BMS 204 Lab 1 Histology - Cardiovascular System

Complete set of vocabulary flashcards describing the histological structures of the heart layers, specialized muscle fibers, and the various components of the vascular system based on lab lecture notes.

Endocardium

The inner lining of the heart wall consisting of an endothelial lining covering trabeculae.

Myocardium

The middle muscle layer of the heart wall.

Epicardium

The visceral layer of the serous pericardium consisting of simple squamous epithelium and connective tissue containing fat and branches of coronary vessels.

Cardiac Muscle Fibers

Spirally arranged, branched, and mononucleated fibers with indistinct striations interrupted by intercalated discs.

Endomysium

The connective tissue surrounding each cardiac muscle fiber that is rich in capillaries.

Lipofuscin

Pigments found within cardiac muscle fibers.

Diad

A structure in cardiac muscle formed of one T-tubule and one ring of sarcoplasmic reticulum at the level of the $Z\text{-lines}$.

Endocrine Cardiomyocytes

Cells in the wall of the atria that contain perinuclear electron-dense secretory granules of $(ANF)$.

Intercalated Disc

A specialized junction between two cardiac muscle fibers showing transverse portions (desmosomes) and lateral portions (gap junctions).

Desmosomes

Junctions in the transverse portion of intercalated discs that prevent the separation of muscle fibers during contraction.

Gap Junctions (Nexuses)

Junctions in the lateral (longitudinal) portion of intercalated discs that allow for the transmission of nerve impulses.

Purkinje Muscle Fibers

Large, vacuolated muscle fibers with eccentric nuclei and few myofibrils, surrounded by a connective tissue sheath and lacking intercalated discs.

Smooth Muscle Fibers

Spindle-shaped, non-striated, non-branched fibers with a single central nucleus, arranged in bundles and attached by desmosomes and gap junctions.

Dense Body

A structure in smooth muscle cells that provides mechanical coupling for thick (myosin) and thin (actin) filaments.

Caveolae

Small invaginations of the plasma membrane in smooth muscle cells.

Tunica Intima

The innermost layer of the blood vessel wall composed of endothelium and an internal elastic lamina.

Tunica Media

The middle layer of a blood vessel which contains circular smooth muscle fibers or elastic laminae.

Tunica Adventitia (Externa)

The outer layer of a blood vessel containing collagen, elastic fibers, vasa vasorum, and nervi vasorum.

Medium-Sized Artery (Muscular Artery)

A vessel with a thick wall, narrow patent lumen, prominent internal elastic lamina, and a thick tunica media.

Medium-Sized Vein

A vessel with a wide collapsed lumen, thin tunica media, and a thick, prominent tunica adventitia as its main layer.

Aorta

A large elastic artery where the tunica media is the main layer, containing many wavy fenestrated elastic laminae.

Inferior Vena Cava

A large vein characterized by a tunica adventitia that contains longitudinal bundles of smooth muscle fibers.

Basilar Artery

A muscular artery characterized by a thin wall, wide irregular lumen, and a well-developed internal elastic lamina.

Coronary Artery

A muscular artery with a thick tunica intima containing smooth muscle fibers and fat droplets that increase with age.

Continuous Capillary

A type of capillary with no fenestrae, a complete basal lamina, and tightly joined endothelium that forms blood barriers.

Fenestrated Capillary

A type of capillary characterized by pores (fenestrae) in the endothelium and a complete basal lamina, found in endocrine organs and the kidney.

Sinusoidal Capillary

A type of capillary with wide fenestrae, gaps between endothelial cells, and an incomplete basal lamina, found in the liver, spleen, and bone marrow.

Pericyte

A cell type associated with continuous capillaries and arterioles, often located outside the endothelial layer.

Vasa Vasorum

Small nutrient vessels located in the tunica adventitia of large blood vessels.