Respiratory System Flashcards
What are the major functions of the respiratory system?
External respiration, maintain blood ph homeostasis, sound production and smell
External respiration
Gas exchange (oxygen and carbon dioxide) between the external environment and the blood
Maintaining blood ph homeostasis
Carbon dioxide reacts with water to form carbonic acid so removing carbon dioxide from the blood increases blood ph
Sound production
the vocal cords in the larynx vibrate as air is forced through producing sound to enable vocalization
smell
air drawn into the nasal cavity where odorants dissolve into the mucous of the olfactory epithelium
conducting zone
series of interconnecting cavities and tubes that conduct air into and out of the lungs, bulk flow of air in and out occurs here but no external respiration
*includes nasal cavity, pharynx, larynx, trachea, bronchi, and most bronchioles
respiratory zone
Portions of the respiratory system where external respiration occurs
*Includes respiratory bronchioles and alveolar sacs
respiratory mucous membrane (mucosa)
ciliated pseudostratified epithelium with goblet cells found lining the nasal cavity, nasopharynx, trachea and bronchi
*filters, moistens and warms air
Mucus
traps bacteria and foreign debris and moistens air
cilia
sweeps mucus towards the pharynx
Nose
primary entrance into the respiratory system
nasal septum
divides nasal cavity into left and right sides
nasal conchae
increases turbulence of inspired air and increases exposure to respiratory mucosa
meatus
groove under the nasal conchae
hard and soft palate
floor of nasal cavity and roof of oral cavity
internal nares
opens posteriorly into the nasopharynx
paranasal sinuses
produce mucus and resonate sound
Pharynx
muscular passage extending from the nasal cavity to the larynx. Divided into three regions-nasopharynx, oropharynx and laryngopharynx
Nasopharynx
superior portion of the pharynx, lies posterior to internal nares and superior to soft palate
pharyngeal tonsil
located on the posterior wall of the nasopharynx
eustachian tubes
open into the nasopharynx
oropharynx
middle portion of the pharynx, lies posterior to the oral cavity, common passageway for food and air
palatine tonsils
located on the lateral walls of the oropharynx
lingual tonsil
found at the base of the tongue
laryngopharynx
inferior portion of the pharynx, extends from the hyoid bone to the esophagus (posterior) and the larynx (anterior)
larynx
passageway that connects the laryngopharynx with the trachea, inferior to the hyoid and anterior to the esophagus, produces sound and prevents food from entering the trachea
true vocal cords
elastic ligaments attached to the arytenoid and thyroid cartilages of the larynx, when pulled tight they vibrate and produce sound as air is expelled from lungs
glottis
opening between vocal cords
epiglottis
spoon shaped elastic cartilage flap that projects from the anterior aspect of the larynx over the glottis, larynx rises and the epiglottis moves down to form a lid over the glottis when swallowing
vestibular folds (false vocal cords)
mucosal folds superior to true vocal cords, sensitive to touch and will provoke coughing reflex to eject anything that enters the larynx
Trachea
anterior to the esophagus from the larynx, divides at the carina into the right and left primary bronchi
lungs
spongy organs composed mostly of elastic connective tissue, found in the thoracic cavity surrounded by the right and left pleural cavities
apex of lungs
superior point, deep to the clavicle
base of lungs
inferior broader portion, rests on diaphragm
right lung
three lobes- superior, middle and inferior, has horizontal and oblique fissure
left lung
two lobes- superior and inferior, separated by the oblique fissure, has cardiac notch on the medial side
pleural membranes
double serous membrane that encloses and protects the lungs, pleural fluid fills area between layers to allow gliding and resist separation
visceral pleura
covers the lung surface
parietal pleura
lines the walls of the thoracic cavity
bronchial tree
branching of bronchi into smaller and smaller branches
primary bronchi
right and left branch from the trachea, enter the right and left lung at the hilus (medial depression)
secondary bronchi
one per lobe
tertiary bronchi
one per segment (subdivisions of the lobes)
bronchioles
small branches that have a thick smooth muscle layer and no cartilage
terminal bronchioles
lined w non ciliated simple cuboidal epithelium
respiratory bronchioles
very thin wall made of simple squamous epithelium, connects to the alveolar ducts within alveolar sacs
respiratory membrane (air-blood barrier)
site of external respiration (gas exchange) between blood and air in the respiratory bronchioles and alveolar sacs
alveolar sacs
clusters of air sacs with a thin wall of simple squamous epithelium
alveoli
thin walled air sacs, each closely associated with capillaries
what type of cells are found in the wall of alveolar sacs?
Type I, type II and macrophages
type I alveolar cells
simple squamous epithelium supported by elastic basement membrane
type II alveolar cells
surfactant secreting cells produce oily fluid that reduces surface tension to prevent collapse of alveoli
macrophages
perform phagocytosis to engulf debris
Inspiration
movement of air into lungs- contraction of primary muscles of inspiration (diaphragm and external intercostal muscles) leads to increased volume of the thoracic cavity, increasing volume decreases pressure and air flows into the lungs
Expiration
movement of air out of the lungs- relaxation of muscles of inspiration leads to decreased volume of the lungs, decreasing volume increases pressure and air flows out of the lungs
During gas exchange
Oxygen and carbon dioxide move through the plasma membrane of cells by simple diffusion
External respiration
gas exchange between the blood of the pulmonary capillaries and air in the respiratory zone of the lungs, oxygen moves into the blood and carbon dioxide moves out
internal respiration
gas exchange between the blood of the systemic capillaries and the tissues of the body, oxygen moves out of the blood and carbon dioxide moves in
