Fichas
Gas Exchange V - Control of Gas Exchange
Fichas del conjunto (49)
- 1What do guard cells control?Air and water movement
- 2What do they open in response to?Open in direct response to K+ influx and turgor pressure
- 3What type of signalling is involved?localised single cell signalling
- 4What regulatory system do mammals have? What does it maintain?A neural network which controls and regulates breathing
Homeostasis - 5Name the components of this regulatory system and their roleBrain stem - central controller
Respiratory muscles - effector
Receptors - sensor - 6What are sensors?Specialised nerve endings
- 7What type of sensors are relevant to this system?Mechanical loading sensors and chemoreceptors
- 8What is the role of sensors?Relay information back to the brainstem
- 9What does this result in?An increase/decrease in minute ventilation pattern, so there's enough O2 influx and CO2 removal to meet metabolic needs
- 10Where do breathing patterns arise?In the medulla
- 11What happens to the breathing pattern when you damage the connection between the medulla and the pons?Pattern of breathing becomes more erratic as inspiratory phase slows down and expiratory phase accelerates
- 12What does this show?That the Pons is responsible for modulating the pattern and rhythm of tidal breathing
- 13How does the pons do this?By driving contraction/relaxation of respiratory muscles in a regular rhythmic way
- 14What sort of damage disables conscious control of breathing?Damage between the brain stem and the cerebral cortex
- 15What is the medulla respiratory centre?A rhythm/pattern generator
- 16How do nerves fire here?Action potentials are fired spontaneously
- 17What is the Pre-Bötzinger Complex?A complex showing the regular burst activity of nerve firing during inspiration
- 18What type of firing is this and what does it cause?Regular rhythmical firing that triggers contraction of the diaphragm
- 19What sort of complex shows the nerve firing of action potentials during pre-inspiration/expiration?A Retrotrapezoid nucleus/ parafacial respiratory group
- 20How do these two complexes work together?When one complex is silent, the other is firing action potentials, so there's 2 oscillations generating an on/off breathing pattern
- 21Summarise the involvement of nerves firing in inspiration (4)Firing of action potentials generates contraction
Causes an increase in the volume of the thorax
Causes changes in pressure and ventilation
Causes air to move into the lungs - 22Draw a diagram showing how the controller, sensor and effectors are all interlinkedCortex
Limbic system (emotion)
Hypothalamus (temperature)
Pneumotaxic centre
Apneustic centre
Sensory receptors
voluntary control
Medullary Respiratory Centre
Spinal cord
Respiratory muscles, diaphragm, intercostals - 23Describe in detail the process by which a regular breathing pattern is generatedM.R.C generates electrical activity which is
relayed down the spinal cord, to the diaphragm and intercostal muscles
PONS modulates rhythm + pattern of breathing
Limbic system and Hypothalamus can modify breathing pattern
These higher centres of the brain relay information via the pons to modulate and adjust the rhythm and patterns of breathing - 24Name 2 lung receptorsStretch receptors
Mechanical receptors - 25How do stretch receptors affect ventilation?Fire when lung is inflated, don't desensitise if inflation is maintained
Prevent over-inflation by modulating inspiration in Tidal Volume
Important in establishing normal breathing patterns, infant's first breath etc. - 26What receptors detect changes in the pulmonary system?Juxta-Pulmonary (J) Receptors
- 27What happens when these receptors are stimulated?Stimulation leads to shorter shallower breaths
- 28What receptors detect position/length?Proprioreceptors
- 29What are these receptors sensitive to and what is their function?Load and length of the muscle
Terminates respiratory phase - 30Name a pain receptorNociceptors
- 31What do chemoreceptors detect?Changes in blood chemistry in systemic arteriole blood
- 32How are the chemicals in blood detected?CO2 production is estimated from PCO2
O2 production is estimated from PO2
H+ production is estimated from pH - 33Which chemoreceptors are responsible for chemical detection in the brain?Central chemoreceptors
peripheral chemoreceptors - 34Where is the central chemoreceptor locatedIn the brainstem near the ventrolateral surface of the medulla
- 35How do CCRs detect changes in blood chemistry?Bathed in CSF and sensitive to changes in pH of CSF (index of PCO2)
- 36How do changes in pH occur in CSF?Charged particles can't cross the BBB
CO2 can freely
Reacts with H2O and dissociates into its ions - 37How is ventilation triggered by an increase in H+ in the CSF?H+ increase stimulates chemoreceptors to increase their firing
Increases ventilation - 38What is characteristic of these CCRs?Has a relatively slow response time
Indirectly sensitive
relatively insensitive to Po2 changes - 39Where are the peripheral chemoreceptors located?Near the carotid and aortic arteries
- 40Draw a diagram showing the neural connection between the brain and the heartBrainstem respiratory area
Carotid sinus nerve
Carotid bodies
Vagus nerve
Aortic bodies - 41Where are PCR nerve endings located?Nerve endings located in areas of high blood flow
- 42What are PCRs sensitive to?sensitive to changes in blood chemistry
Drop in O2% increases action firing - 43What is characteristic of PCRs?Rapid response
Directly sensitive (can detect oscillations in breathing)
Hypoxia, hypercapnia and H+ increase all have the same effect - 44Draw a shitty graph showing what happens when chmoreceptors detect an increase in CO2 partial pressureIncrease in PCO2 in inspired air
1 litre
Start
End - 45Draw another shitty graph showing the relationship between minute ventilation and arterial PO2 in response to hypoxia/hypercapniahigh pco2 line
normal pco2 line - 46How are pCO2 and pO2 interrelated?An increase in pCO2 and decrease in PO2 act synergistically
- 47What is the main drive to breathe?An increase in pCO2
- 48What is typical of organisms that can hold their breath for a long time?High myoglobin content in muscles
High RBC count/Hb concentration - 49Describe the cause and effects of the Diving reflex in mammals (5)Triggered by cold water to the face
Reduced heart rate
increased peripheral vasoconstriction
Latate accumulation in muscle
Energy conservation (Delayed increase in pCO2)
Información
- Descripción
- El usuario ha eliminado su información de asignaturas Fichas sobre Gas Exchange V - Control of Gas Exchange, creado por Usuario eliminado el 27/12/2017.
- Creado por
- Usuario eliminado · dic 2017
- Actualizado
- 27 dic 2017
- Visitas
- 18
- Historial
-
- Creado por J yadonknow · 23 dic 2017
- Copiado por J yadonknow · 27 dic 2017
- Valoración