heart anatomy

Question 1

position

Answer 1

anatomically: lower, middle mediastinum
clinically: ant. mediastinum

*milli 2 og 5 rib/intercostal space
*from right parasternal line to left midclav. line
*1/3 on right. 2/3 on left side

**Axis snýr down, anteriorly og to left

Question 2

relations

Answer 2

anterioly: thymus, sternum og ribs

laterally: lungs (sep. by mediastinal pleura), phrenic nerves

posteriorly: trachea, bifurcation, princ.bronchi, esophagus og thoracic aorta.

inferiorly: diaphragm

Question 3

external features

Answer 3

Surfaces:
1) sternocostal: anterior wall (convex)
-right atrium + left auricle
-2/3 right ventricle + 1/3 left ventricle

2) diaphragmatic: posterior wall (flat)
-2/3 left ventricle + 1/3 right ventricle

3) right og left pulmonary surfaces

Margins:
a) right margin - margo acutus (sharp)
b) left margin - margo obtusus (round)

Sulci:
indicate subdiv. of heart at the surf, and are occ. by vessels og subepicardial fat —>
a) coronary sulcus: sep. atria from ventricles
b) ant+post interventricul. sulci: sep right+left ventricle

Question 4

apex og base

Answer 4

apex=
snýr down, anteriorly og left
-lies in midclavicular line in 5th rib/intercostal space on left side

base=
snýr posteriorly, up og right (dorsocranial p:large vessels enter)

Question 4

apex og base

Answer 4

apex=
snýr down, anteriorly og left
-lies in midclavicular line in 5th rib/intercostal space on left side

base=
snýr posteriorly, up og right (dorsocranial p:large vessels enter)

Question 5

pericardium

Answer 5

Encloses heart. Consists of–>

A) fibr. pericardium, that is conn w:
-sternum (sternopericardiac ligg)
-diaphragm (pericardiophrenic ligg)
-tracheal bifurcation (bronchopericadiac membrane)
**it’s also att. to the large vessels and covers their rooots

B) serous pericardium:
úr 2 lögum
1) parietal layer, conn to fibrous pericardium
2) visceral layer, epicardium (covers heart)

*Parietal layer of serous pericardium transitions to visceral layer (epicardium) near the great vessels —>
forming reflections/folds

*Parietal cav. milli parietal og visceral layer (of serous p.card)
m ca 10-20 ml serous fluid.

Question 5

pericardium

Answer 5

Encloses heart. Consists of–>

A) fibr. pericardium, that is conn w:
-sternum (sternopericardiac ligg)
-diaphragm (pericardiophrenic ligg)
-tracheal bifurcation (bronchopericadiac membrane)
**it’s also att. to the large vessels and covers their rooots

B) serous pericardium:
úr 2 lögum
1) parietal layer, conn to fibrous pericardium
2) visceral layer, epicardium (covers heart)

*Parietal layer of serous pericardium transitions to visceral layer (epicardium) near the great vessels —>
forming reflections/folds

*Parietal cav. milli parietal og visceral layer (of serous p.card)
m ca 10-20 ml serous fluid.

Question 6

pericardium, supply

Answer 6

blood supply:
-br of internal thoracic artery
-pericardiophrenic artery
-musculophrenic artery
-desc. aorta

–venous blood drained into azygous vein

NS: sensory fibers of vagus n and phrenic n
-autonomic fibers from symp.trunk surr the vessels.

Question 7

Chordae tendinae

Answer 7

-Fibr. strings
-conn. free margin of cusps to papillary mm. in ventricles
-prevent cusps from prolapse back to atrium
during systole of ventricles

Question 8

Aortic and pulmonary trunk valves

Answer 8

-formed by semilunar valvules
-each semilunar valvule has lunula + nodulus
–> forming sinus

*pulm.trunk valve (anterior, right+left valvules)
*aortic valve (posterior, right+left valvules)

**Heart sounds=
‘‘lub’’ recoil of blood against closed AV valve
‘‘dub’’ recoil of blood against closed semilunar valves
(heart murmur, defective valves cause hissing sound when blood squirts backwards thru valve)

Question 9

dæmi um valvular diseases

Answer 9

1) Insufficiency-incompetence of valve:
-cusps or valvules do not close completely, so blood leaks backwards across valve

2) Stenosis of valve:
-tissues that form the cusps or valvules verða stiffer
–> narrows valve opening og reduces amount of blood
that flows through

Question 10

right atrium

Answer 10

*dorsal part: sinus venarum—>
m orifice of SVC og IVC (valve of IVC functional in fetal circul.)
og coronary sinus orifice (coronary sinus valve)

*Septal wall-interatrial septum
-in lower part, fossa ovalis, bordered by limbus fossae ovalis)
in fetal circulation it was foramen ovale, milli atrias

*Musculi Pectinati; mest visible in auricle

Question 11

right ventricle - semilunar shape in transverse section

Answer 11

1) inflowing tract:
inflowing right AV orifice, lokað af tricuspid valve
-myocardium forms papillary muscles (ant, post og septal).
+ trabeculae carneae (irregular muscular columns)

2) outflowing tract:
conus arteriosus, smoot surf
-orifice of pulm.trunk, closed by pulm trunk valve

