breathing and respiration Flashcards
(17 cards)
What are the key structures of the human respiratory system?
Nose/nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, alveoli
These structures facilitate air passage and gas exchange.
What is the function of alveoli?
Tiny air sacs designed for rapid diffusion with large total surface area (~70–145 m²) and one-cell-thick walls
Alveoli are surrounded by capillaries to optimize gas exchange.
What adaptations do airways have?
Ciliated epithelium, goblet cells, cartilaginous rings, smooth muscle, elastic fibers
These adaptations help trap debris, maintain airway structure, and regulate airflow.
What occurs during inspiration (inhalation)?
Diaphragm contracts, external intercostal muscles lift ribs, thoracic cavity volume increases, pressure drops
Air flows into lungs down the pressure gradient.
What is the process of expiration (exhalation)?
Diaphragm relaxes, intercostal muscles relax, thoracic cavity volume decreases, pressure increases
Air flows out of lungs; forced expiration involves internal intercostals and abdominal muscles.
What is the tidal volume in normal breathing?
Approximately 500 mL per normal breath
This is the volume of air inhaled or exhaled in a single breath.
How is the Pulmonary Ventilation Rate (PVR) calculated?
PVR = tidal volume × breaths/min
This formula helps assess respiratory efficiency.
What does spirometry measure?
Tidal volume, vital capacity, residual volume, etc.
Spirometry is a common test used to assess lung function.
Describe gas exchange at the alveoli.
O₂ goes to blood, CO₂ goes to lungs via diffusion across a thin blood–air barrier (~0.2 µm)
High surface area and short diffusion distance optimize this process.
What optimizes gas exchange in the alveoli?
High surface area, short diffusion distance, maintenance of concentration gradients
Ventilation and blood flow are crucial for effective gas exchange.
What is aerobic respiration?
Produces ~32 ATP per glucose through glycolysis, link reaction, Krebs cycle, oxidative phosphorylation
This process occurs in the presence of oxygen.
What are the stages of aerobic respiration?
Glycolysis, link reaction, Krebs cycle, oxidative phosphorylation
Each stage contributes to the production of ATP and other energy carriers.
What happens during anaerobic respiration in animals?
Pyruvate → lactate (regenerates NAD⁺)
This occurs in the absence of oxygen.
What is the result of anaerobic respiration in plants and yeast?
Pyruvate → ethanol + CO₂
This process also occurs when oxygen is not available.
What is the ATP yield from anaerobic respiration?
Lower yield (~2 per glucose)
This allows glycolysis to continue even without oxygen.
How are breathing and respiration integrated?
Oxygen from breathing fuels aerobic respiration; CO₂ from respiration is expelled via breathing
This integration maintains metabolic processes.
What role do control mechanisms in the brainstem play?
Maintain blood gas homeostasis via chemoreceptor feedback loops
These mechanisms help regulate respiration based on the body’s needs.
