AnP Chapter 18 (LO5) Flashcards
The respiratory and cardiovascular systems work closely together to provide the body with…
oxygen and remove carbon dioxide
Respiratory system 3 roles
Influences sound production in speech
Makes sense of smell and makes taste possible
Helps the body maintain homeostasis through a regulation of acid base balance
respiratory two tracts
upper respiratory
lower respiratory
The upper respiratory tract 3 purposes
warm and humidify inspired air
responsible for senses of smell and taste
swallowing food
The upper respiratory tract consists of
above the larynx
nose and nasal cavities
pharynx
larynx
Functionally the respiratory system also includes
the oral cavity
rib cage
respiratory muscles
nose and nasal cavities function in respiratory system
air enters and leaves the respiratory system through the nose
nose and nasal cavity: cilia
filter out dust and largen foreign particles
nose and nasal cavity: palate
bony structure that separates the nasal cavity from the mouth
nose and nasal cavity: septum
a vertical plate of bone and cartilage that separates the cavity into two halves
nose and nasal cavity: conchae and turbinates
bones create narrow passages ensuring that most air contacts and mucous membranes on the way through
sphenoid sinus and paranasal sinuses purpose
drain mucous into the nasal cavity
Pharynx
tube aka throat
Located posterior to oral cavity - extends from the soft palate to the hyoid bone
3 sections of the pharynx
nasopharynx
Oropharynx
Laryngopharynx
nasopharynx:
extends from the posterior nares to the soft palate
Oropharynx
the space between the soft palate and the base of the tongue
what does the oropharynx consist of
Palatine tonsils
lingual tonsils found at the base of the tongue
Laryngopharynx
passes dorsal to the laryngopharynx to the oesophagus
what passes through nasopharynx, oropharynx and laryngopharynx
Only air through nasopharynx
Food and air through oropharynx and laryngopharynx
Larynx
Chamber formed by the walls of cartilage and muscle; often called the voice box
connects the pharynx and trachea
3 functions of larynx
It prevents food and liquids from entering the trachea
acts as an air passage between the pharynx and trachea
Produce sound
what is the larynx formed of
9 pieces of cartilage
Epiglottis:
closes over the top of the larynx during swallowing to direct food and liquids into the esophagus
Thyroid cartilage
is the largest piece of cartilage known as the Adam’s Apple
Vestibular folds:
superior pair of folds
No role in speech
They close the glottis during swallowing
Vocal cords
produces sound when air passes over them during exhalation
Glottis
the opening between the vocal cords
what does the larynx contain
epiglottis thyroid cartilage vestibular folds vocal cords glottis
what are Conduction and Respiratory Zones
The respiratory tract can be divided into conduction and respiratory zones.
The conduction zone includes:
Nose Pharynx Larynx Trachea Bronchi Terminal bronchioles
The respiratory zone includes:
Respiratory bronchioles
Alveolar ducts
Alveoli
conduction system
is a series of pipes that carry air to the alveoli where gas exchange takes place
5 Functions of the Nose
- Airway for respiration
- moistens and warms air
- filters and cleans air
- smell
- speech
Olfactory cells
located in the upper part of the nasal chamber detect odors and transmit impulses to the brain
Paranasal Sinuses
air-filled cavities that connect to the nasal cavity.
They are lined with ciliated epithelial cells and mucus-producing goblet cells.
