Transcript
The Respiratory System
B. Pimentel, M.D.
University Of Makati – College of Nursing
Functions
1. Gas exchange
2. Regulation of blood ph
3. Voice phonation
4. Olfaction
5. Innate immunity
Anatomy
Upper Respiratory tract
Nose, nasal cavity, pharynx and associated structures
Lower Respiratory tract
Larynx, trachea, bronchi, and lungs
Upper Respiratory Tract
Anatomy
Upper Respiratory Tract Nose and Nasal Cavity
Epithelial lining Stratified squamous epithelium with coarse hair,
traps dust particles and humidifies air.
Pseudostratified ciliated columnar epithelium with goblet cells
Upper Respiratory Tract Nose and Nasal Cavity
Upper Respiratory Tract Nose and Nasal Cavity
Nares (nostrils), external opening Choane, openings into the pharynx Nasal septum, divides the cavity in to left and
right halves Hard palate, floor of the nasal cavity Conchae, prominent bony ridges on the lateral
wall of each nasal cavity– Increase surface area
Upper Respiratory Tract Nose and Nasal Cavity
Upper Respiratory Tract Paranasal Sinuses
Paranasal sinuses, air filled spaces with in the bone (skull)
Maxillary, frontal, ethmoidal and sphenoidal– Open into the nasal cavity
– Reduce weight, produce mucus and act as resonating chambers
– Susceptible to infection and inflammation
Nasolacrimal duct
Upper Respiratory Tract Paranasal Sinuses
Upper Respiratory Tract Paranasal Sinuses
Upper Respiratory Tract Paranasal Sinuses
1.Sinus frontalis2.Cellulae ethmoidales3.Septum nasi4.Concha nasalis inferior5.Processus alveolaris
mandibulae with teeth6.Sinus maxillaris7.Margo infraorbitalis8.Linea innominata9.Lamina orbitalis ossis
ethmoidalis10.Margo supraorbitalis
Upper Respiratory Tract Pharynx
Common passageway for air and solid particles.
Leads to the respiratory and digestive systems.
3 regions: 1. Nasopharynx
2. Oropharynx
3. Laryngopharynx
Upper Respiratory Tract Pharynx
Upper Respiratory Tract Pharynx (Nasopharynx)
Superior part of the pharynx, from the choane to the level of the uvula.
Soft palate, floor of the nasopharynx
Auditory tubes opens into the nasopharynx
Pharyngeal tonsils
Upper Respiratory Tract Pharynx
Upper Respiratory Tract Pharynx (Oropharynx)
From the uvula to the epiglottis
Palatine tonsils, lateral walls near the border oral cavity and oropharynx
Lingual tonsils, surface on the posterior part of the tongue
Upper Respiratory Tract Pharynx
Upper Respiratory Tract Pharynx (Laryngopharynx)
Posterior to the larynx and extend from the tip of the epiglottis to the esophagus
Lower Respiratory Tract
Lower Respiratory Tract Larynx
Connected superiorly to the pharynx and inferiorly to the trachea.
Consist of 3 unpaired and 6 pair cartilages
Lower Respiratory Tract Larynx (Function)
Open passageway, prevent swallowed material from the larynx
Primary source of sound production.
Lower Respiratory Tract Larynx (Function)
Air moving past vocal cords causes vibration. The greater the amplitude (greater force of air) of
vibrations the louder the sound. The frequency of vibrations determines pitch.
– Higher pitched tones are produced only when the anterior portions vibrate and progressively lower tones as the length of the involved cords increases
Lower Respiratory Tract Larynx (Unpaired Cartilages)
Thyroid cartilage (Adams apple), superiorly attached to the hyoid bone
Cricoid cartilage, base of the larynx Epiglottis, made of elastic cartilage. Its inferior
margin is attached to the thyroid cartilage anteriorly and it superior part projects freely toward the tongue
Lower Respiratory Tract Larynx (Unpaired Cartilages)
Lower Respiratory Tract Larynx
Lower Respiratory Tract Larynx (Epiglottis)
During swallowing, the larynx elevates and the epiglottis moves posteriorly to cover the opening of the pharynx
Lower Respiratory Tract Larynx (Epiglottis)
Lower Respiratory Tract Larynx (Paired Cartilages)
Posterior side of the pharynx Cuneiform cartilage, superiorly located Corniculate cartilage, middle Arythenoid cartilage, inferiorly located and
articulated with the cricoid cartilage
Lower Respiratory Tract Larynx
Lower Respiratory Tract Larynx (Vocal Cords)
Ligaments Vestibular folds (false
vocal cords) Vocal cords (true vocal
cords)
Lower Respiratory Tract Larynx (Vocal Cords)
Lower Respiratory Tract Trachea
Membranous tube that consists of dense connective tissue and smooth muscle reinforced with “C” shaped cartilage
Trachealis muscle – contraction of this smooth muscle narrows the diameter of the trachea
Lower Respiratory Tract Trachea
Primary bronchi – trachea divides to form two smaller tubes.
