Chapter 23 Flashcards
Respiration
The process of supply in the body with oxygen and removing CO2
What are the three basic steps of respiration?
- Pulmonary ventilation or breathing
- External (pulmonary) respiration - is the exchange of gases between the alveoli of the lungs and the blood in the pulmonary capillaries across the respiration membrane in the process pulmonary capillaries gain 02 and loose CO2
- Internal (tissue) respiration - The exchange of gases between blood and systemic capillaries and tissue cells in the step the blood loses oh to engage in CO2 within cells the metabolic reactions that consume O2 and give off CO2 during production of ATP are termed cellular respiration
What are the components of the respiratory system?
Nose, pharynx, larynx, trachea, bronchi, and lungs
What does the respiratory system consist of structurally?
- Upper respiratory system includes the nose, nasal cavity, pharynx, and associated structures
- Lower respiratory system includes the larynx, trachea, bronchi, and lungs
What does the respiratory system consist of functionally?
- The conducting zone consists of a series of interconnected cavities and tubes both outside and within the lungs these include the nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles
their function is the filter warm and moist and air in conducted into the lungs
- The respiratory zone consists of tubes and tissues within the lungs where gas exchange occurs these include the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli and are
the main site of gas exchange between Air and blood
What are the functions of the respiratory system?
- Provides for gas exchange intake of O2 for delivery to body cells and removal of CO2 produced by the body cells
- Contains receptors for sense of smell, filters inspired air, produces vocal sounds and excrete small amounts of water and heat
- Helps regulate blood pH
Parts of external nose?
Boney framework - made up of the frontal bone, nasal bones, and maxillae
Cartilaginous framework - Septal nasal cartilage- forms the anterior portion of the nasal septum; lateral nasal cartilage -forms inferior to the nasal bones; Alara cartilage -form the portion of the walls of the nostrils
External nares or nostrils -which lead into cavities called the nasal vestibules
What are the three functions of the interior structures of the external nose ?
- Warming, moistening, and filtering incoming air
- Detecting olfactory stimuli
- Modifying speech vibrations as they pass through the large, hollow, resonating chambers
Resonance
Refers to prolonging, amplifying, or modifying a sound vibration
Nasal cavity
Internal nose
a large space in the anterior aspect of the skull that lies inferior to the nasal bone and superior to the oral cavity
lined with muscle and mucus membrane and a vertical partition the nasal septum
Internal nares
Choanae
Two openings that communicate with the pharynx
Paranasal sinuses
Drains mucus
Nasolacrimal ducts
Drains tears
Respiratory region
Larger, inferior nasal cavity region
Olfactory region
Smaller, superior nasal cavity
Lines with Ciliated pseudostratified columnar epithelium with numerous goblet cells
Frequently called the respiratory epithelium
Nasal vestibule
Anterior portion of nasal cavity just inside the nostrils
Surrounded by cartilage
What extends out of each lateral wall of the nasal cavity?
Shelves formed by projections of the superior, middle, and inferior nasal conchae
What cells make up the olfactory epithelium?
The olfactory receptor cells, supporting cells, and basal cells which lie in the respiratory region
What is the pharynx function as?
A passage way for air and food, provides a resonating chamber for speech sounds, and houses the tonsils which participate in immunological reactions against foreign invaders
What are the three anatomical regions the pharynx can be divided into?
- Nasopharynx
- Oropharynx
- Laryngopharynx
Nasopharynx
Superior portion of the pharynx lies posterior to the nasal cavity and extends to the soft palate
Soft palate
Forms the posterior portion of the roof of the mouth is an arch shaped muscular partition between the nasal pharynx and oropharynx, lined by mucous membranes
five openings in its wall: two internal nares, two openings that lead into the auditory tubes (commonly known as the eustachian tubes),and the opening into the oropharynx
Pharyngeal tonsil
Found in the posterior wall
also called adenoid
Oropharynx
Intermediate portion of the pharynx
lies posterior to the oral cavity and extends from the soft palette inferiorly to the level of the hyoid bone
one opening the fauces (mouth opening)
What are the two tonsils in the mouth?
