Heart, Blood, Respiratory, Immune, and Skeletal Systems Practice Flashcards

Comprehensive vocabulary flashcards covering the heart's anatomy and physiology, the vascular system, blood composition, the respiratory system, immune response mechanisms, and skeletal system basics based on the BMS Biology 2026 lecture notes.

Cor

The scientific name for the heart, which is a fist-sized hollow muscle weighing between 300–350 g.

Mediastinum

The connective tissue space located between the breastbone and spine where the heart is situated.

Perikard (Herzbeutel)

The connective tissue sac or envelope that surrounds and protects the heart.

Septum

The muscular wall that separates the right and left sides of the heart.

Endokard

The thin internal endothelial layer that lines the inner surface of the heart walls.

Myokard

The functional heart muscle layer responsible for the contraction of the heart.

Segelklappen

Valves located between the atria and ventricles, which include the Trikuspidalklappe and Bikuspidalklappe (Mitralklappe).

Taschenklappen

Valves located between the ventricles and outgoing arteries, specifically the Pulmonalklappe and Aortenklappe.

Herzzeitvolumen

The volume of blood the heart ejects per unit of time, averaging approximately 5 L/min at rest.

Diastole

The phase of the cardiac cycle consisting of myocardial relaxation (Entspannungsphase) and chamber filling (Füllungsphase).

Systole

The phase of the cardiac cycle consisting of myocardial contraction (Anspannungsphase) and blood ejection (Austreibungsphase).

Arterieller Blutdruck

The minimum pressure the left ventricle must apply to eject blood into the body; resting arterial blood pressure is approximately 120/80 mmHg.

Sinusknoten

The primary pacemaker of the heart located in the wall of the right atrium where the upper vena cava enters; it initiates the electrical impulse.

AV-Knoten (Atrioventrikularknoten)

The node at the border of the atrium and ventricle that delays the electrical stimulus before passing it to the His-Bündel.

Purkinje-Fasern

The final small branches of the heart's stimulus conduction system that distribute the impulse to the ventricular muscle.

Windkesselfunktion

The property of elastic arteries to expand during the ejection phase and recoil during diastole to drive blood forward continuously.

Hämatokrit

The proportion of the total blood volume that consists of cellular components, typically around 45%.

Erythrozyten

Red blood cells that are biconcave, lack a nucleus and mitochondria, have a lifespan of 120 days, and are responsible for $O_2$ transport.

Leukozyten

White blood cells, which serve as the immune cells of the body; sub-types include granulocytes, lymphocytes, and monocytes.

Thrombozyten

Blood platelets responsible for hemostasis (blood clotting) with a lifespan of approximately 7 days.

Hämoglobin

The red blood pigment in erythrocytes consisting of four protein subunits and a heme component that binds $Fe^{2+}$.

Albumin

The most abundant plasma protein that maintains osmotic pressure and functions as a transport binder for various substances.

Hämostase

The process of blood clotting and stagnation involving vessel contraction, platelet activation, and a coagulation cascade.

Hämatopoese

The formation of blood cells which occurs in the bone marrow from a common stem cell.

Alveolen

Tiny lung air sacs (approximately 300 million in total) where the actual gas exchange between air and blood takes place.

Surfactant

A substance secreted by Pneumozyten Typ 2 that reduces surface tension in the alveoli to prevent them from collapsing during exhalation.

Pleura

The double-layered chest membrane (Brustfell) consisting of the Lungenfell and Rippenfell with a fluid-filled gap that ensures adhesion via surface tension.

Vitalkapazität

The total moveable volume of air in the lungs, calculated as the sum of Atemzugvolumen (AZV), inspiratory reserve volume (IRV), and expiratory reserve volume (ERV).

MHC-I-Moleküle

Proteins found on all own body cells (except erythrocytes) that allow the immune system to recognize the cell as 'self'.

Plasmazellen

Activated B-lymphocytes that contain extensive endoplasmic reticulum and are specialized in mass-producing antibodies.

Zytokine

A group of proteins, such as Interleukine and Interferone, that serve as signaling molecules to activate or deactivate immune cells.

Lysozym

An enzyme found in saliva, sweat, and tears that attacks and destroys the cell walls of bacteria.

Komplementsystem

A group of over 30 plasma proteins that can destroy pathogens by boring holes in their membranes (lysis) or marking them for phagocytes (opsonization).

V(D)J-Rekombination

The genetic process of combining variable (V), diversity (D), and joining (J) gene segments to create a vast diversity ($10^{12} \times 10^{14}$) of antibodies.

Agglutination

The clumping of red blood cells that occurs when antibodies in the plasma react with incompatible antigens on erythrocyte surfaces.

Rhesus-Antigen-D

The most important antigen in the Rhesus system; its presence classifies a person as Rhesus-positive ($Rh^+$).

Morbus haemolyticus neonatorum

A life-threatening condition where a Rhesus-negative mother's antibodies cross the placenta and attack the erythrocytes of a Rhesus-positive fetus.

Thymus

A primary lymphatic organ where T-lymphocytes undergo maturation and selection processes.

Peyer-Plaques

Secondary lymphatic tissue located in the mucous membrane of the small intestine.

Milz

A secondary lymphatic organ in the upper left abdomen that filters old blood cells and participates in immune defense.

Sesambeine

Bones embedded within tendons, such as the Kniescheibe (patella), to facilitate movement and mechanics.

Diarthrosen

True joints characterized by a joint space containing synovial fluid and articulating surfaces covered in hyaline cartilage.

Synergisten

Multiple muscles that work together to perform a specific movement.

Slow Twitch (Typ I)

Muscle fiber types characterized by long-lasting, less powerful contractions, found dominantly in postural muscles like the back.