Healthy Heart and Lungs Week 1 Flashcards
What are the steps in the diagnostic process of diagnosing someone ?
What is the difference between a symptom and a sign ?
symptom is breathlessness
sign is tachycardia found through examining pulse
Describe the sequence of steps when taking an examination ?
- Inspection
- Palpitation
- Percussion
- Auscultation
Describe how you would inspect the cheat wall when taking a respiratory examination ?
What are some abnormalities you can identify when inspecting the chest wall during an examination ?
- chest wall deformity
- scars
- trapezius - muscle of the back which you can also slightly see from the front.
- scalenus - muscles in the lateral neck
- sternomastoid - most superficial and largest muscle in the front of the neck
As part of the inspection you can assess the respiratory rate.
Normal respiratory rate is about 14beaths/min
Specific signs of opioid poisoning include: small pupils. shallow breathing. drowsiness.
Metabolic acidosis - is the build up of acid in the body due to kidney disease or kidney failure.
Paradoxical respiration - breathing movements were the chest wall moves in on inspiration and out on expiration, which is the reverse of normal movements.
What is VATS ?
Video assisted thoracic surgery.
Leaves a scar.
What is chest wall deformity ?
Chest wall disorders represent deformities and/or injuries that alter the rib cage geometry and result in pulmonary restriction, increased work of breathing, exercise limitations. These disorders are congenital or acquired and affect all ages.
Barrel shaped chest - when chest is puffed up like a barrel.
Cause ? : Barrel chest happens when your lungs become overfilled (hyperinflated) with air. This keeps the rib cage open or expanded for a long time. This happens most often because of chronic lung condition, but other diseases and conditions may cause it as well.
What are the steps involved when inspecting the chest during a respiratory exam ?
Why do we palpate (touching and feeling) the chest during a respiratory examination ?
Palpation is the tactile examination of the chest from which can be elicited: tenderness
asymmetry
diaphragmatic excursion
crepitus
vocal fremitus
Local tenderness can indicate trauma or costochondritis.
costochondritis - is inflammation where your ribs join the sternum. It causes sharp pain in the middle of your chest.
Asymmetry - normal finding are symmetrical chest expansion. Diminished movement of one side of the chest is always abnormal.
The side with reduces expansion is always the side with pathology (disease)
How do you palpate the chest ?
How do you palpate the trachea ?
How and why do you examine the cervical lymph nodes ?
cervical lymph nodes are located in the sides and back of the neck. The glands are usually very small.
when a lymph node is greater than 1cm in diameter it is enlarged.
infection is one of the most common causes of swollen lymph nodes anywhere in the body. when there is an infection somewhere in the body, the lymph nodes in that area fill with white blood cells.
Common infections that lead to cervical lymph nodes are:
- the common cold
- strep throat
- tonsillitis
- ear infections
- dental infections
- HIV
less common causes of swollen cervical lymph nodes:
-cancer
Surface marking of the lung lobes
Right lung - 3 lobes
Left lung - 2 lobes
X ray of lungs ?
Transverse/ Axial CT of lung ?
Transverse/ Axial CT of lung ?
Why do we percuss the chest during a reparatory examination ?
The purpose of percussion is to determine if the area under the percussed finger is air filled (sounding resonant like a drum), fluid filled (a dull sound) or solid (a flat sound).
How do we percuss (tap) the chest ?
Where do we percuss the chest ?
4 down the left front
4 down the right front
4 down the left back
4 down the right back
2 lateral (left and right) down the front
How do you listen to the chest ?
Listening to the chest using a stethoscope is called auscultation.
When Auscultating you listen for breath sounds.
What is the function of the respiratory system ?
- Getting oxygen into the body and getting rid of carbon dioxide waste product.
- Maintain oxygen and carbon dioxide partial pressure gradients to optimise transfer (gas exchange). We manage gas exchange by the equivalent of partial pressure gradients
- Regulate pH of extracellular fluid - acid-base balance.
Outline the concept of internal and external respiration?
External respiration: External respiration involves the external environment
O2 is absorbed from inspired air and CO2 is expelled.
Internal respiration: Internal respiration involves exchange of O2 carried in the blood to the tissues
CO2 by-product collected by the blood
Describe the central control of respiration?
Components of the respiratory control system include:
-Sensors
- Respiratory control center
- Effectors
Sensors - if we are trying to maintain partial pressure of gasses and pH we need a means to sense that, hence we need sensors.
The sensors need to take the information to the brain, which makes up the respiratory control center.
The respiratory control center: is located in the medulla oblonganta and is involved in the minute to minute control of breathing. The inspiratory and expiratory activities are modulated by various sites in the lower brain stem including pons.
Effectors - the muscles that will allow us to make a change.
Describe the role of effectors in the respiratory control system ?
When we carry out quiet breathing (inspiration):
- Diaphragm ( muscle that allows us to breathe)
- Phrenic nerve ( is the nerve that controls the diaphragm)
- Cervical roots C3-C5 (origin of the phrenic nerve)
If the cervical roots in the neck region are damaged this is dangerous as it could affect breathing.
