A&P- Ch. 22: The Respiratory System; Chapter 17: Cardiovascular System-Blood
Describe the process of exhalation and the muscles involved.
- After full inhalation, external intercostals and diaphragm relax, allowing the thoracic cavity to return to its 'resting position'. This decreases the volume of the cavity which increases the pressure within the lungs forcing air out as it goes down its concentration gradient from high to low.
The simple squamous cells of what two structures create the gas exchange surface in respiration?
- Alveoli and endothelial lining of capillary
How is the oxygen-carrying capacity of blood affected by PCO2?
- An increase PCO2, , the curve shifts to the right which means hemoglobin will be less saturated with decreasing partial pressures of oxygen - as concentration of oxygen goes down, hemoglobin more readily releases its oxygen. - A decrease PCO2, the curve shifts to the left meaning hemoglobin remains saturated/bound at lower partial pressures of oxygen.
Which direction do arteries move blood? Veins?
- Arteries --> away from heart - Veins ---> toward the heart
What is the distribution of cartilage and smooth muscle in the bronchial tree?
- As you move down in the bronchial tree, further dividing, the cartilage begins to go away and smooth muscle increases
Even though O2 content might be substantially different between sea level and 6,000 ft of elevation, O2 saturation of Hb for people in those two locations is very close. Why?
- Because people that live at the higher elevation have produced more RBCs to maintain oxygen carrying capacity.
Describe the process of inhalation and the muscles involved.
- Begins when the external intercostals and diaphragm contract pulling the rib cage up and out and increasing the volume of the thoracic cavity. This then decreases the air pressure within the lungs causing air to move from the atmosphere to the lower air pressure within the bronchioles and alveoli.
Which enzyme assists in CO2 temporary conversion? Conversion to what?
- Carbonic anhydrase - Carbonic acid --> bicarbonate and H+ ions
Explain how bicarbonate is formed from water and carbon dioxide.
- Carbonic anhydrase in RBCs converts CO2 and water to carbonic acid which is unstable and will then convert to bicarbonate with H+ ions.
The three factors that influence pulmonary air flow (ventilation).
- Compliance - Resistance - Surface tension
Which cartilage forms the epiglottis and why is that an important structure/function relationship?
- Elastic cartilage allows it to stretch and be flexible when covering and uncovering the trachea
How much blood does an adult Female have?
- Females 4-5L * 8% of total body weight
Describe where and how gas (CO2 & O2) exchange takes place.
- Gas exchange in LUNGS occurs when air enters alveoli and PO2 is greater than the PO2 in the blood in capillaries surrounding alveoli, causing oxygen to move into blood. PCO2 in the capillary blood is higher than in the air of alveoli causing carbon dioxide to move out of the blood and into alveoli. - Gas exchange in TISSUES occurs when PO2 in capillary blood is higher than the PO2 of tissues, causing oxygen to move into the tissues. When PCO2 in blood is lower than PCO2 of tissues, carbon dioxide leaves tissues and moves into blood.
Describe the exchange of oxygen and carbon dioxide between the atmosphere.
- Higher concentration (as is seen with higher partial pressure) of oxygen is in the air in the alveolus compared to the concentration of oxygen in the blood of surrounding capillaries - so oxygen moves across the respiratory membrane from area of higher concentration to lower concentration. CO2 moves from blood into alveoli because there is a higher partial pressure (concentration) of CO2 in the blood than there is in the alveoli.
What structure keeps the trachea from collapsing during negative pressure breathing?
- Hyaline cartilage c-shaped rings
What does lower pH do to the O2 saturation curve? What about higher pH?
- Increased pH --> Left shift - Decreased pH --> Right shift
If you inhaled an irritant to the bronchioles, what would be the response?
- Inflammation of the bronchioles with bronchospasms in the smooth muscle. * Inflammation would result in increased mucus and other immune cells to help rid the body of the irritant
What are the inward forces that keep the alveolus inflated?
