Ventilation and Circulation Flashcards
What are the two actions necessary for gas exchange to take place?
Respiration = gas exchange
Ventilation = moving air in and out of the lungs
What are the two types of afferent input that control the ventilation?
Afferent input (the signal) to the brain may be
- neural (passed to the brain by the nerves)
- humoral (the signal travels in the blood, i.e. co2 levels)
Ventricular relaxation immediately follows ________.
A) atrial depolarization
B) ventricular repolarization
C) ventricular depolarization
D) atrial repolarization
B) ventricular repolarization
The cardiovascular centers are located in which area of the brain?
A) medulla oblongata
B) pons
C) mesencephalon (midbrain)
D) cerebrum
A) medulla oblongata
Why do we have these two pleural layers?
What is the role of the sac?
The two layers create a sac around the lung: pleural sac filled with pleural fluid
Allows:
- Movement of the lungs in the rib cage
- Allows the lung to expand with very little friction
Pleural sac creates a pressure gradient around the lung
Define External Respiration
Delivery of O2 from the air to tissues
and removal of CO2 from tissues into the air
What causes expiration to stop at maximum expiration
Chest wall compliance reaches limit
What are the primary and accessory muscles responsible for inspiration?
Primary :
- Diaphragm
- External intercostals
Accessory :
- Scalenes
- Pecs (Major and minor)
- Lat dorsi
- Serratus anterior
- Trapezius
- Sternocleidomastoid
- Erector spinae
- Abdominals - critical muscles in inspiration!
4 components of the upper respiratory tract and the function of each component
- Nose and nasal cavity - warming, filtration, moistening of air 2. Oral cavity - warming, moistening of air 3. Pharynx (naso, oral, laryngo) - passageway/air conduction, filtration, prevention of food movement into trachea (epiglottis) 4. Larynx - passage way/air conduction, phonation (glottis)
The pressure difference between the intra-alveolar and intrapleural pressures is called ________.
A) atmospheric pressure
B) pulmonary pressure
C) negative pressure
D) transpulmonary pressure
D) transpulmonary pressure
Oxyhemoglobin forms by a chemical reaction between which of the following?
- A) hemoglobin and carbon dioxide
- B) carbonic anhydrase and carbon dioxide
- C) hemoglobin and oxygen
- D) carbonic anhydrase and oxygen
C) hemoglobin and oxygen
Describe the anatomy of the pleural membranes of the lung.
The lung is surrounded with 2 pleural membranes who form the pleural sac:
- Parietal pleura
- Visceral pleura
In between them is the pleural fluid/sac
Viscera: refers to organs
Parietal: the outer layer
Gas exchange that occurs at the level of the tissues is called ________.
- A) external respiration
- B) interpulmonary respiration
- C) internal respiration
- D) pulmonary ventilation
C) internal respiration
In a healthy young adult, what happens to cardiac output when heart rate increases above 160 bpm?
- A) It increases.
- B) It decreases.
- C) It remains constant.
- D) There is no way to predict.
B) It decreases.
Role of surfactant ?
Improve lung compliance.
Why does air move into the alveoli during inspiration
Slight negative alveolar pressure
In which septum is it normal to find openings in the adult?
- A) interatrial septum
- B) interventricular septum
- C) atrioventricular septum
- D) all of the above
C) atrioventricular septum
What is the alveolar wall structure?
Capillaries in the alveolar wall
Black dots = red blood cells that are carried in the capillaries = capillary networks in between alveoli
The ________ circulation picks up oxygen for cellular use and drops off carbon dioxide for removal from the body.
- A) pulmonary
- B) interlobular
- C) respiratory
- D) bronchial
C) respiratory
Which view of the bony thorax is this?
Posterior view
What is a haemothorax of the pleural space.
Why can this be a problem?
Haemothorax : fluid in the pleural space
Tends to be at the bottom of the pleural space
Impairs gas exchange because it is compressing the lung so it may make your alveoli much smaller and it may cause them to collapse
What is the function of internal intercostal muscles?
Bring ribs down during forced expiration, decreasing the thoracic capacity
Which view of the bony thorax is this?
Anterior view
What do the fibroblasts do? What is IPF?
Fibroblast = it produces new cells which are support cells that act as a fibrous structure
IPF = Idiopathic pulmonary fibrosis (IPF) causes scar tissue to grow inside your lungs. Usually, when you breathe in, oxygen moves through tiny air sacs in your lungs into your bloodstream. From there, it travels to organs in your body
What affects the central chemoreceptors, and why can’t hydrogens ions do that?
Hydrogen ion = H+ , the red block = does not pass through the cerebrospinal fluid.
It is the PaCO2 that is increased and that affects the central chemoreceptors
Where are situated the main pacemaker groups for breathing? Name both of them and what their role is.
