Gross anatomy of CVS

Question 1

What is the basic pathway of blood?

Answer 1

Blood enters the right atrium from the superior and inferior vena cava.
Blood enters into the right ventricle, then into the lungs by the pulmonary arteries for oxygenation.
Blood then enters the left atrium via pulmonary veins, and passes into the left ventricle.
Blood is then supplied to the rest of the body by the aorta.

Question 2

Where is the heart?

Answer 2

In the thoracic cavity, protected by the ribcage, with the sternum in the centre.
More of the heart is found left of the sternum.
The apex of the heart (bottom) is located in the 5th intercostal space.

Question 3

What is the mediastinum?

Answer 3

An area in the centre of the thorax that contains the heart and other structures.

Question 4

What are the boundaries of the mediastinum?

Answer 4

Sagittal plane:
The sternum is the anterior boundary.
The vertebrae is the posterior boundary.
The superior boundary is the superior thoracic aperture.
The inferior boundary is the diaphragm.

Question 5

What are the mediastinum subdivisions?

Answer 5

At the T4/5 vertebral layer the mediastinum divides into the superior and inferior mediastinum.
The inferior is subdivided into anterior, middle and posterior.
The middle is where the heart is.
The aorta passes into the superior mediastinum, then the posterior mediastinum.

Question 6

What is lateral of the mediastinum?

Answer 6

Laterally are the right and left lungs.
The lungs have tissue called pleura.

Question 7

What is the pericardium?

Answer 7

A sac structure that surrounds the heart.
Comprised of thin 2 layers that secretes fluid and fills the sac.
Peri - around

Question 8

What are the functions of the pericardium?

Answer 8

Protects the heart
Holds the heart in place above the diaphragm
Provides lubrication by the fluid it secretes

Question 9

What are the layers of the pericardium?

Answer 9

Inner layer is the visceral layer
The outer layer is the parietal layer
Visceral layer is separated from the parietal layer by the pericardial cavity
Cells in the layers secrete fluid into the cavity, lubricates the walls of the heart to prevent friction.

Question 10

What is the orientation of the heart?

Answer 10

Posterior (back) of heart is laid down on the diaphragm.
Apex (tip) of heart points anteriorly - towards ribcage.
Base of heart projects towards the vertebrae posteriorly.

Question 11

What are the divisions of the heart?

Answer 11

Interventricular septum divides the left and right ventricles
Interatrial septum divides the left and right atria
Coronary sulcus separates the atria from the ventricles.
Divisions are visible on the heart surface as grooves - interventricular sulcus

Question 12

What is the right atrium?

Answer 12

Superior vena cava supplies deoxygenated blood from above.
Inferior vena cava supplies blood from below.
The pectinate muscle in the wall contracts and allows the heart to pump blood.
The tricuspid valve prevents backflow from the ventricle into the atria.

Question 13

What is the sinoatrial node?

Answer 13

An electrical conductor.
Nervous tissue found in the wall of the right atrium that determines heart rate.
It is influenced by other nerves.

Question 14

What is the coronary sinus?

Answer 14

Coronary arteries supply blood to the walls of the heart.
The coronary sinus is an opening where the blood from the coronary vessels can enter into the right atrium to go to the lungs.

Question 15

What is the fossa ovalis?

Answer 15

A depression in the interatrial septum.
Remnant from the womb where oxygenated blood was supplied from the mother.
Used to bypass the lungs and go straight into left atria.
Closed upon birth.

Question 16

What is the right ventricle?

Answer 16

The tricuspid valve prevents backflow into the atrium.
The chordae tendineae prevents the vale swinging backwards.
The trabeculae Carneae muscle in the wall pumps blood in the right ventricle.
Blood is then pumped into the pulmonary trunk, and the pulmonary valve prevents backflow into the ventricle.

Question 17

What is the left atrium?

Answer 17

Blood enters left atrium from pulmonary veins, then goes to left ventricle.
Mitral valve prevents backflow from ventricle to atria.
Wall of left atrium is smoother than right atrium, there is less pectinate muscle.

Question 18

What is the left ventricle?

Answer 18

Very thick wall, enough to generate force to pump blood around the whole body from aorta.
Mitral valve prevents backflow into atria.
Chordae tendineae, attaches to valves to prevent swinging by the flow of blood.
Papillary muscle is thick and attaches to tendineae.

Question 19

What are the heart valves?

Answer 19

Tricuspid valve, between right atrium and right ventricle.
Pulmonary valve, between right ventricle and pulmonary trunk.
Mitral valve, between left atrium and left ventricle.
Aortic valve, between left ventricle and aorta.

Question 20

What are the papillary muscles and chordae tendineae?

Answer 20

Tricuspid and mitral valve contain these.
When the left ventricle contracts, papillary muscle contract and pull on tendineae, creates tension, prevents valve cusps from opening backwards, so blood does not flow into atria, rather goes into aorta.

Question 21

What are the coronary arteries?

Answer 21

Supply the walls of the heart.
Left and right arteries branch to supply the different chambers of the heart.
If blocked, heart is not oxygenated enough - myocardial infarction
Coronary bypass can prevent this.

