The Respiratory System

What are the functions of the Respiratory System

• Breathing(pulmonary ventilation)

• Gas exchange

• filters and protects respiratory surfaces from pathogens and dehydration.

• olfaction(smelling)

• acid balance - regulating our blood PH

• Vocalisation

What are the structures of the upper respiratory Tract?

• Nasel cavity + pharynx

• pseudo-stratified columnar-goblet cells - muscin/mucus glands/lysozymes

What is the Nasal septum

• a central wall of bone and cartilage that divides the nasal cavity

  • All bone on one side, all cartilage on the other

  • cartilage on top bone underneath

Explain the wall of the nasal cavity

• conchae: bony plates found on the lateral walls of the nasal cavity that increase the surface area of the mucous membrane

  • Function is to create turbulance, stays longer in your nasel cavity= warms up gets humidified → gives you a chance to smell

Explain the anatomy of the Nasal Meatuses

How is the pharynx divided?

• 3 different regions

  • Nasopharynx

    • Pseudostratified ciliated columnar epithelium

    • alot thinner than..

  • Oropharynx, laryngopharynx:

    • non keratinised stratified epithelium

    • alot tougher, sustain constant friction with the food.

• all structures are named by what they are behind

  • e.g oropharynx is behind the oral cavity

Where is the pharynx?

• originates posterior to the nasal and oral cavities and extends inferiorly near the level of the bifurcation of the larynx and esophagus

What is the Pharynx lined with

• walls lined with mucosa and contains skeletal muscle that permits swallowing

What structures are oposite the Propharynx and the laryngopharynx?

• Vallecula

• Epiglottis

Larynx

• A cartilaginous structure located between the pharynx and trachea, playing a crucial role in phonation and protecting the airway.

• Superior(vestibular) ligaments; vestibular folds: false vocal cords

• inferior(vocal) ligaments; vocal folds: true vocal folds

what are the Larynx cartilages

• Epiglottis

• hyoid bone

• thyrohyoid membrane

• thyroid cartilage

• arytenoid cartilages( on the inside of the thyroid cartilage)

• circoid cartilage

• trachea

What cartilage supports the vocal and vestibular ligament?

Attachment for vestibular ligament: corniculate cartilage

Attachment for vocal ligament: Arytenoid cartilage.

What are the traits and functions of the trachea

• flexible, slightly rigid tube in the mediastinum

• Runs from C6 to T4/T5, where it bifurcates into the primary bronchi

• Functions

  • Filter, warm, humidify air

  • contains 15-20 U-shaped hyaline cartilages and trachealis muscle posteriorly - to help contract and expand to help swallow food

  • annular ligaments connect cartilage rings.

How many bronchi and then what does it divide into

• Primary bronchus 1

• secondary Bronchus 2

• tertiary bronchi 2

then divides into to small airways - they now have no cartilage. now replaces by muscles.

what are bronchioles

Small airways that branch from tertiary bronchi, leading to alveoli. They lack cartilage and are primarily composed of smooth muscle.

• Lined by columnar cuboidal epithelium(facilitates gas diffusion

• terminal bronchioles branch into respiratory bronchioles

what are terminal bronchioles

The last generation of bronchioles before the alveolar ducts. They are small airways that lead directly to the alveoli and are involved in gas exchange.

• Branch into respiratory bronchioles, which branch into alveolar ducts and alveoli

what are alveoli

• functional unit of the lung - where gas exhange happens

• Type 1 and type ll alveolar cells (epithelial cells)

• endothelial cells

• very thin respiratory membrane - 0.5um

What are type 1 alveoli cells

• very thin and it stretches out forming most of the surface area of the alveolus 90-95%

• gas exhange- gas moves past them easily

What are type 2 alveoli cells

• secrete surfactant to reduce surface tension in the alveoli, preventing collapse - help in the repair and maintenance of alveolar epithelium

what are the types of pleura and what are their features

• Parietal pleura lines the outside of the pleural cavity and visceral pleura lines the inside.

• visceral pleura

  • the layer of coelomic epithelium that adheres to the tissue of the lungs (Insensitive to pain)

• Parietal pleura

  • They layer that lines the walls of the thoracic cage (Sensitive to pain)

  • innervated by somatic nerves

  • separated from the intercostal muscles by the endothoracic fascia

• Pleural layer are continuous at the hilum of each lung. goes around and folds in on itself.

Lobes and fissures

• both lungs are conical, with concave base resting on diaphragm and blunt

• lung divided into lobes by fissures

name the lobes and fissures for the right lung

name the lobes and fissures for the left lung

Name the lung surfaces

• mediastinal(medial)

• diaphragmatic(base)

• costal( most lateral, faces the rib cage)

name the lung borders

• anterior

• posterior(smooth)

• Inferior

What is pulmonary circulation?

conducts blood from the heart to and from the gas exchange surfaces of the lungs

what is bronchial circulation?=

component of the systemic circulation. it consists of tiny bronchial arteries and veins that supply the bronchi and bronchioles of the lung,

where do bronchial arteries branch from?

bronchial arteries branch from the anterior wall of the descending thoracic aorta and supply structures in the bronchial tree

• larger bronchial veins collet venous blood and drain into the azygos and hemiazygous systems of veins

Pulmonary ventilation

• from lungs, oxygen transported to body cells through cardiovascular system

• cells use oxygen and generate carbon dioxide as a waste product

• blood transport the carbon dioxide from cells to lungs

• carbon dioxide expelled during exhalation

pulmonary ventilation and boyles law

• the pressure of a gas decreases if the volume of the containers increases, and vice versa

  • PV= constant

• Increasing volume of the thoracic cavity during inhalation decreases intrapulmonary pressure relative to the atmospheric pressure and air flows into the lungs until equilibrium is reached.

• the volume of the thoracic cavity decreases during exhalation relative to outside atmospheric pressure, air is forced out of the lungs

Alveolar pressure changes… beginning of inspiration

beginning of inspiration

• contraction of muscles & increase of thoracic volume

• expansion of lungs and increase in alveolar volume

• decrease in the intrapulmonary pressure below atmospheric pressure

• air flows into the lungs

Alveolar pressure changes… end of inspiration

• alveoli and thorax stop expanding

• air flow into the lungs causes Patm=Palv

• no more movement of air occurs

Alveolar pressure changes… beginning of expiration

• decrease of thoracic volume

• decrease in alveolar volume

• increase in the intrapulmonary pressure above

• atmospheric pressure (Palv>Patm)

• Air flow out of the lungs until Palv=Patm

Alveolar pressure changes… end of expiration

• Patm=Palv

• no more movement of air occurs

respiratory muscles -