Bio 220 Lecture Exam

Question 1

1. **Contrast the epithelium of the bronchi with that of the alveoli and explain how the structural difference is related to their functional difference. **

Answer 1

• The epithelium of the bronchi is ciliated pseudo-stratified columnar, containing goblet cells for mucus production, aiding in trapping particles. In contrast, the alveoli have a simple squamous epithelium, optimizing gas exchange. Structural differences align with function: bronchi protect and cleanse air, while alveoli facilitate efficient gas diffusion.

Question 2

2. **List the two anatomical divisions of the respiratory system. **

Answer 2

• The two anatomical divisions of the respiratory system are the upper respiratory tract (including the nose, pharynx, and larynx) and the lower respiratory tract (encompassing the trachea, bronchi, bronchioles, and lungs).

Question 3

3. **What would happen to the alveoli if surfactant were not produced? **

Answer 3

• Without surfactant, alveoli would collapse due to high surface tension. Surfactant reduces tension, preventing alveolar collapse and enhancing lung compliance for effective breathing.

Question 4

4. **When you inhale, does your chest expand because your lungs inflate, or do your lungs inflate because your chest expands? Explain. **

Answer 4

• Your chest expands because your lungs inflate. When you inhale, the diaphragm contracts and the ribcage expand, creating a pressure gradient that allows air to flow into the lungs.

Question 5

5. **Mark breaks a rib that punctures the chest wall on his left side. What do you expect will happen to his left lung as a result? Will this have an effect on his right lung as well? Why or why not? **

Answer 5

• Breaking a rib that punctures the left chest wall may cause a pneumothorax, collapsing the left lung. It may not directly affect the right lung unless complications arise, such as a tension pneumothorax impacting overall respiratory function.

Question 6

6. **How is most oxygen transported in the blood, and why does carbon monoxide interfere with this? **

Answer 6

• Oxygen is primarily transported in blood bound to hemoglobin. Carbon monoxide interferes by binding more strongly to hemoglobin, reducing its oxygen-carrying capacity.

Question 7

7. **What are the ways in which blood transports CO2? **

Answer 7

• Blood transports CO2 in three ways: dissolved in plasma, as bicarbonate ions, and bound to hemoglobin.

Question 8

8. **Explain how changes in pulmonary ventilation can correct pH imbalances. **

Answer 8

• Changes in pulmonary ventilation impact CO2 levels, influencing blood pH. Increased ventilation removes more CO2, raising pH (alkalosis), while decreased ventilation retains CO2, lowering pH (acidosis).

Question 9

9. **What are the four steps of respiration? **

Answer 9

• The four steps of respiration are pulmonary ventilation, external respiration, transport of respiratory gases, and internal respiration.

Question 10

10. **Describe the different disorders that fall under the COPD category. Link this to lab – would obstructive disorders change the volumes and capacities of the lung or would reduce the ability to move air in and out? **

Answer 10

• The four steps of respiration are pulmonary ventilation, external respiration, transport of respiratory gases, and internal respiration.

Question 11

1. **Name major functions of the urinary system. **

Answer 11

• Kidney failure can disrupt fluid and electrolyte balance, lead to retention of waste products, cause hypertension due to altered blood volume, and disturb acid-base balance.

Question 12

3. **Why don’t plasma proteins pass into the capsular space under normal circumstances? **

Answer 12

• Kidney failure can disrupt fluid and electrolyte balance, lead to retention of waste products, cause hypertension due to altered blood volume, and disturb acid-base balance.

Question 13

4. **Explain why a substance appears in the urine if its rate of glomerular filtration exceeds the Tm of the renal tubule. **

Answer 13

• If the rate of glomerular filtration exceeds the transport maximum (Tm) of the renal tubule, the substance cannot be reabsorbed completely, leading to its appearance in the urine.

Question 14

5. **What effect would an increase in aldosterone have on the K+ concentration in urine? **

Answer 14

• An increase in aldosterone would enhance potassium (K+) reabsorption in the renal tubules, reducing K+ concentration in urine.

Question 15

6. **How does a decrease in blood pressure affect glomerular filtration? **

Answer 15

• A decrease in blood pressure can reduce glomerular filtration rate (GFR) as the filtration pressure decreases, impacting the kidneys’ ability to filter blood effectively.

Question 16

7. **What is the primary mechanism for prompting us to drink water? **

Answer 16

• The primary mechanism prompting us to drink water is the sensation of thirst, regulated by osmoreceptors detecting changes in blood osmolarity.

Question 17

8. **What is the difference between filtrate and urine? **

Answer 17

• Filtrate is the fluid derived from blood plasma in the renal corpuscle before undergoing modification in the renal tubules, while urine is the final product after reabsorption and secretion processes.

Question 18

9. **Explain how Na+ levels, volume of the ECF, and blood pressure are jointly regulated. **

Answer 18

• The renin-angiotensin-aldosterone system responds to low blood pressure, promoting sodium (Na+) and water retention, thereby increasing extracellular fluid (ECF) volume and blood pressure.

Question 19

10. **How does the respiratory system contribute to acid-base balance? What about the urinary system? **

Answer 19

• The respiratory system regulates pH by adjusting CO2 levels through breathing. The urinary system excretes hydrogen ions and reabsorbs bicarbonate to maintain acid-base balance.

Question 20

11. **What is an acid? A base? A buffer? What happens if pH does not remain within the normal range? **

Answer 20

• An acid donates H+ ions, a base accepts them, and a buffer resists pH change. If pH deviates from the normal range, cellular functions can be impaired, affecting enzyme activity and protein structure.

Question 21

12. **Why is it important to regulate electrolyte (Na+, K+ and Ca2+) levels? **

Answer 21

• Electrolyte regulation is crucial for maintaining cell function, osmotic balance, nerve impulse transmission, and muscle contraction. Imbalances can lead to cellular dysfunction and affect overall physiological processes.