Question 22

What is the aortic valve?

Answer 22

Three cusps, no papillary muscles or chordae tendineae.
Cusps collect the blood that flows back, causes widening and the cusps come into contact to close the gap, stops backflow of blood into ventricle from the aorta
Two little openings for coronary arteries so that blood that flows back on next contraction is pumped into coronary arteries.

Question 23

What are the cardiac veins?

Answer 23

Cardiac veins bring deoxygenated blood from the wall of the heart into right atrium.
Blood from veins drains into coronary sinus, which opens into right atrium, to go and become oxygenated in the lungs

Question 24

What is the nervous innervation of the heart?

Answer 24

Heart is under influence from autonomic nervous system - no conscious control, has sympathetic and parasympathetic branches.
Sympathetic branch increase heart rate and force of contraction via the sinoatrial node.

Question 25

What are the great vessels of the heart?

Answer 25

Superior and inferior vena cava bring blood to right atrium. Pulmonary artery brings blood from right ventricle to lung. Pulmonary vein brings blood from the lung into the left atrium - 4 pulmonary veins, 2 for each lung. Aorta takes blood from left atrium to rest of body.

Question 26

What are arteries?

Answer 26

Arteries supply oxygenated blood to tissues and organs. Except for the pulmonary artery. Arteries have branches, that subdivide into further branches.

Question 27

What are veins?

Answer 27

Veins drain deoxygenated blood from tissues and organs. Except for the pulmonary vein. Veins have tributaries - different veins come together to form larger veins.

Question 28

What is the aorta?

Answer 28

Aorta goes from left ventricle to the body. Forms the arch aorta Before the arch is ascending aorta. After the arch is descending aorta, descends through thoracic cavity then into the abdominal cavity - thoracic aorta.

Question 29

What are the branches off the aorta?

Answer 29

Brachiocephalic artery subdivides into right subclavian artery right common carotid artery. Right subclavian artery supplies the upper limbs. Carotid artery supplies the head and neck. Left common carotid and left subclavian come directly off the aorta.

Question 30

What is the abdominal aorta?

Answer 30

Abdominal aorta supplies the abdominal organs and pelvis. It splits into two to form the two vessels which supply the lower limbs - the common iliac arteries.

Question 31

What arteries branch from the abdominal aorta?

Answer 31

The renal arteries supply the kidneys, which filter blood and produce urine. Gonadal arteries supply the testes and ovaries, and are very long.

Question 32

What is the gastrointestinal tract blood supply?

Answer 32

Coeliac trunk supplies upper GIT - stomach and some of small intestine. Superior mesenteric supplies rest of small intestine and some large intestine. Inferior mesenteric artery supplies rest of large intestine and the rectum.

Question 33

What else does the coeliac trunk supply?

Answer 33

Spleen and liver supplied from the coeliac trunk. Spleen and liver filter dead RBCs.

Question 34

What is the upper limb blood supply?

Answer 34

Subclavian artery majorly supplies the upper limb. It passes into the armpit and forms auxiliary artery, then passes to brachial artery.

Question 35

What is the blood supply of the lower arm?

Answer 35

Ulnar artery and radial arteries supply the forearm and hand. Form palmar arch - collateral circulation - tissue is supplied by more than 1 blood vessel. If one branch is blocked, can still have blood supply to the palmar arch.

Question 36

What is the upper limb blood drainage?

Answer 36

Median cubital vein is superficial - for giving injections or taking blood samples as close to the skin. Subclavian vein is pathway from the upper limb.

Question 37

What is the lower limb blood supply?

Answer 37

Aorta bifurcates into two common iliac arteries. Divides into external iliac artery and internal iliac artery. External iliac passes out of pelvis, passes under ligament and becomes femoral artery - major blood supply to lower limb.

Question 38

What is the lower limb drainage?

Answer 38

Deep veins - can't see them at skin level, drain to femoral vein. Superficial veins are the great saphenous and small saphenous vein, also drain to femoral vein. These have valves to prevent backflow of blood, because it is at a lower pressure and against gravity.

Question 39

What happens when valves in the legs stop working?

Answer 39

Valves can stop working properly, cause varicose veins, causes blood pooling in veins. Caused by age or disease.

Question 40

What are the pulse points?

Answer 40

Arteries of lower limb can be used for pulse. Brachial artery often used to measure blood pressure. Carotid pulse can be felt in the neck.

Question 41

What is the head and neck blood supply?

Answer 41

Common carotid artery brings blood to head and neck, it divides into external and internal common carotid artery. External carotid stays superficial - supplies face muscles and skin.

Question 42

What is the internal carotid artery?

Answer 42

Brain is supplied by internal carotid artery and vertebral arteries, which branches from subclavian arteries, they go into the skull and supply the brain. When arteries are cut off can cause stroke.

Question 43

What is the vein drainage of the head and neck?

Answer 43

Internal jugular vein drains from brain to heart. External jugular vein drains from superficial structures. They go to superior vena cava and back to the heart.