Palatine and lingual tonsils
Laryngopharynx
Inferior portion of the pharynx
Also called the hypopharynx
Opens into the esophagus (food tube) posteriorly and the larynx (voice box)anteriorly
Larynx
The voice box is a short passageway that connects the laryngeal pharynx with the trachea
lies in the midline of the neck to the Esophagus
composed of nine pieces of cartilage
The cavity of the larynx
The space that extends from the entrance into the larynx down the inferior border of the cricoid cartilage
Laryngeal vestibule
Above the vestibular folds
Infraglottic cavity
Portion of the cavity below the vocal folds
Thyroid cartilage
Adam’s apple
Consists of two fused plates of hyaline cartilage that formed the anterior wall of the larynx and give it a triangular shape
Epiglottis
Large leaf shaped piece of elastic cartilage that is covered with epithelium
the “stem”of the epiglottis is the tapered inferior portion that is attached to the rim of the thyroid cartilage
the broad superior “leaf” portion of the epiglottis is unattached and is free to move up and down like a trapdoor during swallowing
the pharynx and larynx rise
elevation of the pharynx widens it to receive food or drink
elevation of the larynx causes the epiglottis to move down and form a lid over the glottis closing it off
Glottis
Consists of a pair folds of mucous membrane, the vocal folds in the larynx, in the space between them called the Rima glottidis
Keeps liquids and solids in the esophagus and out of larynx and airways
Cricoid cartilage
Is a ring of hyaline cartilage that forms the inferior wall of the larynx
Arytenoid cartilages
Triangular pieces of mostly hyaline cartilage located at the posterior, superior border of the cricoid cartilage
Corniculate cartilage
Horn shaped pieces of elastic cartilages, located at apex of each arytenoid cartilage
Where do the cilia in the upper respiratory tract move mucous and trapped particles?
Down toward the pharynx; Cilia in the lower respiratory tract move them up towards the pharynx
Structures a voice production?
Vestibular folds (false vocal cords) superior pair
inferior pair vocal folds (true vocal cord)
Rima vestibuli - space between vestibular folds
Laryngeal ventricle - Lateral expansion of the middle portion of the laryngeal cavity inferior to the vestibular folds and superior to the vocal folds
What is the principal structure of voice production?
Vocal folds
What is pitch controlled by?
Tension on the vocal folds
What does sound originate from?
Vibration on the vocal folds
Trachea
Wind pipe
What are the layers of the trachea wall From deep to superficial?
- Mucosa
- Submucosa
- Hyaline cartilage
- Adventitia
Open part of each C-shaped cartilage ring faces posteriorly towards the open esophagus and is spanned by what?
Fibromuscular membrane
What are the transverse smooth muscle fibres called in the fibromuscular membrane?
Trachealis muscle
At the superior border of the fifth thoracic vertebrae the trachea divides into right and left what?
Right (main) primary bronchus, which goes into the right lung, More vertical shorter and wider than left more likely and aspirated object will lodge in the right
left (main) primary bronchus which goes into the left lung
Carina
An internal Ridge at the point where the trachea divides into right and left main bronchi
The main bronchi divide to form smaller bronchi called what?
Lobar (secondary) bronchi
The lobar bronchi continue to branch forming still smaller bronchi called what?
Segmental (tertiary) bronchi
What did the segmental bronchi further divide into?
Bronchioles
What do the bronchioles that continue to divide into even smaller tubes called?
Terminal bronchioles
What kind of cells to the terminal bronchioles contain?
Club (cara) cells
Columnar
Nonciliated cells interspersed among epithelial cells
Bronchial tree
Extensive branching from the trachea through the terminal bronchioles resembling an inverted tree
Structural changes as branching becomes more extensive in the bronchial tree?