- Inward forces include the surfactant that separates water molecules to keep them from collapsing on themselves.
How does the Hering-Breuer reflex protect us?
- It prevents the lungs from over-inflating
Which two cartilage tissues make up the larynx?
- Larynx- Elastic (epiglottis) and hyaline
How much blood does an adult Male have?
- Males 5-6L * 8% of total body weight
What does the pons (pontine center) do to breathing?
- Modifies the VRG to smooth out the transition between inspiration and expiration
What are the three layers of the trachea? Which best transports mucous?
- Mucosa, submucosa, adventitia; Mucosa
What are the outward forces that keep the alveolus inflated?
- Outward forces include the pull of the lung tissue due to the pleural fluid adhering the visceral and parietal pleura together
Why does O2 move from alveoli to pulmonary capillaries?
- Partial pressure/ down concentration gradient * pressure exerted by a gas - alveolar and capillary walls are 1 cell thick- gas exchange surfaces are very thin
Describe the general components of blood as a connective tissue.
- Plasma (proteins, water, ions, nutrients, hormones, etc.); 55% - White blood cells and platelets; < 1% - RBCs - 45%
Name and give the function of the blood formed elements and the plasma proteins.
- Plasma proteins help transport lipid soluble (hydrophobic) molecules through the blood - RBCs - to carry oxygen - WBC * Neutrophils- (first responders) * Lymphocytes (activate immune system by generating T & B cells) * Monocytes (phagocytic & activates lymphocytes) * Eosinophils- (phagocytic & digests parasitic worms) * basophil (contain histamine, active during allergic reaction) - Platelets (clotting) - 45% of blood volume
Explain the purpose of pulmonary surfactant and how it relates to respiratory distress in premature babies.
- Pulmonary surfactant separates water molecules so that alveoli do not stick together, or collapse on themselves. Premature babies have not fully developed their lung tissue yet, including the ability of type II cells to produce surfactant. They are low on surfactant and having trouble getting enough oxygen because there isn't enough surface area in the alveoli to allow gas exchange to occur. Surfactant can be administered to their lungs until they develop their own.
Describe the mechanism by which you can vocalize and adjust volume and pitch
- Pushing air past the vocal folds in various opening and closing formations allows you to form speech/make sounds. - Adjusting the length and tension of the vocal cords changes the pitch. - Force with which air is pushed past vocal folds determines volume
What is the last type of bronchiole before entering an alveolar duct?
- Respiratory bronchiole
Name two changes which may occur after prolonged exposure to high altitude?
- Short-term: * increased respiratory rate & respiratory depth & increased heart rate - Long-term: * increased RBC count & possible larger lung volume
How might you influence blood pH with slow shallow breathing? Why?
- Slow shallow breathing is known as hypoventilation, allowing CO2 to build up in the blood. Since most CO2 is carried as bicarbonate, this results in an increase in H+ ions , or (low pH) acidic pH in the blood. - If you had been experiencing hyperventilation in which too much CO2 was exhaled, hypoventilation can restore homeostasis of blood pH. - On the other hand, if you are experiencing acidosis, you would begin to increase your respiratory rate to remove excess CO2 levels and bring the pH back up.
Describe how oxygen is transported in the bloodstream.
- Small amount dissolved in plasma; majority bound to hemoglobin within RBC
What are alveoli?
- Small lobes of tissue that allow gas exchange to occur across their endothelial lining and in/out of blood capillaries
Which tissue is most responsible for constriction and dilation in bronchioles?
- Smooth muscle
Describe how arterial PO2, PCO2, and pH influence ventilation
- The level of each of these will affect ventilation in that ventilation will change to bring the levels to homeostasis. * For instance, high PCO2 will be detected by chemoreceptors that will send a message to respiratory groups triggering an increase in ventilation to reduce PCO2. * This is true for PO2 and pH, but the ventilation increase or decrease depends on if the levels need to be increased or decreased.
