ACTIVITY 18A – HEART
Anterior Interventricular Sulcus
Comment:
• Surface projection at left 5th intercostal
space in mid-clavicular line
Description:
• Groove on anterior surface of heart
• Extends from coronary sulcus to inferior
margin of heart
• Marks position of interventricular septum
Comment:
• Contains anterior interventricular artery
and great cardiac vein
Chordae Tendineae
Location:
• Heart ventricles
Description:
• Fibrous strands that attach free edges of
atrioventricular valve cusps to papillary
muscles
Aortic Valve
• Composed of collagen
Function:
Location:
• At junction of left ventricle (aortic
• Prevent "flipping" of valve cusps into
atrium
vestibule) and ascending aorta
Description:
• Valve with three semilunar cusps
Function:
• Prevents reflux of blood into left ventricle
Comment:
• Valve closed during ventricular diastole
• Coronary arteries branch from ascending
Coronary Sulcus (Atrioventricular Sulcus)
aorta just distal to aortic valve
Description:
• Surface groove surrounding heart
• Marks junction between atria and
ventricles
Comment:
• Contains right and left coronary arteries,
circumflex branch of left coronary
artery, and coronary sinus
Apex of Heart
Description:
• Blunt tip of left ventricle
Left Atrioventricular valve (Bicuspid or
Mitral)
Description:
• Valve with two cusps between left atrium
Function:
• Contraction forces blood out of ventricle
Comment:
• Myocardium is thinner in atria
and ventricle
• Chordae tendineae attach free edges of
cusps to papillary muscles
Function:
• Prevents reflux of blood into left atrium
Comment:
• Valve is open during ventricular diastole
Myocardium of the Right Ventricle
Description:
• Muscle layer
• Thicker in left ventricle
• Between endocardium and epicardium
• Inner surface has trabeculae carneae and
papillary muscles
Function:
• Contraction forces blood out of ventricle
Muscular Interventricular Septum
Comment:
• Myocardium is thinner in atria
Location:
• Heart ventricles
Description:
• Thick, muscular, inferior part of partition
separating right and left ventricles
• Forms majority of interventricular septum
Opening of Coronary Sinus
Drainage:
• Receives venous blood from heart
Tributaries:
• Great, middle, and small cardiac veins
Course:
• Passes from left to right in posterior
Myocardium of Left Ventricle
Description:
• Muscle layer
• Thicker in left ventricle
• Between endocardium and epicardium
• Inner surface has trabeculae carneae and
papillary muscles
portion of coronary (atrioventricular)
sulcus
Termination:
• Right atrium
Opening of Inferior Vena Cava
Pectinate mm.
Location:
Location:
• Right atrium
Description:
• Opening to receive venous blood from
• Heart (atria)
Description:
• Ridges of myocardium extending from
regions of body inferior to diaphragm
crista terminalis in right atrium
• Ridges also occur in right and left auricles
Pulmonary Trunk
Origin:
• Right ventricle
Papillary mm.
Course:
• Ascends within pericardium
Location:
• Heart ventricles
Description:
• Conical elevations of myocardium in
ventricular chambers
• Chordae tendineae attached to apex
• A type of trabeculae carneae
Function:
• Regulates movement of atrioventricular
valve cusps
• Helps assure proper closure of
atrioventricular valves
Comment:
• Right ventricle has three, left ventricle has
two (number corresponds to number of
respective atrioventricular valve cusps)
• Initially anterior to ascending aorta and
then to its left and slightly posterior
Distribution:
• Lungs
Branches:
• Right pulmonary artery
• Left pulmonary artery
Comment:
• Conveys oxygen-poor blood from right
ventricle of heart
• Has pulmonary (semilunar) valve at its
origin
• Large arteries do not by themselves supply
structures, but do so through their
branches
Pulmonary Valve
• Right atrium
• Right ventricle
Location:
• At origin of pulmonary trunk from right
ventricle
Description:
• Valve with three semilunar cusps
Function:
• Prevents reflux of blood into right ventricle
Comment:
• Valve closed during ventricular diastole
• Interventricular septum
• Left ventricle
Branches:
• Right atrial
• Right marginal
• Posterior interventricular
Comment:
• Large arteries do not by themselves supply
structures, but do so through their
branches
Right Atrioventricular Valve
Superior Vena Cava
Location:
• Heart (between right atrium and right
ventricle)
Description:
• Valve with three cusps
• Chordae tendineae attach free edges of
cusps to papillary muscles
Also known as:
• Tricuspid valve
Comment:
• Valve is open during ventricular diastole
Drainage:
• Head
• Upper limbs
• Posterior thoracic walls
• Mediastinal structures
Tributaries:
• Formed by union of right and left
brachiocephalic veins
• Arch of azygos vein
Course:
• Descends in mediastinum from level of
right 1st costal cartilage
Termination:
• Right atrium
Right Coronary a.