Question 12

Left atrium

Answer 12

4 orifices of pulm.veins in dorsal part.
-musculi pectinati: in ventral p + auricle

Question 13

Left ventricle - circular/oval shape in transv. section

Answer 13

inflowing tract, myocardium forms papillary mm (ant og post)
og trabeculae carneae

outflowing tract - aortic vestibule
-smooth surf
aortic orifice, outflowing orifice closed by aortic valve

**valvules form aortic sinuses
–> from right+left aortic sinuses, coronary arteries arise

Question 14

interv.septum

Answer 14

sep. ventricles

upper membranous p
lower muscular p

Question 15

left coronary artery

Answer 15

arises from left aortic sinus
-short course in left p. of coronary sulcus. Og divides into–>
1) Anterior interventricular br (runs in ant. interv. sulcus)
2) Circumflex a (Atrial br + Marginal br)

*Supplies:
-left atrium
-left ventricle + papillary mm there
-ventral 2/3 interv.septum
-adj. p of ventral wall right ventricle + ant.papillary mm right ventricle

Question 16

right coronary artery

Answer 16

arises from right aortic sinus
-runs in right p. of coronary sulcus. Gefur branches—>
1) A. of sa node
2) Atrial br
3) Marginal br
4) Posterior interventricular br.
(terminal br. runs in post. interv. sulcus)

*supplies:
-right atrium
-right ventricle + papillary mm there
-dorsal 1/3 interv.sulcus
-adj.p of dorsal wall of left ventricle + posterior papillary mm there

Question 17

structures supplied by both right+left coronary aa

Answer 17

Post. papillary mm of left ventricle
Ant. papillary mm of right ventricle
Interv. septum

Question 17

structures supplied by both right+left coronary aa

Answer 17

Post. papillary mm of left ventricle
Ant. papillary mm of right ventricle
Interv. septum

Question 18

veins of heart

Answer 18

Coronary sinus, posteriorly in left p.of coronary sulcus
-opens into right atrium.

Veins drained into coronary sinus:
1) Great cardiac vein: acc. left coronary A.
Upphaf runs in ant. interv.sulcus og cont. in coronary sulcus
to the coronary sinus.

2) Middle cardiac vein: asc. in posterior interv.sulcus
og finally opens into coronary sinus

3) Small cardiac vein: runs along right margin og cont.
in right part, of coronary sulcus, Finally opens into coronary sinus.

4) smallest cardiac veins/thebesian veins:
-open into all chambers of heart

5) anterior cardiac veins:
-open directly into right atrium, independently of
coronary sinus

Question 19

L.drainage

Answer 19

lymph of heart is drained thru;
*subendocardial og myocardial plexuses to the
subepicardial plx
-efferents cont. to the coronary sulcus (og follow the coronary blood vessels)

*l.vessels from heart are drained mainly to :
-brachiocephalic nodes
-tracheobronchial nodes
-other mediastinal l.nodes

Question 20

Conducting system

Answer 20

úr specialized cardiac muscle fibers–>
1) SA node: the pacemaker
in right atrium, near orifice of SVC

2) AV node:
in right atrium, near AV orifice (near coronary sinus orifice)

3) AV bundle of hiss
-from the AV node thru the right fibr.trigone og along
membr interv septum

4) right + left branches (Tawara’s br)
- in muscular p. of interv. septum

5) Purkinje fibers - terminal conducting fibers
(subendocardial fibers)

*internodal fibers: conn. SA + AV nodes
**interatrial fibers: from SA node to myocardium of to left atrium.

Question 21

Nerves heart

Answer 21

affect nodal tissue og components of conducting system
og coronary vessels og myocardium

*cardiac plx:
- parasymp fibers - cardiac branches of vagus N (inhibitory)
- symp fibers - cardiac nerves from cervical+thoracic
symp. ganglia (stimulatory)

Question 22

portal circulation

Answer 22

-two capillary networks conn. by thin walled vein (portal vein), are interposed milli arteries og veins
(carry various of substances milli two organs)

arteries-capillaries-portal vein-capillaries-veins

Question 23

foetal circulation

Answer 23

Placenta=>
a) umblical vein (verður lig. teres) —>
b) ductus venosus (verður lig. venosus) —>
c) IVC —> Right atrium —>
d) foramen ovale (fossa ovalis) limbus ovalis
e) left atrium, left ventricle, aorta (head+upper limbs) –>
…………..

a)SVC–> right atrium, right ventricle, pulm.trunk —>
b) ductus arteriosus (ligg. arteriosus) —>
(thorax, abdomen, pelvis, lower limbs)
c) umblical arteries (median umblical ligg)
==> placenta

Question 24

umbl arteries

Answer 24

distal portion of umbl. arteries –> medial umblical ligament
(forming peritoneal folds at posteriorly on ant abd wall)

-proximal portion of umbl.artery stays opened and gives off branches for the urinary bladder

Question 25

asc og desc aorta foetal circul

Answer 25

-desc. aorta contains less oxygenated blood than the asc. aorta due to mixing with the deoxygenated blood from ductus arteriosus.

-desc aorta foetal supply (organs of pelvis + abdomen + lower limbs)
-asc. aorta foetal supply (head, heart, upper limbs)