When we carry out quiet breathing (expiration):
- This is a passive process. air moves from an area of higher pressure to an area of lower pressure. The lungs are filled with elastic tissue as a result there is a ELASTIC RECOIL.
If the work of breathing has to be increased for example because of exercise then we have to use accessory muscles.
Which accessory muscles do we use during increased breathing?
- Sometimes we need to use extra muscles during increased respiration, such as during exercise.
- Sometimes when we need to use accessory muscles it ca be a sign of respiratory distress. This is a patient doing a huge amount of work just to breathe.
The accessory muscles of respiration include:
- the scalene
- the sternocleidomastoid
- the trapezius
- the external intercostal
In this image a patient has COPD (chronic obstructive pulmonary disease). It is evident he is using accessory muscles such as scalene, sternocleidomastoid and trapezius to breathe.
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What is partial pressure ?
- A concept used to describe the concentration of gas in a mixture of gas.
- The partial pressure total is made up of the partial pressures of the gasses making up that mixture.
- Hemoglobin allows us to bind gas. And by binding gasses this allows us to transport a lot more hemoglobin in the blood.
Alveolar pO2 and pCO2 need to be kept constant and within the normal range.
What is HYPERCAPNIA ?
HYPERCAPNIA : rise in the pCO2
Alveolar pO2 and pCO2 need to be kept constant and within the normal range.
What is HYPOCAPNIA ?
HYPOCAPNIA: fall in the pCO2
Alveolar pO2 and pCO2 need to be kept constant and within the normal range.
What is HYPOXIA ?
HYPOXIA: fall in the pO2
What happens to the partial pressure of oxygen and carbon dioxide when exercising ?
- The partial pressure of oxygen drops
- The partial pressure of carbon dioxide increases
- breathing more will restore both - increased respiratory rate and tidal volume then this will restore pO2 as we breathe more oxygen in and will restore pCO2 levels as we breathe more oxygen out.
What is Hypoventilation and Hyperventilation?
Hyperventilation: ventilation increases without a change in metabolism.
Without a change in metabolism means the tissues don’t require more respiration.
Hypoventilation: ventilation decrease without a change in metabolism.
Why do patients hyperventilate ?
Sometimes when patients panic or get anxiety they will hyperventilate. This is when you have an increased ventilation without the metabolic need for it.
In this case the pO2 and the pCO2 will move away from their ideal ranges. Instead the pO2 of will increase
and the pCO2 will decrease.
Why do patients hypoventilate ?
Patients may hypo ventilate due to nervous system depression, neurological disease or disorders of the respiratory muscles.
This time we decrease ventilation but metabolism is unchanged.
So pO2 will drop and pCO2 will rise.
When we have too little oxygen this is called Hypoxia. Describe the hemoglobin dissociation curve for oxygen ?
This is the hemoglobin dissociation curve for a human.
At a partial pO2 of 13 there is 100% saturation of oxygen.
As this decreases to about pO2 of 8. the saturation of oxygen begins to slip. This shows that pO2 of oxygen can fall considerably before saturation is markedly affected.
What is the Henderson - Hasselbach equation ?
Buffer: is a aqueous solution consisting of a mixture of a weak acid and conjugate base.
The Henderson - Hasselbach equation is used to determine the pH of a buffer.
Formulae:
pH = pKa + log10 ([A-] / [HA])
pH = acidity of a buffer solution
pKa = negative logarithm of Ka
Ka = acid disassociation constant
HA = concentration of an acid
A- = concentration of conjugate base
What is the carbonic acid- bicarbonate buffer system ?
The Carbonic Acid-Bicarbonate buffer system is the most important buffer for maintaining the pH homeostasis of blood.
Blood has a pH between 7.35 and 7.45
If the blood ph is below 7.35 it is too acidic. This means the blood has too many H+ ions
If the blood pH is above 7.45 its too alkaline. This means the blood has too little H+ ions
What is the partial pressure of oxygen and co2 in oxygenated and deoxygenated blood?
Oxygenated:
pO2 = 100 mmHg
pCO2 = 40mmHg
Deoxygenated:
pO2 = 40mmHg
pCO2 = 45mmHg
What does the hemoglobin dissociation curve show ?
- x axis = pO2 (mmHg)
- y axis = saturation of oxyhemoglobin (%) ( this means how much oxygen is bound to the hemoglobin, the more oxygen bound to hemoglobin the higher the oxyhemoglobin)
The oxygen hemoglobin curve has a sigmoid shape.
Plateau close to 100% - this show’s at higher pO2 does not cause large changes in oxygen saturation of hemoglobin. This is because most of the oxygen binding sites are taken so less are available.
Low partial pressure of oxygen 26mmHg produces a oxyhemoglobin saturation of 50%.
26mmHg = 50%
This is because of positive cooperativity. When the first Heam receives oxygen, the affinity increases for the second and so on.
