Respiratory System Flashcards
What is the purpose of the Nasal Conchae?
warms/makes air moist to not damage the lungs as cold dry air is damaging to the lungs
How are the non-respiratory parts (bronchioles) supplied with blood?
Via the bronchiole artery arising from the aorta
How are the Respiratory parts supplied with blood?
Via the pulmonary artery
What nerve supplies the lungs
Vagus nerve CN10
How many lobes are on each lung and why?
Right = 3
Left = 2 because there heart is in the way meaning the left lobe is smaller and more compressed
3 Purposes of Bronchiole Tree
- lined with ciliated columnar epithelial’s which moisten/protect from pathogens
- be a pathway to the respiratory zone for air
- Cartilage towards the top to maintain airway opening (no Cartlidge at the bottom)
What is Dead Space?
vol of air filling conducting zone (30% of tidal volume)
What does the Conducting Zone Include?
All areas of the nose down to the bronchus
What does the Respiratory Zone Include? What’s it for?
All areas from the distal airways down to the alveoli. The place where gas exchange occurs between the alveoli and the capillaries
4 Different Control centres for Blood Pressure
Pons, Medulla, hypothalamus, Cerebrum
Control Centre: Pons
Pontine respiratory group (PRG) including pnuemtaxic and Apneustic
What does the pnuemtaxic and Apneustic parts of the brain control in breathing?
Pnuemotaxic = rate/pattern of breathing Apneustic = intensity of breathing
What are the parts of the medulla?
Dorsal Respiratory group (DRG) and Ventral Respiratory group (VRG)
What are the DRG and VRG responsible for?
DRG = inspiration
VRG = expiration
Why are signals send to the hypothalamus and Cerebrum parts of the brain?
Hypothalamus - sent here due to emotional change e.g. anxiety, fear, pain
Cerebrum - Part of the brain for Voluntary breathing e.g. swimming
What does the Central Chemoreceptor monitor/do. Where is it found?
monitors CO2, pH lvl’s and communicates with control centre via glossopharyngeal nerve CN9. Found in the brain stem.
What does Peripheral Chemoreceptors monitor/do? Where is it found?
monitors O2, CO2 and pH, communicates with control centre via Vagus nerve CN10. Found in aorta/______?
Mechanoreceptors (nose, lungs, GI tract) What do they do?
monitors pressure, registers when lungs are full/empty
Negative Feedback system of Blood Pressure in terms of CO2 conc
- Increase in CO2 conc detected by central chemoreceptors
- Changes to O2, CO2 and pH in blood detected by peripheral chemoreceptors
- The signals from the receptors are sent to the respective parts of the control centre which then send motor neurone impulses to the effectors to increase breathing rate, depth, intensity to remove CO2
- Opposite happens if CO2 conc is too low
What does Hyperventilation cause?
hypocapnia (very low CO2 lvl’s) as well as high blood pH. The lvl of O2 in the blood increases to 100% to due extra breathing
Hyperventilation during Panick Attacks
-Sometimes patients can pass out (but breathing will return to normal and will regain consciousness)
-Ca2+ and K+ deficiency (hypocalcaemia + hypokalaemia) caused by hypocapnia are responsible for the paraesthesia (pins and needles) in fingers
Deliberate and Therapeutic Hyperventilation
Deliberate Hyperventilation - technique used by many people/professions e.g., athletes/free divers
Therapeutic Hyperventilation is used in treatment of traumatic brain injury as it lowers ICP (intra-cranial-pressure)
C1-C3
Accessory Muscles
C3, C4, C5
Diaphragm - “C3 C4, C5 keep the diaphragm alive”
T1-T11
Intercostal Muscles
T6-L1
Abdominal Muscles
Process of Inspiration
- External intercostal muscles contract while internal relax
- Causing ribs to move up and outward
- Diaphragm contracts downwards
- Thorax vol increases, decreasing pressure
- Therefore, pressure outside is higher than inside so air forced in going from high conc to low conc down conc gradient
Process of Expiration
- Internal Intercostal muscles contract while external muscles relax
- Ribs move down and inwards
- Diaphragm relaxes moving upwards
- Causing volume of thorax to decrease, increasing pressure
- Atmospheric pressure now lower than internal pressure so air is forced out from high to low conc
What is Boyle’s Law?
pressure and vol are always inversely proportional at a given temperature
What is the Pleural Membrane?
A membranous sac surrounding the lungs to maintain negative pressure within its 2 layers. The pressure is slightly lower than atmospheric pressure so it’s there to protect the lungs from collapse
How is Negative Pressure maintained in the pleural sac?
1, Visceral Layer adhesion to elastic lung
2. Parietal layer adhesion to thoracic wall
3. Pleural fluid lubrication
Illness’ that disrupts pleural membrane
- infection/inflammation (pleurisy)
- Effusion (XS fluid)
- Pneumothorax
What is a pneumothorax?
When atmospheric air gets through the pleural membrane into the lungs and can’t escape. Pressure build and builds until lung collapses
How can a pneumothorax cause cardiac arrest?
If pressure is too great it can push onto the heart, reducing the space it can beat in causing cardiac arrest
What causes a pneumothorax?
Caused by, puncture, trauma, CPR, spontaneous
Definition of diffusion
Diffusion - the net movement of molecules from an area of high concentration to an area of low concentration down a concentration gradient
Gas Exchange in Alveoli
- O2 will diffuse from the alveoli into the capillaries down the concentration gradient
- Waste (not all) CO2 will then diffuse from the capillaries into the alveoli down the concertation gradient
Haemoglobin is a _______ protein that carries __ O2 molecules
Some O2 carried in _______ but a lot less so
Hb has ___________ (red blood cells)
O2 associates and dissociates to and from the Hb into blood plasma where it is delivered to the _________
globular, 4, plasma, erythrocytes, tissues
Tidal Volume
the amount of air inspired/expired during normal breathing
Total Lung Volume
the total vol of air in which would completely fill the lungs
Vital Capacity
inspiratory/expiratory. How much you breath in/out (what you think is full/empty)
Functional Residual Capacity
how much air is still in your lungs after normal exhalation
Inspiratory Capacity
how much air you can breathe in after normal exhalation
Inspiratory Reserve Volume
how much air you can still breath in after normal inhalation
Expiratory Reserve Volume
how much air you can still breath out (force out) after normal exhalation
Residual Volume
how much air is still in your lungs after you have forced out as much as you can
