LECTURE - Respiratory System Flashcards
function of respiratory tract
- olfaction (smell and sense of taste)
- gas exchange
- speech and phonation
- others: clean air, warm it, humidify
divisions (2) of respiratory system
- upper/lower = arbitrary division; no clear anatomic or functional of upper vs lower
- conducting/respiratory = very specific division; conduction portion carries air (cleaning, humidifying, sterilizing) to the respiratory portion which is involved in gas exchange
sinuses
large cavities in the face that are filled with air, these cavities provide increased SAs of warming, cleaning, and humidifying
epithelium of nasal cavity & paranasal sinuses
keratinizing stratified squamous epithelium to non-keratinizing stratified squamous epithelium to pseudostratified ciliated columnar epithelium
lamina propria
- blood vessels = abundant and fairly large heat air (erectile tissue in nose)
- glands
= serous glands release serous secretions including lysozyme and amylase, have basophilic and eosinophilic cytoplasmic granules, moisten the air
= mucinous glands produce mucinous secretions that create a film on top of the epithelium to trap germs & any particulate matter including pollution/carbon in the air we breathe - inflammatory cells = immune function to protect against germs, near the surface of lamina propria and just below the epithelium; plasma cells, lymphocytes, macrophages, basophils, eosinophils
posterior continuation of the nasal cavity, Eustachian tube enters here, connecting to the ear
nasopharynx
epithelium and subepithelial tissue of nasopharynx
epithelium = respiratory type, foci of non-keratinizing squamous epithelium. If keratinization is seen = abnormal
sub = glands, inflammatory cells, some blood vessels
MALT
mucosa-associated lymphoid tissue
- organized into adenoids, tonsils, Waldeyers ring = a strong line of defense against germs/infections
Olfactory Mucosa
- basal cells: stem cells for #2; closest to basement membrane
- sustentacular cells: tall support cells with nuclei towards the surface
- olfactory receptor cells: bipolar nerve cells with dendritic processes and axons, connect back to olfactory centers of the brain
Bowman’s glands
Bowman’s glands
produce serous secretions to dissolve odourous substances
complex structure made of plates of elastic cartilage held together by strong thick ligaments and intrinsic muscles of the larynx
larynx
function of larynx
- speech and phonation
- prevent aspiration of food into respiratory tract
- prevent air from entering gastrointestinal tract
epiglottis
anterior (lingual) surface
- contiguous with tongue
- epithelium = non-keratinizing stratified squamous
posterior surface
- faces pharynx and larynx
- upper portion is stratified squamous and lower portion is resp epithelium
vocal cords
- false = location is upper/superior; cell type: resp epithelium
- true = lower/inferior; cell type: stratified squamous non-keratinizing epithelium and skeletal muscle also present
trachea
- rigid tube
- runs midline in the neck and divides into left and right mainstem bronchi
- lower portion of neck = trachea wrapped by thyroid gland anteriorly
- epithelium = respiratory epithelium
- subepithelial tissue
- hyaline cartilage; shaped like a horseshoe anteriorly; posteriorly = trachea does not have cartilage
> trachealis muscle is located posteriorly to allows some give to allow for food passage in esophagus (located behind trachea in the neck)
divisions of bronchi
- right = branches into 3 lobar bronchi (right upper lobe, middle lobe, and lower lobe bronchi)
- left bronchus = branches into 2 lobar bronchi (left upper lobe and lower lobe)
cells within respiratory epithelium include …
- ciliated columnar cells
- goblet cells
- basal cells
- intermediate cells = transform into ciliated or goblet cells
- neuroendocrine cells
respiratory bronchioles (2)
- terminal: last part of conducting system
- respiratory: first level of the respiratory portion of respiratory system
- epithelium progressively changes from columnar to cuboidal to simple squamous *
first level of respiration occurs here
respiratory bronchioles but gas exchange is not as efficient as in the more distal locations
- respiratory bronchioles divide into alveolar ducts which lead into alveolar sacs
- epithelium becomes progressively flatter
alveoli #
200-600 million ineach lung
cellular components of alveoli
- type I pneumocyte: 40%; simple squamous pithelium; covers large SA; this is where gas exchange occurs
- type II pneumocyte: 60%; more cuboidal in shape; replaces injured type I pneumocytes; produce surfactant = reduces surface tensions within alveoli so they do not collapse with expiration
- alveolar macrophages: may contain carbon pigment from environment
an essential element in the pulmonary parenchyma located in alveolar septal walls, interlobular septa, and the pleura
elastin
- provides elastic recoil; reduces work of breathing
- lung scrs by laying down elatic + collagen fibres
- diseases may result in loss of elastin or deposition of elastin
disease as a result of loss of elastin in lungs
emphysma
deposition of more elastin in lungs
will increase work of breathing = fibrotic lung disease
deposition of more elastin in lungs
will increase work of breathing = fibrotic lung disease
T or F. basement membranes of type I pneumocytes and endothelium are fused to reduce distance for diffusion
T
pulmonary vasculature
- lungs have dual supply
- right side of heart = deoxygenated blood to lungs for oxygenation via pulmonary arterial circulation; returns it to left side of heart via pulmonary veins
- left side of heart supplies lungs with oxygenated blood via bronchial arterial circulation; arteries are smaller and thicker than pulmonary arteriesq
bronchovascular bundle
pulmonary arteries enter lung at hilum with the bronchus and branch along with bronchi and bronchioles = seens as a pair referred to as bronchovascular bundle
two layers of pleura in the lungs
- visceral (external surface of lungs)
- parietal (attached to chest wall) with a potential space in between
- this pleural space normally contains a small amount of fluid to lubricate movement of lungs as they mve against the chest wall and other surfaces during respiration
- lined by mesothelial cells = two layers of elastin
- nerves and lymphatics
when pleural space fills with fluid
pleural effusion
- congestive her failure
- blockage of lymphatics
when pleural space fills with blood
hemothorax
- bleeding disorders
- trauma
when pleural space fills with pus
empyema
- caused by infections
when pleural space fills with air
pneumothorax
- complications of emphysema
