Respiratory System Flashcards
The term respiration has 3 meanings:
1) Ventilation
2) exchange of gases between air and blood and btwn blood and tissue fluid
3) The use of oxygen in cellular metabolism
The respiratory system:
is an organ system that rhythmically takes in air and expels it from the body, supplying body with oxygen and expelling carbon dioxide.
7 other functions of respiratory system:
1) provides O2 and CO2 exchange between blood and air
2) Speech & other vocalizations
3) Olfaction
4) Control pH by eliminating CO2
5) BP regulation by Angiotensin II
6) Venous return/lymph flow
7) Valsalva maneuver-Breath holding helps expel abdominal contents
Principal Organs of Respiratory system:
Nose, pharynx, larynx, trachea, bronchi and lungs.
Within lungs air flows how?
Bronchi->bronchioles->alveoli
Conducting division
consists of those passages that serve only for airflow, from nostrils to major bronchioles.
Respiratory division
consists of alveoli and other distal gas exchange regions
Upper respiratory tract
airway from nose through larynx
Lower respiratory tract
regions from trachea through lungs
Nose has several functions
warms, cleanses, and humidifies inhaled air
Odors are detected by
sensory cells in OLFACTORY epithelium
Nasal cavity is lined with
respiratory epithelium
Inferior concha
has extensive venous plexus called erectile tisse (swell body)
Pharynx
muscular funnel extending 13cm from chonae to larynx. 1) nasopharynx 2)oropharynx 3) laryngopharynx
Nasopharynx
posterior to chonae. recieves auditory tubes from middle ears and houses pharyngeal tonsil.
Oropharynx
space bwtn inferior margin of soft palate and epliglottis. Contains palatine tonsils
Laryngopharynx
posterior to pharynx. lined by pseudostratified columnar epithlium
Larynx
voice box
epiglottis
flap of tissue opening of larynx. stands vertically
epi-upon glottis-back of tongue
cricoid cartilage
connects larynx to trachea
Trachea
windpipe, tube about 12cm, 2.5 cm wide
adventitia
outermost layer of trachea, fibrous connective tissue tht blends adventitia to other organs of mediastinum
Lung mediastinal surface exhibits:
slit named hilum, lung recieves main bronchus, blood vessels, lymphatics, and nerves. ROOT of lung
Left lung indentation
cardiac impression
Each lung has a branching system of tubes:
bronchial tree, extending to 65,000 terminal bronchials
Bronchioles have what type of cells?
cilliated cuboidal epithelium, well developed layer of smooth muscle in their walls
Each bronchial divides into :
50-80 terminal bronchioles
Terminal bronchioles divides into :
2 or more smaller respiratory bronchioles, have alveoli budding from their walls
Each respiratory bronchiole divides into:
2 -10 elongated thin walled passages called alveolar ducts.
Alveolar ducts have what type of cells?
have non-ciliated simple squamous epithelia.
Alveolar ducts end in:
alveolar sacs, grape-like clusters of alveoli around atrium.
Distinction between alveolar duct and atrium:
Their SHAPE. ELONGATED DUCT. Atrium: EQUAL LENGTH AND WIDTH
Path of airflow
Nasal cavity -> pharynx -> trachea -> main bronchus -> lobar bronchus -> segmental bronchus -> bronchiole ->terminal bronchiole.
Respiatory division gas exchange:
respiratory bronchiole -> alveolar ducts -> atrium -> alveolus
Alveolus
pouch about .2-.5mm in diameter
Squamous (type I) alveolar cells
cover 95% of alveolar suface. THey are thin broad cells. other 5% covered by round to cuboidal great (type II) alveolar cells.
Alveolar cells (type II) have two functions:
1) repair alveolar epithelium when squamous alveolar cells are damaged
2) they secrete pulmonary sufacant, a mixture of phospholipids and protein that coats the alveoli and smallest bronchioles and prevents them from collapsing when one exhales.
Most numerous cells are:
Alveolar macrophages (dust cells). Phagocytize dust particles that escape entrapment.
Respiratory membrane has what type of cells:
squamous alveolar cells, squamous endothelial cell of capillary, and shared basement membrane
Visceral Pleura
serous membrane that covers surface of lung
Parietal Pleura
Visceral pleura turns back on itself and forms this. It attaches to the mediastinum, inner surface of rib cage, and superior surface of diaphragm.
Pleural cavity
This is the space between the parietal and visceral pleura. It wraps around the lung, like a pillowcase. Contains pleural fluid.