- Mucous membrane in the bronchial tree changes from ciliated pseudostratified Columnar epithelium in the main bronchi, lobar bronchi, and segmental bronchi to Ciliated simple columnar epithelium with some goblet cells in larger bronchioles to mostly Ciliated simple cuboidal epithelium with no goblet cells in smaller bronchioles to mostly Nonciliated simple cuboidal epithelium in terminal bronchioles
- Plates of cartilage Gradually replace the incomplete rings of cartilage in main bronchi and finally disappear in the distal bronchioles
- Is the amount of cartilage decreases the amount of smooth muscle increases
Lungs
Paired cone shaped organs in the thoracic cavity
separated from each other by the heart and other structures of the mediastinum
Protected by a double layered serous membrane called the pleural membrane or pleura
Parietal pleura lines the wall of the thoracic cavity
Visceral pleura covers the lungs themselves
Pleural cavity is between the visceral and parietal pleura
Pleural fluid reduces friction between the membranes
Cardiac notch
A concavity on the left lung where the apex of the heart lies
Both lungs have what kind of fissure?
Oblique
What does the oblique Fissure separate in the left lung?
Superior and inferior lobes
The right lung contains an oblique and what other kind of fissure?
Horizontal fissure
How do you the fissures in the right lung separate the lung?
Superior oblique separates inferior love from the middle lobe which is bordered superiorly by the horizontal fissure
The right main bronchus gives rise to what three lobar bronchi?
Superior, middle, and inferior lobar bronchi
The left main bronchus gives rise to what bronchi?
Superior and inferior lobar bronchi
What is the portion of lung tissue that each segmental bronchus supplies called?
Bronchopulmonary segment
Alveolar sac
The terminal dilation of an alveolar duct
What are the two types of alveolar epithelial cells?
Type one alveolar (squamous pulmonary epithelial) cells - Simple squamous epithelial cells that form a nearly continuous lining of the alveolar walls and is the more numerous, main site of gas exchange
Type two alveolar cells/septal cells -
If you were a number and found between type one alveolar cells type 2 aveolar cells rounded or cuboidal epithelial cells with free surfaces containing microvilli secrete alveolar fluid which keeps the surface between the cells and the air moist
Surfactant
Included in the alveolar fluid and is a complex mixture of phospholipids and Lipo proteins
lowers the surface tension of alveolar fluid which reduces the tendency of alveoli to collapse
maintains patency
Alveolar macrophages
Dust cells
Removes fine dust and other other debris from alveolar spaces
Respiratory membrane
Formed by the alveolar and Capillery walls, extending from the alveolar airspace to blood plasma
What are the four layers of the respiratory membrane?
- A layer of type one and type two alveolar cells and associated alveolar macrophages that constitutes the alveolar walls
- An epithelial basement membrane underlining the alveolar wall
- A Capillary basement membrane that is often fused to the epithelial basement membrane
- The capillary endothelium
Where do the lungs receive blood from?
Pulmonary arteries and bronchial arteries
How does deoxygenated blood reach the lungs?
Passes through the pulmonary trunk which divides into a left pulmonary artery that enters the left and right pulmonary artery that enters the right lungs
How does oxygenated blood return to the heart from the lungs?
By one of the four pulmonary veins which drain into the left atrium
Ventilation perfusion coupling
Vasoconstriction in the lungs respond to hypoxia by diverting pulmonary blood from poorly ventilated areas of the lungs to well ventilated regions for more efficient gas exchange
in other body tissues hypoxia causes dilation of blood vessels to increase blood flow
Pulmonary ventilation
Otherwise known as breathing
The flow of air into and out of the lungs
Boyles law
The inverse relationship between volume and pressure
The pressure of a gas in a closed container is inversely proportional to the volume of the container
so if a closed container size is increased the pressure of the gas inside the container decreases, and if the size of the container is decreased then the pressure inside is increased
What is the most important muscle of inhalation?
The diaphragm
What is the second most important muscle of inhalation?
The external intercostals
Intrapleural pressure
The pressure within the pleural cavity
Aveolar (intrapulmonic) pressure
The pressure of air within the alveoli of the lungs
Elastic recoil
The natural tendency of the chest wall and lungs to spring back after they have been stretched
What are the two inwardly directed forces that contribute to elastic recoil?
- The recoil of elastic fibres that were stretched during inhalation
- The Inward pull of surface tension due to the film of intrapleural fluid between the visceral and parietal pleura
What are some factors that affect pulmonary ventilation?
