Unit 14 - Respiratory System

- ventilation (air movement into and out of lungs)

- exchange of gases (O2 and CO2) between lungs and blood

- upper respiratory system (nose, nasal cavity, pharynx)

- lower respiratory system (larynx, trachea, bronchial tree, lungs)

- ciliated pseudostratified epithelium with goblet cells sitting on the lamina propria (CT)

- goblet cells secrete mucous

- cilia sweep mucous to esophagus where swallowed

nose, nasal cavity, paranasal sinuses, pharynx (throat), larynx (voice box), trachea, lungs, bronchial tree, and the respiratory membrane

- supported by bone and hyaline cartilage

- nostrils are called nares

- airway passage (warms, moistens, and filters air)

- olfaction (sense of smell)

- speech (resonance chamber)

- anterior part = hyaline cartilage

- posterior part = vomer, ethmoid, maxillae, palatine bones

vestibule, respiratory area, and olfactory area

- anterior region of the nasal cavity

- no mucosa; lined by thin skin with hair that filters particles (e.g. dust, pollen)

- posterior region

- chonchae protrude medially from lateral walls of cavity

- air passes through meatuses (channels between chonchae) this causes air turbulence that helps humidify air and trap dust on ciliated epithelium

o   superior (projection of the ethmoid)

o   middle (projection of the ethmoid)

o   inferior (separate bones referred to as the inferior nasal chonchae)

—  nasolacrimal duct connects the medial region of eye to the inferior nasal meatus, allowing lacrimal fluid (which includes tears) to drain into nasal cavity

- found in roof on nasal cavity

- mucosa contains olfactory neurons that are sensory receptors for the sense of smell

- 8 air filled spaces in the skull (4 pairs)

- open directly into nasal cavity

- warms and moistens air (& makes skull lighter)

when the mucous membrane becomes inflamed due to infection

- walls are formed of skeletal muscle lined by mucous membrane

- made up of 3 interconnected regions (nasopharynx, oropharynx, laryngopharynx)

- located posterior to nasal cavity, passage for air only

- contains pharyngeal tonsils on posterior wall

- openings: 2 posterior nasal apertures (connects to nasal cavity)

2 pharyngotympanic (auditory) tubes (connects to middle ear)

- posterior to oral cavity, contacts food and air from soft palate to top of epiglottis

- epithelium of mucosa is stratified squamous epithelium

- contains palatine tonsils and lingual tonsils

- posterior to larynx (from epiglottis to opening of larynx)

- epithelium of mucosa is stratified squamous epithelium

- contacts both air and food

red: nasopharynx

green: oropharynx

blue: laryngopharynx

- anterior to laryngopharynx

- air passageway that connects the pharynx to the trachea

contains/made of: 8 hyaline cartilages and 1 elastic cartilage (epiglottis), vocal cords, and glottis

- its flexible and covers the glottis during swallowing to prevent food entering the larynx

- 2 sets of paired folds under the laryngeal mucosa in the mid-larynx

- vestibular folds (are the superior folds, called "false vocal cords", and help close the glottis)

- vocal folds (are the inferior folds, called "true vocal cords", and produce sounds by vibration)

- includes the vocal folds (true vocal cords) and the opening between them

the opening between the vocal folds in the larynx that is generally thought of as the primary valve between the lungs and the mouth

—  inflammation of larynx due to infection or irritation

- anterior to esophagus (air only)

- consists on 20 C-shaped pieces of hyaline cartilage (open face of C faces esophagus, permitting esophagus expansion)

- connects larynx to main bronchi (the two main bronchi branches off trachea to each lung)

- right and left are separated by mediastinum

- pleura (serous membrane, visceral on lung, parietal on inner thoracic wall, superior diaphragm and mediastinum)

- pleural cavity (prevents friction with serous fluid when lungs move, holds lungs to thoracic wall)

- right lung (3 lobes, superior, middle, and inferior)

- left lung (2 lobes, superior and inferior, has cardiac notch (where heart lies))

- air passageway that repeatedly branches into smaller passageways

- connects trachea to alveoli of lungs

- extends from left and right main bronchi to alveolar ducts

- consists of conduction zone structures and respiratory zone structures

- 2 main (primary/1st level) bronchi (left and right)

- 5 lobar (secondary/2nd level) bronchi (3 right, 2 left)

- segmental bronchi (multiple levels of branching)

- terminal bronchioles (multiple levels of branching)

transitions from ciliated pseudostratified epithelium in larger bronchi to ciliated simple cuboidal epithelium in terminal bronchioles and respiratory bronchiles to non-ciliated simple squamous in alveolar ducts

- sites of gas exchange (O2 enters blood, CO2 leaves)

made of: respiratory bronchioles (multiple levels of branching)

- alveolar ducts (tips of bronchial tree)

- alveoli (millions, main site of gas exchange, form part of respiratory membrane)

3 layers (2 epithelia and their fused membrane)

- wall of alveolus

- basement membranes of alveolus and capillary

- wall of capillary (simple squamous epithelium (endothelium))

- simple epithelium

- 2 cell types (type 1 and 2 alveolar cells)

- alveolar pores (openings) allow air movement between adjacent alveoli

- macrophages (freely move between blood and alveoli, remove dust, cellular debris, and pathogens)

Type 1: simple squamous, allows gas diffusion

Type 2: simple cuboidal, secrete surfactant (molecule that covers inner surface of alveoli, reducing attractive forces between water molecules making it easier for alveoli to expand during inhalation)

- subdivision of systemic circulation

- blood to nourish lung tissue

- bronchial arteries: arise from aorta, carry oxy blood to lung tissues (bronchi) but not respiratory portion

- blood to heart returns via bronchial vein (little blood) to right atrium or pulmonary veins (most blood) to left atrium

- accumulation of fluid in the lungs (between cells and within alveoli)

- blockage of pulmonary vasculature

- results from blood clots, arteriosclerosis, air bubbles in vessels, etc.