The Respiratory System Cont. Flashcards
Quiet Breathing
occurs during resting conditions
Quiet Inhalation
- is an active process (used ATP/ energy to contract muscles)
- Diaphragm and external intercostals contract
Quiet Exhalation
- is a passive process (do not need to contract muscles. relax muscle, don’t need ATP)
- Diaphragm and external intercostals relax
Forced Breathing
occurs during exertion or controlled breathing
Forced Inhalation
- is an active process
- diaphragm, external intercostals contract
- Accessory muscles: Scalenes, Sternocleidomastoid, and Pectoralis Minor contract
Forced Exhalation
- is an active and passive process
- Diaphragm and External Intercostals relax
- Abdominal wall muscles contract
Factors Affecting Pulmonary Ventilation
- Alveolar Surface Tension- surfactant decreases surface tension
- Lung Compliance
- Airway Resistance
Lung Volumes + Capacities
- Tidal Volume (TV)- 500ml
- Minute Ventilation (MV)- 6000ml
- Anatomical dead space- 150ml
- Inspirational/ Inspiratory Reserve Volume (IRV)- 3100ml
- Expirational/ Expiratory Reserve Volume (ERV)- 1200ml
- Vital Capacity (VC)- 4800ml
- Total Lung Capacity (TLC)- 6000ml
- Residual Volume (RV)- 1200ml
Tidal Volume (TV)
500ml
-volume of one breath
Minute Ventilation (MV)
6000ml
-volume of air inhaled and exhaled per minute
Anatomical Dead Space
150ml
-volume of air remaining in conducting zone structures where gas exchange does not take place
Inspirational/Inspiratory Reserve Volume (IRV)
3100ml
-volume of air that can be forcefully inhaled over and above the tidal volume
Expirational/Expiratory Reserve Volume (ERV)
1200ml
-volume of air that can be forcefully exhaled over and above the tidal volume
Vital Capacity (VC)
4800ml
-total volume of exchangeable air
Total Lung Capacity (TLC)
6000ml
-total volume of air in lungs after maximal inspiration
Residual Volume (RV)
1200ml
-volume of air remaining in lungs after maximal expiration
External Respiration
exchange of O2 and CO2 between air in lungs and blood
-occurs across the respiratory membrane
Factors affecting External Respiration
- Structure of the respiratory membrane (thin, large surface area)
- Partial pressure gradients for O2 and CO2
- Gas Solubilities for O2 + CO2
Dalton’s Law of Partial Pressures
Partial pressure of a gas is directly proportional to the percentage of that gas in the mixture ex: PO2 in alveoli: 13.7% X 760 mmHg = 105 mmHg PCO2 in alveoli: 5.2% X 760 mmHg = 40mmHg
External Respiration for Alveoli, Pulmonary Capillary, and Arterial Blood
PO2: PCO2:
Alveoli- 105 mmHg 40 mmHg
Pulmonary Cap.- 40 mmHg 45 mmHg
Arterial Blood - 100 mmHg 40 mmHg
- O2 diffuses out of alveoli into pulmonary capillary; 105 - 40 mmHg
- CO2 diffuses out of pulmonary capillary into alveoli 45- 40 mmHg
Henry’s Law
when a mixture of gases is in contact with a liquid, each gas will dissolve in proportion to its partial pressure and solubility
Gas Solubilities
- N2 is almost insoluble in water
- O2 is slightly soluble in water
- CO2 is very soluble in water
Equal amounts of CO2 and O2 are exchanged across the respiratory membrane due to ____ and ____
- Partial pressure gradients
2. Solubilities
Internal Respiration
exchange of O2 and CO2 between blood and tissues
Internal Respiration of Tissue Capillary, Tissues, and Venous Blood
PO2 PCO2
Tissue Capillary 100 mmHg 40 mmHg
Tissues 40 mmHg 45 mmHg
Venous Blood 40 mmHg 45 mmHg
- O2 diffuses out of tissue capillary into tissues: 100 - 40 mmHg
- CO2 diffuses out of tissues into capillary: 45 - 40 mmHg
Transport of O2 by the blood
- 98.5% of O2 attached to hemoglobin in RBC’s
- 1.5% of O2 dissolved in plasma
Hemoglobin is 100% saturated when….
all 4 binding sites have O2 (Oxyhemoglobin)
-in arterial blood
Hemoglobin is partially saturated when…
1, 2 or 3 O2 bound to it
-Venous blood is 75% saturated during rest
Hemoglobin is 0% saturated when…..
no O2 is bound to it (Deoxyhemoglobin)
Binding of O2 to hemoglobin is _____ and ____
reversible and cooperative
binding of one O2 will help the next bind
Venous blood is what percent saturated at rest?
75%
Arterial Blood is what percent saturated?
100%
Factors Affecting rate of O2 binding to Hemoglobin
-PO2 (increase PO2, increase the rate, happens in lungs; Hemoglobin binds O2)
Increase these next factors, you decrease the pH: (happens in the tissues; hemoglobin releases/ unloads O2)
-H+ ion concentration (Bohr Effect)
-PCO2
-Temperature
-BPG
Transport of CO2 by the Blood
-7% CO2 dissolved in plasma
-23% CO2 bound to amino acids of hemoglobin (Carbaminohemoglobin)
-70% transported as bicarbonate ion in plasma
CO2 + H2O H2CO3 H+ + HCO3-1
(bicarbonate)
Haldane Effect
deoxyhemoglobin has a greater affinity for CO2
Control of Respiration (Pulmonary Ventilation- Breathing)
- Medullary Rhythmicity Area- sets normal breathing pattern
- Pons has:
a. Pneumotaxic area- speeds up breathing
b. Apneustic Area- slow, deeper breathing - Higher brain centers:
a. Cerebral Cortex- conscious control
b. Hypothalamus- emotions - Chemicals
1. PCO2
2. PO2
3. pH - Hering-Breuer reflex- prevents over inflation over lungs
What has the greatest effect on breathing?
PCO2
Control of Respiration: Medullary Rhythmicity Area
sets normal breathing pattern
Control of Respiration: Pons
Pons has:
a. Pneumotaxic Area- speeds up breathing
b. Apneustic Area- slow, deeper breathing
Control of Respiration: Higher Brain Centers
a. Cerebral Cortex- Conscious Control
b. Hypothalamus- Emotions
Control of Respiration: Chemicals
- PCO2
- PO2
- pH
Control of Respiration: Hering- Breuer Reflex
prevents over-inflation of the lungs
