respiratory system Flashcards
functions of respiratory system
gas exchange, communication, olfaction, acid base balance, blood pressure regulation, blood and lymph flow, platelet production, blood filtration
principal organs
nose, pharynx, larynx, trachea, bronchi, lungs
facial part is shaped by bone and hyaline cartilage
nose
muscular funnel extending about 5 in. from choanae to larynx
pharynx (throat)
cartilaginous chamber about 4 cm (l.5 in.) long
larynx (voice box)
keeps food and drink out of airway
larynx
rigid tube, anterior to esophagus, 16 to 20 C-shaped rings of hyaline cartilage
trachea
lined by ciliated pseudostratified columnar epithelium
trachea
crowded by adjacent organs, does fill entire ribcage, not symmetrical
lungs
arise from fork of trachea, supported by C-shaped hyaline cartilage rings
main bronchi
trace the flow of air from the nose to the pulmonary alveoli
nose-nasal cavity-pharynx-larynx-trachea- carina-primary bronchus-secondary bronchus-terminal bronchus- respiratory bronchioles -alveoli
highly organized hyaline cartilage, incomplete rings to allow esophagus to expand when eating
trachea
muscles in forced expiration
rectus abdominis, internal intercostals, abdominal, and pelvic muscles
greatly increased abdominal pressure pushes viscera up against diaphragm increasing thoracic pressure, forcing air out; important for “abdominal breathing”
forced expiration
energy saving passive process achieved by the elasticity of the lungs and thoracic cage
normal quiet respiration
as muscles relax, structures recoil to original shape and original (smaller) size of thoracic cavity
normal quiet respiration
inspiration:
inhaling
expiration:
exhaling
prime mover of repiration
diaphragm (contracts to flat shape)
breathing is controlled at what two levels of the brain
cerebral and conscious; unconscious and automatic
automatic, unconscious breathing is controlled by respiratory centers in the reticular formation
medulla oblongata and pons
primary generator of the respiratory rhythm, produces a respiratory rhythm of 12 breaths per minute
ventral respiratory group (VRG)
in quiet breathing (eupnea), inspiratory neurons fire for about 2 seconds, expiratory neurons fire for 3 seconds
ventral respiratory group
modifies the rate and depth of breathing, receives influences from external sources
dorsal respiratory group (DRG)
one pair of respiratory center in the pons
Pontine respiratory group (PRG)
modifies rhythm of VRG by outputs to both VRG and DRG
pontine respiratory group
adapts breathing to special circumstances such as sleep, exercise, vocalization, and emotional responses
pontine respiratory group
describes air flow in and out of lungs during ventilation
boyle’s law
changing volume creates a ___
pressure gradient
F is related to the change in ___
pressure over resistance
____ pressure falls with more volume and rises with less volume
inter pulmonary
slightly negative pressure that exists between the two pleural layers
intrapleural pressure
volume of gas is directly proportional to its absolute temperature, affects expansion of lungs
charles law
two factors influence airway resistance:
bronchiole diameter and pulmonary compliance
increases airflow, epinephrine and sympathetic stimulation
diameter of the bronchioles
decreases airflow, suffocation can occur, histamine, parasympathetic nerves, cold air, and chemical irritants
bronchoconstriction
ease with lungs can expand, reduced by degenerative lung diseases, limited by surface tension of water film inside alveoli
pulmonary compliance
conduction zone of airway where there is no gas exchange, can be altered somewhat by sympathetic dilation
anatomic dead space
space that is filled with air that cannot exchange with the blood
anatomic dead space