respiratory system
respiratory membrane consists of four layers
1. a layer of type I and type II alveolar cells and associated alveolar macrophages that consitutes the alveolar wall 2. an epithelial basement membrane underlying the alveolar wall 3. a capillary basement membrane that is often fused to the epithelial basement membrane 4. the capillary endothelium
layers of the tracheal wall from deep to superficial are...
1. mucosa 2. submucosa 3. hyaline cartilage 4. adventitia
structures that air passes through during inpiration
1. nose 2. pharynx 3. larynx 4. trachea 5. primary bronchi 6. secondary bronchi 7. tertiary bronchi 8. bronchioles 9. terminal bronchioles
functions of external nose
1. warming, moistening, and filtering incoming air; 2. detecting olfactory stimuli 3. modifying speech vibrations as they pass through the large, hollow resonating chambers
surfactant
a complex mixture of phospholipids and lipoproteins. lowers the surface tension of alveolar fluid, which reduces the tendency of alveoli to collapse
alveolus
a cupshaped outpuching lined by simple squamous epithelium and supported by a thin elastic basement membrane
pharynx
a funnel shpaed tube that starts at the internal nares and extends to the level of the cricoid cartialge, the most inferior cartilage of the larynx
pharynx functions
a passageway for air and food, provides a resonating chamber for speech sunds, and houses the tonsils which participate in immunological reactions agains foreign invaders
cricoid cartilage
a ring of hyaline cartilage that forms the inferior wall of the larynx. is the landmark for making an emergency airway called a tracheotomy
mucosa of the trachea consists of....
an epithelial layer of pseudostratified ciliated columnar epithelium
type II alveolar cells (septal cells)
are fewer in numbers and are found between type I alveolar cells. secrete alveolar fluid, which keeps the surface between the cells and the air moist
mucous membrane in the bronchial tree changes from pseudostratified ciliated columnar epithelium in the primary bronchi, secondary bronchi and tertiary bronchi to ciliated simple columnar epithelium with some goblet cells in larger bronchioles to mostly ciliated simple cuboidal epithelium with no goblet cells in smaller bronchioles to mostly nonciliated simple cuboidal epithelium in terminal bronchioles
as the amount of cartilage decreases, the amount of smooth muscle increases
laryngopharynx
begins at the level of the hyoid bone. opens into the esophagus posteriorly and the larynx anteriorly. is both a respiratory and a digestive pathway and is lined by nonkeratinized stratified squamous epithelium
what functions do respiratory system and cardiovascular system have in common?
both cooperate to supply O2 and eliminate CO2. respiratory system provides for gas exchange-intake of O2 and elimination of CO2- and the cardiovascular system transports blood containing the gases between the lungs and body cells. the respiratory system also helps regulate blood pH, if either system were to fail it would disrupt homeostasis and rapid death of cells from oxygen starvation and buildup of waste products
during exercise, activity in the sympathetic division of the ANS increases and the adrenal medulla releases the hormones epinephrine and norepeinephrine
both of these events cause relaxation of smooth muscle in the bronchioles which dilates the airways. because air reaches the alveoli more quickly, lung ventilation improves. the parasympathetic division of the ANS and mediators of allergic reactions such as histamine have the opposite effect, causing contraction of bronchiolar smooth muscle, which results in constriction of distal bronchioles
structure of upper respiratory system
conists of two parts: upper respiratory system- includes nose, pharynx, and associated structures lower respiratory system- includes larynx, trachea, bronchi, and lungs
glottis
consists of a pair of folds of mucous membrane the vocal folds in the larynx and the space between them called the rima glottidis. closing of the larynx in this way during swallowing routes liquids and foods into the esophagus and keeps them out of the larynx and airways
thyroid cartilage
consists of two fused plates of hyaline cartialge that form the anterior wall of the larynx and give it a triangular shape
function of upper respiratory system
consists of two parts: conducting zone- consists of a series of interconnecting cavities and tubes both outside and within the lungs. include nose, pharynx, larynx, trachea, bronchi, bronchioles and terminal bronchioles, their function is to filter, warm, and moisten air and conduct it into the lungs respiratory zone- consists of tissues within the lungs where gas exchange occurs. include the respiratory bronchioles, alveolar ducts, alveolar sacs and alveoli; they are the main sites of gas exchange between air and blood
nasal septum
divides the nasal cavity into right and left sides
pleural membrane
double layered serous membrane that encloses each lung
lobules
each is wrapped in elastic connective tissue and contains a lymphatic vesel, an arteriole, a venule, and a branch from a terminal bronchiole
function of nasopharynx
exchanges small amounts of air with the auditory tubes to equalize air pressure between the pharynx and the middle ear
alar cartilages
form a portion of the walls of the nostrils
soft palate
forms the posterior portion of the roof of the mouth, is an arch shaped muscular partition between the nasopharynx and oropharynx that is lined by mucous membrane
left primary bronchus
goes into the left lung
right primary bronchus
goes into the right lung, is more vertical , shorter, and wider than the left
corniculate cartilages
horn shaped pieces of elastic cartilage, are located at the apex of each arytenoid cartilage
a unique feature of pulmonary blood vessels is their constriction in response to localized hypoxia.
