respiratory system Flashcards
what are the functions of the respiratory system
- respiration
- conditioning of air
- vocalisation
- sense of smell
- endocrine functions
- coughing and sneezing
- protection
- fibrinolysis
what are the parts of the conducting portion
- nasal cavity
- nasopharynx
- larynx
- trachea
- bronchi
- bronchioles
- terminal bronchioles
what are the parts of the respiratory portion
- respiratory bronchioles,
- alveolar ducts,
- alveolar sacs
- alveol
what does the wall of the conducting portion consist of
- mucosa
- submucosa
- fibre-cartilage layer
- adventitia
what are the 3 types of mucosa
- respiratory epithelium - pseudostratified columnar cilliated
- lamina proprica - loose connective tissue, secretes IgA
- muscularis - smooth muscle tissue - promise when airway diameter decreases
what is submucosa
loose connective tissue with mucous and serous glands
- not present beyond tertiary bronchi
what is fibro-cartilage
diminishes as the diameter of airway decreases
- not present beyond tertiary bronchi
what is adventitia
loose connective tissue
what does the respiratory epithelium consist of
- ciliated columnar cells - abundant type
- mucous goblet cells
- brush cells - microvilli, receptor cells for nerve endings from trigeminal and vagus nerves forming epitheliodendritic synapses
- basal short cells - lie on basal lamina and differentiate
- small granule cells - diffuse neuroendocrine system
what are goblet cells
- unicellular glands that produce mucinogen
- store mucinogen in secretary vesicles in the theca
- lower part is called the stem containing most organelles
what happens when mucinogen is released
released into lumen where it becomes hydrated into mucin and is mixed to form mucus
what is the function of cilia
transported mucus from bronchioles towards the pharynx and nasal cavity where it is swallowed or expelled
what is the composition of mucus
- hypophase - lower less dense layer with greater serous component
- epiphase - upper more dense layer - greater mucus component
what is mucostasis
retention and build up of mucus in respiratory tract
what is allergic rhinitis
caused by the release of histamines from mast cells with IgE after contact with allergen
that do histamines do to the respiratory tract
capillaries in nasal mucosa to dilate and increase permeability causing fluid to leave and enter the extracellular matrix leading to edema
what are the 3 regions of the nasal cavity
- nasal vestibule
- respiratory region
- olfactory region
what is the nasal vestibule
dilated space in nasal cavity just inside nostrils and is lined by skin with vibrisae
what is the respiratory region of the nasal cavity
largest part and is lined with respiratory mucosa
what is the olfactory mucosa
located at the apex of nasal cavities and is lined by specialised olfactory mucosa
- has smell receptors
- olfactory epithelium is yellow colour
what are the cells of olfactory epithelium
olfactory receptor cells - bipolar neurone
supporting columnar cells - support and electrical insulation
- basal cells - stem cells that differentiate into globose and horisontal cells
- brush cells
what is lamia propria
- deep in olfactory epithelium
- connective tissue with blood and lymphatic capillaries and olfactory nerve bundles
- olfactory (Bowmans) glands - branched tubuloalveolar serous glands
what is the cavernous layer
rich vascular plexus layer
- heat inspired air- prevent mucosa drying out and allows regeneration of epithelium
what are paranasal sinuses
air filled spaces in bones of the walls of nasal cavity
what are the functions of paranasal sinuses
- reduce weight of the skull
- heat and moisten clean air
- increase the resonance of voice
what is acute sinusitis
accute infection in the sinuses of upper respiratory tract
what is the schneiderian membrane
clinical term of epithelium of nasal cavity and paranasal sinuses
what is the pharynx
connects the nasal and oral cavities to the larynx and oesophagus
what is the pharynx divided into
- nasopharynx
- oropharynx
- laryngopharynx
what connects the nasopharynx to the middle ear
auditory/ eustachian tube
what is the larynx
short tubular organ with the function of voice production