Carina – the most inferior tracheal cartilage, which separates the opening into the two primary bronchi. It is very sensitive to mechanical stimulation and foreign objects reaching it will produce a powerful cough.
Lower Respiratory Tract Trachea
Lower Respiratory Tract Trachea
Lower Respiratory Tract Trachea
Lower Respiratory Tract Tracheobronchial Tree
Beginning with the trachea, all respiratory passageways– Main bronchi → lobar bronchi (2 left, 3 right) →
segmental bronchi (bronchopulmonary segments) → bronchioles → terminal bronchiole → respiratory bronchioles → alveolar duct → alveoli
Conducting zone: From the trachea to the terminal bronchioles
Respiratory zone: Extends from terminal bronchioles to alveoli
Lower Respiratory Tract Tracheobronchial Tree
Lower Respiratory Tract Tracheobronchial Tree
Lower Respiratory Tract Tracheobronchial Tree
Lower Respiratory Tract Tracheobronchial Tree
Lower Respiratory Tract Tracheobronchial Tree (Alveoli)
The tissue surrounding the alveoli contain elastic fibers that allow the alveoli to expand and recoil.
Type I pneumocytes – form 90% of alveolar wall, gas exchange
Type II pneumocytes – secretory cells that produce surfactant
Lower Respiratory Tract Tracheobronchial Tree (Alveoli)
Lower Respiratory Tract Tracheobronchial Tree (Alveoli)
Respiratory membrane – of the lungs is where gas exchange between air and blood takes place.
To facilitate the diffusion of gases – Thin layer of fluid lining the alveolus – Alveolar epithelium simple squamous epithelium – Basement membrane of the alveolar epithelium – Thin interstitial space – Basement membrane of capillary endothelium – Capillary endothelium simple squamous epithelium
Lower Respiratory Tract Tracheobronchial Tree (Alveoli)
a = alveoli, with thin interalveolar septa between them
b = smooth muscle in its wall
c = blood vessel, filled with r.b.c.'s
d = bronchiole
Lower Respiratory Tract Tracheobronchial Tree (Alveoli)
Lower Respiratory Tract Tracheobronchial Tree (Alveoli)
Lower Respiratory TractLungs
Principal organs of respiration Hilum – region on the medial surface for entry and
exit of blood vessels, lymphatic vessels, nerves, and primary bronchus
Root of the lung – all structures passing through the hilum
Right lung has three lobes. Left lung has 2 lobes.
Lower Respiratory TractLungs
Lower Respiratory TractLungs
Lower Respiratory TractLungs
Lower Respiratory TractLungs
Lower Respiratory TractLungs
Lower Respiratory TractLungs
Lower Respiratory TractLungs
Muscles of Respiration
Diaphragm – dome shaped, attaches to the inner circumference of the inferior thoracic wall.
Inspiration – diaphragm, external intercostals pectoralis minor, and scalenes.
Expiration – diaphragm, abdominal muscles and internal intercostals.
Muscles of Respiration
Muscles of Respiration
Muscles of Respiration
Respiratory Physiology (Ventilation)
The process of moving air into and out of the lungs. The flow of air into the lungs requires a pressure
gradient from the outside of the body to the alveoli.
Airflow from the lungs requires a pressure gradient in the opposite direction. – Movement of air into and out of the lungs results from
changes in thoracic volume, which causes changes in alveolar pressure
Respiratory Physiology (Ventilation)
Respiratory Physiology (Ventilation)
Atmospheric Pressure (Patm) - pressure exerted by the air surrounding the body. At sea level its equal to 760mmHg. For our purposes, we'll assume it to be constant and assign it a value of 0mmHg.
Respiratory Physiology (Ventilation)
Intrapulmonary Pressure (Palv) - pressure exerted by the air within the alveoli. It rises and falls during inspiration and expiration, but it always equalizes with atmospheric pressure.
Respiratory Physiology (Ventilation)
Intrapleural Pressure (Pip) - pressure within the pleural cavity. It is always lower than both atmopsheric pressure and intrapulmonary pressure.
Respiratory Physiology (Ventilation)
Respiratory Physiology (Ventilation)
Respiratory Physiology (Ventilation)
Respiratory Physiology (Ventilation)
Respiratory Physiology (Ventilation)
Respiratory Physiology
Lung recoil - causes the alveoli to collapse and it results from
1. Elastic recoil caused by the elastic fibers in alveolar walls.
2. Surface tension of the film of fluid that lines the alveoli.
Respiratory Physiology
Surfactant - mixture of lipoprotein molecules form a layer over the surface of the fluid within the alveoli to reduce surface tension. – Significantly reduces the tendency of the lungs to
collapse.