3 things which can change the oxygen dissociation curve:
- pH
- Temp
- 2,3 DPG
If the curve moves to the right there is a lower affinity for oxygen and if it moves to the left there is a higher affinity for oxygen.
Describe how the carbonic-acid buffer system works ?
H2CO3 = carbonic acid (weak acid)
An acid is anything that can donate a H+ ion
H2CO3 -> H+ + HCO3- ( bicarbonate ion) reversible equation (this part deals with the kidneys )
This is a very simplistic buffer system.
If there is not enough H+ ions the weak acid will split and donate H+ions.
If there is too many H+ ions it will bind to bicarbonate ion and form more carbonic acid.
Our body utilizes this reaction with the help of CO2 and H2O
CO2 + H2O -> H2CO3 (this part deals with the lungs)
If there is not enough H+ ions in the blood. CO2 will bind to H2O to form carbonic acid. This is a weak acid so will dissociate into H+ and HCO3- (bicarbonate ion). One way we can increase H+ in the body is through the accumulation of CO2 (hold your breath)
If you have too many H+ ions it will bind to bicarbonate ion (HCO3-) and produce carbonic acid, which will split into CO2 and H2O. If the pH is too acidic we end up producing more CO2. The patient is breathing out more.
Respiration is an indication of the blood pH.
How does pCO2 effect the plasma pH ?
How does ventilation influence plasma pH ?
How does ventilation influence plasma pH ?
- Hypoventilation leads to an increase in pCO2 ( breathing less CO2 out)
- Hypercapnia leads to a fall in plasma pH = Respiratory acidosis
- Hyperventilation leads to a decrease in pCO2 (breathing out more and losing more CO2)
- Hypocapnia leads to an increase in plasma pH = Respiratory alkalosis
Overall:
Plasma pH depends on the ratio of [HCO3-] to pCO2
Respiratory driven changes in pH compensated by the kidney
Metabolic changes in pH compensated by breathing
Control of breathing depends on the partial pressure of oxygen and carbon dioxide expand on this a little more ?
- You don’t need to control the pO2 as long as it stays above 8kPa
- It is much more critical to control the pCO2.
- Changes in ventilation can correct metabolic disturbances of pH.
Which sensors feed information to the respiratory control center ?
- peripheral chemoreceptors ( detect O2, CO2 and H+ level)
- central chemoreceptors ( detect H+ level)
- pulmonary mechanoreceptors (detect stretch)
- joint and muscle receptors ( stretch and tension)
Which nerves communicate any changes in breathing to the respiratory control center ?
Phrenic nerve: controls the diaphragm
Glossopharyngeal nerve (CN IX): helps moves muscles of the throat and exhibit respiratory burst activity.
Vagus nerve: the vagus nerve listens to the way we breathe and sends messages to the brain and heart.
What are the dorsal and ventral respiratory groups ?
Dorsal respiratory group (DRG)
Ventral respiratory group (VRG)
DRG and VRG are both structures found in the medulla. They receive input from peripheral chemoreceptors and other type of receptors via the vagus and glossopharyngeal nerve.
DRG - generate inspiratory movements
VRG - generate expiratory and inspiratory movements
What are the role of peripheral chemoreceptors (breathing) ?
Peripheral chemoreceptors detect changes in the chemical constitution of plasma. They detect changes on arterial blood oxygen and initiate reflexes that are important for maintaining homeostasis during hypoxemia.
Peripheral chemoreceptors include: carotid and aortic bodies ( these are very small accumulation of nervous tissue)
Peripheral chemoreceptors: we have a set in the aortic arch and bifurcation of the carotid arteries
The peripheral chemoreceptors get a high volume and high rate of flow past the tissues so will pick up quickly a big drop in pO2
Large falls in pO2 will send a message to the brain which will stimulate:
- increased breathing
- changes in heart rate
- changes in blood flow and distribution.
This is important to protect the tissues we need to protect in potential hypoxemia which include the brain and kidneys.
What is the difference between peripheral and central chemoreceptors ?
What are the role of central chemoreceptors (breathing) ?
Central chemoreceptors will detect changes in the arterial pCO2 and any tiny rises will immediately lead to an increase in ventilation:
-small falls in pCO2 will lead to a decrease in ventilation
- small rises in pCO2 will increase ventilation
The extracellular fluid which is measured is subject to a structure called the blood brain barrier which has specialized epithelium. It provides a protective environment for neurons. It helps keep bacteria and drugs out of neuronal tissues.
But it also stops H+ ions and HCO3- (bicarbonate ions) from getting across. The only thing which can influence pH is CO2. Only CO2 can get across the blood brain barrier.
CSF pCO2 determined by arterial pCO2 as CO2 diffuses rapidly across BBB
There is much less protein in CBS so much less buffering.
Describe the feedback control of breathing ?
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Respiratory failure is classified into two types. What are the two types of respiratory failure?
- Type 1: Hypoxia and normal to low levels of pCO2
- Type 2: Hypoxia and hypercapnia.
