Respiratory System

Pharynx: Nasopharynx

Nasopharynx: Conducts air, lined with pseudostratified ciliated columnar epi, most superiormost region of the pharynx. posterior to nasal cavity. auditory tubes open into nasopharynx to equalize air pressure in the middle ear.

Function: olfaction

Olfaction sense of smell these receptors are stimulated when airborne molecules are inhaled and dissolved in the mucus covering this olfactory epithelium.

Alveoli

Alveolar type I cells Alveolar type II cells (pulmonary surfactant) Alveolar macrophage (dust cell)

Upper respiratory tract: Paranasal Sinuses

Named after the Bones in which they are housed: frontal, ethmoidal, sphenoidal, maxillary sinuses All sinuses communicate with the nasal cavity by ducts. Mucosal lining: pseudostratified ciliated columnar epithelium

4 phases of respiration: Pulmonary Ventilation

(breathing) moving of the ambient air ino and out of the lungs (inhalation and exhalation)

4 phases of respiration: Pulmonary gas exchange

(external respiration) exchange of gases between the alveoli and the pulmonary capillaries

4 phases of respiration: Peripheral gas exchange

(internal respiration) exchange of gases between cardiovascular circulation and the cells/tissues.

Pharynx: Larynogopharynx

(la-ringgo-far-inks) conducts air and serves as a passageway for food and drinl. Nonkeratinized stratified squamous epithelium.

Respiratory membrane

diffusion barrier "blood-air-barrier" type I alveolar cell endothelial cell basement membrane Oxygen diffuses from alveoli into the blood within the capillary, and carbon dioxide diffuses in the opposite direction.

THORACIC wall changes during breathing- vertical

during breathing, the dimensions of the thorax change in the vertical, lateral and anterposterior directions. Elevation and depression of the diaphragm significantly alter the vertical dimensions of the thorax (depression results when the muscle fibers of the diaphragm contract, elevation occurs when the diaphragm relaxes)

Muscles of external respiration that move the ribs: external intercostal muscles

extend from a superior rib inferomedially to the adjacent inferior rin. The ribs elevate upon contraction of the external intercostals, therby increasing the transvers dimensions of the thoracic cavity during inhalation

Muscles of external respiration that move the ribs: transversus thoracis

extends across the inner surface of the thoracic cage and attaches to ribs 2-6. iT helps depress the ribs.

Function: Gas conditioning

gases are condiitoned as they pass through conducting airways. They are warmed to body temp, moistened, and cleansed of particulate mater through contact with the repiratory epithelium and its sticky mucous covering. facilitated by the pathways of the nasal cavity and paranasal sinuses.

How the tracheaand the bronchi changes due to chronic irritation

in chronic smokers the lining of the trachea and bronchi changes from a pseudostratified ciliated columnar epithelium to a stratified squamous epithelium because...... What are the consequences? .

THORACIC wall changes during breathing

lateral movements. elevation of the ribs increases the lateral dimensions of the thoracic cavaity while depression of the ribs decreases the lateral dimensions of the thoracic cavity.

Lower respiratory tract: The larynx

most superior structure of the lower respiratory system. 9 cartilage pieces. also called the voice box, is a short somewhat cylindrical airway. conducting: Air produces sound

4 phases of respiration: Gas transport

movement of gases within the cardiovascular circulation

Structural organization: Upper respiratory tract:

nose, nasalcavity, paranasal sinuses, pharynx and associated structures

Trachea

the muscosa lining of the trachea is pseudostratified ciliated columnar epithelim with nemerous mucin-secreting goblet cells and an underlying lamina propria that house mucin secreting glands.

Upper respiratory tract: Pharynx

used by both the respiratory and digestive system commonly called the throat. common pathway for inhaled and exhaled air (respiratory system) and ingested food (digestive system. 3 regions: Nasopharynx, oropharynx, larynogopharynx. lined by a mucosa and contains skeletal muscles that are primarily used for swallowing.

Lung anatomy

They are the primary organs of respiration. Base: concave rest inferiorly upon the muscular diaphragm and its relatively blunt region Apex: blung region projects superiorly to a point that is slightly superior and posterior to the clavical. Hilum where the bronchi, pulmonary vessels, lymph vessels and nerves pass.

Function: sound production

as air is forced out of the lungs and moves through the larynx, sound may be produced, such as speech or singing. nasal cavity, paranasal sinuses, teeth, lips and tongue aid in sound production.

Function: defense

both the structure of the respiratory system and some of the cells within the respiratory epithelium protect the body against infection by airborne molecules. ex: nose is lined with coarse hairs and twisted passageways to prevent large particles, microorganisms from entering.

Pharynx: Oropharynx

conducts air, serves as passageway for food and drink. Lined with nonkeratinized stratified squamous epithlieum. Posteiror to oral cavity.