- Surface tension of alveolar fluid
- Compliance of the lungs
- Airway resistance
Surface tension of alveolar fluid
A thin layer of alveolar fluid that coats the luminal surface of the alveoli and exert a force
Arises at all air water interfaces because the polar water molecules are more strongly attracted to each other than they are to the gas molecules in the air
Compliance of the lungs
How much effort is required to stretch the lungs and chest wall
Hi compliance means that the lungs and chest wall expand easily
What are the two principal factors that are related to compliance?
- Elasticity
- surface tension
Decreased compliance is a common feature in what pulmonary conditions?
- Scar lung tissue as seen in tuberculosis
- Cause lung tissue to become filled with fluid pulmonary edema
- Produce a deficiency in surfactant
- Impede lung expansion in anyway such as paralysis of the intercostal muscles
Airway resistance
Depends on both the pressure differences and the resistance
airflow equals the pressure difference between the alveoli and the atmosphere divided by the resistance
Eupnea
Normal pattern of quiet breathing
Can consist of shallow, deep or combined of shallow and deep breathing
Costal breathing
A pattern of shallow breathing
consisting of an upward and outward movement of the chest due to the contraction of the external intercostal muscles
Diaphragmatic breathing
A pattern of deep abdominal breathing
consisting of the outward movement of the abdomen due to the contraction and descent of the diaphragm
The different amounts of air can be classified into what two types?
- Lung volumes which can be measured directly by use of a spirometer
- Lungs capacities with your combinations of different lung volumes
Spirometer
The apparatus used to measure volumes and capacities of the lungs
inhalation is recorded as an upward deflection and exhalation is recorded as a downward deflection
Spirogram
The record from the spirometer
Tidal volume
The volume of one breath
Anatomic (respiratory) dead space
The conducting airways with air that does not undergo respiratory exchange
Inhaled air here cannot be used in gas exchange
Inspiratory reserve volume (IRV)
The additional inhaled air that is not used for gas exchange
Expiratory reserve volume (ERV)
The extra air during forced exhalation you were able to exhale
Forced expiratory volume in one second (FEV)
The volume of air that can be exhaled from the lungs in one second with maximal effort following a maximal inhalation
Residual volume (RV)
Cannot be measured by spirometry
The volume left in the lungs even after the expiratory reserve volume is exhaled
Minimal volume
The remaining air after the interplural pressure rises to equal the atmosphereic pressure and forces out some of the residual volume
This provides a medical illegal tool for determineing whether baby is born still born or died after birth, fetal lungs contain no air, so the lung of a stillborn baby will not float in water
Lung capacity’s
The combinations of specific lung volumes
Inspiratory capacity (IC)
The sum of tidal volume and inspiratory reserve volume
Functional residual capacity (FRC)
Some of residual volume and expiratory reserve volume
Vital capacity (VC)
Some of inspiratory reserve volume, tidal volume, and expiratory reserve volume
Total lung capacity (TLC)
The sum of vital capacity and residual volume
Minute ventilation (V)
Determines the amount of air that flows into and out of the lungs each minute
totals tidal volume multiplied by respiratory rate
Alveolar ventilation (VA)
Volume of air per minute that actually reaches the respiratory zone typically about 4200 mils per minute
Dalton’s law
Each gas in a mixture of gases exerted on a pressure as if no other gases were present
Partial pressure
The pressure of a specific gas in a mixture
Henry’s law
States that the quantity of a gas that will dissolve in a liquid is proportional to the partial pressure of the gas and it’s solubility
Decompression sickness (the bends)
When nitrogen comes out of a solution to quickly informs gas bubbles in the tissue
Can happen when a diver returns to the surface to quickly
Bubbles form in nervous tissue and can cause joint pain in the arms and legs, dizziness, shortness of breath, extreme fatigue, paralysis, and unconsciousness
External respiration
Pulmonary gas exchange is the diffusion of O2 from air in the alveoli of the lungs to blood in pulmonary capillaries and the diffusion of CO2 in the opposite direction
Converts deoxygenated blood coming from the right side of the heart into oxygenated blood that returns to the left side of the heart
Internal respiration or systemic gas exchange
As 02 leaves the bloodstream, oxygenated blood is converted into deoxygenated blood
unlike external respiration which occurs only in the lungs, internal respiration occurs in tissues throughout the body
The rate of pulmonary and systemic gas exchange depends on what several factors?
