Anatomy: Vertebral Column, Back Muscles, Mediastinum, and Cardiovascular System

Flashcards covering key anatomical terms, structures, blood vessels, muscles, and clinical concepts of the vertebral column, back muscles, mediastinum, and cardiovascular system.

Primary Curvatures

Thoracic and sacrococcygeal vertebral curvatures (kyphotic) that are present during fetal development and are convex posteriorly.

Secondary Curvatures

Cervical and lumbar vertebral curvatures (lordotic) that form after delivery and are concave posteriorly.

Typical Vertebrae

Vertebrae consisting of a body, vertebral arch, and transverse processes, occurring in the middle portion of the cervical, thoracic, and lumbar regions, as well as the sacrum and coccyx.

Atypical Vertebrae

Vertebrae whose structure is highly modified by function and position, occurring in transitioning regions including C1, C2, C7, T1, T9, T10, T11, T12, and L5.

Vertebral Arch

The bone structure at the back of each vertebra that connects to the front vertebral body, forming the vertebral foramen that houses and protects the spinal cord.

Nucleus Pulposus

A central gel-like structure at the center of the intervertebral disc made of 66% to 86% water, type II collagen, and water-retaining proteoglycans like aggrecan.

Annulus Fibrosus

The peripheral component of an intervertebral disc consisting of concentric layers (lamellae) of collagen fibers; the outer portion contains mostly type I collagen and the inner portion contains predominantly type II collagen.

Vertebral Endplate

An upper and lower cartilaginous plate (about 0.6–1 mm thick) covering the superior and inferior aspects of the disc that permits diffusion and provides the primary source of nutrition for the disc.

Superficial Back Muscles

Extrinsic muscles closest to the skin that originate from the vertebral column and attach to shoulder bones to assist with upper limb movement; supplied by anterior rami of spinal nerves, except trapezius.

Trapezius

A superficial back muscle supplied by the 11th cranial (accessory) nerve and proprioceptor fibers from C3 and C4 that elevates, retracts, and depresses the scapula.

Latissimus Dorsi

The largest muscle in the upper body that inserts into the intertubercular sulcus of the humerus and is innervated by the thoracodorsal nerve (C6, C7, C8) to extend, adduct, and medially rotate the upper limb.

Serratus Anterior

A fan-shaped muscle originating from the upper eight/nine ribs and inserting into the medial border of the scapula that protracts and stabilizes the scapula; paralysis leads to medial winging of the scapula.

Intermediate Back Muscles

Extrinsic respiratory muscles attached to the ribs (serratus posterior superior and serratus posterior inferior) that are supplied by anterior rami of thoracic spinal nerves.

Serratus Posterior Superior

An intermediate back muscle located beneath the rhomboids that elevates ribs to contribute to deep inspiration.

Serratus Posterior Inferior

An intermediate back muscle located beneath the latissimus dorsi that depresses ribs to contribute to forced expiration.

Deep Back Muscles

Intrinsic or true back muscles extending from sacrum to skull, supplied by posterior rami of spinal nerves, that act as extensors and rotators to maintain posture and curvature of the vertebral column.

Erector Spinae

The largest group of deep back muscles comprising three vertical columns from lateral to medial: iliocostalis, longissimus, and spinalis.

Transversospinales

The deep layer of intrinsic back muscles consisting of semispinalis, multifidus, and rotatores that turn, straighten, and stabilize the spine.

Anterior Spinal Artery

The single primary blood vessel supplying the anterior spinal cord, formed by vertebral arteries that originate from the first part of the subclavian artery.

Mediastinum

The median movable compartment of the thoracic cavity located centrally between the right and left pleural cavities.

Superior Mediastinum

The space in the mediastinum located superior to the heart that serves as a passageway for structures traveling between the head/neck and thorax.

Pericardium

A protective, fluid-filled sac surrounding the heart and the roots of the major blood vessels.

Pericardial Cavity

A potential space between the visceral and parietal serous pericardial layers containing fluid that reduces friction during heart beats.

Pericardiocentesis

A medical procedure using a needle and small catheter to drain excess fluid accumulated in the pericardial sac.

Sinoatrial Node

The pacemaker of the heart's conduction system located in the right atrium that initiates the electrical excitation signal for each heartbeat.

Atrioventricular Node

A node in the cardiac conduction system that receives signals from the atria and delays electrical transmission until the atria are empty of blood.

Pulmonary Circulation

The smaller, low-pressure blood circuit that pumps deoxygenated blood from the right ventricle to the lungs for gas exchange and returns oxygenated blood to the left atrium.

Systemic Circulation

The larger, high-pressure blood circuit that pumps oxygenated blood from the left ventricle through the aorta to the body and returns deoxygenated blood to the right atrium.

Brachiocephalic Artery

An unpaired short vessel originating from the aortic arch that ascends and divides into the right subclavian artery and right common carotid artery.

Celiac Trunk

A short unpaired branch of the abdominal aorta that divides into the left gastric artery, splenic artery, and common hepatic artery.

Superior Mesenteric Artery

The largest unpaired visceral branch of the abdominal aorta that carries blood to most of the small intestine and the first half of the large intestine.

Inferior Mesenteric Artery

An unpaired branch of the lower abdominal aorta that supplies blood to the second half of the large intestine.

Ductus Venosus

A fetal vascular shunt located at the liver that directs highly oxygenated blood from the umbilical vein directly into the inferior vena cava.

Foramen Ovale

A fetal interatrial shunt that allows oxygenated blood to flow directly from the right atrium to the left atrium, bypassing the non-functional lungs.

Ductus Arteriosus

A fetal shunt connecting the pulmonary artery directly to the aorta to divert mixed blood away from the lungs.

Coronary Sinus

A large venous structure on the posterior aspect of the heart that receives most cardiac veins and drains directly into the right atrium.

Cisterna Chyli

A dilated lymphatic sac located posterior to the abdominal aorta and anterior to L1–L2 vertebrae that forms the origin of the thoracic duct and collects lymph from the lower body.

Thoracic Duct

The main lymphatic channel responsible for draining lymph from approximately three-quarters of the body into the left subclavian vein.

Right Lymphatic Duct

The lymphatic duct that drains lymph fluid from the upper right section of the trunk, right arm, and right side of the head and neck into the right subclavian vein.

Myocardial Ischemia

A condition occurring when blood flow to the myocardium is reduced or obstructed, causing hypoxia without immediate tissue death.

Myocardial Infarction

A heart attack caused by the complete cutoff or severe cessation of blood flow to a portion of the myocardium, resulting in cellular necrosis.

Cardiac Tamponade

A medical emergency caused by abnormal fluid accumulation in the pericardial sac, compressing the heart and decreasing cardiac output.

Beck's Triad

A clinical triad associated with acute pericardial tamponade consisting of low blood pressure, distension of jugular veins, and muffled heart sounds.

Thrombus

A stationary blood clot formed inside the circulatory system that obstructs blood flow at its site of origination.

Embolus

A freely floating mass (blood clot fragment, fat deposit, or air bubble) carried by the bloodstream that lodges in a blood vessel distant from its origination site.

Tetralogy of Fallot

A congenital heart defect composed of four major structural defects: pulmonary stenosis, right ventricular hypertrophy, overriding aorta, and ventricular septal defect.

Rheumatic Heart Disease

Permanent damage to heart valves resulting from an immune-mediated inflammatory reaction triggered by a Group A Streptococcus infection.

Phlebitis

Inflammation of a superficial vein near the surface of the skin, also known as superficial thrombophlebitis.