HS+F W6 | Heart + Circulatory System

For active recall.

Vessel

Tube that carries blood (arteries, veins, capillaries)

Valve

One-way structure inside some vessels (and the heart) that prevents backflow of blood and ensures proper circulation.

Ventricle

The ventricles are the two lower chambers of the heart, one on the right and one on the left. The ventricles receive blood from the heart's upper chambers (atria) and pump it to the rest of the body.

Arterial Anastomosis

An anastomosis is a connection or joining between two blood vessels. This creates collateral circulation - an alternate pathway for blood flow if one vessel becomes blocked.

Atrium (plural: Atria)

Upper receiving chambers that collects blood returning to the heart (from body or lungs)

Ventricle

Lower pumping chambers with thick muscular walls that ejects blood to lungs or body

Septum

Muscular wall that separates right and left sides, preventing mixing of blood (interventricular septum, interatrial septum)

Atrioventricular (AV) Valves

Valves between atria and ventricles that prevent backflow into atria

(Tricuspid = right, 3 cusps | Mitral = left, 2 cusps)

Semilunar Valves

Crescent-shaped valves at ventricular exits that prevent backflow into ventricles

(Pulmonary = RV → pulmonary trunk | Aortic = LV → aorta)

Artery

Carries blood away from the heart under high pressure (usually oxygenated)

Pulmonary artery = deoxygenated❗

Vein

Carries blood toward the heart under low pressure (usually deoxygenated). They are smaller.

Pulmonary vein = oxygenated❗

Coronary

Refers to vessels that supply the heart muscle (myocardium), surrounding it like a crown. FEEDS THE HEART!

Superior vena cava (SVC)

Large vein bringing deoxygenated blood from upper body to right atrium

Inferior vena cava (IVC)

Large vein bringing deoxygenated blood from lower body to right atrium

Right atrium (RA)

Upper right chamber of the heart receives deoxygenated blood

Opening of coronary sinus

Drains deoxygenated blood from heart muscle into right atrium

Fossa ovalis

Depression marking site of foramen ovale (fetal circulation opening) | Leftover fetal hole mark

Right AV valve (tricuspid)

Three-cusped valve between right atrium and right ventricle

Chordae tendinae

Tendinous cords attaching valve cusps to papillary muscles

Papillary muscles

Muscular projections that anchor chordae tendinae

Right ventricle (RV)

Lower right pumping chamber, sends blood to lungs

Trabeculae carnae

Rough muscle ridges inside ventricle walls

Pulmonary semilunar valve

Three-cusped valve at exit of right ventricle (exit valve to lungs)

Pulmonary trunk

Large artery carrying deoxygenated blood from right ventricle to the lungs for oxygenation.

Pulmonary arteries

Branches (right and left) carrying blood to lungs for oxygenation from the pulmonary trunk.

Pulmonary veins (4 total)

Return oxygenated blood from lungs to left atrium

Left atrium (LA)

Upper left receiving chamber of the heart that receives oxygenated blood from the pulmonary veins.

Left AV valve (mitral/bicuspid)

Two-cusped valve between left atrium and left ventricle

Left ventricle (LV)

Lower left pumping chamber with thickest muscular wall. Main pump to body.

Interventricular septum

Muscular wall separating right and left ventricles

Aortic semilunar valve

Three-cusped valve at exit of left ventricle. It is an exit valve to body.

Openings of coronary arteries

Branch points just above aortic valve supplying heart muscle itself.

Ascending aorta

First part of aorta rising from left ventricle and branching into major arteries supplying blood to the body.

Brachiocephalic trunk

First branch of aortic arch (supplies right arm and head)

Left common carotid artery

Second branch of aortic arch (supplies left side of head/neck)

Left subclavian artery

Third branch of aortic arch (supplies left upper limb)

Ligamentum arteriosum

Fibrous remnant of ductus arteriosus (fetal circulation shunt) that closes after birth to connect the pulmonary artery to the aorta.

