A225 - IU - Block 4

Heart

Muscular organ on the left side of the body.

Thoracic cavity

Space housing the heart in mediastinum.

Apex of heart

Pointed tip of heart directing leftward.

Four chambers

Heart consists of two atria and two ventricles.

Right atrium

Chamber receiving deoxygenated blood from body.

Left atrium

Chamber receiving oxygenated blood from lungs.

Right ventricle

Pumps deoxygenated blood to the lungs.

Left ventricle

Pumps oxygenated blood to the body.

Pericardium

Double-walled sac enclosing the heart.

Fibrous pericardium

Outermost layer; prevents heart overfilling.

Serous pericardium

Inner layer with parietal and visceral components.

Pericardial cavity

Space with serous fluid reducing friction.

Pericardial effusion

Excess fluid in pericardial cavity causing pressure.

Endocardium

Inner layer of heart; simple squamous epithelium.

Myocardium

Thick cardiac muscle layer of the heart.

Epicardium

Visceral layer of serous pericardium, thin membrane.

Intercalated discs

Specialized junctions connecting cardiac muscle cells. Transmit nerve impulses

Tricuspid Valve

Valve between right atrium and ventricle.

Papillary Muscles

Muscles that anchor heart valves via chordae tendineae.

Chordae Tendineae

Tendons preventing valve eversion during contraction.

Pulmonary Semilunar Valve

Valve between right ventricle and pulmonary trunk.

left atrioventricular valve (Mitral or Bicuspid)

Valve between left atrium and left ventricle.

Aortic Semilunar Valve

Valve between left ventricle and aorta.

Coronary Sulcus

Groove separating atria from ventricles externally.

Interventricular Sulcus

Groove separating left and right ventricles.

Pulmonary Arteries

Carry deoxygenated blood from heart to lungs.

Pulmonary Veins

Carry oxygenated blood from lungs to heart.

Coronary Sinus

Veins draining into the heart's right atrium.

Myocardial Infarction

Heart attack due to blood flow blockage.

SA Node

Pacemaker initiating heartbeat in the heart.

Atrioventricular Bundle

Conducting fibers splitting into left and right branches.

Aortic Arch

Curved section of the aorta leaving the heart.

Brachiocephalic Trunk

Artery branching to arms and head.

Arteries

Carry blood away from the heart.

Veins

Return blood to the heart.

Common carotid artery

Branches into external and internal carotid arteries.

Internal carotid artery

More posterior branch of common carotid.

External carotid artery

More anterior branch of common carotid.

External jugular vein

Lateral and smaller vein.

Internal jugular vein

Medial and larger vein.

Subclavian vein

Joins with internal jugular vein.

Axillary artery

First portion in armpit region.

Brachial artery

Continues from axillary artery.

Radial artery

Branches from brachial artery to radius.

Ulnar artery

Branches from brachial artery to ulna.

Superficial palmar arch

Formed by radial and ulnar arteries.

Cephalic vein

Lateral vein of forearm and arm.

Basilic vein

Medial vein of arm and forearm.

Median cubital vein

Common site for blood draws.

Abdominal aorta

Continuation of thoracic aorta after diaphragm.

Celiac trunk

Branches into major abdominal arteries.

Superior mesenteric artery

Supplies blood to small intestine.

Inferior mesenteric artery

Supplies blood to large intestine.

Common iliac arteries

Branches from abdominal aorta.

Internal iliac arteries

Supply pelvic organs.

External iliac arteries

Become femoral artery in the leg.

Femoral artery

Continuation of external iliac artery.

Popliteal artery

Branches from femoral artery behind knee.

Anterior tibial artery

Branches from popliteal artery, more lateral.

Posterior tibial artery

Branches from popliteal artery, more medial.

Fibular artery

Branches from posterior tibial artery.

Great saphenous vein

Longest vein in the body.

Small saphenous vein

Visible only posteriorly.

Lymph

Fluid containing excess substances from blood.

Lymph nodes

Checkpoints filtering lymph fluid.

Thoracic duct

Returns lymph to venous system.

Erythrocytes

Red blood cells transporting oxygen.

Leukocytes

White blood cells involved in immune response.

Platelets

Cell fragments aiding in blood clotting.

Buffy coat

Layer containing white blood cells and platelets.

Neutrophil

Most numerous white blood cell, fights bacteria.

Lymphocyte

Involved in adaptive immunity, produces antibodies.

Monocyte

Largest leukocyte, becomes macrophage in tissues.

Eosinophil

Phagocytizes allergens and parasitic worms.

Basophil

Releases histamine during allergic reactions.

Capillaries

Small vessels for gas exchange.

Venules

Collect blood from capillaries. smaller veins

Tunica externa

Outermost layer of blood vessels.

Tunica media

Middle layer, mainly smooth muscle.

Tunica intima

Innermost layer, forms valves.

Elastic arteries

Contain large amounts of elastic fibers.

Muscular arteries

More smooth muscle, less elastic fibers.

Arterioles

Smallest arteries leading to capillaries.

Innate immunity

Non-specific defense mechanism present at birth.

Adaptive immunity

Specific defense developed after antigen exposure.

T lymphocytes

Coordinate immune response and attack infected cells.

B lymphocytes

Produce antibodies against antigens.

Dendritic cells

Present antigens to lymphocytes.

MALT

Mucosa-associated lymphoid tissue in various tracts.

Thymus

Site of T cell maturation.

Spleen

Largest lymphoid organ in the body.

White pulp

Contains lymphocytes for immune response.

Red pulp

Rich in blood; removes old cells.

Macrophages

Cells that break down old erythrocytes.

Respiration

Process of gas exchange in the body.

Inhalation

Breathing in oxygen from the environment.

Exhalation

Breathing out carbon dioxide from the body.

Conducting portion

Air passage without gas exchange.

Respiratory portion

Site of gas exchange in lungs.

Alveoli

Tiny air sacs for gas exchange.