goblet cells
mucus producing cells
functions of paranasal sinuses
Lighten the skull
Resonance chambers
Warm and moisten air
Four Sinuses:
Frontal
Maxillary
Sphenoidal
Ethmoidal
pseudostratified ciliated columnar epithelial cells
the epithelial lining of the respiratory region of the nasal cavity
This lining produces mucus which helps with filtering and humidifying the air we breathe
what does the lower respiratory tract consist of
Consists of the trachea, bronchi, and lungs
where does gas exchange occur
Gas exchange occurs deep within the lungs
what do The trachea and bronchi distribute
air to the interior of the lungs
Trachea
windpipe
Lies just in front of the esophagus
divides into right and left bronchi
4.5 inches long and 1 inch wide
Lined with ciliated pseudostratified columnar epithelial cells and goblet cells
C shaped rings of cartilage encircle the trachea to reinforce it and keep it from collapsing
Bronchial tree consists of
primary branch secondary bronchi tertiary bronchi bronchioles alveolar ducts alvelar sacs
Primary bronchi
are supported by C shaped rings of cartilage
Primary bronchi branch into secondary bronchi
Secondary bronchi
one for each lungs lobe
Secondary branch into tertiary bronchi
Tertiary bronchi
18
irregular cartilaginous rings disappear
Tertiary bronchi branch to bronchioles
Lined by pseudostratified ciliated columnar epithelium
terminal Bronchioles
less than 1 mm wide
No cartilage
lined by nonciliated simple columnar epithelium
bronchial tree ends
Bronchioles branch into respiratory bronchioles
Alveolar ducts:
thin walled passages
Respiratory bronchioles divide to form
lead into alveolar sacs and finally alveoli
Alveolar sacs
clusters of alveoli, primary structures for gas exchange
Alveoli
within the alveoli that gas change occurs
composed of two types of epithelial cells) with elastic tissue
separated from one another by a thin layer of tissue
Deoxygenated blood flows into alveoli through
Oxygenated blood leaves Alveoli via
pulmonary arterioles
pulmonary venules
what encases each alveolus
a massive pulmonary capillary
what happens once Once alveoli are filled with oxygen
crosses the respiratory membrane and moves into red blood cells
Hilum
opening on the lungs medial surface where are the primary bronchi and pulmonary blood vessels enter each lung
Right lung
Shorter broader and larger than left
Has three lobes the superior, middle, and inferior
Handles 55% of the gas exchange
Contains two fissures: horizontal fissure and oblique fissure
Left lung
Only has two lobes the superior and inferior
Cardiac notch that accommodates the heart
Handle’s 45% of gas exchange
Contains one fissure: oblique fissure
Visceral pleura
a serous membrane that covers the surface of long
Parietal pleura
entire thoracic cavity
Pleural cavity
the space between the visceral and parietal pleurae
Fluid in the pleural cavity serves 2 purposes
Lubricates the pleural surfaces
Creates a pressure gradient that assists lung inflation
macrophage
(dust cell) – wanders around ingesting foreign material – “cleaning crew” of the lungs
pleural
enclose and protect lungs
where are the following in the lungs:
- base
- apex
- cardiac notch
Base - Concave inferior surface that rests on the diaphragm
Apex - Narrow superior tip of the lung, just behind the clavicle
Cardiac Notch - A concave impression in the medial aspect of the left lung which accommodates for the heart
mediastinum
a structure containing the heart, great vessels, esophagus, and trachea
define;
Pulmonary ventilation:
Inspiration:
Expiration:
Respiratory cycle:
Pulmonary ventilation: breathing
Inspiration: the repetitive process of inhaling
Expiration: the repetitive process of exhaling
Respiratory cycle: one inspiration and one expiration
Diaphragm
The main muscle responsible for pulmonary ventilation
Inspiration how it works
External intercostal: muscles pull the ribs upward and outward, widening the thoracic cavity
Internal intercostals: help elevate the ribs
Diaphragm: contracts, flattened, and drops, pressing the abdominal organs downward and enlarging the thoracic cavity
Air rushes into equalize pressure
expiration how it works
The intercostal muscles relax, pulling the ribs downward
The diaphragm relaxes bulging upward and pressing against the base of the lungs, reducing the size of the thoracic cavity
Air is pushed out of the lungs
Accessory muscles of respiration:
deep inspiration
Forced expiration
deep inspiration: muscles of the neck and the chest contract to help elevate the chest
Forced expiration: the rectus abdominis and external abdominal oblique’s contract to pull down the lower ribs and sternum as the internal intercostals pull the other ribs downward
This reduces chest size to expel air more rapidly
where are the respiratory centers responsible for automatic unconscious breathing
found in the medulla and pons
what muscles are used for breathing
skeletal muscles
The medulla contains two interconnected centers that control breathing:
Inspiratory center
Expiratory center
Inspiratory center
the primary respiratory center