Origin:
• Ascending aorta
Course:
• Passes between pulmonary trunk and right
auricle
• Lies in coronary (atrioventricular) sulcus
Distribution:
Anterior Interventricular Branch of Left
Coronary a.
• Large arteries do not by themselves supply
structures, but do so through their
branches
Origin:
• Left coronary
Course:
• Descends in anterior interventricular
sulcus toward apex of heart
Distribution:
• Right ventricle
Great Cardiac v.
• Left ventricle
• Interventricular septum
Also known as:
• Left anterior descending branch of left
coronary artery or LAD
Drainage:
• Left atrium
• Left ventricle
• Right ventricle
Course:
Comment:
• Commonly crosses apex of heart and
ascends in posterior interventricular
sulcus
• Anastomosis with posterior interventricular
artery
• Anastomosis refers to the end-to-end
union of vessels
• Ascends in anterior interventricular sulcus
• Enters coronary sulcus
Termination:
• Coronary sinus
Also known as:
• Anterior interventricular vein
Comment:
• Companion to anterior interventricular
artery
Ascending Aorta
Inferior Vena Cava
Origin:
• Left ventricle (aortic vestibule)
Drainage:
Course:
• Ascends short distance (approx. 5 cm)
within pericardium
Distribution:
• Heart (via coronary arteries)
Branches:
• Right and left coronary arteries
• Continues as arch of aorta
Comment:
• Has aortic valve at origin
• Everything inferior to diaphragm, except
posterior abdominal wall, which drains
into azygos system
Tributaries:
• Common iliac
• Lumbar
• Right testicular/ovarian
• Renal
• Right suprarenal
• Inferior phrenic
• Hepatic
• Also called left diagonal artery
Course:
• Ascends from level of L4 vertebral body,
through diaphragm, to heart
Termination:
• Right atrium of heart
Comment:
• Largest vein of body
Small Cardiac v.
Drainage:
• Right atrium
• Right ventricle
Course:
• Lies in coronary sulcus between right
atrium and right ventricle
Left Anterior Ventricular v.
Termination:
• Coronary sinus
Drainage:
• Left ventricle
Course:
• Ascends across anterior surface of left
ventricle
Termination:
• Great cardiac vein
Circumflex branch of Left Coronary a.
Origin:
• Left coronary
Course:
Left Lateral a.
• Passes from anterior to posterior surface
of heart in left portion of coronary sulcus
Origin:
Distribution:
• Anterior interventricular branch (LAD) of
left coronary artery
Course:
• Left ventricle
Branches:
• Courses laterally and obliquely (i.e.,
diagonally) to the anterior aspect of the
left ventricle
Distribution:
• Left ventricle (anterior aspect)
Comment:
• Left atrium
• Left marginal
• May continue as posterior interventricular
branch
Left Atrial a.
• Great cardiac
Origin:
• Right coronary
Course:
• Ascends across posterior surface of left
atrium
Distribution:
• Left atrium
Left Pulmonary vv.
Drainage:
• Lungs
Tributaries:
• Lobar veins
Course:
• Two veins pass through root of each lung
(i.e., four pulmonary veins in total) and
directly into left atrium
Left Posterior Ventricular a.
Termination:
• Left atrium
Comment:
Origin:
• Circumflex branch of left coronary artery
• Carry oxygen-rich blood
Course:
• Courses across posterior surface of left
ventricle
Distribution:
• Left ventricle
Middle Cardiac v.
