Respiratory Flashcards
functions to supply oxygen for the metabolic needs of the cells and to remove one of the waste materials of cellular metabolism, carbon dioxide.
respiratory system
respiratory system involves the processes of
- External respiration
- absorption of O2 and removal of CO2 from the lungs- Internal respiration
- gaseous exchanges between the cells of the body and their fluid medium
- Internal respiration
Its is the - absorption of O2 and removal of CO2 from the lungs
External respiration
it is the gaseous exchanges between the cells of the body and their fluid medium
Internal respiration
Movement of air in and out of the respiratory system
Pulmonary ventilation
A. Conducting passages (dead spaces)
- for passage of air
- Nose
- Pharynx
- Larynx
- Trachea
- Bronchi and their divisions
- where absorption of O2 and removal of CO2 from the blood takes place.
Respiratory passages
(respiratory bronchioles, alveolar ducts,alveoli)
Lungs
External nose
Boundaries:
Superiorly– nasal and frontal bones
Laterally - maxillary bones
Inferiorly– plates of hyaline cartilage ( the lateral septal and alar cartilages)
The nasal cavity lies posterior to the external nose
- Anterior nares (nostrils)
- communication between nasal cavity and outside
- are separated by septum mobile nasi or columella\
Internal nose (Nasal Cavity)
Roof - ethmoid bone, sphenoid bone, frontal bone
Floor - Hard palate
Laterally - Conchae or turbinates
(Superior, middle, inferior) Which protrude medially forming grooves inferior to each conchae called meatus.
Medially - The nasal septum which is formed anteriorly by hyaline cartilage, and posteriorly by the vomer bone and perpendicular plate of ethmoid.
Recess and Meatuses
Superior Meatus
Middle Meatus
Inferior Meatus
Nasal Conchae
(1.Superior Concha
2. Middle Concha ) Parts of ethimoid*
3. Inferior Concha
PHARYNX
Nasopharynx
Oropharynx
Laryngopharynx
- soft palate to epiglottis
- located behind the oral cavity
Oropharynx
- located behind the larynx
Laryngopharynx
- Extends 5 cm from the level of the 4th - 6th cervical vertebra
- With 9 cartilages (3 paired, 3 unpared)
Larynx
- Largest
- Shield shaped; unpaired
- With laryngeal prominence (Adam’s Apple): angulation formed from the union of 2 laminae
Thyroid Cartilage
- Unpaired: signet ring shaped
Cricoid Cartilage
- Unpaired: spoon or leaf- shaped
- Found behind the tongue
- Only elastic cartilage (the rest are hyaline)
Epiglottis
Vocal Cords
FALSE VOCAL CORDS (VESTIBULAR FOLD)
TRUE VOCAL CORDS (VOCAL FOLDS)
FALSE VOCAL CORDS
(VESTIBULAR FOLD)
TRUE VOCAL CORDS
(VOCAL FOLDS)
- non-movable
- surrounds the opening called rima vestibuli
FALSE VOCAL CORDS (VESTIBULAR FOLD)
- movable
- surrounds the opening called rima glottidis (the narrowest part of the adult larynx)
TRUE VOCAL CORDS (VOCAL FOLDS)
- the trachea or “windpipe” is a cylindrical tube about 10-12 cm in length, 2.5 cm in
diameter - 16-20 C-shaped cartilage
- lined by pseudostratified columnar ciliated epithelium
- C6 - T5
TRACHEA
- Each primary bronchi divides into
3 right and 2 left
- which supply the lobes of the lungs (superior, middle and inferior in the right lung; superior and inferior in the left)
Secondary lobar bronchi
in turn divides into tertiary, or segmental bronchi, each of which is distributed to a unit of the lung called a bronchopulmonary segment.
secondary bronchi
continue to divide into successively smaller branches.
segmental bronchi
- Fine branches, now called?
