Lab #6 - Human respiratory system physiology

Question 1

Alveoli

Answer 1

thin-walled tiny air sack in the lung. Where gas exchange takes place

Question 2

Bronchi

Answer 2

rigid tube that acts as an airway, connecting th trachea with one lung

Question 3

Bronchioles

Answer 3

smaller airways branching from the bronchi

Question 4

Tidal volume

Answer 4

the volume of air inhaled and exhaled in one breath

Question 5

inspiratory reserve volume

Answer 5

the amount of additional air a person can inhale forcefully after normal tidal volume inspiration

Question 6

expiratory reserve volume

Answer 6

after expiration, the exhale of additional air from the lungs

Question 7

residual volume

Answer 7

The air that remains in lungs after a complete, forced exhalation

Question 8

vital capacity

Answer 8

The maximum tidal volume of air that an individual can inhale and exhale

Question 9

Spirometer

Answer 9

tests how well your lungs work by measuring how much air you inhale, how much you exhale and how quickly you exhale

Question 10

Spirometry

Answer 10

used to diagnose conditions that affect breathing

Question 11

Chemoreceptor

Answer 11

special receptors that sense changes in the chemical composition of blood

Question 12

respiratory center

Answer 12

located in the medulla oblongata and is involved in the minute to minute control of breathing

Question 13

compare lung volumes, breathing rate and minute respirometry volume between rest and exercise and link it with to oxygen requirements in tissues.

Answer 13

Breathing rate
- When you exercise your body uses more oxygen to produce carbon dioxide
- Your breathing rate changes from about 15 times a minute to about 40-60 times a minute
Lung volumes
- The volume of air entering and leaving the body during inhalation and exhalation is called the tidal volume
- In a human at rest, the tidal volume amounts to about 500ml
- As physical activity increases, the tidal volume increases to match the body’s demands for O2. At maximal levels the tidal volume reaches about 3400ml in females and about 4800ml in males
- This maximum tidal volume is called the vital capacity of an individual
- Even after the most forceful exhalation, about 1200ml of air remains in the lungs in males and about 1000ml in females (residual volume of the lungs)
Minute respiratory volume
- Mean tidal volume x breathing rate
Since your breathing rate and tidal volume increases, the minute respiratory volume increases during exercise

Question 14

explain physiological changes that occur in respiratory system in response to exercise.

Answer 14

• When exercise increases the body’s demand for 02, contractions of other muscles help expel the air by forcefully reducing the volume of the chest cavity
• Increased volume of air in the lungs
• Increased breathing rate
• Increased cardiac output

Question 15

explain the physiological differences associated with lung capacities between men and women.

Answer 15

• Females have reduced airway diameters and lung volume, so men have more capacity in their chest cavity
• On average men are taller than females
• As physical activity increases, the tidal volume increases to match the body’s demands for O2. At maximal levels the tidal volume reaches about 3400ml in females and about 4800ml in males (vital capacity)
• Even after the most forceful exhalation, about 1200ml of air remains in the lungs in males and about 1000ml in females (residual volume of the lungs)

Question 16

Why is diffusion an inefficient respiratory strategy for organisms that are more than a few millimeters thick? Describe why oxygen uptake is more challenging for animals living in water than for animals living in air.

Answer 16

• If the barrier is thick, the concentration gradient will be shallow, resulting in slow transfer of molecules.
• Oxygen dissolves poorly in water
• The amount of oxygen that can be dissolved in water at atmospheric pressure Is far less than there is in an equivalent volume of air at the same pressure. Although, the animals have proteins that reverse bind to oxygen called haemoglobin, increasing the oxygen carrying capacity of blood seventy fold compared with water.

Question 17

Animals including humans that live at higher altitudes do not suffer from chronic hypoxia and reduced aerobic performance. What physiological adaptations do they have that make them capable of that?

Answer 17

• Increase in the rate of breathing even at rest
• An expansion in the width of blood vessels that carry oxygenated blood to the cells
• Increased concentration of hemoglobin
• Erythropoietin is secreted