The Respiratory System 3 Flashcards
(38 cards)
describe INTERNAL RESPIRATION
- have CAPILLARY GAS EXCHANGE within the BODY’S TISSUES
- our PARTIAL PRESSURES and DIFFUSION GRADIENTS—are now REVERSED compared to EXTERNAL RESPIRATION
describe OXYGEN TRANSPORT
OXYGEN + HEMOGLOBIN:
- each Hb molecule has FOUR POLYPEPTIDE CHAINS—all containing a IRON-CONTAINING HEME GROUP
- each HB can transport FOUR OXYGEN MOLECULES
- OXYHEMOGLOBIN (HbO2):
- HEMOGLOBIN-O2 COMBINATION
- REDUCED HEMOGLOBIN (DEOXYHEMOGLOBIN) (HHb):
- hemoglobin that has released OXYGEN
definition of the HEMOGLOBIN OXYGEN DISSOCIATION CURVE
- DISSOCIATION CURVE:
- the RATE OF LOADING and UNLOADING of OXYGEN is REGULATED to ENSURE ADEQUATE OXYGEN DELIVERY TO CELLS
- the specific curve is S-SHAPED; the HEMOGLOBIN SATURATION PLOTTED AGAINST Po2 is NOT LINEAR
what are the VARIABLE FACTORS for the DISSOCATION CURVE?
- VARIABLE FACTORS (shifts CURVE TO RIGHT);
- Po2
- TEMPERATURE (increase)
- BLOOD pH (decrease)
- Pco2 (increase)
- DPG (increase)
describe the INFLUENCE of PO2 on HEMOGLOBIN SATURATION
- IN ARTERIAL BLOOD:
- Po2 - 100 mm Hg
- contains around 20 ml OXYGEN per 100 ml blood (20% volume)
- HEMOGLOBIN is 98% SATURATED
- IN VENOUS BLOOD:
- Po2 - 40 mm Hg
- contains around 15% volume of oxygen
- HEMOGLOBIN is 75% SATURATED
- VENOUS RESERVE:
- oxygen remaining in venous blood
what happens if our HEMOGLOBIN is LESS SATURATED?
- known as the BOHR EFFECT; begins to ENHANCE OXYGEN UNLOADING to where it is needed the MOST
definition of HYPOXIA
the INADEQUATE OXYGEN DELIVERY to the TISSUES; also known as CYANOSIS
describe CARBON DIOXIDE TRANSPORT
*CO2 transported into BLOOD in THREE FORMS:
- DISSOLVED IN PLASMA as PCO2 (7-10%)
- BOUND TO GLOBIN (part of HEMOGLOBIN) (20%) – CARAMINOHEMOGLOBIN
- TRANSPORT OF BICARBONATE IONS HCO3 in PLASMA (70%)
describe the TRANSPORT and EXCHANGE of Co2 + O2 in SYSTEMIC CAPILLARIES
- begins after HCO3 is created—begins to DIFFUSE from RBCS into PLASMA
- process is balanced through the CHLORIDE SHIFT;
- CL moves into RBCS from PLASMA as HCO3 OUTRUSHES
describe the TRANSPORT and EXCHANGE of CO2 + O2 in PULMONARY CAPILLARIES
- opposite processes happen
- HCO3 MOVES IN RBCS while CL MOVES OUT of RBCS back into the PLASMA
- HCO3 binds with another HYDROGEN to create H2CO3
- split by CARBONIC ANHYDRASE into CO2 and WATER
- CO2 diffuses into the ALVEOLI
definition of HALDANE EFFECT
- OXYGENATION of BLOOD WITHIN THE LUNGS — begins to DISPLACE CARBON DIOXIDE from HB (INCREASES REMOVAL OF CO2)
- also reduces affinity for carbon dioxide in oxygenated blood
- known as the BOHR EFFECT (oxygen dissociates from Hb due to more co2)
describe the CARBONIC-ACID-BICARBONATE BUFFER SYSTEM
- helps blood RESIST CHANGES in PH
- HCO3 acts as the ALKALINE RESERVE for the system
how can one ADJUST the CARBONIC-ACID-BICARBONATE BUFFER SYSTEM
- CHANGES IN RESPIRATORY RATE + DEPTH can affect BLOOD ph:
- SLOW SHALLOW BREATHING = INCREASE in CO2 in BLOOD = DROP in PH
- RAPID DEEP BREATHING = DECREASE in CO2 in BLOOD = RISE in PH
- CHANGES IN VENTILATION:
- helps in adjusting pH due to issues with metabolism
- BREATHING—super important for body’s ACID-BASE BALANCE
what are RESPIRATORY RHYTHMS regulated by (3)?
