The thorax anatomy Flashcards
What is the role of latissimus dorsi in ventilation?
When the arm is fixed can elevated ribs 9-12 during deep inspiration
What is the role of the serratus posterior muscles during ventilation?
Inferior and superior are both accessory muscles of respiration
Superior - elevates ribs during inspiration
inferior - depresses during expiration
Two pair to help stabilise the thoracic cage
What is the role of levatores costarum in respiration?
Helps elevate the ribs during inspiration
Stabilise the ribs against the vertebral column.
Label the muscles in the image
levatores costarum
How do the pectoralis muscles aid respiration?
P.major - expands cage when arms are fixed
P,minor - deep inspiration lifts the chest up and out
What is the role of the subcostal muscle?
Small rectangular muscles found on the deep surface of ribs 7 to 10.
Depresses the ribs to oppose levatores costarum
What is the key function of the thymus?
Located deep to the manubrium
Responsible for the production of T cells
A supply of T-lymphocytes is established at pubery, so the organ becomes redundant and degenerates replaced by fat
What are some important branches of the descending thoracic aorta?
Intercostal
Superior phrenic
Bronchial
Oesophageal
Mediastinal
Pericardial
What are some tributaries of the superior vena cava?
External and internal jugular
Vertebral
Subclavian
Brachiocephalis
Azygous system
What is the azygous system for the venous circulation of the thorax?
The azygous vein drains the right thoracic wall
Has two tributaries the hemiazygos (inferior) and the accessory azyoug (superior) that drain the left thoracic wall
What nerves supply the thoracic wall?
Intercostal nerves
Anterior rami spinal nerves T1 to T11
Anterior rami of spinal nerve T12 is the subcostal nerve
What innervates pectoralis major?
Lateral pectoral nerve - clavicular head (lateral cord of brachial plexus)
medial pectoral nerve - sternocostal head
What innervates the pectoralis minor muscle?
Medial pectoral nerve -> from medial cord of brachial plexus
What innervates serratus anterior?
Long thoracic nerve
Anterior rami of C5 to C7
What valve is shown centrally in the parasternal short axis view of the heart?
The aortic valve
From which structures do the coronary arteries arise?
Right = anterior aortic sinus
Left = left posterior aortic sinus
Describe the key venous drainage of the heart?
Coronary sinus - enlargement of the great cardiac vein, found inferior to the left atrium
Great cardiac vein - originates at apex drains the anterior interventricular space then to the le
Small cardiac vein - coronary sulcus - between the left and right atrium.
Middle - posterior interventricular space
Posterior - posterior surface of the left ventricular
What nerve innervates the pericardium?
The phrenic nerve C3,4,5
What are the five types of atrial septal defect?
- Patent Foramen Ovale
- Ostium secundum defect
- Ostium primum defect
- Sinus venosus defect
- Coronary sinus defect
What is the most common cause of aortic stenosis?
Age-related calcification of the valve
What are the different placements of ICD electrodes?
Single chamber = right ventricle
Dual chamber = right ventricle and right atrium
Three chamber - RV, RA, LV
What is the function of an ICD?
Monitor heart rate/rhythm
Responds with electrodes = electrical activity to help treat abnormal electrical activity.
Name 6 muscles of inspiration
Diaphragm
External intercostal muscles
Sternocleidomastoid
Scalenes
Levator costarum
Seratus anterior
Name 4 muscles of expiration
Internal intercostal muscles
External oblique muscle
Rectus abdominus muscles
Posterior thoracic muscle
Subcostal muscles