Apex of the heart

Pointed inferior tip of heart (points left and anteriorly)

Coronary Artery

Arteries that supply blood to the heart muscle itself, branching from the aorta.

Left Coronary Artery

Artery that supplies blood to the left side of the heart, including the left atrium and ventricle.

Anterior interventricular (Left anterior descending - LAD)

Major artery supplying blood to the anterior portion of the left ventricle and interventricular septum.

Circumflex

Circles left side of heart, supplies left atrium and lateral/posterior left ventricle

Right Coronary Artery

Artery that supplies blood to the right side of the heart, including the right atrium and ventricle.

Marginal

Branch of right coronary, supplies right ventricle lateral wall

Posterior interventricular

Artery that supplies blood to the inferior wall of both ventricles, stemming from the right coronary artery.

Subclavian artery

Major artery supplying blood to the arms and a portion of the head and neck, branches from the aorta.

Axillary artery

Major artery that continues from the subclavian artery, supplying blood to the shoulder and upper arm.

Brachial artery

Major and main artery (of arm) extending from the axillary artery, supplying blood to the upper arm and branching into the radial and ulnar arteries.

Profunda brachii

Branch of the brachial artery that supplies blood to the deep structures of the arm, including muscles and bones.

Radial artery

Major artery that branches from the brachial artery and runs along the radial/lateral side of the forearm, supplying blood to the forearm and hand.

Ulnar artery

A major artery branching from the brachial artery that runs along the ulnar/medial side of the forearm, supplying blood to the forearm and hand.

Palmar arches

(Radial and Ulnar Arches)

Network of blood vessels formed by the anastomosis of the radial and ulnar arteries in the palm, supplying blood to the hand.

Abdominal aorta

The largest artery in the abdominal cavity, it branches off from the descending aorta and supplies oxygenated blood to the abdominal organs and lower limbs.

Common iliac artery

Branches into internal iliac (pelvic organs) and external iliac (lower limb)

External iliac artery

Passes under inguinal ligament to become femoral artery

Femoral artery

Main artery of thigh; palpable in femoral triangle

Deep femoral (profunda femoris)

Largest branch of femoral; supplies thigh muscles

Anterior tibial artery

Descends in anterior leg compartment; becomes dorsalis pedis

Dorsalis pedis artery

Continuation of anterior tibial artery; supplies dorsum of foot.

Posterior tibial artery

Artery that descends in the posterior compartment of the leg; supplies the plantar surface of the foot.

Fibular (peroneal) artery

Branch supplying lateral leg muscles

Collateral Circulation

Around major joints (shoulder, elbow, wrist, hip, knee, ankle), multiple arteries anastomose to ensure blood supply is maintained even if one vessel is compressed during joint movement.

Radial pulse

Lateral wrist, just proximal to thumb; pressed against radius bone

Ulnar pulse

Medial wrist, just proximal to little finger; pressed against ulnar bone (harder to detect)

Brachial pulse

Front of elbow in cubital fossa; or along medial arm pressed against humerus

Carotid pulse

Lateral neck, beside trachea (never press both sides simultaneously!)

Temporal pulse

Just in front of the top of the ear

Facial pulse

Located at the jawline, anterior to the masseter muscle.

Femoral pulse

Located in the groin, where the femoral artery is near the surface.

Popliteal pulse

Middle of back of knee (popliteal fossa); press firmly through adipose tissue

Posterior tibial pulse

Behind medial malleolus of ankle (location varies between individuals)

Dorsalis pedis pulse

Located on the dorsum of the foot, between the first and second metatarsal bones.

Apical pulse

Mid-clavicular line, 5th intercostal space (just below male nipple)

Allen Test Procedure

1. Compress both arteries

2. Observe blanching

3. Release one artery

4. Observe reperfusion

5. Repeat with other artery

What does the Allen Test assess?

The Allen Test evaluates the patency (openness) and functional adequacy of the radial and ulnar arteries and their anastomoses in the palmar arches. It ensures that if one artery is damaged or occluded, the other can provide sufficient blood flow to the hand.