it controls inspiration and indirectly expiration
how the inspiratory CENTER works
- The inspiratory center send impulses to the intercostal muscles
- The inspiratory muscles contract causing inhalation
- Nerve output then ceases abruptly causing inspiratory muscles to relax
- –The elastic recoil of the thoracic cage produces exhalation
The pons contain two centers that can influence basic breathing rhythm
apneustic center and Pneumotaxic center
apneustic center
stimulates the inspiratory center the inspiratory center to increase the length and depth of inspiration re to increase the length and depth of inspiration
Pneumotaxic center
inhibits both that apneustic center and the inspiratory center; this contributes to a normal breathing rhythm and prevents over inflation of the lungs
Expiratory center:
send impulses to the abdominal and other accessory muscles when more forceful exhalations are needed
————- allows you to voluntarily change your breathing rate or rhythm
cerebral cortex
Atmospheric pressure
the weight of the air around us
It drives respiration
inspiration
when pressure within the lungs drop lower than atmospheric pressure air flows from the area of higher pressure (outside the body) to an area of lower pressure (the lungs)
Active process
Expiration
when pressure within the lungs rises above atmospheric pressure air flows out of the lungs until two pressures equalize
Passive process
how inspiration works
- The intercostal muscles contract pulling the ribs up and out; the diaphragm contracts and moves downward.
- —–This enlarges the chest cavity in all directions - The lungs expand along with the chest because of the two layers of pleurae
- —Parietal pleurae is firmly attached to ribs
- —Visceral pleura covers the lungs
- —Intrapleural pressure: the potential space between the two pleurae maintains a pressure slightly less than atmospheric pressure (negative pressure)
- —–The visceral follows the parietal, pulling the lung with it - When the lungs expand, the volume of air in the lungs spreads throughout the enlarging space causing the intraplumonic pressure to drop
- —-intraplumonic pressure: pressure within the bronchi and alveoli
- —-When intraplumonic pressure drops lower than atmospheric pressure air flows down the pressure gradient into the lungs
Expiration
- The diaphragm and external intercostal muscles relax in the thoracic cage springs back to its original size
- The lungs are compressed by the thoracic cage
- Intrapulmonary pressure rises
- Air flows down the pressure gradient and out of the lungs
Boyles law
a given volume of gas will exert more pressure in a smaller space than it will in a larger space
decrease volume=increase pressure
increase volume=decrease pressure
Factors affecting airflow
Determined by resistance the greater the resistance the slower the flow
Factors that affect resistance
bronchioles, pulmonary compliance, and alveolar surface tension
Bronchodilation
an increase in diameter of a bronchiole
Triggered by Epinephrine and sympathetic nerves
Bronchoconstriction
a reduction in diameter of a bronchiole
Triggered by parasympathetic nerves as well as histamine, cold air and chemical irritants
Pulmonary compliance
Refers to the elasticity of lung tissue
Ventilation can’t occur unless the lungs and thorax can stretch and recoil
Some diseases such as tuberculosis or black lung disease cause scarring which makes the lungs stiffer
Alveolar Surface Tension
The inner surface of each alveoli is covered with a thin film of water causing the inside of the Alveolus to move toward each other creating a force that will collapse the alveoli
If alveoli collapse gas exchange can’t occur
Surfactant
a lipoprotein secreted by alveolar cells that disrupts the electrical attraction between water molecules
this lowers the surface tension and prevents alveolar collapse
Tidal volume
the amount of air inhaled and exhaled during the quiet breathing
Inspiratory reserve volume
the amount of air inhaled using maximum effort after normal inspiration
Expiratory reserve volume
the amount of air that can be exhaled after normal expiration using maximum effort
1300ml of air usually remain in lungs
Residual volume
the 1300 ML of air that remains in the lungs ensures that gas exchange continues even between breaths
Vital capacity
the amount of air that can be inhaled and exhaled with the deepest possible breath
The tidal volume combined with the inspiratory and expiratory reserve volumes
Total lung capacity
the maximum amount of air that the lungs can contain
the maximum amount of air that the lungs can contain
Anatomical dead space
the 150 mL of air that remains in the conducting airways instead of the alveoli
why do variations in breathing occur
because of respiratory centres receive input from a number of sensory receptors throughout the body alerting it to the bodies changing needs
what is the primary regulator of respiration
Carbon dioxide because it can easily cross the blood brain barrier
influencers on breathing: oxygen
sensory receptor?
action?