Main pacemaker groups are in the medulla of the brain.
Two groups of cells: dorsal respiratory group, and ventral respiratory group.
Cells here have a role for inspiration, it sets the rhythm of your breathing
One is about inspiration (dorsal), but the other one is about inspiration AND expiration (ventral)
Hypocapnia
Low arterial CO2 (Low PaCO2)
Dyspnea
Difficulty breathing or the sensation of difficulty breathing
Name 2 fibrous contributors to lung elasticity
Collagen and elastin fibers
How is surface tension contributory to compliance/lung elasticity
Decreases lung compliance.
Which of the following factors play a role in the oxygen-hemoglobin saturation/dissociation curve?
- A) temperature
- B) pH
- C) BPG
- D) all of the above
D) all of the above
Which component of the heart conduction system would have the slowest rate of firing?
- A) atrioventricular node
- B) atrioventricular bundle
- C) bundle branches
- D) Purkinje fibers
D) Purkinje fibers
What are the roles of the bony thorax (rib cage)?
Role is to protect the lungs
It also protects the heart
Expansion of the rib cage allows the ventilation, change of pressures to get air into the lungs. The framework upon which the muscles work
Define compliance
the magnitude of change in lung volume as a result of change to pulmonary pressure
A decrease in volume leads to a(n) ________ pressure.
- A) decrease in
- B) equalization of
- C) increase in
- D) zero
C) increase in
What is the interstitium?
What happens when the lymphatic system doesn’t function properly?
Interstitium- a contiguous fluid-filled space existing between a structural barrier
Pink around the dark red blood cells : the interstitium, it is the fine tissue part of this very fine alveolar wall.
The lung becomes boggy when fluid isn’t taken up by the lymphatic system or because it changes the pressure in the vascular system: the fluid is being pushed out, into the lungs = makes it harder to breathe
Apnea
Suspension/cessation of breathing
What is the innervation of the diaphragm?
The Nerve supply to the diaphragm: phrenic nerve from C3, 4 and 5 = keep the diaphragm alive
What happens to preload when there is venous constriction in the veins?
- A) It increases.
- B) It decreases.
- C) It remains constant.
- D) There is no way to predict.
B) It decreases.
What is asthma? Describe its pathology.
Asthma = bronchoconstriction makes it harder to breathe = medication directed to relax the smooth muscles
asthma is an inflammatory disease = so it makes the airway smaller and the airway wall gets thick (inflammatory reaction)
Inflammation : bronchial wall, or airway smooth muscle
Part of external respiration. Inflow and outflow of air between the atmosphere and the lungs
What definition is this?
Pulmonary Ventilation
Which of the following occurs during the chloride shift?
- A) Chloride is removed from the erythrocyte.
- B) Chloride is exchanged for bicarbonate.
- C) Bicarbonate is removed from the erythrocyte.
- D) Bicarbonate is removed from the blood.
B) Chloride is exchanged for bicarbonate.
The cardiac cycle consists of a distinct relaxation and contraction phase. Which term is typically used to refer ventricular contraction while no blood is being ejected?
A) systole
B) diastole
C) quiescent
D) isovolumic contraction
D) isovolumic contraction
The force the heart must overcome to pump blood is known as ________.
- A) preload
- B) afterload
- C) cardiac output
- D) stroke volume
B) afterload
Name the2 cell types that compose the alveolar cell wall structure.
What are their roles and their distribution?
Pneumocyte type 1 cell = they are the most common (about 90% of the cells) = these give structure to the lung
Other 10% = type II pneumocytes = they make surfactant
Gas flow decreases as ________ increases.
- A) resistance
- B) pressure
- C) airway diameter
- D) friction
A) resistance
What are the muscles responsible for normal expiration?
Internal intercostals
Abdominals
Minute ventilation is equal to:
- A) FiO2 X PEEP
- B) FiO2/PEEP
- C) Tidal Volume X Respiratory Rate
- D) Tidal Volume/Respiratory Rate
C) Tidal Volume X Respiratory Rate
Define elasticity
Tendency to recoil
Which of the following processes does atmospheric pressure play a role in? A) pulmonary ventilation B) production of pulmonary surfactant C) resistance D) surface tension
A) pulmonary ventilation
What are the two rib cage actions during breathing? Be precise.
Two movements (actions) that have a 3D effect on increasing the volume:
Bucket handle: increase of the lateral diameter of the rib cage
Pump handle action: up and out.
The partial pressure of carbon dioxide is 45 mm Hg in the blood and 40 mm Hg in the alveoli. What happens to the carbon dioxide?
- A) It diffuses into the blood.
- B) It diffuses into the alveoli.