This type is much trickier. This happens classically in COPD.
The diagram shows which illnesses/ substances will affect a specific part of the respiratory system
What is hypoxemia ?
Is a below - normal level of oxygen in your blood, specifically in your arteries.
Why do we cough ?
- Normal - to get rid of foreign bodies from the upper respiratory tract
- Associated with disease
Cough can become chronic and a condition in its own right.
Describe the mechanism of cough ?
- So rather than the central respiratory center generating nice respiratory rhythm if a cough reflex is triggered it will set off a different chain of steps.
Each cough occurs through the stimulation of the reflex arc:
- Initiated by the irritation of cough receptors which are found in the trachea, main carina, branching points of the large airways and more distal smaller airways ( they are present in the pharynx)
- Chemical receptors are sensitive to heat, acid, capsaicin-like compounds trigger the cough reflex via activation of type 1 vanilloid receptor.
- Impulses from cough receptors travel through the vagus nerve (afferent nerve) to the ‘cough center’ in the medulla. The cough center generates an efferent signal (travels down vagus then phrenic then spinal motor nerves) to expiratory musculature to produce the cough.
What are the afferent, central and efferent pathway in a cough reflex ?
Therefore, the cough reflex arc is constituted by:
- Afferent pathway: Sensory nerve fibers (branches of the vagus nerve) located in the ciliated epithelium of the upper airways (pulmonary, auricular, pharyngeal, superior laryngeal, gastric) and cardiac and esophageal branches from the diaphragm. The afferent impulses go to the medulla diffusely.
- Central Pathway (cough center): a central coordinating region for coughing is located in the upper brain stem and pons.
- Efferent pathway: Impulses from the cough center travel via the vagus, phrenic, and spinal motor nerves to diaphragm, abdominal wall and muscles. The nucleus retroambigualis, by phrenic and other spinal motor nerves, sends impulses to the inspiratory and expiratory muscles; and the nucleus ambiguus, by the laryngeal branches of the vagus to the larynx.
Name some noxious stimuli that can stimulate a cough ?
Noxious stimuli: A noxious stimulus is a stimulus strong enough to threaten the body’s integrity. Noxious stimulation induces peripheral afferents responsible for transducing pain, throughout the nervous system of an organism
The respiratory system is divided into the upper respiratory tract and lower respiratory tract ?
What does each include ?
- Sometimes whether the larynx belongs to the upper or lower respiratory tract varies. We are today going to include the larynx as part of the upper respiratory tract.
What infections/ inflammation/ illnesses are possible in different parts of the respiratory tract ?
Describe the thoracic cage ?
The thoracic cage forms a conical enclosure for the lungs and heart.
Describe muscles of inspiration and expiration
When you breathe the thoracic cage expands. There is a variety of muscles that allow this to happen.
Muscles of inspiration:
- sternocleidomastoid muscles and scalene muscles (accesory muscles) attach on the skull and help pull the ribcage up.
- external intercostal muscles work to contract and raise the thoracic cage which results in expansion.
- diaphragm - separates the thoracic and abdominal cavity. Dome shaped.
Inspiration: the diaphragm contracts and flattens increasing the thoracic space
Expiration: the diaphragm relaxes and is dome shaped again which decreases the thoracic space.
Muscles of Expiration:
Muscles of expiration ?
Expiration
- Normal quiet breathing - elastic recoil
- Forced expiration - abdominal musculature is used ( in particular rectus abdominus)
What are the functions of the respiratory system ?
- Conductance
- Gas exchange
What cells are the trachea lined with ?
- specialized ciliated pseudostratified columnar epithelial cells
- macrophages - involved in the detection, phagocytosis and destruction of pathogens.
- goblet cells - secrete mucin and create a protective mucus layer
- Clara / Club cells (aka non-ciliated bronchiolar secretory cells) - found in bronchioles. They are found in the ciliated epithelium and their function is to protect the bronchiolar epithelium by secreting a protein called uteroglobin
- tracheal glands - The tracheal glands are composed of sacs of serous cells, which form acini. Serous cells secrete a watery-like secretion rich in bactericidal enzymes. Acini run into tubules of mucous cells, which secrete a thicker gel-like substance rich in glycosylated proteins.
- cartilage and smooth muscle in the wall
What are the main functions of the conductance part od the respiratory system ?
- Conductance
- Protecting the lower airways by removing dust particles, atmospheric pollutants and other debris from the airways.
- Humidifying and warming inspired air
Describe the anatomy of the nose ?
External : made up of mainly cartilage covered by facial muscles and skin.
We have a aperture at the nasal cavity which is the nostrils.
What are the choanae (internal nares) ?
The Choanae are the posterior nasal aperture (opening).
Learn the anatomy of the nasal cavity
Bones of the nose ?
The nasal septum divides the nose into about 2 equal halves.
The nasal septum consists of cartilage and bone.
3D schematic to better see the structures inside the nose.
Describe the surface of the inside of the nose ?
