Rep anatomy 1 Flashcards
(35 cards)
What are the main functions of the respiratory tract?
Gas exchange and regulation of blood pH.
What is the order of airflow through the respiratory tract?
Nose/Mouth → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli.
What cells line the respiratory tract?
Epithelial cells, goblet cells, and cilia.
Why do we study the respiratory system?
To understand physiology, pathophysiology, and pharmacology for conditions like asthma and COPD.
What is the function of the nose in respiration?
Warming, filtering, and moistening air; smell via olfactory nerves.
What is epistaxis?
Nosebleed, commonly from the turbinate.
What is the function of the pharynx?
A muscle-lined passageway connecting nasal cavity, larynx, and oesophagus.
What is the function of the larynx?
Protects airway (epiglottis), filters air, aids cough reflex, and sound production.
What is the trachea and its function?
A cartilaginous tube from the larynx to bronchi, stays open to carry air.
How does the parasympathetic system affect the airways?
- Activation
A β₂-agonist drug (like salbutamol) binds to β₂-adrenergic receptors on airway smooth muscle cells. - Receptor Type
β₂ receptors are a type of G-protein coupled receptor (GPCR).
Specifically, they are Gs-coupled → they activate the stimulatory G-protein.
- cAMP Production
Gs activates adenylyl cyclase → converts ATP into cyclic AMP (cAMP). - PKA Activation
cAMP activates Protein Kinase A (PKA). - Smooth Muscle Relaxation
PKA phosphorylates and inhibits myosin light chain kinase (MLCK).
This reduces calcium-mediated contraction.
Result = Relaxation of bronchial smooth muscle
How does the sympathetic system affect the airways?
. Activation
A β₂-agonist drug (like salbutamol) binds to β₂-adrenergic receptors on airway smooth muscle cells.
- Receptor Type
β₂ receptors are a type of G-protein coupled receptor (GPCR).
Specifically, they are Gs-coupled → they activate the stimulatory G-protein.
- cAMP Production
Gs activates adenylyl cyclase → converts ATP into cyclic AMP (cAMP). - PKA Activation
cAMP activates Protein Kinase A (PKA). - Smooth Muscle Relaxation
PKA phosphorylates and inhibits myosin light chain kinase (MLCK).
This reduces calcium-mediated contraction.
What do bronchi contain?
Cartilage rings and mucus-producing cells.
What are bronchioles made of?
Smooth muscle; they control airway diameter via contraction or relaxation.
What is the function of alveoli?
Site of gas exchange with extremely thin membranes.
What is pulmonary surfactant?
A protein-lipid substance that reduces surface tension and prevents alveolar collapse.
What condition results from surfactant deficiency?
Neonatal respiratory distress syndrome (NRDS).
What is lung compliance?
The ease with which the lungs expand. High compliance is ideal for efficient ventilation.
What is α1-antitrypsin (AAT)?
An enzyme inhibitor that protects lung tissues from elastases released during infection and inflammation; deficiency can lead to lung damage.
What is the role of acetylcholine on M3 receptors?
Causes bronchoconstriction and mucous secretion via increased intracellular calcium.
What is the role of noradrenaline on β2 receptors?
Causes bronchodilation by increasing cAMP and relaxing smooth muscle.
What is mucus composed of?
90-95% water, mucins, proteins, lipids, and electrolytes.
What is the function of CFTR?
Regulates Cl⁻ and HCO₃⁻ secretion and Na⁺ absorption, maintaining proper mucous hydration.
What happens in cystic fibrosis?
CFTR mutation causes thick, sticky mucus due to reduced chloride and bicarbonate secretion and increases sodium absorption
What muscles are involved in ventilation?
Diaphragm and external intercostals (inhalation); passive exhalation or abdominal muscles in forced breathing.
