Anatomy

Lecture mediastinum and GA of heart

Describe internal features of atrium and ventricle(unknown)

Right atrium Left atrium

● Receive the blood from the systemic ● Receive blood from the lung via
circulation & heart muscle via pulmonary vein
○ SVC ● Wall of left atrium are smooth but walls of
○ IVC left auricle composed of pectinate muscle
○ Coronary sinus
● RA pumps blood to RV
● Anterior wall composed pectinate muscle
● Posterior wall smooth muscle
● Internally, Smooth and rough part of RA
wall is separated by crista terminalis
● Externally, this separation is indicated by
sulcus terminalis cordis
● Walls of right auricle composed of
pectinate muscle

Right ventricles Left ventricles

● LV has similar structure as RV however
● Outflow tract of RV has conus arteriosus the traveculae carneae in LV are fine &
● RV wall composed of trabeculae carnage delicate in contrast to RV
● Papillary muscle attached to chordae ● Anterior & posterior papillary muscles are
tendinae usually found in LV & are larger
● 3 papillary muscle ● Left ventricle has a thicker wall to exert
○ Anterior papillary muscle more pumping force
○ Posterior papillary muscle
○ Septal papillary muscle
● Septomarginal trabecula(moderator band)
forms a bridge between lower portion of
the interventricular septum & base of the
anterior papillary muscle

Anatomy(lumiere)
A. Name sulci and its content
 B. Diagram of interior right atrium
C. Blood supply interventricular septum
D. Location of apex beat

A.Name sulci and its content B. Diagram of interior right atrium

There are two sulci:
1. Coronary sulcus
a. Coronary arteries
i. Right coronary artery
ii. Left coronary artery
iii. Circumflex branch of left
coronary artery
b. Cardiac vein
i. Great cardiac vein
ii. Coronary sinus
iii. Small cardiac vein
2. Anterior & posterior interventricular
sulcus
a. Anterior
i. Anterior interventricular
branch of left coronary
artery
ii. Great cardiac vein
b. Posterior
i. Posterior interventricular
branch of right coronary
artery
ii. Middle cardiac vein

c. Blood supply interventricular septum D.Location of apex beat

1. Anterior interventricular branch of left left 5th intercostal space, half-inch medial to the left
coronary artery midclavicular line and 3–4 inches left of left border
2. Posterior interventricular branch of right of sternum.
coronary artery

Genezen
a) Draw the division, boundaries of mediastinum (inferior and superior including sub-division)
[4M]
b) Contents of posterior mediastinum [2M

A.

B.Content of mediastinum

Superior 1. Thymus,
2. Trachea,
3. Esophagus,
4. thoracic duct,
5. aortic arch,
6. veins (superior vena cava, brachiocephalic, left
superior intercostal),
7. nerves (vagus, phrenic, left recurrent laryngeal),
 8. lymphatics, other small arteries and veins
Mnemonic: Try To Eat Toast And Vitamins Now Little
Oliver

Anterior inferior mediastinum remnants of the thymus, lymph nodes

Middle inferior mediastinum 1. phrenic nerve,

2. heart,
3. pericardium,
4. ascending aorta,
5. pulmonary trunk,
6. superior vena cava,
7. pericardiacophrenic artery

Posterior inferior mediastinum 1. descending thoracic aorta,

2. azygos veins,
3. hemiazygos veins,
4. accessory hemiazygos veins,
5. thoracic duct,
6. cisterna chyli,
7. esophagus,
8. esophageal plexus,
9. vagus nerve,
10.greater, lesser and least splanchnic nerves,
lymphatics
Mnemonic: on the DATE Vivian Slapped Larry

Describe the right atrium under the following headings:(Oddityx)

A. External features [2 marks]

B. Openings [3 marks]

Right atrium Left atrium

A. External feature A. External feature
1. The right atrium is a thin-walled 1. It is a thin-walled quadrangular
chamber that sits at the top right chamber found posteriorly at the
side of the heart. back and towards the left side of
2. The muscular walls of the right right atrium. It creates greater
atrium are much thinner than part of the base of the heart (left
those of the ventricles. 2/3rd).
3. The right atrium features a 2. In order to create the left auricle,
wrinkled flap shaped like a which overlaps the infundibulum
floppy dog ear, known as the of right ventricle Its upper end is
auricle. prolonged anteriorly.
 4. The right atrium has an 3. Structures behind the left atrium:
extension known as the right Oblique sinus of serous
atrial appendage. pericardium. Fibrous
5. Between the right atrium and pericardium.
right ventricle is a one-way B.openings
valve known as the tricuspid 1. Four ostia of pulmonary vein
valve
B.openings
1. SVC
2. IVC
3. Coronary sinus
4. Foramina venarum minimarum
5. Atrioventricular opening

Right ventricle Left Ventricle

A. External feature A. External features
1. It creates the most of 1. Seperated from the left atrium by
sternocostal surface along with coronary sulcus
the small part of the
diaphragmatic surface of the
heart.
2. The inferior border is also
created by it.
3. A relatively vertical anterior
portion of the coronary sulcus or
atrioventricular groove separates
it from the right atrium.
Lecture blood & nerve supply of the heart
Describe the component, location, arterial supply of conducting system of the heart

