respiratory system Flashcards
what are the functional divisions of the respiratory system? which parts of the lung mark the boundary?
conducting zone from the nasal cavity to the terminal bronchioles
respiratory zone: respiratory bronchioles and alveoli
what is the main cell found in the alveoli?
type I pneumocyte (squamous epithelial cell)
what is atmospheric pressure at sea level?
760mm Hg
what part of the lungs is regulated by the autonomic nervous system?
the bronchioles
what is RV?
residual volume = amount of air left in passageways and lungs after maximal exhalation
about 1200ml men//1100ml women
what is normal tidal volume at rest?
200-500ml
what is VC?
vital capacity - the amount of air you can move through the lungs
IRV+TV+ERV
about 4.8L men // 3.3L women
define the respiratory defence system
a series of filtration mechanisms the prevent airway contamination by debris and pathogens
includes mucociliary escalator
what physical changes affect the total volume of the lungs?
movement of the diaphragm and ribs
why is the lining of the nasopharynx different from that of the oropharynx and the laryngopharynx?
nasopharynx and nasal cavity - psuedostratified ciliated columnar epithelium - this area only receives air through the nose.
oropharynx and laryngopharynx need more protection as they also have contact with food, so have stratified squamous epithelium
define internal respiration and external respiration
internal - absorption of oxygen and release of carbon dioxide by body’s cells
external - all processes involved in exchange of oxygen and carbon dioxide between body’s interstitial fluids and external environment
what is ERV?
expiratory reserve volume - the amount you can force out beyond tidal volume
about 1000ml male//700ml female
which muscles are involved in forced expiration?
internal intercostals
abdominal muscles
what are the accessory muscles for forced inspiration?
scalenes
sternocleidomastoids
what are the five basic functions of the respiratory system?
- provide extensive surface area for gas exchange
- move air to and from gas exchange area
- protect respiratory surfaces against dehydration and defend against pathogens
- producing sounds
- facilitating the detection of odours
what kind of membrane are the pleura?
serous membrane
trace the pathway of air as it enters the upper respiratory system
external nares nasal vestibule meatuses internal nares nasopharynx oropharynx laryngopharynx larynx
what are the superior/middle/inferior meatuses also know as
the (superior/middle/inferior) conchae
what structures make up the nasal cavity?
the nasal vestibule, guarded by hairs, and the meatuses
which arteries supply blood to the gas exchange surfaces and the conducting portions of the respiratory system
the pulmonary arteries supple the gas exchange surfaces
the external carotid arteries, the thyrocervical trunks and the bronchial arteries supply the conducting portions
identify the paired and unpaired cartilages that compose the larynx
unpaired:
thyroid cartilage
cricoid cartilage
epiglottis
paired:
arytenoid cartilage
corniculate cartilage
cuneiform cartilage
if food accidentally enters the bronchi, which bronchus is it more likely to lodge in?
the right bronchus because it is larger in diameter and slopes more steeply into the lung
list the defenses of the respiratory system
- hairs in nose
- mucociliary escalator
- cough and sneeze reflexes
- alveolar macrophages
- normal flora
- antibodies in mucosal membrane
what are the partial pressures of oxygen and carbon dioxide in the alveoli?
PO2 = 100 PCO2 = 40
give five reasons for efficiency of gas exchange
- substantial differences in partial pressure across the membrane
- very short distance across the membrane
- oxygen and carbon dioxide are lipid soluble
- total surface area is large
- blood flow and airflow are co-ordinated
when the diaphragm and external intercostals contract, what happens to intrapleural pressure?
it decreases