- Hairs which can trap dust and debris
- With the exception of the entrance the inside of the nose is covered in pseudostratified ciliated columnar epithelium with goblet cells. These produce mucus to trap any wanted particles. Ciliated so we can push anything we don’t want back out.
- The respiratory mucosa can warm the inhaled air sufficiently to raise the temperature of the inspired air from 6 degrees Celsius to 30 degrees Celsius. Inhaled air is then fully warmed and humidified to 37 degrees Celsius as it travels through the treacheas.
What is Olfactory Mucosa ?
Where: olfactory mucosa is found in the nasal mucosa. It is a small region of the roof of the nasal cavities.
Olfactory mucosa: contain sensory receptors for smell
They send signals to the olfactory bulb which sends the signals to the olfactory nerve.
What is Olfactory Mucosa ?
Where: olfactory mucosa is found in the nasal mucosa. It is a small region of the roof of the nasal cavities.
Olfactory mucosa: contain sensory receptors for smell
They send signals to the olfactory bulb which sends the signals to the olfactory nerve.
What is another word for conchae ?
Turbinates
3 conchae:
-Inferior conchae
-Middle conchae
-Superior conchae
There is a meatuses for each conchae. Meatuses are broad opening inferior to the conchae.
3 meatuses:
- inferior meatuses
- middle meatuses
- superior meatuses
Opening at the top called the sphenoethmoidal Recess
What is the function of the conchae?
Function of the conchae: They increase the surface area of these cavities, thus providing for more surface area for rapid warming and humidification of air as it passes to the lungs.
Name the paranasal sinuses ?
Paranasal means near the nose.
The paranasal sinuses are hollow air-filled spaces (cavities) in the bones around the nose. The sinuses are lined with cells that make mucus, which keep the inside of the nose from drying out.
- Maxillary sinus: located under the eyes
- Frontal sinus: are above the eyes
- Ethmoidal sinus: are between the eyes
- Sphenoidal sinus: are behind the eyes
This is a CT scan of the paranasal sinuses.
In a healthy individual:
The black areas are less dense and represent hollow spaces like the sinuses
What drains into the middle meatus ?
- The paranasal sinuses have openings into the nasal cavity.
What drains into the middle meatus:
- The maxillary sinus drains into the middle meatus.
- The frontal sinus also drains into the middle meatus.
- The ant and mid ethmoid cells also drain into the middle meatus
-The posterior ethmoid sinus drains into the superior meatus
-The sphenoethmoidal recess is a small space in the nasal cavity into which the sphenoidal sinus and posterior ethmoid sinus open
- the nasolacrimal duct drains into the inferior meatus
What is Sinusitis ?
Sinusitis is a common condition in which the lining of the sinuses becomes inflamed.
Inflamed sinuses are filled with fluid. The sinuses can become blocked so that the fluid cant be drained which can cause symptoms such as pain in your face, a blocked runny nose and headache.
Why do we blow our nose when we cry ?
There is another cavity before the inferior meatus called the nasolacrimal duct.
After crying a lot you have to blow your nose. This is because of the Lacrimal gland which secretes tears.
If there is excessive tears it drains into the lacrimal sac, down the nasolacrimal duct and exit in the inferior meatus of the nasal cavity.
This produces a lot of fluid which causes you too blow your nose ?
Describe the capillaries of the nose ?
- The nose has a thick capillary bed which helps keep the nasal cavity warm.
The arterial supply of the nose is made up of 4 main arteries:
- Ethmoidal artery
- Sphenopalatine artery
- Greater palatine artery
- Superior labial artery.
These arteries anastomose in the nasal cavity. Anastomosis means the branches join together so you have a good blood supply.
So if you cut your nose artery it means you are going to get a lot of blood because your getting blood supply from all of these regions. This is why you can have a very heavy bleed from the nose very quickly.
Upper blue area is known as Little’s area. This is a key anastomosis. A very small cut to this area can cause a large bleed.
Epistaxis - is the medical name for a nose bleed
Describe the structures around the pharynx ?
Pharynx
Superior: base of the skull
Posterior: to the nasal cavity, oral cavity and larynx.
Inferior: Cricoid cartilage (is recognizable because its less tall anteriorly and more tall posteriorly.
Cricoid cartilage is an important marker for various boundaries.
Describe the constrictor muscles of the larynx ?
There are 3 constrictor muscles of the pharynx.
- Superior constrictor
- Middle constrictor
- Inferior constrictor
Describe the 3 parts the pharynx is divided into ?
- Nasopharynx
- Oropharynx
- Laryngopharynx
These structure are all anterior to it.
Describe the nasopharynx ?
There are 2 tonsils in the nasopharynx. These are the tubal tonsil and adenoid (pharyngeal tonsil).
- Tonsils are collections of lymphoid tissue. They are your immune systems first line of defense.
- When a person has an infection there tonsils will swell.
Describe the opening of the Eustachian tube ?
Eustachian tube drains into the tubal tonsil (nasopharynx)
Otitis media: another name for middle ear infection.