- C) The gradient is too small for carbon dioxide to diffuse.
- D) It decomposes into carbon and oxygen.
B) It diffuses into the alveoli.
What causes inspiration to stop at maximum inspiration
Lung and chest wall compliances reach limits
Gas moves from an area of ________ partial pressure to an area of ________ partial pressure.
- A) low; high
- B) low; low
- C) high; high
- D) high; low
D) high; low
What do the peripheral chemoreceptors do?
Peripheral chemoreceptors
aortic body receptors and carotid body receptors = they communicate through nerves to the respiratory system regarding chemical levels of the blood i.e. PaO2/PaCO2
Hypoxia
Poor O2 delivery/oxygenation of the tissues
What are the main functions of the upper respiratory system? What is the hilum?
- Warms the air that we breathe
- Filters out dirt
Hilum (at the start of the main bronchi): where the blood vessels, nerve supply and the lymphatics all enter the lungs
Name one difference between the pulmonary and systemic circulation. Why is that?
Lower blood pressure in the pulmonary vascular system
Pulmonary: 4 mm Hg
Systemic: 60 mm Hg
This is to prevent damage to the lung, essentially to alveoli
The entire cardiac output from the right ventricle goes to the lung: into a relatively small space = pulmonary capillaries are fine, delicate structures that can’t tolerate a high pressure
On the left side of the heart, the entire cardiac output gets distributed into a much larger system, it goes into arms, legs, etc.
Why is lung compliance higher in patients with COPD?
Chronic immune response in patients with COPD results in destruction of alveolar walls (less collagen and elastin), increasing lung compliance in these patients
The myocardium would be the thickest in the ________.
- A) left atrium
- B) left ventricle
- C) right atrium
- D) right ventricle
B) Left Ventricle
The pleura that surrounds the lungs consists of two layers, the ________. A) visceral and parietal pleurae. B) mediastinum and parietal pleurae. C) visceral and mediastinum pleurae. D) none of the above
A) visceral and parietal pleurae.
What is the role of cilia? Can they be damaged? Give an example of when this happens. What is the significance of this damage?
Air = up over the goblet cells and ciliated epithelial cells
Cilia = help clear the lungs with their wavelike movements = the role of this is that they move particles and mucus of some sort … they will push the particles and mucus into a larger area so that we can be able to cough it out.
Eg: smoking = chronic lung disease: the epithelial cells change and the cilia may not beat properly or even disappear from the surface.. Also causing inflammation and infection
The implication is that the lungs won’t be able to move the mucus and obstructs the airways. It can generate a chronic inflammatory response.
Which portion of the ECG corresponds to repolarization of the atria? A) P wave B) QRS complex C) T wave D) none of the above: atrial repolarization is masked by ventricular depolarization
D) none of the above: atrial repolarization is masked by ventricular depolarization
Why do we have these alveoli? Why not just one big balloon?
More surface area for gas exchange = estimated to 70 square meters
What composes the hilum of the lung? Where is it located?
Pulmonary artery = it is the only artery in the body that carries deoxygenated blood
Veins = red: oxygenated blood
Veins = purple : deoxygenated blood
At rest, is intrapleural pressure positive or negative compared to atmospheric pressure
Negative
Increased ventilation that results in an increase in blood pH is called ________. A) hyperventilation B) hyperpnea C) acclimatization D) apnea
Answer: A) hyperventilation
What is the role of the lymphatic system? What is lymphoedema?
Lymphatics = it’s where fluid excess is picked up and re-enters the circulatory system (it drains the interstitial fluid)
The lymph system is part of your immune system, and it carries lymphocytes (it carries white blood cells but not red blood cells)
People with lymphoedema = refers to swelling that generally occurs in one of your arms or legs. Sometimes both arms or both legs swell. Lymphedema is most commonly caused by the removal of or damage to your lymph nodes as a part of cancer treatment.
Name and describe a possible dysfunction in the pleural space. Why can this be a problem?
