Respiratory Physiology (struc) Flashcards
WHY DO WE BREATHE?
WHY DO WE NEED OXYGEN?
The body’s metabolism require ? (recall biochemical pathways such as oxidative phosphorylation!)
An animal/organism needs a certain volume of air into the lungs, especially its ?, each minute → to supply oxygen demand
WHY DO WE BREATHE?
WHY DO WE NEED OXYGEN?
The body’s metabolism require oxygen (recall biochemical pathways such as oxidative phosphorylation!)
An animal/organism needs a certain volume of air into the lungs, especially its alveoli, each minute → to supply oxygen demand
TERMINOLOGY
EUPNEA: normal ? breathing (normal, good, healthy and unlabored breathing)
DYSPNEA: ? breathing
HYPERPNEA: increased or decresed? breathing depth, frequency or both (deeper breaths than usual, which increases the volume of
air in the lungs)
* This condition is often a response to an increase in ? demand when the body needs more ?, such as during exercise
POLYPNEA: ? shallow breathing (like ?)
* Like hyperpnea regarding frequency, but is unlike hyperpnea regarding ?
APNEA: ? of breathing (could be a transient state)
TACHYPNEA: a breathing rate that is ? than the normal breathing rate (could be physiologic or pathologic)
BRADYPNEA: abnormal slow or fast? breathing rate
The Respiratory System Transports O2 and CO2 Between the ? and the ?
TERMINOLOGY
EUPNEA: normal quiet breathing (normal, good, healthy and unlabored breathing)
DYSPNEA: difficult breathing
HYPERPNEA: increased breathing depth, frequency or both (deeper breaths than usual, which increases the volume of
air in the lungs)
* This condition is often a response to an increase in metabolic demand when the body needs more oxygen, such as during exercise
POLYPNEA: rapid shallow breathing (like panting)
* Like hyperpnea regarding frequency, but is unlike hyperpnea regarding depth
APNEA: cessation of breathing (could be a transient state)
(note: AP similar to ab meaning not/stop)
TACHYPNEA: a breathing rate that is higher than the normal breathing rate (could be physiologic or pathologic)
BRADYPNEA: abnormal slow breathing rate
The Respiratory System Transports O2 and CO2 Between the Environment and the Blood
The respiratory system provides ? to support tissue metabolism and ? the byproduct of metabolism → ? (cellular respiration)
O2 consumption and CO2 production vary with the ? ? and metabolic ?:
Basal metabolism
* the metabolism rate of the ? animal, is a function of metabolic body ? (body weight in 𝑀𝑀0.75)
Metabolic rate
* dependent on the animal’s level of ? and ? condition
* 𝑉 O2 max (maximal oxygen consumption) is directly related to the total mass of ? within the ? muscle
The respiratory system provides oxygen to support tissue metabolism and removes the byproduct of metabolism → Co2 (cellular respiration)
O2 consumption and CO2 production vary with the basal metabolic and metabolic rate:
Basal metabolism
* the metabolism rate of the resting animal, is a function of metabolic body weight (body weight in 𝑀𝑀0.75)
Metabolic rate
* dependent on the animal’s level of activity and physical condition
* 𝑉 O2 max (maximal oxygen consumption) is directly related to the total mass of mitochondria within the skeletal muscle
The respiratory system is also involved in:
? mechanism of the respiratory system (mucociliary system, cough, phagocytic cells)
? fluid exchange (production of ? and pleural fluid)
Metabolism and elimination of ? and ? substances i.e.:
→ ? and ? of hormones and toxins, biogenesis of platelets,
→ ?, redistribution and ? of drugs (e.g. propofol, inhalant anesthetics)
Protection against inhaled ?, ? gases, and ? agents
Communication (by sound and ?)
?
Facilitates urination, ?, and parturition
→ due to the increase in abdominal ? exerted by the active participation of the respiratory muscles
The respiratory system is also involved in:
defense mechanism of the respiratory system (mucociliary system, cough, phagocytic cells)
pulmonary fluid exchange (production of lymph and pleural fluid)
Metabolism and elimination of endogenous and exogenous substances i.e.:
→ removal and inactivation of hormones and toxins, biogenesis of platelets,
→ metabolism, redistribution and elimination of drugs (e.g. propofol, inhalant anesthetics)
Protection against inhaled dust, toxic gases, and infectious agents
Communication (by sound and pheromones)
thermoregulation
Facilitates urination, defecation, and parturition
→ due to the increase in abdominal pressure exerted by the active participation of the respiratory muscles
RESPIRATORY SYSTEM - STRUCTURE
CONDUCTING ZONE (Also known as the ? ? SPACE → gas exchange does not occur in these pathways) Conducting zone brings ? into and out of the ? zone for gas exchange
Includes: nasal cavity, ?, larynx, trachea, bronchi, bronchioles and ? bronchioles
Important to ?, warm and ? the air before it reaches the gas exchange area
The tracheobronchial tree (trachea and bronchi):
supported by ? (preventing them from ?)
contain ?-secreting and ? cells
filter small particles that enter the airways
→ swept upward or downward? by the rhythmic beating of the ?
