Thoracic Cavity 1 Flashcards
What is the function of body cavities?
Confine large organs and systems
What are body cavities lined by?
Serous membrane
What is the function of serous membranes?
Allows movement, expansion and contraction of organs
What is the meaning of a serous membrane?
Closed to the outside
What is contained within the thoracic cavity?
Lungs, heart and chest wall
What allows friction free movement within a serious membrane?
minuscule layer of fluid lubricates the potential space
What is the heart covered by?
Pericardium
What is a mucous membrane?
cavities that open to the outside
What lines the abdominal and pelvic cavities?
Peritoneum
What 3 compartments is the thoracic cavity divided into?
Right and left pleural cavities and the mediastinum between them
What is pleura and how is it distributed in the thoracic cavity?
Covers the lungs and reflects onto itself around the root of the lung and cover the diaphragm and thoracic wall
Can lung compartments communicate with each other?
NO
What is parietal pleura attached to?
Thoracic wall (costal), fascia in the thoracic inlet (neck; at 1st rib and T1), fibrous pericardium and other mediastinal structures and diaphragm
Viscera
organ
Paries
wall
What is the mediastinum?
Space between the 2 pleural sacs, the sternum and costal cartilages, thoracic vertebrae and diaphragm
What is contained within the mediastinum and why are the suited to this region?
filled with hollow organs. Highly mobile region that permits volume and pressure changes
Where is the superior mediastinum?
Behind the manubrium between the inlet and the plane between the sternal angle and T4/5
Where is the inferior mediastinum?
Inferior to the transverse plane through the sternal angle and the diaphragm
What is the inferior mediastinum divided into?
Anterior, middle and posterior mediastinum
What structures are located in the right of the mediastinum? And what are they related to?
Superior vena cava, ach of azygos and inferior vena cava; right atrium
What structures are located in the left mediastinum? And what are they related to?
Left common carotid artery, left subclavian artery. Arch of aorta and thoracic aorta; left ventricle
What is contained within the middle mediastinum?
heart, pericardium (origins of great vessels - aorta, pulmonary trunk, vena cava and pulmonary veins), phrenic nerves and vagus
What is the pericardium?
Fibro-serous sac that encloses the heart and the roots of the great vessels
What is the function of the pericardium?
Anchoring the heart to surrounding tissues without compromising cardiac movement and preventing overfilling of the heart
What 2 layers is the pericardium composed of?and how is it attached to the sternum
serous and fibrous; by ligaments
What is the apex of the fibrous pericardium attached to?
adventitia of great vessels
What does the fibrous pericardium attach to anteriorly?
Attached by sterno-pericardial ligament to the body of the sternum and 3rd-6th costal cartilages
What does the fibrous pericardium attach to posteriorly?
Attached by pericardiovertebral ligaments to 5th-8th thoracic vertebrae
What does the fibrous pericardium attach to inferiorly?
Blends with the central tendon of the diaphragm (pericardiophrenic ligament)
Where is the serous pericardium located? And what 2 layers does it have?
Located inside the fibrous pericardium and has parietal and visceral layers
Describe the parietal layer of the serous pericardium
Lines the inner aspect of the fibrous pericardium and reflects onto itself around the roots of the great vessels and continues as the visceral layer
Describe the visceral layer of the pericardium
Epicardium
What is the pericardial cavity?
Between parietal and visceral layers of serous pericardium
What is pericardial fluid?
Fluid produced by the serous pericardium to reduce friction during contraction of the heart
What happens to the heart tube during embryological development?
Heart tube folds and invaginates into the serous pericardium (within the fibrous sac)
What is the transverse pericardial sinus? And where is it located?
Separates the arterial and venous ends of the heart tube; posterior to ascending aorta and pulmonary trunk, anterior to superior vena cava and superior to LA and pulmonary veins
What is the clinical significance of the transverse pericardial sinus?
Clamped in cardiac surgery
What is the oblique pericardial sinus? And where is it located?
Surrounded by the reflection of serous pericardium around the right and left pulmonary vein and the inferior vena cava
Where does the pericardium receive its sensory nerve fibres from?
Phrenic nerve
Where does the pericardium receive its vasomotor fibres from?
Vagus nerve and cardiopulmonary splanchnic nerves (Sympathetic)
What plexus does the phrenic nerve branch from? And what rami does it arise from?
Cervical plexus; ventral rami of C3,4,5
What muscle does the phrenic nerve travel over?
Scalenus anterior
Where does the phrenic nerve enter the mediastinum?
Between the venous and arterial planes (subclavian)
Where does the phrenic nerve lie? And what does it lie between and pass through?
Lies between fibrous pericardium and parietal pleura; and passes through Caval opening
What is the motor function of the phrenic nerve?
Sole motor supply to the diaphragm
What is the sensory function of the phrenic nerve?
Mediastinal parietal pleura; peritoneum and pleura related to the central tendon of the diaphragm
What can an infected gallbladder irritate? And what dermatome does this affect?
Irritation of the diaphragm; Dermatome C4 affected
