Lecture 21: Respiratory System Flashcards
Identify the organs forming the respiratory passegway in descending order until the alveoli are reached
Major organs:
- Nose, nasal cavity, and paransal sinuses
- pharynx
- larynx
- trachea
- bronchi and their branches
- lungs and alveoli
Respiratory muscles:
-diaphragm and other muscles that promote ventilation
What does respiration involve?
In the respiratory system:
1. Pulmonary ventilation (breathing): movement of air into and out lungs
In circulatory system:
2. External respiration: O2 and CO2 exchange between the lungs and the blood
3. Transport: O2 and CO2 in the blood
4. Internal respiration: O2 and CO2 exchange between systemic blood vessels and tissues
Be able to label the respiratory system
Slide 5
Do it!!
Describe the anatomy and functions of the nose
Functions: moistens and warms the entering air
- filters and cleans inspired air
- serves as resonating chamber for speech
- houses olfactory receptors
Two regions: external nose and nasal cavity
1. External nose:
-nostrils: bounded laterally by the alae
2. Nasal cavity: in and posterior to the external nose
-divided by middle nasal septum
-posterior nasal apertures (choanae) open into the nasal pharynx
-Roof: ethmoid and sphenoid bones
-floor: hard and soft palates
Be able to label it slide 7
What is the structure and function if the nasal cavity?
Be able to label the diagram on pg 9
Vestibule: nasal cavity superior to the nostrils
-filter coarse particles from inspired air
Olfactory mucosa:
-lines the superior nasal cavity
-contains small receptors (chemoreceptors)
Superior, middle and inferior nasal conchae
-protrude from the lateral walls
-increase mucosal area
What is the function of the nasal mucosa and conchae and paranasal sinuses?
Functions if the nasal mucosa and conchae:
- during inhalation, the conchae and nasal mucosa
- filter, heat, and moisten air
- during exhalation these structures
- reclaim heat and moisture
Paranasal sinuses:
- in frontal, sphenoid, ethmoid and maxillary bones
- lighten the skull and help to warm and moisten the air
What is the structure and function of the pharynx?
Muscular tube that connects to the
- nasal cavity and mouth superiorly
- larynx and esophagus inferiorly
- from the base of the skull to the level of 6th cervical vertebrae
Nasopharynx structure and function:
View side 11 for picture
- air passageway posterior to the nasal cavity
- soft palate and uvula close nasopharynx during swallowing
Pharyngeal tonsil (adenoids) on posterior wall Pharyngotympanic (auditory) tubes open into lateral walls
Oropharynx structure and function?
- passageway for food and air from the level if the soft palate to the epiglottis
- palatine tonsils in the lateral walks of fauces (arches)
- lingual tonsil on the posterior surface of the tongue
Laryngopharynx structure and function
- Passageway for food and air
- Posterior to the upright epiglottis
- extends to the larynx, where it is also continuous with the esophagus
Larynx structure and function:
What are the cartilages of the larynx
Continuous with the trachea
Functions:
1-provides a patent airway
2-routes air and food into proper channels
3-voice production
Cartilages of the larynx:
-thyroid cartilage with laryngeal prominence (Adams apple)
-ring shaped cricoid cartilage
-epiglottis: elastic cartilage; covers the laryngeal inlet during swallowing
Vocal ligaments contain elastic fibres, form core of vocal cords
-opening between them is the glottis
-folds vibrate to produce sound as air rushes up from lungs
Voice production:
-speech: intermittent release of expired air while opening and closing the glottis
-pitch is determined by the length and tension of the vocal cords
-loudness depends on force of air
-chambers of pharynx, oral, nasal, and sinus cavities amplify and enhance sound quality
Vocal folds may act as a sphincter to prevent air passage
Eg: valsalvas maneuver
-glottis closes to prevent exhalation
-abdominal muscles contracts
-intra-abdominal pressure rises
-helps to empty the rectum or stabilise the trunk during heavy lifting
How is our voice created?
Voice production:
- speech: intermittent release of expired air while opening and closing the glottis
- pitch is determined by the length and tension of the vocal cords
- loudness depends on force of air
- chambers of pharynx, oral, nasal, and sinus cavities amplify and enhance sound quality
Trachea structure and function
Windpipe: from the larynx into the mediastinum
Carina:
-last tracheal
-the point were trachea branches into 2 bronchi
Wall composed of 3 layers
1. Mucosa: ciliated epithelium with goblet cells
2. Submucosa: connective tissue with seromucous glands
3. Adventitia: outermost layer made of connective tissue
Brachial tree (branching) describe how the two branches of bronchi form and what they form into. Also what are the changes that occur in structure as you move down
Trachea-> right and left main (primary) bronchi
-each main bronchus enters the hilum of one lung
-right main bronchus is wider, shorter, and more vertical than the left
-each main bronchus branches unto lobar (secondary) bronchi (three right, 2 left)
-each lobar bronchus supplies one lobe
-each lobar bronchus branches into segmental (tertiary) bronchi
-bronchioles are less than 1mm in diameter
Change that occur:
From bronchi-> bronchioles, structural changes occur
-cartilage in bronchi and cartilage is absent from bronchioles
-cilia and goblet cells become sparse
-relative amount of smooth muscle increases
Respiratory zone:
Respiratory bronchioles, alveolar ductsm alveolar sacs (clusters of alveoli)
Alveoli:
-walls are single layer squamous epithelium
-surrounded by fine elastic fibres
-house alveolar macrophages that keep alveolar surfaces sterile