Peripheral chemoreceptors (located in the carotid and aortic bodies)
Low blood levels of oxygen cause peripheral chemoreceptors to send impulses to the medulla to increase the rate and depth of respiration’s bringing more air and oxygen into the lungs
influencers on breathing: hydrogen ions
sensory receptor?
action?
Central chemoreceptors
(located in the brain stem)
—Central chemoreceptors monitor the pH of cerebrospinal fluid CSF which mirrors the level of carbon dioxide in the blood
—Falling pH levels indicate an excess of carbon dioxide
—When this occurs central chemoreceptors signal respiratory centres to increase the rate and depth of breathing allowing the body to blow off excess carbon dioxide raising the pH
influencers on breathing: stretch
sensory receptor?
action?
Receptors in the lungs and chest wall
—Hering-Breuer reflex: as the lungs insight during inspiration, receptors detect the stretching in signal the respiratory centres to exhale and inhibit inspiration
—Prevents lung damage from over inflation
influencers on breathing: pain/emotion
sensory receptor?
action?
Hypothalamus and limbic system
–These areas of the brain send signals that affect breathing in response to pain and emotions
influencers on breathing: irritants (smoking, dust, etc.)
sensory receptor?
action?
Nerve cells in the airway
–Nerve cells respond to irritant by signalling the respiratory muscles to contract, resulting in a cough or sneeze
–Coughing or sneezing propels air rapidly from the lungs helping to remove the offending substance
biot respirations
Abrupt, irregular breathing pattern in which periods of apnoea alternate with periods of breathing better consistent in rate and depth
often results from increase in cranial pressure
apnea
Temporary cessation of breathing
Bradypnea
Abnormally slow breathing
Cheyne- strokes respirations
Cyclical breathing pattern that begins with an increase in rate and depth of respirations followed by a gradual decreasing rate and depth of respirations culminating in a short period of apnea before repeating
Often seen in terminally ill or brain-damaged adults
Dyspnea
Laboured or difficult breathing
Eupnea
Relaxed, quiet breathing
Hypernea
Increased rate of breathing
Maybe Physiological or maybe Pathological
Hyperventilation
Increased rate of respirations resulting in lower blood levels of carbon dioxide
Often results from anxiety
Hypoventilation
Reduced rate and depth of respirations
Resulting in increase blood levels of carbon dioxide
Kussmaul respiration
Very deep, gasping respirations associated with diabetic ketoacidosis
Orthopnea
Laboured breathing that occurs when a person is lying flat but improves when standing or sitting up
a classic symptom of left ventricular heart failure
Tachypnea
Rapid breathing
Gas exchange
depends on differences in pressure
Goal of respiration is
the delivery of oxygen to organs and tissues and the removal of carbon dioxide
The air we breathe has a total atmospheric pressure of
760 MMHG
The atmosphere consist of –% nitrogen, –% oxygen, –% carbon dioxide, and about –% other gases
78% nitrogen, 21% oxygen, 0.03% carbon dioxide, and about 1% other gases
Partial pressure
the contribution of a single gas in any mixture of gases
Symbolized by the letter P followed by the formula for the gas
The partial pressure of oxygen and carbon dioxide vary between the air we breathe, the alveoli, arterial blood, and venous blood
Process of Gas Exchange
Inspired Air has a PO2 of 159 and a PC02 of 0.3
When it arrives at the alveoli, Air has a PO2 of 104 and a PC02 of 40
On the other side of the Alveoli’s thin membrane are pulmonary capillaries containing blood with a PO2 of 40 and a PCO2 of 46
The differences in partial pressures of O2 and CO2 on either side of the respiratory membrane cause O2 to move out of the alveoli and into the capillaries and CO2 to move out of the capillaries into the alveoli
Blood in the capillaries now has a PO2 of 100 and a PCO2 of 40
This oxygen enriched blood travels to the hearts left ventricle where it is pumped to the bodies tissues