Respiratory Physiology (Gas Exchange)
The factors that influence the rate of gas diffusion across the respiratory membrane include
1. Thickness of the membrane. Increasing membrane thickness decreases
diffusion– Ex. Pulmonary edema, TB, Pneumonia
Respiratory Physiology (Gas Exchange) Pulmonary edema
Respiratory Physiology (Gas Exchange) Pulmonary edema
Respiratory Physiology (Gas Exchange) Pulmonary edema
CXR 51 year old male with
shortness of breath. bilateral parahilar
infiltrates
Respiratory Physiology (Gas Exchange)
2. Surface area Healthy normal individuals 70 square meters Decreases in area caused by diseases
– Ex. Emphysema, lung ca.
Respiratory Physiology (Gas Exchange) Emphysema
CXR 65 y/o female with a
120 pack year history of tobacco use. – hyperaerated lungs
– flattened diaphragms
– narrow heart shadow
– widened rib spaces
– decreased vascular markings
Respiratory Physiology (Gas Exchange)
3. Partial pressure difference The difference between the partial pressure of the
gas in the alveoli and the partial pressure of gas in the blood of the pulmonary capillaries.
Pressure gradient diffuses from high to low.
Respiratory Physiology (Gas Exchange) Partial Pressure Difference
Respiratory Physiology (Gas Transport)
1. Molecular oxygen is carried in blood– 98.5% bound to hemoglobin
– 1.5% in plasma.
Binds in a reversible fashion.
2. Carbon dioxide is transported in three major ways – 7% is transported dissolved in plasma.
– 23% transported in combination with blood proteins.
– 70% transported in the bicarbonate form.
Binds in a reversible fashion.
Respiratory Physiology (Gas Transport)
3.Haldane effect – hemoglobin that has released its oxygen binds more readily to carbon dioxide than hemoglobin that has oxygen bound to it.
4. Chloride shift – Bicarbonate ion concentration inside RBC’s are lowered by exchanging them for chloride ions. As bicarbonate ions are produced, carrier molecules in RBC membranes move bicarbonate ions out of the RBC’s and chloride ions into the cell.
Respiratory Physiology (Gas Transport)
4. Chloride shift – Bicarbonate ion concentration inside RBC’s are lowered by exchanging them for chloride ions. As bicarbonate ions are produced, carrier molecules in RBC membranes move bicarbonate ions out of the RBC’s and chloride ions into the cell.
Regulation of Respiration (CNS)
CNS Medullary respiratory system – dorsal
portion of medulla oblongota, and ventral portion. – Although the dorsal and ventral respiratory
groups are bilateral, cross communication does exist, so that respiratory movements are symmetrical
Regulation of Respiration (CNS)
Dorsal respiratory system is most active during inspiration but is responsible for stimulation of the diaphragm.
Ventral respiratory group is active during both inspiration and expiration. Stimulate the external and internal intercostals, and abdominal muscles.
Pontine Respiratory group – neurons in the pons, some are active in expiration or inspiration and/or both.
Regulation of Respiration (CNS)
Regulation of Respiration
(Cerebral and Limbic System Control) Possible to voluntarily or involuntarily to control
rate of breathing through the cerebral cortex.
Apnea – absence of breathing.
Voluntary apnea increases a greater and greater urge to breathe due to increasing PCO2 levels.
Regulation of Respiration (Chemical Control of Ventilation)
The Chemoreceptors involved with the regulation of respiration responds to changes in hydrogen ion concentration and PO2, or both.
Chemosensitive areas are located in the medulla oblongota.
Peripheral Chemoreceptors are found in the carotid and aortic bodies.
Regulation of Respiration (Effect of pH)
Chemosensitive area of the medulla oblongota is bathed in cerebrospinal fluid and is sensitive to changes in pH.
The chemosensitive area reacts indirectly to change in blood pH.
Carbon dioxide levels change pH. Respiratory system plays an important role in
acid-base balance.
Regulation of Respiration (Effect of Carbon Dioxide)
The major regulator of respiration.
Hypercapnia – greater than normal levels of carbon dioxide in the blood.
Hypocapnia – lower than normal carbon dioxide levels.
Regulation of Respiration (Effect of Carbon Dioxide)
Regulation of Respiration (Effect of Oxygen)
Hypoxia – decrease in oxygen levels below normal levels.
The effect of oxygen concentration in the blood has a small role in regulation of respiration.
O2-Hemoglobin Dissociation CurveDescribes the percentage of hemoglobin saturated with oxygen at any
given PO2
Revised ScheduleMaySat 20 - Respiratory System
- Digestive and GI System
Sun 21 - Urinary System & Acid Base Balance
Sat 27 Midterms!!!
- Reproductive System (Male and Female)- Endocrine System
Sun 28 - Nervous SystemsPreceptorials 2
JuneSat 3 Pre-final Review Sun 4 Finals!!! All schedules are subject to
changes
top related