The walls of the conducting airways contain
? muscle
?
* Sympathetic (? – ? of airways)
* Parasympathetic (Ach – ? of airways)
RESPIRATORY SYSTEM - STRUCTURE
CONDUCTING ZONE (Also known as the ANATOMIC DEAD SPACE → gas exchange does not occur in these pathways) Conducting zone brings air into and out of the respiratory zone for gas exchange
Includes: nasal cavity, nasopharynx, larynx, trachea, bronchi, bronchioles and terminal bronchioles
Important to humidify, warm and filter the air before it reaches the gas exchange area
The tracheobronchial tree (trachea and bronchi):
supported by cartilage (preventing them from closing)
contain mucus-secreting and ciliated cells
filter small particles that enter the airways
→ swept upward by the rhythmic beating of the cilia
The walls of the conducting airways contain
smooth muscle
innervation
* Sympathetic (epinephrine – dilation of airways)
* Parasympathetic (Ach – constriction of airways)
RESPIRATORY ZONE
Respiratory zone lined with alveoli where ? exchange occurs
Includes: respiratory ?, alveolar ? and alveolar ?
Respiratory bronchioles: ? structures, have cilia and ? muscle, ? occasionally bud off their walls
Alveolar ducts are completely lined with alveoli, contain no ? and little ? muscle
Alveolar sacs: lined with ?
Alveoli: thin or thick?? walled pouchlike evaginations of the walls of respiratory ?, alveolar ducts and sacs.
Large or small? surface area, covered by ? (gas exchange)
RESPIRATORY ZONE
Respiratory zone lined with alveoli where gas exchange occurs
Includes: respiratory bronchioles, alveolar ducts and alveolar sacs
Respiratory bronchioles: transitional structures, have cilia and smooth muscle, alveoli occasionally bud off their walls
Alveolar ducts are completely lined with alveoli, contain no cilia and little smooth muscle
Alveolar sacs: lined with alveoli
Alveoli: thin walled pouchlike evaginations of the walls of respiratory bronchioles, alveolar ducts and sacs.
Large surface area, covered by capillaries (gas exchange)
RESPIRATORY ZONE
Alveolar walls contain 2 types of epithelial cells (pneumonocytes) and macrophages:
Type I pneumonocyte: covers ?% of alveolar surface
Extremely thin, efficient ? exchange between alveolus and ? capillaries
Type II pneumonocyte: covers ?% of alveolar surface.
Synthesize pulmonary ? (reduce surface tension of ? and prevent it from collapsing)
Secrete ? (recruitment of inflammatory cells)
? capacity for type I and type II cells
Macrophages: ? line of defense against invading respiratory ?. Also remove inhaled particles from the ?
RESPIRATORY ZONE
Alveolar walls contain 2 types of epithelial cells (pneumonocytes) and macrophages:
Type I pneumonocyte: covers 95% of alveolar surface
Extremely thin, efficient gas exchange between alveolus and pulmonary capillaries
Type II pneumonocyte: covers 5% of alveolar surface.
Synthesize pulmonary surfactant (reduce surface tension of alveoli and prevent it from collapsing)
Secrete cytokines (recruitment of inflammatory cells)
regenerative capacity for type I and type II cells
Macrophages: first line of defense against invading respiratory pathogens. Also, remove inhaled particles from the alveolus
Respiration consists of 4 distinct processes:
- Pulmonary Ventilation
moving air into and out of the ?
? and ? muscles promote ventilation - Pulmonary gas exchange (alveoli-blood)
diffusion of gases from the ? to the blood of the ? capillaries - Gas transport
transport of oxygen and carbon dioxide from the ? to tissues - Peripheral gas exchange (blood ↔ tissue)
diffusion of gases from the blood of the ? capillaries to the cells
Respiration consists of 4 distinct processes:
- Pulmonary Ventilation
moving air into and out of the lungs
diaphragm and intercoastal muscles promote ventilation - Pulmonary gas exchange (alveoli-blood)
diffusion of gases from the alveoli to the blood of the pulmonary capillaries - Gas transport
transport of oxygen and carbon dioxide from the lungs to tissues - Peripheral gas exchange (blood ↔ tissue)
diffusion of gases from the blood of the systemic capillaries to the cells
Difference between breathing and respiration?