Pneumothorax : tends to be at the top of the lungs
Sometimes air gets in the pleural space
Why is that a problem?: changes the pressure gradient = sometimes the lung collapses
Air from the outside atmosphere is positive so the lung will collapse
The air is actually compressing the lung and the lung can’t expand as much
This could be life-threatening
What muscles are involved in quiet breathing
Diaphragm - inspiration only. Expiration is passive
The first heart sound represents which portion of the cardiac cycle? A) atrial systole B) ventricular systole C) closing of the atrioventricular valves D) closing of the semilunar valves
C) closing of the atrioventricular valves
Which of the following structures separates the lung into lobes? A) mediastinum B) fissure C) root D) pleura
B) fissure
Hypoxemia
- Low arterial O2 (low PaO2)
Which of the following prevents the alveoli from collapsing? A) residual volume B) tidal volume C) expiratory reserve volume D) inspiratory reserve volume
A) residual volume
What muscles are involved in forced breathing
Inspiration: accessory neck muscles (scalenes, SCMs) Expiration: internal intercostal muscles, abdominal muscles
Transpulmonary pressure is the difference between…
Intrapleural (interstitial) pressure and intra-alveolar pressure
Epiglottis function and structure
`elevates and inverts during swallow to protect airway from food/foreign bodies cartilaginous, base anchored to thyroid cartilage, extends superiorly into laryngopharynx
When ventilation is not sufficient, which of the following occurs? A) The capillary constricts. B) The capillary dilates. C) The partial pressure of oxygen in the affected alveolus increases. D) The bronchioles dilate.
A) The capillary constricts.
What are three functions of the thorax/chest wall
Protection of vital structures (bony cage) Maintenance of posture Mechanical facilitation of breathing/respiration
What causes surface tension of alveoli?
Alveoli contain surfactant which creates surface tension from H2O interactions.
What causes pneumothorax
Air in pleural space leads to lost vacuum, there is no difference in transpulmonary pressure, so the lung collapses
Most blood enters the ventricle during ________. A) atrial systole B) atrial diastole C) ventricular systole D) isovolumic contraction
B) atrial diastole
What is the role of alveolar macrophages? A) to secrete pulmonary surfactant B) to secrete antimicrobial proteins C) to remove pathogens and debris D) to facilitate gas exchange
C) to remove pathogens and debris
A low partial pressure of oxygen promotes hemoglobin binding to carbon dioxide. This is an example of the ________. A) Haldane effect B) Bohr effect C) Dalton’s law D) Henry’s law
A) Haldane effect
What is the function of the external intercostal muscles and inter-cartilaginous portions of the internal intercostal muscles?
Elevate the ribs during inspiration, enlarging the rib cage.
Which of the following is unique to cardiac muscle cells? A) Only cardiac muscle contains a sarcoplasmic reticulum. B) Only cardiac muscle has gap junctions. C) Only cardiac muscle is capable of autorhythmicity D) Only cardiac muscle has a high concentration of mitochondria.
C) Only cardiac muscle is capable of autorhythmicity
What are some ways you can impair respiratory function, regarding the bony thorax?
- Rib fractures
- Scoliosis
- Through a birth defect or a growth defect, change in the bony rib cage shape.
- It may be following some trauma, like surgery.. Therefore the rib cage might not be able to expand.
- Neurological diseases
Contraction of the external intercostal muscles causes which of the following to occur? A) The diaphragm moves downward. B) The rib cage is compressed. C) The thoracic cavity volume decreases. D) The ribs and sternum move upward.
D) The ribs and sternum move upward.
Describe the macroanatomy of the lungs, and name the differences between the right and left lungs.
Main stem bronchi, left and right, right is a little straighter and wider than the left. If you accidentally inhale something in your lungs, chances are in goes in the right lung.
Notice the difference between the right and left lung:
Right lung: upper, middle and lower lobe
Left lung: large upper lobe, smaller lower lobe
Bronchioles and terminal bronchioles, they have alveoli attached to them : conducting airways : where there is gas exchange, in the periphery of the lung
What is the influence of the higher brain center and limbic system on the control of ventilation? Give some examples.
The higher brain center and limbic system influence the control of the ventilation.
Because of that we are able to control our ventilation.
When you hold your breath, when you’re emotional (scared, excited, anxious), it affects your breathing through the limbic (or emotional) system.
What kind of system is the pulmonary circulation?
a closed-loop system as part of the larger circulatory system
Hypercapnia
High arterial CO2 (High PaCO2)
How is O2 and Co2 transported to/from the tissues
Bound to Hb in blood
What is humoral control? Name the three different types of receptors, where they are situated and what is their mechanism of action.
HUMORAL CONTROL = signal travels through the blood (chemoreceptors can be peripheral or central)
Lung receptors:
- Stretch receptors
- Irritant receptors
- J receptors
Eg: they make you cough when a particle is detected
Irritant receptors :
- Tend to be found in the epithelium of small airways
- Stimulate by toxic particles in lungs
- Stimulate coughing and smooth muscle constriction
- Can also increase RR to limit toxic particles from the lung
Stretch receptors:
- Tend to be in smooth muscle
J receptors are in the interstitium beside the capillaries:
- They are sensitive to changes in capillary blood pressure
- They can cause shallow breathing
- They tend to cause coughing or more rapid respiratory rate
Five components of the lower respiratory tract
Trachea Mainstem bronchi (R and L) Secondary and Tertiary bronchi Bronchioles Alveoli