1. Sinu atrial nodes 2. Atrioventricular node

Location Location
● Aterolaterally at junction of SVC & right ● Posteroinferior region of interatrial
atrium septum. Beneath the right atrial
Artery supply endocardium
● Sinu-atrial nodal branch ● Superior to the opening of coronary sinus
Artery supply
● AV nodal branch

3. Atrioventricular bundle( Bundle of his) 4. Purkinje fiber

Location Location
● Descend through fibrous skeleton of ● Extend into walls of ventricle
heart & through the membranous part of Artery supply
IV septum ● Coronary artery
● Divides into rt and lt branches at the
junction of the membranous & muscular
parts of IV septum
Artery supply
● Septal branch

Describe the blood supply of the heart(oddityx)

A. Arteries [2 marks]
B. Area of supply [4 marks]
C. Coronary artery dominance [2 marks]
D. Applied anatomy [2 marks]

Right coronary artery Left coronary artery

Branches Branches
1. Sinu-atrial nodal branch 1. Anterior interventricular branch
a. Supply SA node a. Adjacent part of both ventricles
2. Right marginal branch b. Anterior ⅔ of IV septum
a. Anterior wall of RV 2. Circumflex branch
3. Atrioventricular nodal branch
a. Supply AV nodes Supply
4. Posterolateral branch 1. Lt atrium
5. Posterior interventricular branch(PDA) 2. Lt ventricle- except area adjacent to
a. Diaphraghmatic wall of RV posterior IV groove
b. Adjacent area of LV 3. Rt ventricular- small part adjacent to
 c. Posterior ⅓ of IV septum anterior IV groove
Supply 4. Anterior ⅔ IV septum
1. Rt atrium 5. SA node
2. Rt ventricle except adjacent area to 6. AV node
anterior IV groove 7. Bundle of his & bundle branches
3. Lt ventricle but a small part on
diaphragmatic surface adjacent to
posterior IV groove
4. Posterior ⅓ IV septum
5. SA node
6. AV node
7. Bundle of his & bundle branch

Coronary dominance
● Defined by which coronary will branch gives off the posterior descending artery and
supply inferior wall
● The vessel most commonyly originated from RCA(70-80%), Lt circumflex
artery(5-10%), both (10-20%)

Describe the tributaries of coronary sinus (predicted)

1. Great cardiac vein 2. Middle cardiac vein

Function: drains area of heart supplied by ● Begins at apex of hear
LCA ● Ascends in post. IV groove,
Has 2 part accompanying post. IV branch
● 1st part ● Opens into the right end of coronary
○ Begins at apex of heart sinus
○ Ascends in ant. IV groove with
ant. IV branch
○ Become 2nd part before reach
coronary sinus
● 2nd part
○ Runs into anterior coronary
sulcus
○ Accompanied by circumflex
branch of LCA
○ Curve around the left border
of heart
○ Drains into the left end of
coronary sinus

3. Small cardiac sinus

● Present in posterior coronary sulcus, in between RA & RV
● Opens into the right end of coronary sinus
Lecture Circulatory system & great vessels
c) Describe the course of thoracic aorta and branching (genezen)

1. Describe the arch of aorta under following headings :(xanthron)

a. Course [3marks]
b. Relations with diagram [5marks]
c. Branches
2. Course and relation of descending thoracic aorta + 3 branches of descending thoracic
aorta (atma)

Aorta Course Relation Branches

Ascending aorta 1. Begins at the 1. Close to aortic

base of the anulus
lower left 2. Sinuses of
ventricle at valsalva
the lower 3. Aorticopulmonary
border of the bodies
3rd left costal 4. Inferior and
cartilage middle
2. Ascends aorticopulmonary
obliquely, body
curving
forwards and
to the right

Arch of aorta 1. Begins when 1. Left phrenic nerve 3 branches

the ascending 2. Left lower cervical 1. Brachiocephalic
aorta cardiac branch of a. Rt common
emerges from the vagus carotid a
the pericardial 3. Left superior b. Rt subclavian
sac and cervical branch of a
courses the sympathetic n c. Thyroid ima a
upward, 4. Left vagus 2. Left common carotid
backward and artery
to the left as it 3. Left subclavian artery
passes a. Axillary a
through the
superior
mediastinum
2. Ending on the
left side at
vertebral level
TIV/V

descending/thoracic 1. Begins at the 1. Anterior: vertebral 1. Pericardial branches

aorta level of lower column, 2. Bronchial a.
border of accessory 3. Mediastinal branches
 fourth thoracic hemiazygous vein 4. Phrenic branches
vertebra 2. Posterior: left 5. Phrenic branches
2. Ends anterior pulmonary hilum 6. Post. intercostal a.
to lower 3. Right lateral: 7. Subcostal a.
border of the azygos, thoracic 8. Aberrant a
twelfth duct and below,
thoracic right pleura and
vertebra lung
4. Left lateral:
oesophagus and
its plexus