Cardiovascular Anatomy Flashcards
From right to left, what are the main branches coming off the aortic arch?
RIGHT LEFT
Brachiocephalic artery Left common carotid artery Left subclavian artery
What is the composition of the pericardium?
Fibrous layer (tough) on outside and serous layer (thin) on inside
Serous layer made up of parietal (lines inner surface of fibrous layer) and visceral (adheres to heart)
Note: pericardium attaches to diaphragm inferiorly by the central tendon
What valves are present in the right heart and left heart respectively?
RIGHT HEART:
Tricuspid valve & pulmonary valve
LEFT HEART:
Mitral valve & aortic valve
How is the heart innervated?
Phrenic nerve innervates on both sides (innervates diaphragm below the heart)
Vagus nerve…. ++++
What is the structure of large elastic arteries? What is the main purpose of elastic arteries?
Conduct blood away from the heart (ability to stretch keeps pressure constant)
TUNICA INTIMA:
Endothelial cells + narrow subendothelium of connective tissue + discontinuous internal elastic lamina
TUNICS MEDIA:
40-70 fenestrated elastic membranes + smooth muscle cells + collagen + thin external elastic lamina
TUNICA ADVENTITIA:
thin layer of fibroelastic connective tissue + vaso vasorum + lymphatic vessels + nerve fibres
What are vaso vasorum?
Small nutrient arteries and veins in the walls of larger blood vessels (for blood vessels so thick that they need their own blood supply)
What is the structure of muscular arteries? What is the main purpose of muscular arteries?
Distribute blood around the body (influenced by vasodilation/vasoconstriction)
TUNICA INTIMA:
Endothelium + subendothelium + thick internal elastic lamina
note: protruding endothelial cells indicates vasoconstriction
TUNICA MEDIA: (circular arrangement)
40 layers of smooth muscle cells connected by gap junctions + prominent external elastic lamina with fenestrations for noradrenaline diffusion
note: as diameter diminishes, the no. of smooth muscle layers decreases
TUNICA ADVENTITIA: (longitudinal arrangement)
Thin layer of fibroelastic connective tissue + vaso vasorum + lymphatic vessels + nerve fibres
What is the structure of arterioles? What is the main purpose of arterioles?
Resistance vessels (ensures brain is perfused against gravity)
TUNICA INTIMA:
Endothelial cells + thin layer of subendothelial tissue
TUNICA MEDIA:
1-3 layers of continuous smooth muscle cells + thin internal elastic lamina (in large arterioles)
TUNICA ADVENTITIA:
Scant (no layer of external elastic lamina) + layer of fibroblasts
What are metarterioles?
Arteries that supply blood to capillary beds
Smooth muscle is discontinuous unlike arterioles
Individual muscle cells are spaced apart and each encircle the endothelium of capillaries, forming precapillary sphincters (control blood flow into capillary bed)
What are the general features of capillaries? What are some specific subtypes?
Single layer of endothelium + basement membrane
- continuous: nervous, muscle, connective tissue, exocrine glands, lungs (continuous endothelial layer - tight junctions + pericytes)
- fenestrated: gut, endocrine glands, renal glomerulus
(windows across thin parts of endothelium bridged by thin diaphragm - except in renal glomerulus) - sinusoidal: liver, spleen, bone marrow (gaps exist in walls to allow whole cells to move between blood and tissue - slow flowing)
What is the structure of postcapillary venules?
Endothelium + pericytes
Diameter 10-30um: very permeable
Low pressure -> fluid drains into veins (except during an inflammatory response) -> leukocyte & fluid emigrate from blood to tissues
Diameter >50um
Smooth muscle fibres associate with endothelium (tunica media appears)
Intimal extensions
What are intimal extensions?
Small valves in venules that restrict retrograde blood flow (act with muscles)
What is the structure of medium-sized veins?
Compared to accompanying artery: larger diameter but thinner wall; more connective tissue and fewer elastic &muscle fibres
Well developed adventitia & thin tunica intima & media (thickens with increased diameter)
note: superficial veins in legs have well-defined muscular wall to resist distension by gravity
What are venae comitantes?
Deep paired veins that accompany one of the smaller arteries on each side of a larger artery
Three vessels wrapped in one sheath
Pulsing of artery promotes venous return within the adjacent veins
e.g. bronchial, ulnar, tibial
What is the structure of large veins?
Well developed longitudinal smooth muscle in tunica adventitia + circular smooth muscle in tunica media
e.g. vena cavae, pulmonary, portal, renal, internal jugular, iliac,
What is the difference between the transverse and oblique sinus?
TRANSVERSE: separates arteries from veins
OBLIQUE: formed by reflection onto the pulmonary veins of heart
Describe what areas of the heart are supplied by what vessels.
Right coronary artery:
- right side of the heart
- back of septum
- base of both ventricles
Left coronary arteries:
- CIRCUMFLEX: left atrium and ventricle
- LEFT ANTERIOR DESCENDING: front and base of left ventricle and front of septum
Great cardiac vein: drains areas supplied by left coronary arteries
Middle cardiac vein: drains area supplied by posterior interventricular branch of right coronary artery
Small cardiac vein: drains posterior part of right atria and ventricle
What is pericarditis? What is constrictive pericarditis? What is Kussmaul’s sign?
Inflammation of the pericardium e.g. due to viral & bacterial infections, systemic illnesses (chronic renal failure), post-MI
Continuous central chest pain that may radiate to one or both arms, but the pain may be relieved by sitting down
ECG to differentiate from MI
CONSTRICTIVE PERICARDITIS = abnormal thickening of pericardial sac compresses heart -> heart failure
Open pericardial sac
Kussmaul’s sign = jugular venous pulse raises on inspiration
What is a pericardial effusion?
Excess fluid between visceral and parietal layers of serous pericardium which compresses the heart (fibrous pericardium cannot expand easily)
Causes cardiac tamponade —–> Biventricular failure
Remove fluid with a needle
What are the key anatomical features of the right atrium?
Fossa ovalis (remnant of foramen ovale)
Crista terminalis (….)
Pectinate muscle (…)
Opening of coronary sinus
Right auricle
Tricuspid valve
Valve of IVC
What are the key anatomical features of the right ventricle?
Ligamentum arteriosum (remnant of ductus arteriosus)
Pulmonary valve
Chordae tendineae (…..)
Tricuspid valve
Anterior papillary muscle (….)
Trabeculae carneae (…..)
What are the key anatomical features of the left atrium?
Valve of foramen ovale
Mitral valve
Left auricle
What are the key anatomical features of the left ventricle?
Mitral valve
Chordae tendineae (…..)
Trabeculae carneae (…..)
Posterior papillary muscle (…..)
Coronary sinus
Which vessels supply the front, back, right, and left aspects of the heart?
Front & right = right coronary artery
Front & left = anterior interventricular branch & great cardiac vein
Back & right = right coronary artery & coronary sinus
Back & left = posterior left ventricular veins & posterior left ventricular branch
+ circumflex branch of left coronary artery -> left atrium
+ left anterior descending coronary artery -> left atria, left ventricle, and interventricular septum