What does the oxygen-hemoglobin disassociation curve tell us?
- The percentage of hemoglobin that is saturated with oxygen at a given partial pressure of oxygen.
Explain Boyle's Law
- The volume of a gas is inversely proportional to its pressure if the temperature and the number of particles are constant * Increase volume results in decreased pressure * Decreased volume results in increased pressure
What is the chloride shift?
- This is an influx of chloride into the RBCs when bicarbonate ions leave the RBCs. It is to maintain electrical neutrality of the RBCs.
Why does CO2 move from the blood to lungs just as well as O2 even though it has a much smaller partial pressure gradient?
- This is because of the different properties of O2 and CO2 - One of which is that CO2 is more soluble than O2 so the pressures are smaller. - Both gases still move based on the high to low partial pressures.
How is the oxygen-carrying capacity of blood affected by PO2?
- This relates to the oxygen-hemoglobin dissociation curve. When you increase the PO2, the saturation of hemoglobin increases as well.
Which brain center sets eupnea?
- Ventral respiratory group
Describe the exchange of oxygen and carbon dioxide between systemic capillaries and body tissue.
- When blood is traveling from the heart to the system and it reaches tissues, there is a higher partial pressure/concentration of oxygen and a lower partial pressure/concentration of CO2 in the blood than there is in the tissues. Because of this oxygen will move from high concentration to lower concentration and into the tissues, while CO2 will leave the tissues and enter the blood.
How is the oxygen-carrying capacity of blood affected by pH?
- When you increase pH (you are becoming more alkaline/basic (pH=7.5+) - therefore more OH- groups, or fewer H+) - When you decrease pH (pH < 7.0; more free floating H+ ions) acidic
How is the oxygen-carrying capacity of blood affected by temperature?
- With an increase in temperature, the curve shifts to the right which means hemoglobin will be less saturated with decreasing partial pressures of oxygen - as concentration of oxygen goes down, hemoglobin more readily releases its oxygen. - With a decrease in temperature, the curve shifts to the left meaning hemoglobin remains saturated/bound at lower partial pressures of oxygen.
How does surface tension influence lung expansion?
- With surfactant, water molecules can be separated enough to allow alveoli to expand and have circular shape. This allows volume in alveoli to change with thoracic cavity expansion and relaxation. - decreased surface tension in airways reduces the amount of energy required to expand the lungs
Asthma
- coughing, bronchiospasms, inflammation, wheezing, chest tightness;
tuberculosis
- due to bacterial infection, fever, cough, spitting up blood
vestibular folds
- false vocal cords which aid in protecting tracheal opening and help with speech.
epiglottis
- folds over the tracheal opening during swallowing to prevent food from entering the trachea.
adenoids
- house immune system cells to help fight infections
conducting zone
- is all of the structures listed above (nose and its adjacent structures, pharynx, larynx, trachea, bronchi) that are involved in moving air toward/away from the smallest bronchioles and alveolar ducts.
forced expiration
- is an active process because you use internal intercostals and diaphragm to push that thoracic cavity in word, making it smaller and thereby increase pressure. Increased pressure causes air to move out of the lungs.
expiration
- is passive; relaxation of the muscles used to inhale (external intercostals & diaphragm)
external respiration
- is the exchange of gases between air in alveoli and blood in pulmonary capillaries.
internal respiration
- is the exchange of gases between blood in capillaries and tissues.
pulmonary circulation
- is the movement of blood from heart to lungs and back to heart for oxygenation of blood.
systemic circulation
- is the movement of blood from heart to the rest of the body and back to heart again.
cellular respiration
- is the use of electron transport chain to make ATP.
