Respiratory System Flashcards
(27 cards)
main components of the respiratory system??
Nasal passages, pharynx, larynx, trachea, bronchi, and bronchioles.
Alveoli (air sacs) are clustered at the end of the terminal bronchioles and are where gas exchange occurs.
What role do the alveoli play in the respiratory system?
Alveoli are tiny air sacs where gas exchange occurs, allowing oxygen to enter the blood and carbon dioxide to be expelled from the blood.
What is the structure and function of the pharynx?
The pharynx is a muscular tube that connects the mouth and nasal passages to the esophagus and trachea.
It is lined with ciliated epithelium that helps trap and move dust and debris to the esophagus for removal.
How do macrophages in the lungs assist with cleaning?
Macrophages in the lungs trap and phagocytose particulate matter.
They then migrate up the trachea and deposit the material into the oesophagus for expulsion.
Describe the process of ventilation during inhalation.
The diaphragm contracts, and the chest wall moves outward, increasing the volume of the chest cavity.
This reduces pleural cavity pressure and causes the alveolar pressure to drop below atmospheric pressure, allowing air to enter the lungs.
Describe the process of ventilation during exhalation.
The diaphragm relaxes, and the chest wall returns to its resting position, increasing the pressure in the pleural cavity and alveoli.
This forces air out of the lungs.
What is passive diffusion, and how does it relate to gas exchange in the lungs?
Passive diffusion refers to the movement of gases from areas of higher pressure to areas of lower pressure.
Oxygen diffuses from the alveoli into the blood, and carbon dioxide diffuses from the blood into the alveoli.
How is oxygen carried in the blood?
About 10% of oxygen dissolves in plasma.
90% binds to hemoglobin in red blood cells.
What is the Bohr effect, and how does it affect oxygen release?
The Bohr effect describes how low pH (in tissues) causes hemoglobin to release oxygen.
Higher pH in the lungs promotes oxygen binding to hemoglobin, while lower pH in tissues promotes oxygen release to tissues.
What is the process for carbon dioxide transport in the blood?
Most CO₂ is carried as bicarbonate ions (HCO₃⁻) in plasma.
CO₂ reacts with water to form carbonic acid (H₂CO₃), which dissociates into bicarbonate and hydrogen ions.
What is the role of the sodium-potassium pump in the lungs?
The sodium-potassium pump in the epithelial cells of the lungs helps maintain fluid balance and electrolyte regulation, which is essential for proper lung function and maintaining air quality.
What are the clinical signs of pigment dispersion syndrome?
Characterised by Krukenberg’s spindle (pigment deposition on the corneal endothelium).
Pigment can block the trabecular meshwork, increasing the risk of pigmentary glaucoma.
What is uveitis and what are its symptoms?
Uveitis is inflammation of the uveal tract (iris, ciliary body, choroid).
Symptoms include pain, reduced vision, and photophobia.(extreme light sensitivity)
Signs include limbal redness, aqueous flare, and keratic precipitates.
What is the Bohr effect in terms of hemoglobin and carbon dioxide?
CO₂ in tissues decreases the pH, which reduces hemoglobin’s affinity for oxygen, facilitating oxygen release where it is needed most.
What is Tyndall effect and what does it signify in the context of uveitis?
The Tyndall effect occurs when light is scattered by particles in suspension, such as cells in the aqueous humor in cases of uveitis.
This scattering of light is visible as aqueous flare.
What are drusen, and why are they important for optometrists?
Drusen are yellowish deposits in Bruch’s membrane, commonly associated with aging.
Large drusen may be a precursor to age-related macular degeneration (AMD), making them important to monitor.
What is the significance of naevi in the iris and choroid?
Naevi are benign pigmented spots in the iris and choroid.
They must be monitored to distinguish them from melanoma, which can threaten vision and life.
How do sympathomimetic and parasympathomimetic drugs affect pupil size?
Sympathomimetic drugs dilate the pupil (mydriasis).
Parasympathomimetic drugs constrict the pupil (miosis) and may induce accommodative spasm.
What is the role of the ciliary body in the production of aqueous humor?
The ciliary processes in the pars plicata of the ciliary body produce aqueous humor, which flows into the posterior chamber, through the pupil, and into the anterior chamber.
what are the major functions of the choroid?
Nourishes the retina and helps remove waste from the outer retina.
Absorbs stray light, ensuring proper retinal function and reducing glare.
How does gas diffusion occur in the lungs??
Oxygen diffuses from the alveoli (high concentration) to the blood (low concentration) and carbon dioxide moves in the opposite direction, from the blood to the alveoli.
Which of the following structure ensures food and liquid does not go down the windpipe?
epiglottis
mitochondira facts:
has DNA
it is formed of a double membrane
it doesnt have it’s own nucleus
it is where ATP is produced
fact abt Hb:
Haemoglobin has a lower affinity for oxygen in more acidic conditions