Types of respiration
1. external respiration = breathing
2. internal respiration = exchange of ?
3. cellular respiration = breakdown of food molecules in the cells; ? of biological fuels
PULMONARY VENTILATION
Pulmonary ventilation = breathing
Physical movement of air flowing into the lungs during ? and out of the lungs during ?
Depends on ? and ? changes in the thoracic cavity → air flows from areas of high pressure to areas of low pressure (so towards conc gradient)
requires ? energy and lung ?
Respiratory pressure is always described relative to ? pressure
Boyle’s law: P1V1 = P2V2; decreasing volume increases pressure
Difference between breathing and respiration?
Types of respiration
1. external respiration = breathing
2. internal respiration = exchange of gases
3. cellular respiration = breakdown of food molecules in the cells; oxidation of biological fuels
PULMONARY VENTILATION
Pulmonary ventilation = breathing
Physical movement of air flowing into the lungs during inhalation and out of the lungs during exhalation
Depends on volume and pressure changes in the thoracic cavity → air flows from areas of high pressure to areas of low pressure (so towards conc gradient)
requires muscular energy and lung elasticity
Respiratory pressure is always described relative to atmospheric pressure
Boyle’s law: P1V1 = P2V2; decreasing volume increases pressure
Respiratory cycle: begins with ? and ends with ?
INHALATION - requires ? contraction (muscular energy) of:
?
External ? muscles
? muscles attached to external nares, pharynx and ?
↑ Intrapulmonary volume ↓ Pressure (air inhaled)
- during inhalation, diaphragm moves up or down?
EXHALATION – relaxation of ? muscles
Normally ? at rest
Elastic energy stored in the stretched lungs and thorax causes them to increase or decrease? volume
Can be assisted during exercise and in some disease conditions (abdominal and intercostal muscles)
↓ Intrapulmonary volume ↑ ? (air exhaled)
Respiratory cycle: begins with inhalation and ends with exhalation
INHALATION - requires active contraction (muscular energy) of:
diaphragm
External intercostal muscles
abductor muscles attached to external nares, pharynx and larynx
↑ Intrapulmonary volume ↓ Pressure (air inhaled)
- during inhalation, diaphragm moves down
EXHALATION – relaxation of inspiratory muscles
Normally passive at rest
Elastic energy stored in the stretched lungs and thorax causes them to decrease volume
Can be assisted during exercise and in some disease conditions (abdominal and intercostal muscles)
↓ Intrapulmonary volume ↑ pressure (air exhaled)
PHYSICAL FACTORS INFLUENCING PULMONARY VENTILATION
- FRICTIONAL RESISTANCE
Is the major ? source of resistance to airflow
Flow = ΔP /R*
*ΔP = atmospheric pressure – alveolar pressure
R = resistance is determined primarily by the ? of the airways (resistance is proportional to 1/radius4) - ELASTICITY
Is how readily the lungs ? (recoil) after being stretched
Elasticity of ? tissue (mainly due to ?) causes lungs to return to its original shape after it has been stretched or compressed - COMPLIANCE
Is the ability to stretch, the ease with which lungs can be expanded due to change in transpulmonary pressure
Determined by 2 main factors:
a) ? of the lung tissue and surrounding thoracic cage
b) ? ? of the alveoli*
Alveoli and alveolus -> which one is singular and plural?
PHYSICAL FACTORS INFLUENCING PULMONARY VENTILATION
- FRICTIONAL RESISTANCE
Is the major nonelastic source of resistance to airflow
Flow = ΔP /R*
*ΔP = atmospheric pressure – alveolar pressure
R = resistance is determined primarily by the radius of the airways (resistance is proportional to 1/radius4) - ELASTICITY
Is how readily the lungs rebound (recoil) after being stretched
Elasticity of connective tissue (mainly due to elastin) causes lungs to return to its original shape after it has been stretched or compressed - COMPLIANCE
Is the ability to stretch, the ease with which lungs can be expanded due to change in transpulmonary pressure
Determined by 2 main factors:
a) distensibility of the lung tissue and surrounding thoracic cage
b) surface tension of the alveoli*
alveolus: singular
Alveoli: plural
*Surface Tension of the alveoli:
* Is the tension that results from the forces acting on the ? surfaces of the alveoli
(thin fluid layer between alveolar cells and the air)
* Acting to reduce the alveoli to the ? possible size
Surfactant: a ?-like complex secreted by Type I or II? pneumocytes, reduces ? tension and helps keep the alveoli from ?
