Respiratory Physiology Flashcards
What are the main functions of the pulmonary system?
Warm air
Filter air
Humidify air
Gas exchange
Regulate blood pH
what consist of upper airway
nose and nasal cavity
pharynx
what consist of Lower Airway
Larynx (voice-box)
Trachea (windpipe)
Left and right primary bronchi
Bronchioles –> alveolar ducts –> end in alveoli
Bronchial Epithelium
functions
Defensive barrier against pathogens
Immune & inflammatory responses
Mucous secreting goblet cells
Ciliated cells
Alterations in epithelium in acute/chronic respiratory diseases
____ Serve as the gas exchange surfaces of the lungs
alveoli
Acinus
refers to the combined structures of the bronchioles, alveolar ducts and alveoli
Type I Alveolar Cells
squamous epithelial cells
main sites of gas exchange
most predominant cells
Type II Alveolar Cells
cuboidal, interspersed among Type I cells
secretory cells – pulmonary surfactant
PULMONARY SURFACTANT composed of __ & ____
phospholipids & proteins
PULMONARY SURFACTANT functions
Functions to decrease surface tension, stabilize the alveoli (prevents alveolar collapse during breathing) & protect lungs from injury & infection
two layers of pleura
visceral pleura (outer)
parietal pleura (inner)
Involuntary control of respiration
Respiratory center in brainstem (pons and medulla oblongata)
Voluntary control of respiration
Motor cortex in cerebrum, spinal cord, nerves
3 Groups of Neurons in Respiratory Center (brainstem):
Dorsal Respiratory Group
Ventral Respiratory Group
Pontine Respiratory Group
Dorsal Respiratory Group
Inspiratory neurons; sets basic automatic rhythm of respiration
Receives impulses from peripheral chemoreceptors in carotid and aortic bodies
Detects PaCO2 and amount of oxygen in arterial blood
Ventral Respiratory Group
Consists of inspiratory & expiratory neurons
Active when increased respiratory effort is needed
Pontine Respiratory Group
Consists of inspiratory & expiratory neurons
aka ‘Pneumotaxic Center’
Modifies the depth, rate and pattern of breathing
Controls when inspiration is stopped
Two types of chemoreceptors send signals to inspiratory center of brainstem
Central Chemoreceptors (medulla):Sense arterial CO2 and a decrease in pH of CSF
Peripheral Chemoreceptors (aortic & carotid bodies): Detect changes in partial pressure of arterial oxygen, CO2 and pH
Pulmonary Receptors
‘Irritant’ Receptors
Stretch’ Receptors
Juxtapulmonary’ capillary (J) Receptors
Ventilation is dependent on the ______ & ________ changes that occur in the thoracic cavity
volume & pressure
PaCO2
PaO2
partial pressure of carbon dioxide in arterial blood (Normal range 35-45 mmHg)
partial pressure of oxygen dissolved in arterial blood (Normal range: 80-100 mmHg)
Oxyhemoglobin Dissociation Curve
Shifts to the right due to
Shifts to the left due to
Causes of a right-shift include: fever, acidosis (low pH), increased PaCO2
Causes of a left-shift include: hypothermia, alkalosis, decreased PaCO2
