Ch 23 Respiratory system Flashcards
what includes in the upper respiratory system?
Nose
Nasal cavity
Paranasal sinuses
pharynx
what includes in the lower respiratory system?
Larynx
Trachea
bronchus
Lungs
Bronchioles
Alveoli
Functions of the respiratory system
- Provide extensive surface area for gas exchange
- Move air to and from respiratory surfaces of lungs
- protect respiratory surfaces
- Produce sound
- detect odor (olfaction)
what two systems work together for respiration?
Respiratory system
cardiovascular system
what are the four processes of respiration
- Pulmonary ventilation (inspiration & expiration)
- External respiration (duffusion of O2 to blood and CO2 to lungs)
- Transport of respiratory gasses via cardivascular system, blood as transporting fluid.
- Internal repiration (diffusion of O2 and Co2 to tissue cells and blood).
Functoinal division of the respiratory system
-Conducting = passageways for air through terminal bronchioles)
-Respiratory = respiratory bronchioles, alveolar duct, alveolar sacs then alveoli
Functions of external nose and nasal cavity
- Airway for respiration
- Moisten and warm the air.
- Filter and clean air
- Resonating chambers for speech
- Houses olfactory receptors
Hard palate and soft palate
Hard palate separate nasal cavity from oral cavity
Soft palate shuts when swallowing food to prevent to go to nasal cavity
What does turbulence do?
It increases the time for air spends in nasal cavity, helps remove debris and odrants reach the olfactory epithelium.
Tissue present in the nasal cavity, nasopharynx and trachea.
Pseudostratified ciliated columnar epithelium. They helps sweep the mucous away and push in to the pharynx
tissue of oropharynx, laryngopharynx, and beginning larynx
stratified squamous epithelium. at risk from mechanical and chemical damage from food.
Tissue of bronchioles
simple columnar to the simple cuboidal epithelium. maintain the tube structure with less cartilage in smallest diameter tubes.
tissue of alveoli
simple squamous epithelium
thin for gas exchange.
Functions of the voice box (layrnx)
- Provide and maintain an open airway
- Provide a switching mechanism for food and air.
- voice production
- protect entrances to glottis and trachea
Define phonation
Production of sound
- vocal cords vibrate as air passes
What determines the pitch?
Tension on the vocal cords
tenser=faster vibrations= high pitch
Controlled by intrinsic muscles.
what determine the loudness
the force applied to the air.
what’s in the root of the lung
hilum which is a groove at the mediastinal surface.
Main bronchus, pulmonary vessels and nerves lymphatic pass through it.
why C shaped cartilage are important in trachea
protect the anterior and lateral sides
Disconnection at posterior allow food to pass freely from esophagus
Trachealis muscle
- band of smooth muscles
- connect the end of tracheal cartilages
- constriction reduces the diameter
which vessel provide blood to the lungs
Bronchial arteries branched from thoracic aorta supply resources to all lung tissue except alveoli
What happens to the structure of walls of bronchi as they branch off
It loses its cartilage and smooth muscle increases, it gives greater ability to change diameter.
Functions of elastic fibers
- it helps maintain alveoli relative position and respiratory bronchioles.
- it helps lungs to return to its original position.
Blood-air barrier
it is composed of the two cell layers of alveolar cells and capillary endothelium with basement membrane fused in the middle.
Pneumocyte type 1
- very thin
- sites for gas exchange
- made of simple squamous epithelium
Pneumocyte type 2
- Large
- It produce surfactant
Alveolar macrophages
- Patrol epithelial surface
- engulf any particle that elude defence
Surfactant
Oily secretion containing phospholipids, and proteins
- it breaks the surface tension
How the volume of thoracic cavity increased
-Diaphragm contracts
- ribs and sternum elevates
Accessary and primary muscles for inspiration
Primary- external coastal muscles & diaphragm
Accessory- sternocleidomastoid, scalenes, pectoralis minor, Serratus anterior
Accessary muscles for expiration
- transverse thoracis
- rectus abdominis
- internal intercostal muscle
Which forces pull the lungs in?
Elasticity of the lungs
alveolar fluid surface tension
FOrces that pull the lungs out?
Elasticity of the chest wall pulls the thorax outwards and enlarge the lungs
what keeps the lungs from separating from thoracic
adhesive forces of pleural fluid
pneumothorax
collapsing of the lung (either puncture in the visceral pleura or parietal pleura.
collapsing of lung also called as
atelactasis
What physical factors affect pulmonary ventilation?
- Resistance
- Compliance
tell me more about resistance
it can be caused by inflammation, infection, mucous buildup, tumors
how to adjust resistance
By bronchodilation(with SNS for higher flow) or bronchoconstriction(with PNS for less flow).
Define compliance
expand the lungs to fill with air. low compliance means greater force to fill lungs.
Factors those affect compliance
- level of surfactant production(cannot expand alveoli)
- connective tissue of lungs(scare tissue decrease compliance)
- mobility of thoracic cage
How can the amount of air reaching the lungs be adjusted to deal with changing oxygen demands?
- number of breaths per minute (respiratory rate)
- amount of air moved per breath(tidal volume)
Define respiratory minute volume
amount of air moved per minute
calculaed as: respiratory rate* tidal volume
what set the basic pattern and rate of respiratory muscle contraction
Respiratory rhythmicity centers of the medulla oblongata
which centers of pons modify the rate
Apneustic and pneumotaxic centers
rythmic center takes input from
- chemoreceptors
- Baroreceptors
- Strech receptors in the lungs
inflation reflex
prevent overexpansion of lungs
deflation reflex
inhibits expiratory centers and stimulates inspiratory centers during lung deflation.
Hering-breuer reflexes
inflation and deflation
For efficient gas exchange
- Concentration gradient
- short distance and large surface area
- coordination of airflow and blood flow at alveoli.
WHat is solubility of gasses
CO2 has fairly high solubility
O2 has somewhat less solubility
N2 has very limited solubility.
Dalton’s law of partial pressure
each gas contributes to total pressure in proportion to its relative abundances
Partial pressure
Every gas has its own partial pressure.
gas percentage* 760 mm Hg
henry’s Law
at give temperature, amount of gas in solution is proportional to partial pressure of that gas
relation between pressure and solubility
more pressure more solubility
How hemo affinity changes for gasses
when substance bing to hem it changes it structure, change also change afinity towards O2.
define hem saturation
percentage of heme units bound to oxygen
factors affecting the heme saturation
- P of O2 of blood
- Blood pH
- temperature
- metabolic activity within RBC (BPG production)
curve is no linear benefits of it
- we can maintain sufficient oxygenation over wide range of atm partial pressur e
- Large change oxygen pressure, low affect on the oxygenation of oxygen
- higher metabolic activity low affinity more giving up oxygenation .
Effect of pH & temperature
Blood pH lower–> O2 release–> curve shifts to right
Blood temperature increase–> O2 release–> curve shifts to right
