chapter 23 Flashcards
What does the respiratory system require?
- Requires oxygen and produces carbon dioxide
- Oxygen is obtained from air by diffusion across exchange surfaces in lungs
What are the functions of the respiratory system?
- Provide extensive surface area for gas exchange between air and circulating blood (alveoli)
- Move air to and from exchange surfaces of lungs (diaphragm/intercostal muscles)
- Protect respiratory surfaces from dehydration, temperature changes, pathogens and particulates
- Produce sounds
- Detect odors with olfactory receptors in nasal cavity
What is in the upper respiratory system?
Nose, nasal cavity, paranasal sinuses, and pharynx
What is in the lower respiratory system?
Larynx, trachea, bronchi, bronchioles, and alveoli
What is in the Respiratory tract?
- Conducting portion
From nasal cavity to larger bronchioles - Respiratory portion
Smallest respiratory bronchioles and alveoli
What is the alveoli?
- Air-filled pockets within lungs
- Where all gas exchange takes place
What is Respiratory mucosa?
- Lines conducting portion of respiratory system
- Consists of
An epithelium
Areolar tissue layer (lamina propria)
What are the functions in the respiratory defense system?
1.A series of filtration mechanisms
2. Removes particles and pathogens from inhaled air
What is the structure of respiratory epithelium?
Pseudo stratified ciliated columnar epithelium
What does alveolar epithelium?
Very delicate, simple, squamous epithelium
What is the nasal vestibule?
Space contained within flexible, tissues of nose
What are nasal hairs?
Trap large particles in hair
What is nasal septum?
Divides nasal cavity into left and right sides
Anterior portion (hyaline cartilage) supports dorsum of nose and apex of nose
What is the superior portion of nasal cavity?
olfactory region, which provides sense of smell
Where does airflow?
From vestibule to choanae (openings of nasal cavity)
Through superior, middle, and inferior nasal meatuses
Meatuses produce air to what?
- Trap particles in mucus
- Warm and humidify incoming air
What is nasal mucosa?
Warms and humidifies inhaled air for arrival at lower respiratory system
Where does air flow from?
Air flows from pharynx to larynx
What is thyroid cartilage?
- hyaline cartilage
- adams apple
- Ligaments attach to hyoid bone, epiglottis, and smaller laryngeal cartilages
What is epiglottis?
Covers glottis when swallowing
What is the function of epiglottis during swallowing?
Epiglottis folds back over glottis
What does trachea contain?
- Contains 15–20 C-shaped tracheal cartilages
- Discontinuous where trachea contacts esophagus, allowing distortion
What is bronchial tree?
- Right main bronchus and left main bronchus
- Each divides to form lobar bronchi that supply lobes of lungs
- Lobar bronchi branch to form segmental bronchi
What is bronchitis?
Inflammation and constriction of bronchi and bronchioles due to infection
What is Bronchodilation?
- Caused by sympathetic (purposeful) activation
- Enlarges luminal diameter of airway
- Reduces resistance to airflow
What is Bronchoconstriction?
1.Parasympathetic activation
2. Histamine release (allergic reactions)
What is asthma?
Excessive stimulation of smooth muscles
Causing severe bronchoconstriction
Restricts airflow
What is surfactant?
- Oily secretion
- Contains phospholipids and proteins
- Coats alveolar surface and reduces surface tension
What is Respiratory distress syndrome?
- Alveoli collapse after each exhalation
- Caused by inadequate amounts of surfactant due to injury or genetic abnormalities
What is Pneumonia?
- inflammation of lung tissue
- Causes fluid to leak into alveoli
Where are left and right lungs?
- In left and right pleural cavities
- Inferior portion (base) rests on diaphragm
What does right lung have?
- three lobes
- superior, middle and inferior
What does left lung have?
- two lobes
- superior and inferior
What is in the left lung?
Indented on medial margin forming cardiac notch
How is the bp in pulmonary circuit?
- Lower than that in systemic circuit
- Pulmonary vessels are easily blocked by blood clots, fat, or air bubbles
What is pulmonary embolism?
A blocked branch of pulmonary artery that stops blood flow to lobules or alveoli
What is pleura?
Consists of two layers
What is parietal pleura?
lines inner surface of thoracic wall
What is visceral pleura?
covers outer surfaces of lungs
What is pleural fluid?
Lubricates space between the two layers
What is hypoxia?
Low tissue oxygen levels
What is anoxia?
Complete lack of oxygen in tissues
What is atmospheric pressure atm?
Weight of Earth’s atmosphere
Has several important physiological effects
What does Respiratory cycle consist of?
An inspiration (inhalation)
An expiration (exhalation)
What does pulmonary ventilation cause?
volume changes that create changes in pressure
What are the primary respiratory muscles?
The diaphragm
External intercostals
What are the mechanics of breathing?
Inhalation is always active
Exhalation can be active (if trying to blow out) or passive (on a typical breath)
What is tidal volume?
Amount of air moved into or out of lungs in a breath
What is Expiratory reserve volume (ERV)?
Additional amount of air capable of being exhaled
What is Residual volume?
Amount of air in lungs after maximal exhalation
Minimal volume (in a collapsed lung)
What is Inspiratory reserve volume (IRV)?
Additional amount of air that can be inhaled
What is inspiratory capacity?
Tidal volume + inspiratory reserve volume
What is Functional residual capacity (FRC) ?
Expiratory reserve volume + residual volume
What is vital capacity?
Expiratory reserve volume + tidal volume + inspiratory reserve volume
What is total lung capacity?
Vital capacity + residual volume
What is dalton’s law?
Each gas contributes to total pressure in proportion to its relative abundance
What is henry’s law?
At a given temperature, amount of a gas in solution is proportional to partial pressure of that gas
What is the solubility of gases in body fluids?
CO2 is highly soluble
O2 is somewhat less soluble
In external respiration, blood arriving in pulmonary arteries (co2 rich) has
Low PO2
High PCO2
What does the concentration gradient cause?
O2 to enter blood (come inside)
CO2 to leave blood (go to outside)
What is internal respiration?
Oxygenated blood mixes with deoxygenated blood from conducting passageways
What are the factors that affect Hb saturation?
PO2 of blood
Blood pH
Temperature
Metabolic activity within RBCs
What is in fetal hemoglobin?
Fetal Hb binds more O2 than does adult Hb