- Partial pressure differences of the gases
- surface area available for gas exchange
- diffusion distance
- molecular weight and solubility of gases
Common signs and symptoms of high altitude sickness?
Shortness of breath, headache, fatigue, insomnia, nausea, and dizziness - due to a lower level of oxygen in the blood
What percentage of oxygen in the blood is bound to hemoglobin?
98.5%
The relationship between hemoglobin and oxygen partial pressure
The factor that determines how much 02 binds to hemoglobin is the PO2 the higher the PO2, the more 02 can combine with hemoglobin
Fully saturated hemoglobin
When reduced hemoglobin is completely converted to oxyhemoglobin
Percent saturation of hemoglobin
The average saturation of hemoglobin with oxygen
What are other factors that affect affinity of hemoglobin for oxygen?
- Acidity (pH) - As acidity increases the affinity of haemoglobin for O2 decreases, An02 disociates more readily from haemoglobin. increasing acidity enhances the unloading of oxygen from hemoglobin
- Partial pressure of carbon dioxide - Increased PCO2 produces more acidic environment which helps release 02 from hemoglobin
- Temperature - Increase temperature increases the amount of O2 released from hemoglobin
- BPG - A substance called 2, 3-bisphosphoglycerate (BPG) , Decreases the affinity of hemoglobin for O2 which helps unload 02 from the hemoglobin
Bohr effect
When the pH decreases the entire oxygen haemoglobin dissociation curve shifts to the right
at any given PO2, HB is less saturated with O2
An increase in hydrogen in blood causes 02 to unload from haemoglobin and the binding of 02 to hemoglobin causes the unloading of hydrogen from hemoglobin
Oxygen affinity of fetal and adult hemoglobin
Fetal hemoglobin differs from adult hemoglobin in structure and in its affinity for O2 fetal hemoglobin has a higher affinity for O2 because it binds BPG less strongly
What are the three main forms of how CO2 is transported in the blood?
- Dissolve CO2 - Smallest percentage of 7% is dissolved in the blood plasma when it reaches the lungs it diffuses into the alveolar air and is exhaled
- Carbamino compounds - 23% combines with amino group of amino acids and proteins in blood to form carbamino compounds most of the CO2 transported in this manner is bound to hemoglobin
- Bicarbonate ions - Greatest percentage of 70% is transported in blood plasma is bicarbonate is CO2 diffuses into systemic capillaries and enters red blood cells it reacts with water in the presence of the enzyme carbonic anhydrase to form carbonic acid
Haldane effect
The lower the amount of oxyhemoglobin the higher the CO2 carrying capacity of the blood
What are the two principal areas of the respiratory center?
- The medullary respiratory centre in the medulla oblongata
- The Pontine respiratory group in the pons
Medullary respiratory centre
Made up of two collections of neurons called the dorsal respiratory group and the ventral respiratory group
Ventral respiratory group
Contains a cluster of neurons called the prebotzinger complex that is believed to be important in the generation of the rhythm of breathing
Pontine respiratory group
Collection of neurons in the pons plays a role in both inhalation and exhalation by modifying the basic rhythm of breathing generated by the VRG as when exercising, speaking, or sleeping
Chemo receptor regulation of breathing
Certain chemical stimuli modulate how quickly and how deeply we breathe
Central chemoreceptors - Located near the medulla oblongata in the central nervous system response to changes in hydrogen concentration or PCO2 or both in cerebrospinal fluid
Peripheral chemoreceptors - Located in the aortic bodies clusters of chemo receptors located in the wall of the arch of the Orida and in the carotid bodies
Hyperventilation
Rapid and deep breathing allows the inhalation of more 02 and exhalation of more CO2 until PCO2 and hydrogen are lowered to normal
