Ch 22 Respiratory System Flashcards
Pseudostratified columnar epithelial
- lines nasal cavity
- warms air due to high vascularity
- mucous moistens air and traps dust
- cilia moves mucous towards pharynx
Paranasal sinuses
- found in ethmoid, sphenoid, frontal and maxillary
- lighten skull and resonate voice
Pharynx
- muscular tube hanging from skull
- passageway for food and air
- resonating chamber for speech prod
- tonsils in the walls protects the entryway into body
Nasopharynx
- from conchae to soft plate
- passageway for air only
Oropharynx
- from soft plate to epiglottis
- common passageway for food and air
Laryngopharynx
Extends from epiglottis to cricoid cartilage
- passageway for food and air and ends as esophagus inferiorly
Cartilages of the larynx
Thyroid cartilage, epiglottis, cricoid cartilage
Thyroid cartilage
Forms the Adam’s apple and houses the vocal cords
Epiglottis
- leaf-shaped piece of elastic cartilage
- during swallowing, larynx moves upward
- bends to cover glottis
Cricoid cartilage
Ring of cartilage attached to top of trachea
Trachea
- 5 in long and 1 in diameter
- extends from larynx to T5 anterior to the esophagus and then splits into bronchi
4 layers of the trachea
Mucosa, submucosa, hyaline cartilage, adventitia
Mucosa
Pseudo stratified columnar with cilia and goblet cells
Submucosa
Loose CT and seromucous glands
Hyaline cartilage
16-20 incomplete rings
Adventitia
Binds it to other organs
Primary bronchi
Supply each lung
Secondary bronchi
Supply each lobe of the lungs
Tertiary bronchi
Supply each bronchopulmonary segment
Bronchioles
Repeated branchings that form a bronchial tree
Type I alveolar cells
Simple squamous cells: where gas exchange occurs
Type II alveolar cells
- septal cells
- free surface has microvilli
- secrete alveolar fluid containing surfactant
Alveolar dust cells
Wandering macrophages to remove debris
Alveolar-capillary membrane
- exchange of gas from alveoli to blood
- 4 layers to cross: alveolar epithelial wall of type I cells, alveolar epithelial basement, capillary basement membrane, and capillary endothelial cells
Breathing or pulmonary ventilation
- air moves into lungs when pressure inside lungs is less that atmospheric pressure
- air moves out of lungs when pressure inside lungs is greater than atmospheric pressure
Forced expiration
- abdominal mm forces diaphragm up
- internal intercostals depress ribs
Forced inspiration
sternocleidomastoid, scalenes, and pectoralis minor lift chest upwards as you gasp for air
Pneumotaxic area
- superior pons
- constant inhibitory impulses to inspiratory area
- neurons trying to turn off inspiration before lungs get too expanded
Apneustic area
- inferior pons
- stimulatory signals to inspiratory area to prolong inspiration
- only if pneumotaxic area is inactive
Cortical influences
- voluntarily alter breathing patterns
- limitations are build up of CO2 and H+ in blood
- inspiratory center is stimulated by increase in either
Central chemoreceptors in medulla
Respond to changes in hydrogen or CO2 concentrations in CSF
Peripheral chemoreceptors
- respond to changes in H+, O2, or CO2
- in walls of aorta and common carotids
Negative feedback regulation of breathing
- increase of arterial pCO2
- stimulates receptors
- inspiratory center
- muscles of respiration contract more frequently and forcefully
- pCO2 decreases
- return to homeostasis
The respiratory system
- cells continually use O2 and release CO2
- designed for gas exchange
- cardiovascular system transports gases in blood