- HIGHER BRAIN RECEPTORS
- CHEMORECEPTORS
- OTHER REFLEXES
describe the NEURONAL MECHANISMS
control of respiration involving the NEURONS in the RETICULAR FORMATION of the MEDULLA + PONS
- MEDULLA RESPIRATORY CENTER (within the MEDULLA OBLONGATA)
-
PRG (PONTINE RESPIRATORY GROUP) (within the PONS)
- important for inhalation and exhalation while ACTIVE—ex. during exercise, sleeping, or talking
describe the MEDULLARY RESPIRATORY CENTERS
MRC:
- CLUSTERED NEURONS in the MEDULLA
describe the VENTRAL RESPIRATORY GROUP (VRG)
- responsible for MOTOR CONTROL of INSPIRATORY and EXPIRATORY MUSCLES during exercise
- has both inspiratory and expiratory neurons (excites the inspiratory and expiratory muscles — through the PHRENIC NERVE
- ex. the diaphragm
- controls around 12 - 16 breaths per minute
describe the BOTZINGER COMPLEX
- BOTZINGER COMPLEX:
- cluster of neurons—helps with GENERATION OF RHYTHM OF BREATHING
describe the DORSAL RESPIRATORY GROUP (DRG)
- responsible for GENERATION OF INSPIRATION
- network of neurons located near ROOT OF CRANIAL NERVE IX
describe the PONTINE RESPIRATORY CENTERS
- helps INFLUENCE and MODIFY ACTIVITY of VRG
- helps SMOOTH OUT TRANSITION between INSPIRATION and EXPIRATION
- helps TRANSMIT IMPULSES TO VRG—helps MODIFY and FINE-TUNE BREATHING RHYTHMS (VOCALIZATION, SLEEP, EXERCISE)
what are the factors that INFLEUNCE BREATHING RATE and DEPTH ?
- RESPIRATORY CENTERS:
- CHEMICAL FACTORS
- INFLUENCE OF HIGHER BRAIN CENTERS
- PULMONARY IRRITANT REFLEXES
- INFLATION REFLEX
describe the CHEMICAL FACTORS
- CHEMICAL FACTORS:
- the MOST IMPORTANT for affecting depth and rate of INSPIRATION—the arterial pressure of carbon dioxide
- changes the levels of PCO2, PO2, and pH
- brain changes breathing depth in order to INCREASE OUR PH due to INCREASED ARTERIAL PCO2 (this has decreased our pH in our brain)—back to homeostatic balance
where are the CHEMICAL and PERIPHERAL CHEMORECEPTORS FOUND?
- CHEMICAL CHEMORECEPTORS
- located throughout BRAIN STEM
- PERIPHERAL CHEMORECEPTORS
- aortic arch and carotid arteries
what happens if we have a RISE OF BLOOD PCO2 LEVELS?
- known as HYPERCAPNIA—carbon dioxide begins to accumulate and become CARBONIC ACID once joined with water
- this begins to RELEASE HYDROGEN IONS—DROPPING OUR PH (INCREASED ACIDITY—known as ACIDEMIA)
- this STIMLATES CENTRAL CHEMORECEPTORS (which works hand in hand with RESPIRATORY REG. CENTERS)
- this INCREASES DEPTH and RATE OF BREATHING in order to get shit back to normal 🙉
- this STIMLATES CENTRAL CHEMORECEPTORS (which works hand in hand with RESPIRATORY REG. CENTERS)