Drainage:
• Right ventricle
• Left ventricle
Course:
• Ascends in posterior interventricular sulcus
Left Posterior Ventricular v.
from apex of heart
Termination:
Drainage:
• Left ventricle
Course:
• Ascends across posterior surface of left
ventricle
Termination:
• Coronary sinus
Also known as:
• Posterior interventricular vein
Comment:
• Companion to posterior interventricular
artery
Oblique v. of Left Atrium
Posterior Interventricular sulcus
Drainage:
Description:
• Left atrium
• Groove on posterior surface of heart
• Extends from coronary sulcus to apex of
Course:
• Descends across posterior surface of left
atrium
Termination:
• Coronary sinus
heart
• Marks position of interventricular septum
Comment:
• Contains posterior interventricular artery
and middle cardiac vein
Posterior Interventricular a.
ACTIVITY 18B – BLOOD VESSELS
Origin:
• Right coronary artery
Arteriole
Course:
• Courses through posterior interventricular
sulcus
Location:
• Connect muscular (distributing) arteries
with capillaries
Distribution:
• Left ventricle
• Right ventricle
• Interventricular septum
Description:
• Arteries with overall diameter 40-200 µm
• Tunica media has one to three layers of
smooth muscle
Comment:
• Accompanies middle cardiac vein in
posterior interventricular sulcus
• Right dominant heart: Posterior
interventricular artery derived from right
coronary artery (80%)
• Left dominant heart: Posterior
interventricular artery derived from
circumflex branch of left coronary artery
(20%)
Function:
• Supplies blood to capillaries
Comment:
• Companion vessels to venules
• Primary point for control of blood flow to
organs
Tunica Externa of Arteriole
Location:
• Outermost layer of vessel wall
Description:
• Composed of elastic and collagen fibers
Tunica Intima of Arteriole
Location:
• Innermost layer of vessel wall
Description:
Function:
• Anchor blood vessel to surrounding
• Composed of endothelium and its
basement membrane
structures
Also known as:
• External limit formed by internal elastic
• Tunica adventitia of arteriole
lamina
Function:
Comment:
• In arteries, tunica media is thickest layer;
• Selectively permeable barrier to blood
solutes
in veins, thickest layer is tunica externa
• Secretes vasoconstrictors and vasodilators
• Provides smooth inner lining that repels
blood cells and platelets
Tunica Externa of Venule
Location:
• Outermost layer of vessel wall
Description:
• Minimal tunica externa with a few collagen
fibers and some fibroblasts
Tunica Intima of Venule
Function:
• Anchor blood vessel to surrounding
structures
Also known as:
• Tunica adventitia of venule
Location:
• Innermost layer of vessel wall
Description:
• Composed of endothelium and its
basement membrane
Comment:
• In arteries, tunica media is thickest layer;
in veins, tunica externa is thickest layer
Function:
• Selectively permeable barrier to blood
solutes
• Secretes vasoconstrictors and vasodilators
• Provides smooth inner lining that repels
blood cells and platelets
Function:
• Vasoconstriction and vasodilation (when
Comment:
muscular tunica media present)
• Tunica intima also known as tunica interna
Comment:
• In arteries, tunica media is thickest layer;
in veins, tunica externa is thickest layer
Tunica Media of Arteriole
Location:
Vasa Vasorum
• Middle layer of vessel wall
Description:
• Composed of one to three layers of
circularly arranged smooth muscle cells
and connective tissue
• External elastic lamina inconspicuous
Function:
Location:
• Tunica externa
Description:
• Small blood vessels
Function:
• Supply outer 1/2-2/3 of tunica media
• Vasoconstriction and vasodilation
Comment:
• In arteries, tunica media is thickest layer;
in veins, tunica externa is thickest layer
Venule
Location:
• Connects capillaries with small and
Tunica Media of Venule
medium-sized veins
Description:
• Veins with overall diameter 15-100 µm
Location:
• Middle layer of vessel wall
• Acquires tunica media of smooth muscle in
larger venules
Description:
• Small venules lack tunica media
• Larger venules acquire incomplete tunica
media of smooth muscle
Function:
• Exchange fluid with surrounding tissues
• Diapedesis (migration of leukocytes from
blood vessel into interstitial fluid) occurs
in postcapillary venules
Comment:
• Companion vessels to arterioles
• Smallest venules called postcapillary
venules