IB Exam Review Unit 3 Flashcards
How many principle structures of the ventilatory system are there?
9
What are the principle structures of the ventilatory system? (9)
- nose
- mouth
- pharynx
- larynx
- trachea
- bronchi
- bronchioles
- lungs
- alveoli
Nose and Mouth
breath oxygen rich air into system
Pharynx
branches to form esophagus
Trachea
carries air to your lungs
Larynx
upper opening into trachea that contains muscles cartilages, and vocal cords
Bronchi
passageways that connect trachea and lungs
Bronchioles (2)
- smaller branches of bronchi
- increase surface area for gas exchange
Alveoli
small air sacs where gas exchange happens
What are some conducting airways? (3)
- nasal/oral passages
- trachea
- bronchi
What are the functions of conducting airways? (3)
- low resistance path for air
- warming, moistening of air
- air filtration by lining
What is the function of the nose as a conducting airway?
humifies and filters entering air
What is the function of the pharynx as a conducting airway?
a low resistance path for airflow into the larynx and then trachea
What is the function of the larynx as a conducting airway?
protecting the trachea from invasion of foods and fluids
Diaphragm (2)
- muscular partition separating the thorax from the abdomen
- its contraction increases the volume of the thorax and inflates the lungs for breathing
What happens during inspiration at rest? (4)
- diaphragm contracts, creating a larger thoracic cavity
- external intercostal muscles contract, moves ribs up and out making the rib cage expand
- lung volume increases and air pressure decreases
- air moves into the lungs
What happens during exhalation at rest? (4)
- diaphragm relaxes, creating a smaller thoracic cavity
- external intercostal muscles relax, moves ribs down and in making the rib cage contract
- lung volume decreases and air pressure increases
- air moves out lungs
What is different about pulmonary ventilation during exercise? (2)
- more oxygen is needed by muscles
- more carbon dioxide is released by muscles
What additional muscles work during ventilation during exercise? (3)
- internal intercostal muscles
- muscles of abdomen
- muscles of shoulders
What is energy for muscle contraction used for? (3)
- inspiration at rest
- inspiration during exercise
- expiration during exercise
What happens during inhalation during exercise? (2)
- ribcage up and out
- internal intercostal muscles relax
- external intercostal muscles contract
What happens during exhalation during exercise? (3)
- ribcage down and in
- externa intercostal muscles relax
- internal intercostal muscles contract
Spirometry (2)
- test used to measure pulmonary ventilation in humans
- measures the volume and rate of air inhaled and exhaled over a period of time
Tidal Volume
volume of air breathed in and out in one normal breath
Inspiratory Reserve Volume
additional inspired air over and above tidal volume
Expiratory Reserve Volume
volume of air in excess of tidal volume that can be exhaled forcefully
Residual Volume
volume of air in lung after a maximal exhalation
Total Lung Capacity (2)
- volume of air in lungs after a maximum inhalation
- the sum of the vital capacity and residual volume
Vital Capacity
maximum volume of air that can be exhaled after a maximum inhalation
Lung Volumes (2)
- can’t be trained
- are mostly determined by natural body size
Rate of Exhalation (2)
- can be trained with exercise
- muscle controlling exhalation can be worked
- a very sensitive marker of lung function
Cellular Respiration
- metabolic process that produces energy from food molecules
- requires O2 and produces CO2 as waste
What is increased during exercise? (2)
- breathing rate
- tidal volume
How does the brain regulate breathing rate?
brain monitors blood pH and alters breathing rate accordingly
How is blood pH related to ventilation?
- blood becomes more acidic when carbon dioxide levels rise
- lower blood pH = more acidic
- faster/deeper breathing expels CO2 and raises blood pH
Oxygen Deficit (2)
- when the body cannot deliver enough oxygen to the muscle cells during exercise
- caused by exercise when there is an increase in blood CO2
How many receptors send signals to the brain to regulate ventilation appropriately?
3
What receptors send signals to the brain? (3)
- chemoreceptors
- pulmonary stretch receptors
- muscle proprioceptors
Chemoreceptors
detects changes in blood pH
Pulmonary Stretch Receptors
respond to stretching of the lung describing breaths
Muscle Proprioceptors
detect changes in the tension and pressure of muscle involved in breathing
Alveoli (4)
- air sacs where exchange of O2 and CO2 takes place
- numerous and cover a large surface area
- have thin walls so gases have a short distance to diffuse
- have a good blood supply
How do gasses enter and exit the alveoli?
O2 and CO2 move across a thin barrier that separates alveoli from passing blood
Partial Pressure of Gas
measure of concentration of the gas in a mixture
What causes gas exchange in the correct directions? (4)
- air in alveoli has higher O2 pressure than blood
- O2 moves from alveoli to blood
- blood has higher CO2 pressure than alveoli
- CO2 moves from blood alveoli
How is the pressure gradient between blood and alveoli?
it is maintained due to ventilation and blood flow
Hemoglobin
- in red blood cells
- high affinity for O2
- transports most O2 in the blood and CO2
- iron containing protein
