Coelom, Cardiovascular, and Lymphatic Systems Lecture

Vocabulary flashcards covering major anatomical and physiological terms from the lecture on body cavities, serous membranes, blood, cardiovascular, and lymphatic systems.

Coelom

A fluid-filled body cavity completely lined by mesoderm, housing internal organs.

another name for ventral cavity

• the ventral body cavity( thoracic & abdominalpelvic)

Viscera

The internal organs located within the body cavities, especially those of the thorax and abdomen.

Peritoneum

Serous membrane lining the abdominopelvic cavity and covering its organ

• mbn lining

Membrane (anatomical)

Thin, flexible sheet of tissue, composed of Epithelial layer& underlying CT (includes mucous mbn, serous mbn, cutaneous mbn, synovial mbn) that serves various functions such as protection, lubrication, and supporting organs.

Embryonic germ layers

The three primary cell layers—ectoderm, mesoderm, endoderm—formed during gastrulation that give rise to all body tissues.

Pleura

Serous membrane surrounding the lungs and lining the thoracic cavity.

Pericardium

Double-walled serous sac enclosing the heart and defining the pericardial cavity.

Ventral body cavity

Large anterior cavity subdivided into thoracic and abdominopelvic cavities.

Thoracic cavity

Superior subdivision of the ventral cavity containing pleural cavities and the pericardial cavity.

Abdominopelvic cavity

Inferior subdivision of the ventral cavity containing abdominal and pelvic organs.

Peritoneal cavity

Potential space between parietal and visceral peritoneum filled with serous fluid.

Parietal peritoneum

Layer of peritoneum lining the internal surface of the abdominopelvic wall.

Visceral peritoneum

Layer of peritoneum directly covering abdominal organs.

Omentum

A double layer of peritoneum extending from stomach to other organs; includes greater and lesser omenta.

Mesentery proper

Peritoneal fold attaching the small intestine to the posterior abdominal wall.

Mesocolon

Peritoneal fold anchoring parts of the colon to the posterior abdominal wall.

(Peritoneal) Ligament

Double layer of peritoneum connecting one organ to another or to the abdominal wall without a conduit for vessels.

Serous membrane

Moist, friction-reducing membrane composed of simple squamous epithelium and areolar connective tissue; lines closed cavities.

Mucous membrane

Epithelial membrane lining cavities that open to the exterior and secreting mucus.

Retroperitoneal

Describes organs located posterior to the parietal peritoneum and only partly covered by it.

Diaphragm ( openings)

Dome-shaped skeletal muscle with three parts (sternal, costal, lumbar) separating thoracic and abdominal cavities.

Caval opening

Central tendon aperture in the diaphragm for the inferior vena cava.

Esophageal hiatus

Diaphragmatic opening for the esophagus and vagal trunks.

Aortic hiatus

Posterior diaphragmatic passageway for the aorta, thoracic duct, and azygos vein.

Femoral canal

Medial compartment of the femoral sheath conveying lymphatics; potential site of femoral hernia.

Inguinal canal

Oblique passage in the anterior abdominal wall transmitting the spermatic cord in males and round ligament in females.

Zygote

Single-cell stage formed by fertilization, beginning human development.

Organogenesis

Embryonic period during which the germ layers differentiate into organs and organ systems.

Circulatory system

The transport network comprising cardiovascular and lymphatic systems.

Cardiovascular system

• Heart and blood vessels circulating blood

• fxn: Transport O2, deliver nutrients, and waste removal, hormones to/from organs, protecting (blood clots)

Lymphatic system

Network of lymphatic vessels, lymph organs, lymph nodes, lymph and tissues that return interstitial fluid to blood and mediate immunity.

Blood

Fluid connective tissue consisting of plasma and formed elements transporting substances throughout the body.

Plasma

Liquid extracellular matrix of blood containing water, proteins, and solutes.

Formed elements

Cellular components of blood—erythrocytes, leukocytes, and platelets.

Red blood cell (RBC)

Anucleate cell specialized for oxygen transport via hemoglobin; also called erythrocyte.

White blood cell (WBC)

Immune cell defending the body against pathogens; also called leukocyte.

Granulocyte

Leukocyte with cytoplasmic granules (neutrophils, eosinophils, basophils).

Agranulocyte

Leukocyte lacking visible granules (lymphocytes, monocytes).

Pericardial sac

Fibro-serous enclosure of the heart composed of fibrous pericardium and serous pericardium (parietal & visceral).

Epicardium

Visceral layer of serous pericardium forming the outer surface of the heart wall( mesothelium & loose CT)

Myocardium

• Middle, muscular layer of the heart wall responsible for contraction

• striated and involuntary

• Joint by intercalated dics w/gap jxns &desmosomes

Endocardium

Inner endothelial lining of the heart chambers and valves.

Loose CT & endothelium

Heart chambers

Two atria and two ventricles that receive and pump blood.

Great vessels

Large arteries and veins entering or leaving the heart: aorta, pulmonary trunk, SVC, IVC, pulmonary veins.

Cardiac valves

Atrioventricular and semilunar valves ensuring unidirectional blood flow through the heart.

Coronary circulation

Network of vessels supplying blood to the myocardium.

Pulmonary circulation

Route carrying deoxygenated blood from heart to lungs and back with oxygenated blood.

Systemic circulation

Route delivering oxygenated blood from heart to body tissues and returning deoxygenated blood.

Hepatic portal circulation

Venous system directing nutrient-rich blood from digestive organs to the liver before entering systemic circulation.

Artery

Blood vessel carrying blood away from the heart; thick muscular walls.

Elastic artery

Large artery with abundant elastin (e.g., aorta) that dampens pressure fluctuations.

Arteriole

Small artery regulating blood flow into capillary beds by vasoconstriction or dilation.

Capillary

Microscopic vessel where exchange between blood and tissues occurs.

Venule

Small vessel receiving blood from capillaries and beginning the return to the heart.

Vein

Vessel returning blood to the heart; contains valves and thin walls.

Venous return mechanisms

Muscle pump, respiratory pump, and venous valves assisting blood return to the heart.

Continuous capillary

Capillary with uninterrupted endothelium; most common type, found in muscle and skin.

Fenestrated capillary

Capillary with pores allowing increased filtration; found in kidneys and endocrine glands.

Sinusoidal capillary

Leaky capillary with large gaps; found in liver, spleen, and bone marrow.

Lymphatic vessels

Thin-walled channels that collect and transport lymph toward the venous system.

Lymphatic organ

Encapsulated structure (e.g., thymus, spleen, lymph node) involved in immunity and lymph filtration.

Lymphatic nodule

Unencapsulated cluster of lymphoid tissue such as tonsils or Peyer’s patches.

Primary lymphatic organs

Sites of lymphocyte production and maturation—bone marrow and thymus.

Secondary lymphatic organs

Sites where immune responses are initiated—lymph nodes, spleen, MALT.

Thymus

Primary lymphatic organ in the mediastinum where T cells mature.

Lymph node

Bean-shaped secondary organ filtering lymph and housing lymphocytes & macrophages.

Spleen

Largest lymphatic organ filtering blood, recycling erythrocytes, and mounting immune responses.

Lymphocyte

Agranular leukocyte (B, T, NK cells) central to adaptive immunity.

Macrophage

Phagocytic cell derived from monocytes that engulfs pathogens and debris.

Development sequence:

Zygote(2 gamets)→ morula→ blastocyst→ gastrulation → embryonic disc→ neurulation→ coelom formation

Where is the heart located?

• in pericardial cavity, in mediastinum, in thoracic cavity, directly behind sternum

• 2/3 of mass lies to the left of midline