BIOL 3330 Midterm Lab Review - Blood, Cardiovascular, & Lymphatic Systems

Comprehensive vocabulary flashcards reviewing formed elements of blood, heart anatomy and histology, blood vessel structure, and lymphatic system components.

Erythrocytes

Anuclear, biconcave disc-shaped red blood cells (approx. $7.6\,\mu m$) that transport oxygen from lungs to tissues and carbon dioxide from tissues to lungs, with an average lifespan of 120 days.

Neutrophils

The most abundant white blood cells ($50\text{--}70\%$ of differential count) featuring 2 to 6 lobed nuclei and fine pale pink granules; primary phagocytes that engulf pathogens and release cytotoxic enzymes.

Eosinophils

Granulocytes constituting $2\text{--}4\%$ of leukocytes, possessing a bilobed nucleus and large bright red-orange (eosinophilic) granules; involved in engulfing antibody-labeled materials and responding to allergies and parasitic infections.

Basophils

The rarest granulocytes ($<1\%$ of leukocytes), containing dense dark blue or purple granules that obscure the bilobed nucleus; they release histamine to promote inflammation in damaged tissues.

Monocytes

The largest leukocytes ($14\text{--}20\,\mu m$), making up $2\text{--}8\%$ of WBCs, with a distinct kidney bean-shaped nucleus and abundant pale cytoplasm; they enter tissues to become macrophages.

Lymphocytes

Agranulocytes comprising $20\text{--}40\%$ of blood leukocytes, characterized by a large round deeply heterochromatic nucleus surrounded by a thin rim of cytoplasm; essential for adaptive immune defenses.

Thrombocytes

Anucleated, small round to disc-shaped cell fragments ($1\text{--}2\,\mu m$) derived from megakaryocytes in red bone marrow that play a critical role in blood clotting and hemostasis.

Differential Blood Count

A lab test performed to determine the relative proportions of various leukocytes in a blood smear, calculated using the formula $\left(\frac{\text{number of specific leukocytes}}{\text{total number of leukocytes}}\right) \times 100$.

Intercalated Discs

Specialized transverse junctional complexes connecting adjacent cardiac muscle cells end-to-end, containing desmosomes and gap junctions for structural anchoring and rapid electrical transmission.

Purkinje Fibers

Modified cardiac muscle fibers specialized for electrical conduction, characterized by a larger neuron-like morphology and lighter staining due to high glycogen content.

Moderator Band

A muscular band connecting the interventricular septum to the anterior papillary muscle in the right ventricle of the heart.

Ligamentum Arteriosum

A fibrous ligament connecting the pulmonary trunk to the aortic arch, serving as the anatomical remnant of the fetal ductus arteriosus.

Fossa Ovalis

An oval depression located on the interatrial septum of the heart, representing the remnant of the fetal foramen ovale.

Tunica Intima

The innermost layer of a blood vessel wall, composed of a simple squamous endothelial lining and an underlying subendothelial connective tissue layer.

Tunica Media

The middle layer of a blood vessel wall composed primarily of smooth muscle cells and elastic fibers, serving as the thickest layer in arterial walls.

Tunica Adventitia

The outer connective tissue layer of a blood vessel wall, serving as the thickest layer in veins and housing the vasa vasorum in larger vessels.

Vasa Vasorum

A network of small blood vessels located within the tunica adventitia that supplies nutrients and oxygen to the outer walls of large blood vessels.

Elastic Artery

A large conducting blood vessel (such as the aorta) whose thick tunica media contains abundant concentric elastic sheets allowing expansion and recoil during cardiac cycles.

Muscular Artery

A medium-sized distributing artery characterized by a thick smooth muscle tunica media and a prominent scalloped internal elastic membrane.

Arteriole

A small blood vessel leading into capillaries, having a thin tunica media with only 1 to 2 layers of smooth muscle and usually lacking internal or external elastic laminae.

Thoracic Duct

The main lymphatic vessel that collects lymph from the lower body, left upper limb, left side of head, neck, and thorax, draining into the left venous angle.

Cisterna Chyli

A prominent dilated sac at the origin of the thoracic duct that receives lymph from the intestinal and lumbar lymphatic trunks.

Hassall's Corpuscles

Concentric epithelial structures found specifically within the medulla of the thymus gland.

Peyer's Patches

Aggregated lymphoid follicles located specifically within the submucosa of the ileum of the small intestine.

White Pulp

Splenic lymphoid tissue organized around central arteries, composed of lymphatic nodules containing lymphocytes and macrophages involved in immune responses.

Red Pulp

Splenic tissue consisting of venous sinuses and splenic cords rich in macrophages, responsible for filtering blood and removing worn-out red blood cells.