Cardiovascular System Thorax 2 pre practical Flashcards
Where is the mediastinum?
The mediastinum lies between the right and left pleurae. It extends from the sternum in front to the vertebral column behind.
What is contained in the mediastinum?
All the organs except the lungs
What are the divisions of the mediastinum?
It is divided into two parts: a superior part and an inferior part.
The inferior part is subdivided into three regions all relative to the pericardium: The anterior mediastinum is in front of the pericardium. The middle mediastinum contains the pericardium and its contents. The posterior mediastinum is behind the pericardium.
What is the contents of the superior mediastinum?
Brachiocephalic vein
Superior vena cava
Arch of aorta
Vagus, phrenic nerves
Trachea
Oesophagus
Thoracic Duct
What does the anterior mediastinum contain?
Thymus
Lymph nodes
Fat
What is contained within the posterior mediastinum?
Oesophagus and vagus nerve
Azygos vein
Sympathetic trunk
Thoracic duct
Descending aorta
Splanchnic nerve
What vertebrae does the heart lie opposite?
Lies opposite middle 4 thoracic vertebrae (T5-8) in recumbent position
Where is the apex of the heart?
5th left ic space, midclavicular line
= l. ventricle
What makes the base of the heart?
Left atrium
What makes up the right border of the heart?
Superior vena cava and the right atrium
What makes up the left border of the heart?
Aortic arch and the left ventricle
What makes up the anterior surface of the heart?
Anterior surface: = r. atrium (1/4),
r. ventricle (2/4), l. ventricle (1/4)
What does the internal thoracic artery give off?
Anterior intercostal arteries
What does the internal thoracic veins receive?
Anterior thoracic veins
What are the main arteries, veins and lymphatics of the chest wall?
Internal Thoracic a.
Gives off anterior intercostal arteries
Internal Thoracic v.
Receives anterior thoracic veins
Descending aorta
Inferior vena cava
Azygos vein
Thoracic duct
How do the IVC and SVC lie with the aorta?
IVC & SVC lie to right of aorta
Aortic “tango” with IVC
Look
Where does the subclavian artery arise from?
The aortic arch
Where does the subclavean artery become the axillary artery?
At the lateral border of the first rib
Where does the axillary artery become the brachial artery?
At the inferior border of teres major
Where does the brachial artery divide into the radial and ulnar arteries?
The cubital fossa
What forms the digital arteries?
Palmar arches in the palm of the hand formed by the radial and ulnar arteries
Where do superficial veins arise on the upper limb?
From the dorsal venous arch on the bac of the hand
What does the cephalic vein do?
Travels up the limb on lateral side. Drains into axillary vein below clavicle
What does the basilic vein do?
Travels up the limb on the medial side
Becomes continuous with brachial veins (deep veins accompanying brachial a.)
(Cephalic - axillary
Basilic - brachial)
What is the median cubital vein?
Median cubital connects cephalic and basilic across cubital fossa
What happens to the external iliac artery in the anterior thigh?
Becomes the common femoral artery
What does the common femoral give off?
Superficial and deep femoral arteries
What happens to the superficial femoral artery?
Popliteal (in the popliteal fossa)
What gives the posterior and anterior tibial artery in the leg?
Popliteal artery
What does the posterior tibial give off?
The fibular artery and continues medially down to plantar surface of foot (= medial & lateral plantar aa)
What does the anterior tibial artery give off?
Ant. tibial continues down anteriorly to dorsum of foot where it becomes dorsalis pedis between 1st & 2nd toes
Where do the superficial veins arise in the lower limb?
Superficial veins arise from dorsal arch of foot
Where does the long saphenous vein travel?
Long saphenous travels up the limb medially to drain into femoral vein
Where does the short saphenous vein drain ?
Short saphenous travels up the limb posteriorly to drain into popliteal
What does the popliteal vein become?
Femoral vein proximally
What does the femoral vein become proximally?
External iliac
Where do superficial veins drain?
Into deep veins
Where do the following pulse points of the body arise from?
Superficial temporal and facial
Common carotid
Brachial
Radial
Femoral
Popliteal
Posterior tibial
Dorsalis pedis
Superficial temporal and facial - branches of the external carotid
Common carotid - branch of the aortic arch
Brachial - continuation of the axillary
Radial - lateral branch of the brachial
Femoral - continuation of the external iliac
Popliteal - continuation of the femoral
Posterior tibial - branch of the popliteal
Dorsalis pedis - continuation of the anterior tibial
What chambers of the heart are in line with the sternum?
Right ventricle and the left atrium
What are the following landmarks on the CT scan?
What are the 2 pericardia surrounding the heart?
Fibrous and serous pericardia
What payer if the heart is also known as the visceral layer of the serous pericardium?
Epicardium
What is the space between the visceral and parietal layers of the pericardium called and what is it filled with?
Called the pericardial cavity, it is filled with fluid.
What is the epicardium composed of?
Endothelial cells and a thin layer of fat and connective tissue
What are the labelled areas of the heart?
