Anatomy of coughing Flashcards
What structures do you find the sensory receptors in the mucosa that are responsible for the cough?
Oropharynx
Laryngopharynx
Larynx
Respiratory tree
What nerves control the the diaphargm?
Phrenic nerves
What nerves control the intercostal muscles?
Intercostal nerves
What nerve causes adduction of the vocal cords to close the rima glottidis?
Vagus nerve
What prevents the stream of air coming out the nose as a sneeze?
The soft palate tenses and elevates to close of the entrance into the nasopharynx
What nerve causes the soft palate to tense?
Cranial nerve V - trigeminal
What verse causes the soft palate to elevate?
Vagus nerve
At what level does the larynx become the trachea and the pharynx become the oesophagus?
Level of the C6 vertebra
What is the sensory nerve supply to the mucosa lining of the nasal cavities, pharynx and larynx
Nasal cavity - CN V (trigeminal)
nasopharnyx and oropharnyx - CN IX (glossopharngeal)
Larynx - CN X (vagus nerve)
What are the sensory receptors stimulated in coughing?
CN IX and CN X
What is the carotid sheath?
Protective ‘tube’ of cervical deep fascia
Attaches superiorly to the bones of the base of the skull
inferiorly blends with the fascia of the mediastinum
What does the right carotid sheath contain?
Right…. vagus nerve, internal carotid artery, common carotid artery and internal jugular vein
Define the lower respiratory tract
Trachea –> alveoli
What lines the LRT and to what level?
Respiratory mucosa
To the level of the terminal bronchioles/alveoli
What makes up the pulmonary plexus?
Sympathetic axons
Parasympathetic axons
Visceral afferents
How do visceral pleura and respiratory tree visceral afferents connect with the CNS?
The plumonary visceral afferents travel from visceral pleura and respiratory tree to the plexus, then follow the vagus nerve to the medulla of the brainstem
What happens in inspiration?
Diaphragm contracts and descends Intercostal muscles contract Chest walls pull lungs outwards Lungs expand Air flows down pressure gradient
How do the chest walls pull the lungs out with them?
Surface tension between the parietal and visceral pleurae created by the pleural fluid
Potential vaccum becomes actual vaccum when the chest wall begins to move .. sucks visceral pleura towards moving parietal pleura
What are the muscles of normal quiet inspiration?
Diaphragm
External, internal and innermost intercostal muscles
Where do phrenic nerves orginate?
Originate in the neck (C3-C5)
Combined anterior rami of cervicle spinal nerves 3, 4 and 5 and pass down between the lungs and the heart to reach the diaphragm.
Where are the phrenic nerves found?
Found in the neck on the anterior surface of scalenus anterior
Found in the chest descending over the lateral aspect of the fibrous pericardium anterior to the lung root
What do the phrenic nerves supply?
Supplies somatic sensory and sympathetic axons to:
- fibrous pericardium
- mediastinal parietal pleura
- diaphragmatic partietal pleura
- diaphragmatic parietal peritoneum
Supplies somatic motor axons to the diaphragm
What spinal nerves are the intercostal nerves?
Anterior rami of the spinal nerves T1-T11
What are the accessory muscles of deep (forced) inspiration?
Pectoralis major
Pectoralis minor
Sternocleidomastoid
Scalenus anterior, medius and posterior
Where does pectoralis major attach and what is its function?
Between sternum/ribs and humerus
Pulls trunk towards raised upper limb - “climbing” muscle
Pulls ribs upwards and outwards
Where does pectoralis minor attach and what is its function?
Ribs 3-5 to the coracoid process of the scapula
Pulls the ribs 3-5 superiorly to the scapula
Where does the sternocleidomastoid attach?
Sternum/clavicle and mastoid process of the temporal bone
Where do the scalenus anterior, medius and posterior attach
Between cervical vertebrae and ribs 1 and 2
Where do the intrinsic muscles of the larynx attach?
Between the cartilages
What type of muscle are the intrinsic muscles of the larynx?
Skeletal (voluntary) muscles
What nerves supply the intrinsic muscles of the larynx?
Somatic motor branches of the vagus nerve (CN X)
What do the intrinsic muscles of the larynx do and what is their role in the cough reflex?
Move the vocal cords
Adduct the vocal cords to close the rima glottidis
Name the 3 laryngeal cartilages
Thyroid
Cricoid
Arytenoid
Where do the vagus nerves connect with the CNS?
The medulla or the brainstem
What is the name of the hole in the base of the skull that the vagus nerves pass through?
Jugular foramen
What is the vagus nerve contained in as it descends through the neck?
Carotid sheath
What is the vagus nerve’s role in coughing?
Supplies somatic sensory to the mucosa lining the larynx and somatic motor axons to the the intrinsic muscles of the larynx
What type of nerve supply does the vagus nerve have to the chest organs?
Parasympathic axons
What is the mechanism of quiet expiration?
Diaphragm relaxes and ascends Intercostal muscles relax Chest walls return to resting position Lungs elastically recoil Air flows out of the lungs, down a pressure gradient
What are the accessory muscles of deep (forced) expiration?
Anterolateral abdominal wall muscles
Name the 4 anterolateral abdominal wall muscles on the right
Right... Rectus abdominis External oblique Internal oblique Transverus abdominus
Where does the external oblique attach superiorly and interiorly?
Superiorly - the superficial aspects of the lower ribs
Inferiorly - the anterior part of the iliac crest and the pubic tubercle
What is an aponeurosis?
A flattened tendon
Where does the aponeurosis of right and left external oblique blend?
Midline linea alba
Where does the internal oblique attach?
Superiorly - inferior border of the lower ribs
Inferiorly - iliac crest and the thoracolumbar fascia of the lower lack
Where does the aponeurosis of right and left internal oblique blend?
Midline linea alba
Where does the transverse abdominus attach?
Superiorly - deep aspects of the lower ribs
Inferiorly - iliac crest and thoracolumbar fascia of the lower back
Where does the aponeurosis of right and left transverse abdominus blend?
Linea alba
What is the rectus sheath constructed from?
The aponeuroses of the other 3 muscles
What dived the 2 long flat muscles of the rectus abdominis into 4 smaller quadrate muscles?
Tendinous intersections
Name the three thoracoabdominal nerves and where they originate from?
Subcostal nerve (T12 anterior ramus) iliohypogastric nerve (half of L1 anterior ramus) ilioinguinal nerve (the other half of L1 anterior ramus)
What do tonic contractions of the anterolateral abdominal wall muscles do?
Maintain posture
Support the vertebral column
What do contracts of the anterolateral abdominal wall muscles move?
The vertebral column - flexion, lateral flexion and rotations
What do ‘guarding’ contracts of the anterolateral abdominal wall muscles protect?
Abdominal viscera
Contracts of the anterolateral abdominal wall muscles increase intra-abdominal pressure. What 3 things does this assist?
Defecation
Micturition
Labour
What kind of respiration does contraction of the anterolateral abdominal wall muscles aid?
Forced expiration
