Resp. Physiology & Exercise Flashcards
Breathing is controlled by what in the brain?
Apneustic + pneumotaxic areas
An FVC manoeuvre allows you to estimate the peak expiratory flow rate. We can traditionally do this by placing which two variables on the X and Y axes?
X - Time; Y - Volume
What comes under the structural anatomy of the lungs
Upper resp tract
Lower resp tract
What comes under the functional anatomy of the lungs
Conduction zone
Respiratory zone
What comes under the upper respiratory tract
Nose
Nasal cavity
Mouth
Pharynx
Larynx
What is Adams apple known as?
Laryngeal prominence
Is laryngeal prominence restricted to just males??
No
It’s just larger + more visible in males
What is the laryngeal prominence exactly?
Thyroid cartilage surrounding the larynx.
Function of the laryngeal prominence
Protects the front of the larynx
Why is the LEFT main bronchus slightly more lateral than the right?
To prevent choking
How many lobes are found in the RIGHT lung and what are they?
3
Upper, middle + lower lobes
How many lobes are found in the LEFT lung and what are they called?
2
Upper + lower lobes
What are some of the types of cells found in the alveoli?
Macrophages
Type 1 cell
Type 2 cell
Purpose of Type 1 cells
Form continuous lining surrounding alveoli
Main site of GE
Purpose of Type 2 cells
Contain microvilli which secrete alveolar fluid to ⬇️ tendency for the alveolus to collapse = SURFACTANT
Purpose of both Type 1 + Type 2 cells together
Aid in optimising cond for GE
Where can the respiratory control centres be found in the brain?
Pons Area
Medulla Rhythmicity Area
What comes under the Pons Area?
Apneustic centre/area
Pneumotaxic centre/area
What comes under the Medulla Rhythmicity Area?
Ventral Respiratory Group (VRG)
Dorsal Respiratory Group (DRG)
List the main nerves for breathing
Phrenic nerve
Intercostal nerve
Vagus nerve
Glossopharyngeal nerve
What root does the phrenic nerve have?
C3-C5 Root
What root does the intercostal nerve have?
T1-T11 Root
What root does the vagus nerve have?
X Root
What root does the glossopharyngeal nerve have?
IX root
What are the main receptors involved in breathing?
Chemoreceptors
Mechanoreceptors
Irritant receptors
Peripheral proprioceptors
What are the main muscles involved in breathing?
Accessory muscles
Diaphragm
Intercostal muscles
Abdominal muscles
Which muscle works the most in breathing?
Diaphragm - Takes about 75% of the work for breathing.
Equation for boyles law
P ∝ 1/V
Where is Elastin found?
In alveoli
What is elastin?
Structural proteins wrapped around the outside of the alveoli.
Overview of exhalation during exercise
Active process
Internal intercostals
External obliques
Rectus abdominus
Transverse abdominus
PONS
Purpose of the Apneustic area/centre
Prolongs + slows rate of breathing.
Stimulates the insp. neurones found in the DRG + VRG.
PONS
What can overstimulation of the apneustic area/centre cause?
Apneustic breathing = long gasping inspirations interrupted by occasional expirations.
PONS
Purpose of the pneumotaxic centre/area
Tune the transition of inhaling + exhaling.
⬆️ signals from here ⬆️ resp rate.
BUT –> Weak signals from here prolongs the insp rate + ⬆️ TV.
Also sends inhibitory signals to the insp centre of the medulla to control insp time.
PONS
What does a non-functioning pneumotaxic area/centre mean?
No smooth transition between inhaling + exhaling.
Where is the Medulla Rhythmicity Area found?
Medulla oblongata
What does the Medulla Rhythmicity Area control?
Basic rate of breathing
Medulla Rhythmicity Area
What does the DRG contain?
Mainly insp neurones located bilaterally w/in the medulla.
Medulla Rhythmicity Area
DRG
What do its insp neurones do?
Send impulses to motor nerves of diaphragm + external intercostal muscles.
Medulla Rhythmicity Area
Purpose of the DRG
Controls the basic rhythm of breathing by triggering insp impulses.
Which extends into which?
DRG + VRG
DRG extends into the VRG.
VRG does NOT extend into DRG.
Medulla Rhythmicity Area
What does the VRG contain?
BOTH insp + exp neurones.
Medulla Rhythmicity Area
When is the VRG primarily active?
During exercise + stress
Where do the vagus + glossopharyngeal nerves bring sensory impulses into the DRG from?
Lungs
Airways
Peripheral chemoreceptors
Joint proprioceptors
Medulla Rhythmicity Area
Where does the VRG send insp impulses to?
Laryngeal + pharyngeal muscles, diaphragm + external intercostals.
Medulla Rhythmicity Area
Where does the VRG send exp impulses to?
Abdominal + internal intercostal muscles.
Central chemoreceptors
Exercise ⬆️ CO2 prod.
H+ can’t pass across blood brain barrier into CSF.
– BUT –>
CO2 can diffuse across.
Once CO2 in CSF:
- Combines w/ H20 via carbonic anhydrase = Carbonic acid.
- Carbonic acid dissociates into bicarb + H+.
H+ in CSF is sensed by the central chemoreceptors which then send signals to the DRG + the pneumotaxic region.
Where are the peripheral chemoreceptors found?
Carotid body
Aortic body
What can glomus cells respond to?
⬆️ PCO2
⬇️ PO2
What do glomus cells have?
K+ channels so K+ leaks out of cell - NOT a problem.
What keeps the K+ channels open in the glomus cell?
O2
What happens with the glomus cell when there’s low O2 i.e due to exercise?
It’s K+ channels close = ⬆️ conc of K+ in cell.
= Membrane depolarises
Ca2+ channels open = Ca2+ enter cell.
Exocytosis of dopamine across + OUT of cell.
FVC (Force vital capacity) Manoeuvre
A deep inspiration then a forced expiration.
Maximum voluntary ventilation
Rapid deep breathing for 15 seconds
Problems with Maximum voluntary ventilation
Can make some very light headed
