₂.
• Under resting conditions, 100ml of venous blood carries 14.4ml O₂ at a pressure of 40mm of Hg and 75% saturation, which leads to the correct answer B, "14.4 ml O₂".

Detailed Hints:

• The oxygen content in the blood, particularly in the venous blood departing from active tissues, provides insights into metabolic activity.
• The given options indicate the amount of oxygen in 100 ml of venous blood ranges from 1.34 ml to 19.4 ml.
• However, by subtracting the amount of oxygen consumed by tissues (15 ml) from the total oxygen content (19.4 ml), we obtain a final value of 4.4 ml, which corresponds to the correct answer A, "4.4 ml/100 ml of blood".

Detailed Hints:

• The form in which oxygen is transported in the blood, notably as oxyhemoglobin in red blood cells, is critical for understanding bodily function.
• The potential percentages for oxyhemoglobin transport range from 96% to 99%.
• The commonly accepted value is 97% of oxygen being carried by RBCs as oxyhemoglobin, with the remaining as dissolved oxygen in plasma, matching the correct answer B, "97%".

Detailed Hint:

• The size of the vocal cords differs between males and females, which contributes to the variations in pitch and tone of voice.
• The given options propose different size comparisons of male vocal cords to female ones.
• Men typically have larger vocal cords than women, which results in a lower pitch. This size difference aligns with the correct answer B, "Larger in size".

Detailed Hint:

• The structure of the trachea (windpipe) and bronchi in humans is unique and designed to ensure optimal functioning of the respiratory system.
• The options suggest that they could be lined with either cartilaginous plates, chitinous rings, cartilaginous rings, or muscular rings.
• It's crucial to note that the trachea and bronchi are equipped with incomplete, horseshoe-shaped cartilaginous rings, which prevent them from collapsing. Thus, the correct answer is C, "Lined with cartilaginous rings".

Detailed Hint:

• Understanding the mechanism employed for gaseous exchange in the respiratory surface is crucial for comprehending respiratory physiology.
• Options given indicate diffusion, active transport, osmosis, or a combination of all as possible mechanisms.
• However, the primary process in gaseous exchange is diffusion, as gases move from an area of high concentration to an area of low concentration. Hence, the correct answer is A, "Diffusion".

Detailed Hint:

• The measure of oxygen intake per minute is important for understanding the oxygen demand of the body under normal conditions.
• Options suggest the oxygen intake per minute could range anywhere from 20 ml to 300 ml.
• Given that 5 liters of air have a 5% O2 intake, the calculation 5000 x (5%) ÷ 100 equals 250. Consequently, the correct answer is B, "250 ml".

Detailed Hint:

• The ability of arterial blood to transport oxygen under a particular partial pressure of oxygen (PO2) is a crucial aspect of respiratory physiology.
• The options suggest varying oxygen capacities at 100 mmHg PO2, ranging between 4.4ml and 20ml per 100ml of blood.
• Applying the fact that 1 gm of Hemoglobin (Hb) can dissolve 1.34ml of O2, and 100ml of blood contains around 15gm of Hb, leads to the calculation 15 x 1.34 which equals 20. Therefore, the correct answer is A, "20ml/100ml of blood".

Detailed Hint:

• It's essential to understand how carbon dioxide is carried in the blood as part of our respiratory physiology.
• Given options present various forms carbon dioxide could take during transport.
• Remember that around 70% of CO2 is transported as bicarbonate ions, which is a significantly larger proportion compared to the other forms. Hence, the correct answer is C, "Bicarbonate ions".

Detailed Hint:

• The quantity of oxygen in venous blood plasma is a vital factor in understanding human respiration.
• The options propose different measures of oxygen contained in 100ml of venous blood plasma.
• Under conditions of 40mm of Hg, each 100ml of venous blood plasma contains 0.12ml of dissolved oxygen. Therefore, the correct answer is B, "0.12 ml".

Detailed Hint:

• Comprehending the embryonic origin of our body organs, such as the lungs, is key to understanding developmental biology.
• The available options indicate that the lungs could originate from endoderm, ectoderm, mesoderm, or be preformed.
• However, embryonic development studies reveal that the lungs are derived from the endoderm, making the correct answer A, "Endodermal".

Detailed Hint:

• Knowledge of how much oxygen is dissolved in venous blood plasma is vital to understanding oxygen transportation and exchange in the human body.
• The possible answers range from 0.17 ml to 0.47 ml of oxygen per 100ml of venous blood.
• Given that the difference between total O2 and the O2 dissolved in plasma is 0.17ml, the correct answer is A, "0.17 ml".

Detailed Hint:

• The production of surfactant, a detergent-like substance, plays a pivotal role in reducing the tension in the fluid layer lining the alveolus, hence easing the breathing process.
• The options suggest that surfactant could be secreted by cells in the bronchi, lungs, alveoli, or all of these.
• However, it's important to remember that surfactant is specifically secreted by cells in the walls of the alveoli. Therefore, the correct answer is C, "Alveoli".

Detailed Hint:

• The respiratory system serves multiple functions essential to life, ranging from the ability to smell to the exchange of gases.
• The options offer four different possibilities of what could be considered the primary function of the respiratory system.
• However, the inherent function of the respiratory system, which is core to all its other functions, is the ability to breathe. Hence, the correct answer is B, "Ability to breathe".

Detailed Hint:

• Understanding how carbon dioxide is transported when human blood leaves the tissue capillary bed is integral to comprehending our respiratory physiology.
• The choices suggest various forms that carbon dioxide may adopt during this transportation process.
• Recalling that approximately 70% of carbon dioxide is transported as bicarbonate ions confirms that the correct answer is B, "Bicarbonate ions".

Detailed Hint:

• Recognizing the gas associated with Hamburger's phenomenon or the chloride shift is crucial for understanding gas transport within the blood.
• The options suggest that the phenomenon could be related to the transport of oxygen, nitrogen, carbon dioxide, or all of these gases.
• It's important to remember that Hamburger’s phenomenon is associated specifically with the transport of carbon dioxide. Hence, the correct answer is C, "CO2".

Detailed Hint:

• Appreciating the factors that influence the oxygen-carrying capacity of blood is essential for understanding respiratory physiology.
• The available choices suggest that the capacity could be swayed by the partial pressures of CO₂ and O₂, altitude, or the blood volume.
• However, it's essential to recognize that while the three former factors can influence the oxygen-carrying capacity, the volume of blood does not directly impact the pressure of O₂. So the correct answer is D, "Volume of blood".

Detailed Hint:

• Understanding the structure and function of the trachea, including the role of its cartilage rings, is pivotal to understanding respiratory anatomy.
• The options suggest that the cartilage rings could prevent bending, shortening, collapse, or swelling of the trachea.
• It's essential to recall that these C-shaped hyaline cartilaginous rings are rigid and non-collapsible, primarily preventing the trachea from collapsing and ensuring a clear airway. Therefore, the correct answer is C, "Collapsing".