A ‘pop’ when you go in a plane and the air pressure changes is when the eustachian tube opens.
Infants are more prone to ear infection because of their anatomy. The passageway is more narrow in an infant, so if there is swelling it is more likely to get blocked and cause an infection.
Describe the Oropharynx ?
The oropharynx your going from the soft pallet to the epiglottis.
Important features in the oropharynx:
-palatine tonsil ( what’s most often refereed to when people say their tonsils are swollen)
- Lingual tonsil
What is the larynx proper ?
Larynx allows air to pass from your throat (pharynx) to your trachea on your way to the lungs.
- It contains your vocal chords which is essential to human speech.
Larynx is used for:
- Phonation (speech)
- Cough reflex
- Protection of the lower respiratory tract.
There are receptors in the larynx which trigger the vagus nerve to contract and produce a cough.
When you try to cough the epiglottis pulls down before hand so that ai isn’t expelled at a high force. This protects the lower respiratory tract.
Of these structures there are paired and unpaired versions.
Paired means there is one on both sides.
Unpaired means there is one on either side.
Unpaired structures:
- epiglottis
- thyroid cartilage
- cricoid cartilage (relatively taller on a posterior view)
Paired structures (one on either side):
- Arytenoid cartilage ( key for producing vocalization)
- Cuneiform
- Corniculate
Ligaments you can see:
- Vocal ligament
- Vestibular ligament
Vocal folds move and change the gap between them which is the airway and the pitch changes based on how the fold is pulled. Like when you pinch a balloon filled with air it makes different noises.
False vocal folds
True vocal folds
What are the functions of true and false vocal chords ?
The vocal chords ( true and false) move to open. The air passes through and changes the pitch and vibrations.
False vocal (vestibular folds) chords are not used in phonation generally. They can be used to make some noise. Theya re not used for normal phonation. There main role is closing to stop food getting into the trachea.
True vocal chords: make sound (phonation)
What are the muscles of the larynx ?
There are muscles associated to the vocal folds to actually move these structures.
- oblique arytenoid
- transverse arytenoid
- vocalis muscle
When we swallow the vocal folds are closed.
As air moves through the vocal chords when we talk they change position which changes teh pitch
At what positions are important features in the pharynx and larynx found ?
At level C6 of the vertebrae we have:
- Arch of the cricoid cartilage
- superior end of the osophagus
- superior end of the trachea
Describe the trachea ?
- Anterior to the osophagus
- C-shaped cartilage rings bridged by trachealis.
Trachealis is important for the cough reflex and forceful expulsion of air.
At what point does the trachea bifurcate into tow primary bronchi ?
- Level T4/ T5.
This point is called the manubriosternal angle or Angle of louis
x - ray of the lungs
Describe the bronchioles?
Formation of the torso. Excluding limbs and head.
Can divide the thorax into two regions.
The thoracic cavity and abdominal cavity.
The cavities which we are going to be looking at the development of from an embryological point of view are:
- pleural cavity
- pericardial cavity
- diaphragm
- peritoneal cavity
What lines the pleural cavity, pericardial cavity and peritoneum ?
- pleura
- pericardium
- peritoneum
These are all examples of mesothelial lining
This is the view in which we will see the embryo. We are looking at the top surface of the trilaminar disc.
- We’ve cut away the amniotic cavity. So that surrounding area around would be filled with amniotic fluid.
- The embryo has polarity meaning it has a cranial and caudal end.
- At the top of the caudal end is an area called cardiogenic mesoderm and this gives rise to the heart. It is above what will be the head right now but it will reposition into the right place when we fold the embryo.
Know the features of the embryo when looking from the median plane ? 21 days
Oropharyngeal membrane eventually becomes the mouth
Day 22 Ventral folding ?
The heart and cloacal membrane (anus) have folded round.
Day 28 folding of embryo median plane ?
Allantois is like a embryonic temporary bladder
Umbilical cord will be the blood supply between the mother and developing fetus
Describe the horizontal plane of a 28 day embryo ?
Describe the migration of the septum tranversum ?
Septum Transversum is the precursor of the muscular diaphragm. It will separate the thoracic and abdominal cavities.
Day 22 - (Image) Just in front of the developing heart is the beginning of the septum transversum.
Day 26 - (image) the septum transversum has become wedged between the under of the developing heart and the yolk stalk.
Day 28 - the heart is between the yolk sac and developing heart ( more clear)
What an embryo would look like at one month ?
The heart is disproportionally large.
You can see head, spine
The limbs are growing as outgrowths
Describe the pericardioeritoneal canal ?
The septum transversum is incomplete dorsally. The septum transversum does not completely meet the back wall of the body cavities. There is a little hole on both either sides that communicate with both sides of the cavity ( these are the pericardioperitoneal canals)
The pericardial and peritoneal cavities communicate via the pericardioperitoneal canals.
Lungs: evagination of ventral gut wall cranial to septum tranversum
Describe the development of the lungs?