Muscles of external respiration that move the ribs: internal intercostals

contraction of the II depresses the ribs, but this only occurs during forced exhalation. normal exhalation require no active muscular effort

How many lobes does the right lung have? How many does the left lung have?

3 lobes 2 lobes

Lungs: Which one is slightly smaller? and Why?

. . . . .

Histology of the mucosa

... . . . . ..

Structural organization: Lower Respiratory tract

...made up of conducting airways (larynx, trachea, bronchi, bronchioles, and their associated structures.) as well as the respirator portion of the respiratory system. (respiratory bronchioles, alveolar ducts and alveoli).

The larynx and minor cartilages

Artenoid: pyramidal shape and rest on the superoposterior border of the cricoid cartilage corniculate: attach to the superior surface of he aryenoid cartilage Cuneiform: do not directly attatch to any other cartilages. instead are supported with a sheet called the aryepiglottic fold. .

Bronchial tree

Bronchi-> bronchioles Cartilage diminishes because they are the sites of bronchodilation/constriction epithelium changes to simple columnar or simple cuboidal epithelium -> terminal bronchioles. it is a highly branched system of air-conducting passages that originate form the left and right primary bronhi and progressively branch into narrower tubes as they diverge throughout the lungs before ending in terminal bronchioles.

Functions: Gas exchange

External respiration: involves the exchange of gases between the atmosphere and the blood. oxygen is inhaled and carbon dioxide diffuses from the blood into the lings in order to be exhaled.. internal respiration: exchange of gases between the blood and the cells of the body. blood transports oxygen from the lungs to the body cells and transports carbon dioxide produced by the body cells to the lungs

Lung Pleura; plueral cavity

Lined with serous membrane called Pleura (simple squamous epithelium called a mesothelium. visceral pleura: outer surfface of each lung parietal pleura: internal thoracic walls, the lateral surfaces of the mediastinum and the superior surface of the diaphragm are lined by this pleura. between these serous membranes is the pleural cavity which is a potential space due inflation of the lungs.

Respiratory control centers in brainstem

Pons: pneumotaxic center apneustic center Medulla oblongata- respiratory rhythmicity center -dorsal respiratory group (DRG) -ventral respiratory group (VRG)

Major Functions of the respiratory system

Primary is breathing (pulmonary ventilation) two cycels: inhalation (DRAWS GASES INTO THE LUNGS) and exhalation (FORCES GASES OUT OF THE LUNGS). Gas exchange, Gas conditioning, sound production, olfaction, defense. The respiratory and cardiovascular system are inseparable partners. Te RS exchanges gases between the atmosphere and the blood, the CS transports those gases between the lungs and the body cells.

Muscles of external respiration that move the ribs: Scalenes

Scalenes: help increase thoracic vacity dimensions by elevating the first and second ribs during forced inhalation

Trachea

Supported by 15-20 C-shaped tracheal cartilages: reinforce and provide some rigidty to the tracheal wall to ensure it stays open. Anular ligaments: how the cartilage rings are connected (elastic CT) Trachealis muscle:the open ends of the C-shapeed piece are bound together by this muscle wich is an elastic membrane. distends during swallowing and bulges into the lumen of the trachea to allow for expansion of the asophugs to accommodate larger materials being swallowed. Bifurcates into primary bronchi.

Function organization: Conducting Portion

TRANSPORTS AIR: includes, the nose, nasal cavity, and pharynx of the upper respiratory tract and the larynx, trachea, and progressively smaller airways of the lower respiratory tract

Innervation of the Respiratory System

The lower respiratory system is under autonomic control. Sympathetic and parasympathetic fibers from the pulmonary plexus -enter the lungs at the hilum -sympathetic-bronchodilation -parasympathetic- bronchoconstriction

The larynx: major cartilages

Thyroid cartilage: hyaline cartilage. has laryngeal prominence (adam's apple) Cricoid cartilage forms te inferior base of the larynx and conects to the trachea. fromed out of hyaline c. Epiglottis: formed primarly of elastic cartilage. prokects superiorly into the pharynx from its attatchment to the thyroid cartilage.

Functional organization: Respiratory portion

WHERE GAS EXCHANGED WITH THE BLOOD OCCURS Composed of small airways called respiratory bronchioles and alveolar ducts as well as air sacs called alveoli in the lower respiratory tract.

Respiratory portion

respiratory bronchioles: terminal bronchioles branch to form this. Alveolar the smaller respiratory bronchioles subdivide into thin alveolar duct airways which are lined with a simple squamous epithloum. the distal end of an alveolar duct terminates as a dilated alveolar sac. both of these airways respiratory bronchioles and alveolar ducts- contain small saccular outpocketings called alveoli. promotes diffusion of gases between the alveolus and the blood in the pulmonary capillaries.