Anatomy Flashcards
Where are the sensory receptors located to stimulate a cough?
Oropharyngeal mucosa
Laryngopharyngeal mucosa
Laryngeal mucosa
Respiratory tree
What are the nerves involved in sneezing?
CN 5 - Trigeminal
CN 9 - Glosopharyngeal
What are the nerves involved in coughing?
CN 9 - Glosopharyngeal
CN 10 - Vagus
What is the carotid sheath?
A protective tube of cervical deep fascia that attaches superiorly to the bones of the base of the skull. It blends inferiorly with the fascia of the mediastinum
What does the carotid sheath contain?
Vagus nerve
Internal carotid artery
Common carotid artery
Internal jugular vein
How do visceral pleura and respiratory tree visceral afferents connect with the CNS?
The pulmonary visceral afferents travel from the visceral pleura and respiratory tree to to the pulmonary plexus which then follows the vagus nerve to the medulla of the brainstem
How do motor axons connect with the bronchiolar smooth muscle?
They travel from the tracheal bifurication along the branches of the respiratory tree to supply all mucus glands and all bronchiolar smooth muscle
How does the CNS respond rapidly to a stimulation of the sensory receptors?
It coordinates a deep inspiration using the diaphragm (phrenic nerves), intercostal muscles (intercostal nerves) and accessory muscles of inspiration
What is the mechanism of inspiration?
The diaphragm contracts and descends increasing the vertical chest dimension
The intercostal muscles contract elevating the ribs, increasing the anterior-posterior and lateral chest dimensions
The chest walls pull the lungs outwards with them (pleura) allowing air to flow into the lungs via negative pressure. This is due to the parietal pleura being stuck to the chest walls and creating a vacuum that pulls the visceral pleura and therefore the lungs out with them
What nerves supply the diaphragm?
Supplied by the combined anterior rami and cervical spine nerves C3, 4, 5 which are found in the neck on the anterior surface of the scalenus anterior muscle.
What is the route of the phrenic nerves?
They travel from the neck descending over the lateral aspects of the fibrous pericardium anterior to the lung root.
What type of innervation can the phrenic nerves supply?
Somatic sensory and sympathetic axons to the diaphragm and fibrous pericardium and somatic motor axons to the diaphragm.
How do the phrenic nerves influence breathing?
In a deep (forced) inspiration, a greater outflow of action potentials of longer duration via the phrenic nerves occurs causing the diaphragm to flatten then descend maximally
Where does the scalenus anterior muscle run from?
The neck to the first rib
Where is diaphragmatic pain referred to?
The shoulder
What are the muscles of quiet inspiration?
External intercostal muscles
Internal intercostal muscles
Innermost intercostal muscles
What way do the muscle fibres of normal inspiration run?
External intercostal muscles run hands in pocket orientation
Internal intercostal muscles run hands pointing upwards on the chest
Innermost intercostal muscles run hands pointing towards pockets
What happens during a deep inspiration?
The intercostal muscles contract forcefully and raise the ribs maximally
What are the accessory muscles of deep inspiration?
Pectoralis major
Pectoralis minor
Sternocleidomastoid
Where does the pec major attach and what is its function?
Attaches between the sternum/ribs and the humerus
Adducts and medially rotates the humerus and if it is fixed (holding onto the arm of a chair or the thigh) then the muscle can pull the ribs upwards/outwards
What does the pectoralis minor do?
Pulls the ribs 3-5 superiorly towards the coracoid process of the scapula
Where does the sternocleiodomastoid attach?
Between sternum/clavicle and mastoid process of the temporal bone
What is the use of accessory muscles a clinical sign of?
Dyspneoa
What happens to the vocal chords in a cough?
They are adducted to close the rima glottidis (vagus nerve)