respiratory zone
- is within the lungs where gas exchange can occur (respiratory bronchioles, alveolar ducts, and alveoli)
parietal pleura
- lines inside of thoracic cavity
visceral pleura
- lines outside of lung tissue
emphysema (COPD)
- loss of smaller, lose surface area for gas exchange, difficult and labored breathing, coughing
cancer
- lung tissue destroyed, coughing and difficulty breathing
ventilation
- movement of air
intrapleural pressure
- pressure between the visceral and parietal pleura
Partial pressure
- pressure exerted by a gas
Atmospheric pressure
- pressure of gasses in the atmosphere
Intapulmonary Pressure
- pressure within the lungs/alveoli
uvula
- prevents food from entering nasal cavity and produces saliva.
inspiration
- pulling air into the lungs (essentially same as inhalation)
expiration
- pushing air out of lungs (essentially same as exhalation)
Define surface tension.
- the attraction of water molecules to one another. This exists within the alveoli.
Mediastinum
- the cavity that holds the heart, pericardium, and thymus - it is essentially the cavity/area in between the lungs.
pleural cavity
- the space between the visceral and parietal pleuras filed with pleural fluid
vocal folds
- the true vocal cords which produce speech
Describe the overall functions of the respiratory system
-Ventilate air - Allow for gas exchange - Regulate pH - Enable smell/olfaction - Protects from foreign molecules - Voice production - Transport of gases
Describe the boundaries for each of the 3 parts of the pharynx
1) Nasopharynx - nasal cavity to uvula 2) Oropharynx - 3) Laryngopharynx - superior tip of epiglottis to division between epiglottis & trachea (around vestibular folds)
How is most CO2 transported in blood?
As bicarbonate ions
Which gas influences breathing most?
CO2
What components of erythrocytes allow them to transport oxygen and carbon dioxide?
Heme groups and iron
What happens during a pneumothorax?
Pneumothorax occurs when air gets between the visceral and parietal pleura and into the pleural cavity & can lead to lung collapse.
Which cells secrete surfactant?
Type II alveolar cells (simple cuboidal)
Name the organs (in order) and their basic functions included in the respiratory system:
Upper Respiratory Tract (all work to ventilate/move air in/out of lungs): 1) nares 2) nasal cavity 3) superior/medial/inferior nasal conchae (humidifies and warms air) 4) pharynx 5) larynx Lower Respiratory Tract: 1) trachea 2) bronchi 3) bronchioles 4) alveoli (gas exchange)
List in order from nose to alveoli the pathway for air entering the body
Upper Respiratory Tract: 1) nares 2) nasal cavity 3) nasal conchae (superior/medial/inferior) 4) pharynx 5) larynx Lower Respiratory Tract: 6) trachea 7) bronchi - (primary, secondary, tertiary) 8) respiratory bronchioles 9) alveolar ducts 10) alveolar sac 11) alveoli
inhalation
breathing in; inspiration
exhalation
breathing out; exhalation
erythropoiesis
formation of RBCs
hemopoiesis
formation of blood cells - red &white & platelets
erythropoietin
hormone from kidneys that triggers RBC production in red bone marrow
Nasopharynx
nasal cavity to uvula
Oropharynx
palatine tonsil to superior tip of the epiglottis
Once a hemocytoblast commits to the erythrocyte line, the cell is called a __________.
proerythroblast
hemoglobin
quaternary protein composed of heme group, globin protein and iron
Resistance
size of bronchioles decreases and medium size ones generate the most resistance; resistance is anything that decreases air flow through the 'tube'
Laryngopharynx
superior tip of epiglottis to division between epiglottis & trachea (around vestibular folds)
Compliance
the ability for the lungs to expand and recoil, continue movement
Surface tension
the surface tension within the alveoli
What is the importance of carbonic anhydrase?
Converts CO2 and water to carbonic acid and bicarbonate ions
Life Cycle of Erythrocytes (RBCs)
Erythropoiesis: Hemocytoblast differentiates into proerythroblast and undergoes ribosome synthesis, hemoglobin accumulation and near the end, nucleus ejected and become reticulocyte and leaves bone marrow. Matures and become erythrocyte in circulation.