The lung bud forms just off the foregut. Invagination of the foregut.
Right hand side has 3 buds -
Left hand side has 2 buds -
Describe the development of the pleura and pericardium ? (5th week)
This is the view we will slice the embryo. (5th week)
The heart and lungs developing in one continuous space ( this is called the pericardial cavity).
Pleuropericardial folds
Describe the development the pleura and pericardium ? (6th week)
The lungs have increased in size.
Pleuropericardial fold move more inward. Eventually this will form a membrane (pleuropericardial membrane) so there will be a separate pericardial cavity and pleural cavity.
Describe the development of pleura and pericardium ? (7th week)
- There is a nerve situated in the fibrous pericardium (phrenic nerve). It is the nerve that will eventually innervate your diaphragm.
- So far the pericardial cavity has formed separating the heart. It helps separate the pleura cavity for the left and right lung.
How does the pleural cavity develop (embryology ) ?
- The lung grows into the pleural cavity. Like an overinflated balloon.
- As the lung becomes bigger the gap the cavity becomes very small.
- The portion of the pleura stuck to the organ (lung) is called visceral pleura.
- The portion of the pleura stuck to the body wall is the parietal pleura.
Remember the pleura is one continuous sheet we just change the name depending on whether the pleura is stuck to the viscera or body wall.
Describe the development of the diaphragm? (embryology)
As Pleuropericardial folds form and fuse
Pleuroperitoneal membranes form and fuse with septum transversum. They zip up the pericardioperitoneal canal on either side.
We should eventually end up with no pericardioperitoneal canal on either side.
So there is a complete separation from the peritoneal cavity and thoracic cavity.
There are precursor cells to muscles cells in the body wall. They are called myoblasts. The myoblasts move towards area within the pleuroperitoneal membrane so this area becomes muscular.
Which 4 embryonic structures does the definitive musculotendinous diaphragm derive from ?
- Septum transversum
- Pleuroperitoneal membranes
- Dorsal mesentery of Oesophagus
- Mesoderm of the Body Wall
Describe the innervation of the diaphragm ?
Describe development abnormality of the diaphragm ?
- Sometimes the pericardioperitoneal canals fail to close properly. So we get weakness or a hole in the diaphragm.
- This can lead to Congenital Diaphragmatic Herniation.
- Herniation refers to when one structure ends up in a place it is not meant to be.
- Sometimes this can lead to situations like the gut ending up in the pleural cavity.
- This can lead to follow on conditions like Hypoplasia (underdevelopment of an organ) or lung compression
Describe the eventration of the diaphragm ?
- If you don’t get a lot of myoblasts going to the wall of the diaphragm you will have less muscle cells in the wall of the diaphragm. So you end up with a weak floppy diaphragm. So the weak diaphragm doesn’t go through a hole but is pushed up because its so weak. So instead of this being a herniation it is known as Eventration of the diaphragm. It can still lead to hypoplasia due to lung compression
Describe the pleura ?
- A pleura is a serous membrane that folds back on itself to form a two-layered membranous pleural sac.
- The outer layer is called the parietal pleura and attaches to the chest wall. The inner layer is called the visceral pleura and covers the lungs, blood vessels, nerves, and bronchi.
- Between the pleura is a space called the plaural cavity.
Describe the pleura ?
- A pleura is a serous membrane that folds back on itself to form a two-layered membranous pleural sac.
- The outer layer is called the parietal pleura and attaches to the chest wall. The inner layer is called the visceral pleura and covers the lungs, blood vessels, nerves, and bronchi.
- Between the pleura is a space called the pleural cavity. It is filled with a serous fluid which is secreted from the apical region of the parietal pleura.
- The pleura cushions the lungs and reduces friction.
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Describe the bones of the nasal cavity ?
What are the Choanae ?
- The choanae are the posterior nasal aperture.
- It is the opening between the nasal cavity and nasopharynx.
- They are separated by the vomer.
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What are the conchae ?
The nasal conchae or turbinates are long, narrow curled shelves of bone that protrude into the nasal cavity.
The superior, middle and inferior conchae divide the nasal cavity into four groove-like air passages
What are the nasal meatus?
Underneath each conchae is a meatus.
The nasal meatuses are distinct air passages of the lateral nasal cavity located inferior to each nasal conchae.
The inferior meatus has the biggest opening.
The middles meatuses has the second biggest opening.
The superior meatuses has the smallest opening.
What are the paranasal sinuses ?
- Maxillary Sinus
- Ethmoidal Sinus
- Frontal sinus
- Sphenoidal sinus
What are the main bones of the skull ?
- Maxillary bone
- Ethmoidal bone
- Frontal bone
- Sphenoidal bone
- Mandible (jaw)
- Zygomatic bone (cheek bone)
What is the pharynx ?
What are the constituent parts of the pharynx ?
- The pharynx forms the connecting pathway between the nasal cavities and the larynx, and between the mouth and the
oesophagus. - Pharynx:
Nasopharynx
Oropharynx
Laryngopharynx
- Identify the auditory tube leading to the middle ear. ( Eustachian tube)
- Identify the ‘pillars of fauces’ - the palatoglossal fold and palatopharyngeal fold.