LAPLACE’S LAW
For spherical alveoli, the pressure exerted by the surface tension increases as the radius of the alveolus goes down
alveoli without surfactant with smaller radius (volume) will have higher pressure
HOWEVER alveoli 1 and 2 both WITH surfactant will have EQUAL pressure even alveoli has a smaller radius
alveoli 1 will have less surface tension (more surfactant per area); 1 will inflate at a faster rate than 2 until equal in size.
*Surface Tension of the alveoli:
* Is the tension that results from the forces acting on the liquid surfaces of the alveoli
(thin fluid layer between alveolar cells and the air)
* Acting to reduce the alveoli to the smallest possible size
Surfactant: a detergent-like complex secreted by Type II pneumocytes, reduces surface tension and helps keep the alveoli from collapsing
LAPLACE’S LAW
For spherical alveoli, the pressure exerted by the surface tension increases as the radius of the alveolus goes down
alveoli without surfactant with smaller radius (volume) will have higher pressure
HOWEVER alveoli 1 and 2 both WITH surfactant will have EQUAL pressure even alveoli has a smaller radius
alveoli 1 will have less surface tension (more surfactant per area); 1 will inflate at a faster rate than 2 until equal in size.
The velocity of airway flow ? progressively from the trachea toward the bronchioles
- As a result of the ? pattern of the tracheobronchial tree, the TOTAL CROSS-SECTIONAL AREA increases or decreases? dramatically toward the ? of the lungs
FRICTIONAL RESISTANCE
Flow = Δ? /?*
- The high-velocity turbulent airflow in the ? and ? produces the lung sounds heard through a stethoscope in normal animals
- ? velocity flow in the bronchioles produces no sound
The velocity of airway flow diminishes progressively from the trachea toward the bronchioles
- As a result of the branching pattern of the tracheobronchial tree, the TOTAL CROSS-SECTIONAL AREA increases dramatically toward the periphery of the lungs
FRICTIONAL RESISTANCE
Flow = ΔP/R*
- The high-velocity turbulent airflow in the trachea and bronchi produces the lung sounds heard through a stethoscope in normal animals
- low velocity flow in the bronchioles produces no sound
The pulmonary circulation and the bronchial circulation
Pulmonary circulation → blood from the right ventricle → perfuses the ? capillaries (gas exchange)
Pulmonary ? carry deoxygenated blood from the right ventricle to the pulmonary ? (becomes oxygenated) → return to the left side of the heart in pulmonary ?
The bronchial circulation provides a ? blood supply to airways and other structures within the lung
Bronchial arteries carry ? blood and veins carry ? blood (does the opposite of pulmonary so pulmonary arteries carry deoxygenated blood thus bronchial arteries will do the opposite which is carrying oxygenated blood)
The pulmonary circulation and the bronchial circulation
Pulmonary circulation → blood from the right ventricle → perfuses the pulmonary capillaries (gas exchange)
Pulmonary arteries carry deoxygenated blood from the right ventricle to the pulmonary capillaries (becomes oxygenated) → return to the left side of the heart in pulmonary veins
The bronchial circulation provides a nutritional blood supply to airways and other structures within the lung
Bronchial arteries carry oxygenated blood and veins carry deoxygenated blood (does the opposite of pulmonary so pulmonary arteries carry deoxygenated blood thus bronchial arteries will do the opposite which is carrying oxygenated blood)
BLOOD FLOW THROUGH THE LUNGS
The Distribution of Pulmonary Blood Flow Within the Lung Differs Between Quadrupeds and Bipeds
Bipedal animals → pulmonary circulation is ?-dependent → so blood flow highest at the ? of the lungs and lowest at the ? of the lungs
Quadrupeds animals → blood flow distributed to the caudodorsal region of the lungs
* It is not determined by ? → the branching pattern of pulmonary ? and ? and the relative ? of each vessel are the major determinants of blood flow distribution
BLOOD FLOW THROUGH THE LUNGS
The Distribution of Pulmonary Blood Flow Within the Lung Differs Between Quadrupeds and Bipeds
Bipedal animals → pulmonary circulation is gravity-dependent → so blood flow highest at the bottom of the lungs and lowest at the top of the lungs
Quadrupeds animals → blood flow distributed to the caudodorsal region of the lungs
* It is not determined by gravity → the branching pattern of pulmonary arteries and arterioles and the relative resistances of each vessel are the major determinants of blood flow distribution