At the bottom is the coronary sinus
•Openings for:
IVC, SVC, Coronary sinus
- Interatrial septum
- Fossa ovalis in ia septum
- Musculi pectinati
- Tricuspid valve
What are the labelled areas of the heart? (right ventricle)
•Tricuspid valve
3 valve cusps
Chordae tendineae
Papillary muscles x3
- Trabeculae carneae (contractile fleshy struts)
- Moderator band (Septomarginal trabeculum)
- Opening for pulmonary trunk
- Interventricular septum
What is the purpose of the trabeculae carnae?
Most likely to prevent suction that would occur with a flat surface and thus imparir the hearts ability to pump efficiently.
The papillary muscles themselves are just a specialised form of trabeculae carneae.
What are the main identification features of the left atrium?
•Openings for:
l + r superior pulmonary veins
l + r inferior pulmonary veins
- Bicuspid (mitral) valve
- Smooth-walled, small chamber
How does the left atrium lie in respect to the oesophagus?
Lies postero-superiorly against the oesophagus
What portion of the heart forms the base?
Left atrium
What is the function of the musculi pectinati?
Some sources cite that the pectinate muscles are useful in increasing the power of contraction without increasing heart mass substantially
What is the funciton of the moderator band?
It carries part of the right bundle branch of the AV bundle to the anterior papillary muscle. This shortcut across the chamber of the ventricle seems to facilitate conduction time, allowing coordinated contraction of the anterior papillary muscle
How does the number of papillary muscles differ between left and right atrium?
Left ventricle has 2
Right ventricle has 3
What are the labelled areas of the left ventricle?
Main features
•Biscuspid (mitral valve)
2 valve cusps
Chordae tendineae
Papillary muscles x2
- Trabeculae carneae
- Opening for aorta
- Interventricular septum
- Wall 3x as thick as right ventricular wall.
Which part of the heart forms the apex?
The left ventricle
What is abnormal about this chest xray?
Dextrocardia
What is abnormal about this chest x-ray?
Cardiomegaly
Label the following picture of the heart and the coronary arteries
Where does the right coronary artery arise from?
The right aortic sinus of ascending aorta.
What sulcus does the right coronary artery run in?
The atrioventricular sulcus
At what point does the right coronary artery give off the right marginal artery?
At the inferior margin of the heart
Where does the left coronary artery arise from?
The left aortic sinus of the ascending aorta
What sulcus does the left coronary artery run in?
The coronary sulcus
What does the left coronary artery divide to form?
Divides immediately to form left anterior descending artery and the circumflex artery
WHich coronary artery gives off the posterior descending artery in the interventricular sulcus?
The right coronary artery on the posterior surface of the heart.
What are the two different anastomoses of the coronary arteries?
- Ant + Post descending
- Circumflex + RCA
Occur on post surface of heart
What do anatomists call the anterior descending artery and the posterior descending artery?
The anterior interventricular artery and the posterior interventricular artery respectively
What are the two major sulci that contain the branches of the coronary arteries?
- Coronary (Atrioventricular) sulcus - between atria + ventricles
- Interventricular sulcus - between r + l ventricles
What are the labelled areas of the heart and the cardiac veins?
What does the great cardiac vein lie alongside?
The anterior interventricular artery
What does the middle cardiac vein lie alongside?
The posterior interventricular artery
What does the small cardiac vein lie alongside?
The right marginal artery
Where do all th cardiac veins drain?
Into the coronary sinus lying alongside the circumflex artery
Where does the coronary sinus drain into?
The right atrium
Which vein drains directly into the right atrium?
The anterior cardiac vein
What sets the heart’s inherent rate of contraction?
Set by a small group of specialized cardiac cells found in the SA node - this rate can be altered through the autonomic nervous system
What part of the heart does the phrenic nerve innervate?
Fibrous pericardium and parietal layer of serous pericardium. Carries pain sensation.
What part of the heart does the vagus nerve innervate?
Innervates the heart and visceral layer of serous pericardium.
Where do the sympathetic fibres originate that innervate the heart and the visceral layer of the serous pericardium?
Cervical and upper thoracic sympathetic ganglia
Where do signals inside the heart travel ?
Arise in the SA node - stimulate atria to contract
Travel to the AV node - delayed
Conducted through the bundle of his (AV bundle) to the left and right bundle branches and purkinje fibres to the endocardium at the apex of the heart
Then to the ventricular epicardium
Describe the artery
- Thick smooth muscular wall
- Lumen smaller relative to wall than vein
Describe the vein
- Thinner wall than artery.
- Less smooth muscle.
- Lumen wider relative to wall than artery
What is the structure of cardiac muscle?
- Branching striated fibres
- Central rounded nuclei
- Intercalated discs
Describe muscular arteries
•= smaller distributing arteries
•
•Thick smooth muscle in wall, few elastic fibres
Describe elastic arteries
- = larger conducting arteries receiving blood directly from heart
- Numerous laminae of dark-staining, wavy, elastic fibres in wall in amongst smooth muscle fibres
