RS Flashcards
What are the major accessory muscles involved in the respiratory pump?
Give their function
Sternocleidomastoid - active inspiration
Recuts abdominus - active expiration
Internal intercostals - active expiration
3 types of stretch receptors involved in respiratory sensation
Give their function
Slow adapting - changes in lung Volume
Rapidly adapting - detect pollutants/ irritants
Juxtapulmonary / J receptors
Dalton’s law
Ptotal = P1 + P2……
The total pressure of a gas mix is equal to the sun of the partial pressures of each component
Henry’s law
At a given temp, the amount of dissolved gas in a liquid is proportional to its partial pressure above the liquid.
Average total lung capacity
5.9L
What diseases can cause airways obstruction
COPD
Asthma
Bronchiectasis
What disease can cause airway restriction
Pulmonary fibrosis
Muscular failure
What is more reduced in airway obstruction
FEV1 is more reduced
Describe the parasympathetic effect on smooth muscle in the bronchioles
ACh binds to M3 receptors causing bronchoconstriction
Describe the sympathetic control of the smooth muscle in the bronchioles
Adrenaline/noradrenaline bind to B2 receptors causing bronchodilation
In foetal circulation where is pressure the highest
Right side of the heart due to pulmonary vasoconstriction
How does blood travel from the RA to LA
Through the Foramen ovale
What connects the umbilical vein to the IVC
Ductus venosus
What shunts blood from the PA into the aorta
Ductus arteriosus
What is the pre-botzinger complex
Pacemaker cells located in superior ventral respiratory group acting as a breathing rhythm generator
What are central chemoreceptors sensitive to
pCO2 change
Detected via [H+] in the CSF
What are peripheral chemoreceptors most sensitive to
pO2 change
What are the 2 groups found in the medullary centres
Give their function
Dorsal respiratory group - inspiration control
Ventral respiratory group - inspiration and forced expiration
What are the 2 groups found in the pontine centres
Give their functions
Apneustic centre - acts on the DRG (promotes inspiration)
Pneumotaxic centre - Off switch. inhibits apneustic enter
What effect would I rise in CO2 have on an oxygen dissociation curve
Would shift it to the right
What is the theory behind laplaces law
As alveoli get smaller at the end of expiration, surface tension increase
Surfactant is therefore require to prevent collapse
Mechanism of anaphylaxis
1st exposure:
IgE indirectly activated which presensitises mast cells
2nd exposure:
- antigen binds to IgE in blood
This complex then binds to a high affinity IgE receptors on mast cells
- mast cells degranulates and inflammatory mediators are released from the cell via exocytosis (trypsin)
How do the function differ in Th-1 vs Th-2
1 - kill pathogens
2 - stimulates B cell
What epithelium lines the opening of the nose
Keratinsed squamous epithelium with hairs to trap large particulates
What epithelium lines the region of the nose beyond the opening
Respiratory epithelium
Where is the olfactory centre located
in the roof of the nose below the cribriform plate
What neurons are found in the olfactory epithelium
Bipolar neurons
What epithelium lines the vocal cords
True - Non keratinising Stratified squamous epithelium
False - ciliated columnar
What are the ends of the C shaped rings of cartilage in the trachea joined by
Involuntary smooth muscle (trachealis muscle)
What epithelium lines the terminal and respiratory bronchioles
Simple cuboidal ciliated epithelium
What epithelium lines the alveoli
Simple squamous composed of thin type 1 pneumocytes and globular type 2 pneumocytes
What nerves supply the peripheral chemoreceptors
Glossopharyngeal
Vagus
What is the respiratory quotient
Ratio of the volume of CO2 produced to the volume of O2 used
How is physiological deadspace calculated
Anatomic + alveolar dead space
Where are central chemoreceptors located
Pontomedullary junction in brain stem
What are central chemoreceptors sensitive to
PaCO2 of blood perfuming brain
What is the response of peripheral chemoreceptors to hypoxia
Type I cells release stored neurotransmitters that stimulate the cup like ending of the carotid sinus nerve
Give the 3 components of the sternum
Sup to inf
Manubrium
Body
Xiphoid process
What costal cartilage does the sternal angle mark the level of
2nd
What fissure separates the superior and middle lobe of the right lung
Horizontal fissure
What surface of the lung is the hilum located on
Mediastinal
What structure make up the Hilum
Principal bronchus
Pulmonary artery
2 pulmonary veins
What type of pleura covers the lungs
Visceral
What pleura covers the internal surface of the thoracic cavity
Parietal
What is the space between the parietal and visceral known as pleura
Pleural cavity
What does the pleural cavity contain a small volume of
What is the function of this
Serous fluid
It lubricates the surfaces of the pleurae, allowing them to slide over each other.
The serous fluid also produces a surface tension, pulling the parietal and visceral pleura together. This ensures that when the thorax expands, the lung also expands, filling with air.
Nerve and blood supply to the parietal pleura
Phrenic and intercostal nerve
Intercostal arteries
Nerve and blood supply to visceral pleura
Autonomic innervation from pulmonary plexus
Bronchial arteries
What spinal level does the larynx span
C3 - C6
What are the 3 unpaired cartilages of the larynx
Epiglottis
Thyroid
Cricoid
What is the only comp,eye circle of cartilage in the larynx
Cricoid cartilage
What type of cartilage is cricoid cartilage
Hyaline
What type of cartilage is epiglottis
Elastic
What are the 3 paired cartilages
Arytenoid
Corniculate
Cuneiform
How are the vocal cords changed
Arytenoid cartilages rotates on the cricoid cartilage
Which nerve supplies almost all the laryngeal muscle
Name the muscle that isn’t supplied by this nerve
Inferior (Recurrent) laryngeal nerve
Cricothyroid is innervated by external (superior) laryngeal nerve
What are the names of the 3 circular pharyngeal constrictors
Give their function
Superior
Middle
Inferior
The circular muscles contract sequentially from superior to inferior to constrict the lumen and propel the bolus of food inferiorly into the oesophagus.
What connects the 2 lobes of the thyroid gland
Central Isthmus
Arterial supply to the thyroid gland
Superior and inferior thyroid artery
Purpose of coughing
Move material from vocal cords to pharynx
How does shortness of breath present with pneumothorax
Normal breath sound on one side but no breath sounds on the other
What provides the graters stimulus to increase breathing rate
High [CO2] in the brain
What is primarily responsible for exhalation
Elastic recoil of lungs
Epithelium of epiglottis
Upper - stratified squamous epithelium
Lower - respiratory epithelium