in all other body tissues, hypoxia causes dilation of blood vessels to increase blood flow. in the lungs however, vasoconstriction in response to hypoxia diverts pulmonary blood from poorly ventilated areas of the lungs to well ventilated regions, known as ventilation-perfustion coupling
lateral nasal cartilages
inferior to the nasal bones
internal nose
large cavity beyond the nasal vestibule in the anterior aspect of the skull that lies inferior to the nasal bone and uperior to the mouth. is lined with muscle and mucous membrane
epiglottis
large, leaf shaped piece of elastic cartilage that is covered with epithelium, during swallowing the pharynx and larynx rise. elevation of the pharynx widens it to receive food or drink; elevation of the larynx causes the epiglottis to move down and form a lid over the glottis closing it off.
lining of the larynx superior to vocal folds consists of....
nonkeratinized stratified squamous epithelium
oropharynx is lined with....
nonkeratinized stratified squamous epithelium
oropharynx
one opening called the fauces, this portion of the pharynx has both respiratory and digestive functions serving as a common passageway for air, food, and drink.
trachea
or windpipe, is a tubular passageway for air. is located anterior to the esophagus of the tfifth thoracic vertebra where it divides into right and left primary bronchi.
lungs
paired cone shaped organs in the thoracic cavity
septal nasal cartilage
part of the cartilaginous framework of the external nose, forms the anterior portion of the nasal septum
nasopharynx is lined with....
pseudostratified ciliated columnar epithelium
primary bronchi is lined with...
pseudostratified ciliated columnar epithelium
lining of the larynx inferior to vocal folds...
pseudostratified ciliated columnar epithelium consisting of ciliated columnar cells, goblet cells and basal cells
the lungs receive blood via two sets of arteries:
pulmonary arteries and bronchial arteries
larynx
short passageway that connects the laryngopharynx with the trachea.
type I alveolar cells
simple squamous epithelial cells that form a nearly continuous lining of the alveolar wall, main sites of gas exchange
what structural and functional features are different in the upper and lower respiratory systems?
structurally different: upper respiratory system contains the nose, pharynx, and associated structures, the lower respiratory system consists of larynx, trachea, bronchi, and lungs. functionally different: upper respiratory system will filter, warm, and moisten air and conduct it into the lungs, lower respiratory system is where gas exchange occurs between air and blood
structure and function of external nose
structure: external nose is the portion of the nose that is visible, consists of a supporting framework of bone and hyaline cartilage covered with muscle and skin and lined by a mucous membrane. functions: 1. warming, moistening, and filtering incoming air 2. detecting olfactory stimuli 3. modifying speech vibrations as they pass through the large, hollow resonating chambers
structure and function internal nose
structure: large cavity beyond the nasal vestibule in the anterior aspect of the skull that lies inferior to the nasal bone and superior to the mouth. lined with muscle and mucous membrane. contain paranasal sinuses in the cranial and facial bones function: paranasal sinuses produce mucus and serve as resonating chambers for sound as we speak or sing.
respiratory bronchioles
terminal bronchioles that have subdivided into microscopic branches, as they penetrate more deeply into the lungs, the epithelial lining changes from simple cuboidal to simple squamous
respiratory membrane
the exchange of O2 and CO2 between the air spaces in the lungs and the blood takes place by diffusion across the alveolar and capillary walls
arytenoid cartilage
the most important cartilage because they influence changes in position and tension of the vocal folds. form synovial joints with the cricoid cartialge and have a wide range of mobility
ventilation-perfusion coupling
the perfusion (blood flow) to each area of the lungs matches the extent of ventilation (airflow) to alveoli in that area
carina
the point where the trachea divides into right and left primary bronchi, is formed by a posterior and somewhat inferior projection of the last tracheal cartilage
external nose
the portion of the nose visible on the face and consists of a supporting framework of bone and hyaline cartilage covered with muscle and skin and lined by a mucous membrane.
bronchopulmonary segment
the segment of lung tissue that each tertiary bronchus supplies