- enter basic units of the lung called lobules.
bronchioles
The respiratory bronchioles open into __________ from which alveoli arise
alveolar ducts
Each bronchiole divides upon entering a lobule into several ___________, each of which further subdivides into two or more respiratory bronchioles.
terminal bronchioles
Respiratory Zones
- RESPIRATORY bronchioles
- branch into alveolar ducts—
—> alveolar sacs——-
—> alveoli
- branch into alveolar ducts—
RESPIRATORY MEMBRANE
a. Type I pneumocytes
b. Type II pneumocytes
c. Alveolar macrophages
- walls of alveoli composed of simple squamous epithelium.
a. Type I pneumocytes
- secretes surfactant
b. Type II pneumocytes
- dust cells, defense against inhaled dust, bacteria, and foreign particles
c. Alveolar macrophages
- soft, spongy, elastic organs, 0.5 kg each
- essential organs of respiration
- situated on either side of the heart and the mediastinal structures
THE LUNGS
FEATURES OF THE RIGHT LUNG
- three lobes
- superior, middle and inferior - two fissures
- horizontal and oblique - shorter, wider and heavier as compared to left
- deeper diaphragmatic surface due to presence of liver
FEATURES OF THE LEFT LUNG
- two lobes - superior and inferior
- one fissure - oblique only
- anterior border with cardiac notch
- lingula is present (tongue-like portion of the upper lobe between cardiac notch and oblique fissure)
- a serous membrane covering the lungs and made up of parietal and visceral layers.
- between visceral and parietal layer is the pleural cavity which contains a small amount of serous fluid
- the 2 layers are continuous at the root of the lungs
PLEURA
MECHANISM OF BREATHING
PHASES OF BREATHING
- Inspiration/inhalation
- Expiration/exhalation
- air is flowing into the lungs, active phase
Inspiration/inhalation
- air is flowing out of the lung, passive phase
Expiration/exhalation
- Gases travel from area of high pressure to area of lower pressure
A. Pressure relationship in the Thoracic Cavity
A. Pressure relationship in the Thoracic Cavity
- Intrapulmonary pressure
- Intrapleural/Intrathoracic pressure
- pressure inside the alveoli
Intrapulmonary pressure
- pressure in the pleural cavity
Intrapleural/Intrathoracic pressure
Physical Factors Influencing Pulmonary ventilation
- Friction in the air passageways
- Lung compliance
- Surface tension of the alveolar fluid
Friction in the air passageways
- resistance
Lung compliance
- elasticity and flexibility
Surface tension of the alveolar fluid
surfactant decreases surface tension
Gas exchange in the body
A. External respiration: Pulmonary gas exchange
1. Partial pressure gradient and gas solubility
- CO2 and O2
2. Thickness of the respiratory membranes
3. Surface area- alveoli increase the surface area 140 meters
4. Ventilation- perfusion coupling
GAS TRANSPORT
A. Oxygen
B. Carbon dioxide
Oxygen
- Oxyhemoglobin- O2 and Hemoglobin- 97%
- Dissolved in plasma- 3%
Carbon dioxide
- Dissolved in plasma- 7-10%
- Carbaminohemoglobin- 20-30%
- Bicarbonate (HCO3)- 60-70%
Carbonic anhydrase
CO2 + H2O_______________ HCO3 + H
H2CO3 -> carbonic anhydrase-> HCO3 +H
CONTROL OF RESPIRATION
A. Medullary Respiratory Centers
B. PONS Respiratory centers
C. Herring-Breuer Reflex
- responsible for the rhythm of breathing. Impulses travel to phrenic and intercostal nerve to diaphragm
- Dorsal respiratory group or inspiratory centers
Medullary Respiratory Centers
- Dorsal respiratory group or inspiratory centers
- Ventral respiratory group/expiratory center
- contains both inspiratory and expiratory neurons
- during forceful breathing
Ventral respiratory group/expiratory center
- continuously sends inhibitory impulses to the inspiratory center of the medulla
- sets duration of inspiration
Pneumotaxic center
-provides inspiratory drive
-sends signals for inspiration for long & deep breaths
-controls intensity of breathing
-inhibited by stretch receptors or by pneumotaxic center
-increases tidal volume
Apneustic center
- Stretch receptors in the visceral pleura that transmit inhibitory signals to medullary inspiratory center
Herring-Breuer Reflex
- located in the medulla oblongata
- sensitive to changes in blood CO2 and Ph
- increase CO2 or hypercapnia- respiratory stimulant
- Central chemoreceptors
PONS Respiratory centers
- Pneumotaxic center
- Apneustic center
Chemical control of Respiration
- Central chemoreceptors
- Peripheral chemoreceptors
- located in the medulla oblongata
- sensitive to changes in blood CO2 and Ph
- increase CO2 or hypercapnia- respiratory stimulant
Central chemoreceptors
- carotid bodies
- sensitive to changes in blood 02 levels
Peripheral chemoreceptors
- Increase of ventilation
- Changes of blood pH, CO2 and O2
Effects of Exercise