mechanics of breathing

how do gases move from the atmosphere to the cells?

bulk flow: atmosphere → lungs

diffuse: lungs → blood

bulk flow: blood → cells

what are the functions of the respiratory system?

exchange of gases

homeostatic regulation of body pH

vocalisation

sense of smell

filtering inhaled pathogens

heat + water loss

what is the function of the nose?

cleanse, warm & humidify air

detect odour

resonating chamber for voice

what composes the nose?

shaped by bone and cartilage

lined with stratified squamous epithelium

what is the mucous membrane made of?

ciliated psuedo-stratified columnar epithelium

goblet cells

what is the function of goblet cells?

secrete mucus that traps foreign matter

what is the nasopharynx made of?

ciliated-psuedo stratified columnar epithelium

what is the oropharynx?

the space between the soft palate and the epiglotis

what is the laryngopharynx lined with?

abrasion resistant cells → stratified squamous epithelial cells

what is the larynx?

cartilage chamber that keeps food and drink out of airway

what is the trachea?

16-20 rings of supportive cartilage

what lines the trachea?

psuedostratified columnar epithelia

what is the role of cilia?

beat upward to remove debris

what is the bronchial tree?

branching system of bronchi tubes

how does the bronchial tree divide?

bronchi → secondary bronchi → bronchioles

what are bronchioles regulated by?

smooth muscle. under the control of autonomic nervous system.

what is the role of the alveoli?

increase surface area for gas exchange

what is the role of squamous type I cells?

thin, allowing for rapid diffusion

what is the role of cuboid great type II cells?

repair alveolar epithelium

secrete surfactant that prevents bronchioles collapsing

what is the role of alveolar macrophages?

phagocytose dust particles and bacteria

what is the barrier between the alveoli and the capillaries known as?

respiratory membrane

what is the process of oxygen entering the blood?

dissolve in water surface layer in lungs → pass through alveoli cells → pass through basement membranes → endothelial cells of capillaries

what is the role of the mucociliary escalator?

clean the lungs

protect alveolar from pathogens and dust

what is ventilation?

the movement of air between external environment and alveoli of lungs

what is the pleural cavity

double layered cavity surrounding the lungs

visceral pleura (inner) + parietal pleura (outer)

what is the role of the serous fluid in the pleural cavity?

lubricate the lungs

act as adhesive force that causes lungs to expand

what keeps the lungs inflated?

sub-atmospheric pressure (negative pressure) in the pleural cavity

what is pneumothorax?

air flow into the pleural cavity disrupts balance of pressure

pressure equalises, lungs collapse

what is the role of the diaphragm?

responsible for moving 2/3 of the airflow

contracts and drops, enlarging thoracic cavity

what is the ventral respiratory group?

primary generator of rhythm

what is the dorsal respiratory group?

modifies the basic rhythm of breathing

what is the pontine respiratory group?

receives input from higher brain to adapt to sleep,cry,laugh,pain,emotion,voluntary control.

what is the equation for airflow in the lungs, F?

F = ∆P/R

what is compliance?

how easily the lungs expand