- composed of cartilage, skeletal muscle and connective tissue and is lined with mucosa (internally) and adventitia (externally)
what are the 2 folds in the laryngeal lumen
- superior vestibular folds - donut move and have mo muscle, covered by respiratory epithelium
- inferior vocal folds - contain a vocal ligament and muscle, covered by stratified squamous epithelium
what are the two surfaces of the epiglottis
- lingual - oral cavity
- laryngeal - larynx
what is the epithelium of the epiglottis made of
- lingual surface and apical portion - stratified squamous non-keratinised epithelium
- laryngeal surface - respiratory epithelium
what is the 4 layers of the trachea
- mucosa
- submucosa
- fibre-cartilage
- adventitia
what are the two sub types of the mucosa of the trachea
- respiratory epithelium - pseudostratified columnar ciliated
- lamina propia - loose connective tissue with elastic fibres
describe the bronchial tree
1) trachea
2) primary bronchi
3) 3 secondary bronchi (R) 3 bronchi (L)
4) lobar bronchi –> tertiary bronchi
5) bronchopulmonary segment - R- 10 , L - 8
what do tertiary bronchi divide into
bronchioles
what do bronchioles branch into
5 to 7 terminal bronchioles
what are the features of primary bronchi
- same structure as trachea
- o shaped cartilage
what are the features of large bronchi
- lined with pseudostratfied columnar ciliated epithelium with globlet cells
- muscularis mucosa formed closed rings
- discontinuous cartilage - replaced with isolated plates
what are the features of middle bronchi
- pseudostratified columnar epithelium
- goblet cells
- smooth muscle cells from crisscrossing bundles
- glands
- islands of an elastic cartilage
what are the features of small bronchi
- lower epithelium than in middle
- individual goblet cells
- no glands or cartilage
- smooth muscle absent in some places
what are the features of bronchioles
- mucosa - epithelial layer , ciliated pseudostratifed columnar, goblet cells, dissociated endocrine cells, lamina propria
- muscular layer
- adventitia
what are the features of terminal bronchioles
- epithelial layer - ciliated simple cuboidal epithelium
- lamina propria - loose tissue rich in smooth muscle cells
- muscular layer - smooth muscle
- adventitia - loose connective tissue
what are club cells
- non ciliated bronchiolar exocrine secretory cells
- found in bronchioles
what are the functions of club cells
- secrete glycosaminoglycans, CCSP, surfactant proteins and mucin
- detoxification of harmful substances inhaled
- able to divide and differentiate
what do CCSP proteins do
protect bronchiolar epithelium
what do SP-A and SP-D do
coating the surface of the epithelium and regulate the transport of chloride ions
what do MUC5AC and MUC5B do
present as polymers in the airway mucus
what is the functional unit of the respiratory portion
acini - included bronchioles, alveolar ducts and alveolar sacs
what forms the pulmonary lobule
acini separated by thin layers of LCT 12-18 acini
what are the features of alveolar ducts
- lined with simple squamous epithelium
- has air sacs called atrium
- lamina propria surrounding alveolar network of smooth muscle
what connects neighbouring alveoli
smaller alveolar called Kohn pores
what is the wall between adjacent alveoli
inter-alveolar septa
what does alveolar epithelium consist of
- alveolocyte/ pneumocyte type 1 - flattened irregular shape , component of air blood barrier
- alveolocyte/ pneumocytu type 2 - round in shape, secretory cells - recreate surface active lipoprotein complex called surfactant
what is the function of surfactant
decreases alveolar surface tension and actively participates in the clearance of foreign materials
what is the critical agent in surfactant
dipalmitoylphosphatidylcholine (DPPC
what is infant respiratory distress syndrome
premature newborns have a deficiency in surfactant causing pulmonary alveoli to collapse
what are alveolar macrophages and dust cells derived from
blood monocytes
what is the function and structure of the inter alveolar septum
- separate two adjacent alveoli
- contains dense network of capillaries, blood vessels and skeletal connective tissue fibres
what is the function of the alveolar capillary membrane
prevents air bubbles from forming in the blood and from blood entering the alveoli