Meanwhile cells in the bodies tissues have been using oxygen for energy production and producing CO2 as a byproduct
–The fluid surrounding the cells has a PO2 of 40 and a PCO2 of 46
When the blood from the left ventricle (PO2 of 100) arrives at the tissues (PO2 of 40) oxygen diffuses out of the blood and into the tissues
–Simultaneously carbon dioxide diffuses from the tissues (PCO2 of 46) and into the blood (PCO2 of 40)
Ventilation perfusion coupling
the ratio between the amount of air flowing into the alveolus (ventilation) and the flow of blood through the capillaries (perfusion)
If a portion of the lung has poor airflow oxygen levels in the blood vessels serving that area fall
In response pulmonary vessels in that area constrict
This redirect blood to better ventilation alveoli where blood cells can upload oxygen
If a portion of the lung has good airflow oxygen levels in the blood vessels rise
This causes pulmonary vessels in that area to dilate
In turn blood flow to the area increases providing more blood cells to take up the abundance of available oxygen
When systematic arteries experience a lack of oxygen
vessels dilate to allow more blood flows into the area
This occurs when available blood flow changes to allow blood cells to take up oxygen
Systematically this occurs when blood flow changes to allow the delivery of oxygen to areas that need it most
Factors affecting gas exchange: adequate airway
Potential disruption
A foreign body, tumour or obstruction can block the airflow in an airway
Certain diseases such as asthma chronic bronchitis Can narrow airways limiting airflow
Factors affecting gas exchange: adequate respiratory
Potential disruption
Anything that diminishes the respiratory rate less than the amount of oxygen entering the blood
Factors affecting gas exchange: adequate alveolar surface area
Potential disruption
Some disorders can cause the alveoli to fill with something other than air
Less Air in the alveoli means less oxygenation
Other disorders decrease the function surface area of the lungs making less area for gas stay fusion and blood oxygen levels decline
Factors affecting gas exchange: Pressure gradient between oxygen and alveolar air and oxygen in pulmonary blood
Potential disruption
At high altitudes the partial pressure of oxygen in inspired air is less then at sea level
As a result alveolar PO2 decreased and less oxygen enters the blood
Factors affecting gas exchange: Complaint lung tissue
Potential disruption
Certain lung disorders caused lung tissue to stiffen which impairs the ability of alveoli to expand and fill with air
Factors affecting gas exchange: Adequate blood supply
Potential disruption
Diminish supply blood to the alveoli means that fear blood cells are available to take up oxygen
how blood transports oxygen
Oxyhemoglobin: In the lungs oxygen forms a weak bond with the iron portion of hemoglobin
Oxyhemoglobin travels through the circulatory system to tissue cells
Once there is a difference in pH between the arterial and venous blood is enough to break the bond between the oxygen and hemoglobin
The oxygen is released to the tissues
Oxygen saturation
the number of oxygen molecules hemoglobin takes up
Varies depending on partial pressure of oxygen
Partial pressure of oxygen
Depending on the amount of oxygen dissolved in the surrounding fluid
how blood transports carbon dioxide
3 ways
- About 10% is dissolved in the plasma
- Another 20% is bound to hemoglobin forming carbaminohemoglobin
- —-Hemoglobin can transport both O2 and CO2 at the same time because they buy in two different sites on the hemoglobin molecule - The vast majority about 70% is carried in the form of bicarbonate ions (HCO3-)
- —when CO2 dissolved in plasma it reacts with water in the plasma to form carbonic acid
- –Carbonic acid that dissolves into bicarbonate and hydrogen ions
Hemoglobin has a strong affinity for ————– than it does for ————-
Hemoglobin has a strong affinity for carbon monoxide than it does for oxygen
