Chapter 17 Flashcards
Explain the term “breathing”
Muscular mechanism which is applied to transport air containing oxygen from air to lungs (inhalation) and carbon dioxide from lungs to air (exhalation)
- Also called ventilation
Explain the term “gaseous exchange”
Diffusion of oxygen from alveoli to blood capillaries and vice versa with carbon dioxide
Explain the term “respiration”
The release of energy in all body cells 24/7 (in mitochondria)
Name the membranes by which the lungs are covered, and also name the fluid secreted and maintained by these membranes
- Pleural membranes
- Pleural fluid
What is the function of pleural fluid?
Protects the lungs from friction during breathing movements
Name the adaptations of the gaseous exchange system, in terms of alveoli structures and blood capillaries
- Alveoli are in large numbers, which provides a large surface area
- Alveoli walls are made up of one layer of epithelial cells
- Alveoli are surrounded by capillary networks
- Capillary walls also made up of one layer of epithelial cells
- A small distance exists between blood and air
- Blood is constantly flowing trough capillaries
- Moist layer keeps alveoli open and prevents cells from drying out
Name the features of an effective gaseous exchange surface
- Large surface area
- Thin surface
- Efficient transport system
- Must always be moist
- Concentration gradient between air and blood
Explain how leaves also illustrate the features of an effective gaseous exchange surface
- Large surface area
- Leaves are thin
- Efficient transport system (xylem and phloem)
- Air spaces for gases to diffuse into
Inhalation: Explain. Go!
- Active phase
- Diaphragm contracts
- Abdominal muscles relax (to accommodate intestines)
- External intercoastal muscles contract
- Internal intercoastal muscles relax
- Ribs move up and out
- Thoracic cavity increases in volume
- Internal pressure decreases
- Elastic lungs expand
- Oxygen rich air flows into the lungs (inflation)
Describe one test for carbon dioxide OTHER than the limewater test
Hydrogen carbonate indicator turns from RED to ORANGE-YELLOW in the presence of CO2
State the typical breathing rate of an adult at rest and then ruring exercise
- 16-18 times per minute (at rest)
- 20-30 per minute (during exercise)
Describe the effects of exercise on breathing and heartrate
- More oxygen will be exchanged
- Ensures active muscle cells are supplied with sufficient O2
- Faster respiration will occur in cells
- More energy will be released for the cells
- More carbon dioxide will be excreted at the same time
Name the effects of nicotene on the respiratory system
- Stimulant which makes you feel more alert and active
- Reduces the diamted of arterioles
- Increases heartrate and blood pressure
- Very poisenous
- Increases the stickiness of platelets, leading to thrombosis
Name the effects of tar on the respiratory system
- Carcinogen
- Absorbed by cells in lining of bronchi and can cause mutations in DNA (cancer)
- Irritant
- Leads to bronchitis
- Damages cilia in air passages, preventing the sweeping out of dust, bacteria, pollen and mucus
- Causes goblet cells to secrete extra mucus, ideal breeding ground for bacteria
- Coughing damages alveoli leading to emphysema
Name the effects of carbon monoxide on the respiratory system
- Combines with haemoglobin to form carboxyhaemoglobin
- Less haemoglobin is available to transport oxygen
- Haemoglobin has a higher affinity for carbon monoxide than for oxygen
- One fifth of haemoglobin can be occupied by CO
- CO Damages lining of arteries, leading to atherosclerosis