Are two mucosal folds that extend inferiorly from each lateral border of the soft palate.
The palatoglossal fold is located anteriorly. It contains the palatoglossus muscle and connects the soft palate with the root of the tongue.
- Identify the laryngeal inlet ( opening of the larynx from the laryngopharynx) and the piriform fossae lying lateral to it
- The oesophagus
- The pharyngo - oesophageal junction. (c6) is the point where the pharynx and oesophagus meet
What is the larynx ?
The larynx protects the airway during swallowing, permits breathing and contributes to speech, coughing and sneezing.
- Identify the:
epiglottis
arytenoid cartilage
aryepiglottic fold. - Identify the:
hyoid bone
thyroid cartilage - Identify the:
cricothyroid membrane between the thyroid and cricoid cartilage
Identify the vestibular folds ( superior) and vocal folds (inferior) - two folds in the interior of the larynx produce phonation
- Identify the:
rima glottidis - the space between the two adjacent vocal folds
What landmarks are at the following positions:
- C4:
- C6:
- T2:
- T4/ T5:
- C4: Bifurcation of the common carotid artery / thyroid cartilage (superior)
- C6: cricoid cartilage / trachea begins ( end of the larynx) / oesophagus begins (end of pharynx)
- T2: superior angle of scapula/ sternoclavicular joint / suprasternal notch
- T4/ T5: sternal angle of louis / bifurcation of the trachea (carina) / arch of the aorta
What are the sub section of the larynx ?
The larynx contains:
- epiglottis - which is a flap of tissue that sits beneath the tonge at the back of the throat. It prevents food and drink from entering your windpipe.
- supraglottis (supraglottic larynx) - the top of the larynx. Function id to protect the lower airway.
- vocal cord (vocal folds) - are two bands of smooth muscle tissue found in the larynx. the vocal chords vibrate and air passes through the chords to produce the sound of your voice.
- glottis - is the opening between the vocal folds in the larynx
- subglottis - the lowest part of the larynx. The area from just below the vocal cords down to the top of the trachea.
Describe the anatomy of the larynx ?
First image:
Epiglottis
Hyoid bone
Thyroid membrane
Thyroid cartilage
Cricoid cartilage
Tracheal cartilage
Second image:
- True vocal cords
- false vocal cords
What does Erythematous mean ?
Erythematous: exhibiting abnormal redness of the skin or mucous membranes due to the accumulation of blood in dilated capillaries (as in inflammation)
How does the voice box make sound ?
- the vocal fold is attached to a small arytenoid cartilage ( many small muscles also attach to the arytenoid. These muscles contract and relax to allow breathing, swallowing and speaking.
- Control of these muscles is provided by two branches of the vagus nerve:
the recurrent laryngeal nerve
superior laryngeal nerve
Thes nerves can be injured by trauma, surgery and other causes. If this occurs paralysis of the vocal cords can occur. This can lead to hoarseness and aspiration aswell as other injuries.
- Making sound (speaking):
the vocal folds are bought together by muscles attached to the arytenoid cartilage.
As air is forced into the vocal folds, they vibrate and produce sound.
By tightening or relaxing the laryngeal muscles the sound of your voice can be changed.
Describe the paranasal sinuses of the nasal cavity ?
Sinuses are apertures that you find in certain bones in the skull.
Maxillary sinus
Ethmoid sinus
Frontal sinus
Sphenoidal sinus
They are lined with the same mucosa that line the nasal cavity. Help with humidification due to their lining as well as resonation of speech due to their hollow nature. They also allow the skull to be lighter.
- Inflammation of the sinuses are known as sinusitis.
Understand the concept of refence changes ?
A reference is usually defined as the set of values 95 per cent of the normal population falls within.
Two sided distribution the uncertainty is split on both sides of the bell curve. These are called the upper limits and lower limits.The top 2.5% and bottom 2.5% are the not normal groups.
One sided distribution all of the 5% is on one side of the bell curve.
What is standard deviation ?
- Standard deviation is a measure of the amount of variation of a set of values.
- A low standard deviation indicates the values are close to the mean ( or expected value)
- A high standard deviation indicates that the values are spread out over a wider range.
Image 1: is the equation for standard deviation
Image 2 : shows normal distribution
What is interquartile range ?
The interquartile range is the first quartile subtracted from the third quartile.
IQR = Q3 - Q1.
How to find IQR of data set:
- Organize data from least to highest value.
- Split data into half. So 1st 50% quartile and 2nd 50% quartile.
- Find the median of the lower half of data to find 25% (First quartile value)
- Find the median of the upper half of the data to find 25% (third quartile)
- IQR = Q3 - Q1
Understand what a normal distribution is and recognise the implication of a skewed distribution.
Normal distribution
A function that represents the distribution of many random variables as a symmetrical bell-shaped graph.
