Photo of Embryo
Photo of Embryo: An embryo photo shows the early stages of human development, typically with visible somites, neural tube, limb buds, and heart bulge around week 46.
Cooperation Between Innate and Immune Responses
Cooperation Between Innate and Immune Responses: The innate immune system provides immediate defense, while the adaptive system offers targeted responses; they cooperate through antigen presentation and cytokine signaling to eliminate pathogens.
Factors in Cardiac Output
Factors in Cardiac Output: Cardiac output depends on stroke volume and heart rate, influenced by preload, afterload, contractility, and autonomic nervous system regulation.
Mucosa Associated Lymphoid Tissue MALT Nodule
Mucosa Associated Lymphoid Tissue MALT Nodule: MALT includes lymphoid nodules in mucosal tissues like the tonsils and Peyers patches, providing immune defense at sites exposed to external pathogens.
Stethoscope Placement
Stethoscope Placement: Stethoscope placement for heart auscultation includes four key areas: aortic, pulmonic, tricuspid, and mitral regions, each corresponding to the position of a specific heart valve.
FlowChart Veins into VenaCava
FlowChart Veins into VenaCava: This flowchart maps venous drainage from body regions into the superior and inferior vena cavae, the major veins returning blood to the right atrium.
Erythrocyte Life Cycle
Erythrocyte Life Cycle: Red blood cells are produced in the bone marrow and circulate for about 120 days before being phagocytized in the spleen or liver, where their components are recycled for new cell formation or excretion.
Erythroblastosis Fetalis
Erythroblastosis Fetalis: Erythroblastosis fetalis is a hemolytic disease of the newborn caused by Rh incompatibility, where maternal antibodies attack fetal red blood cells, leading to anemia and jaundice.
The Posterior Pituitary Complex
The Posterior Pituitary Complex: The posterior pituitary stores and releases oxytocin and antidiuretic hormone (ADH), both produced in the hypothalamus, affecting uterine contractions and water reabsorption in the kidneys, respectively.
Varicose Vein
Varicose Vein: Varicose veins occur when valves in superficial veins become incompetent, causing blood to pool and the veins to become enlarged, twisted, and visible beneath the skin, typically in the legs.
Mendelian Pea Plant Cross
Mendelian Pea Plant Cross: Mendels pea plant crosses revealed predictable inheritance patterns through dominant and recessive traits, forming the foundation of classical genetics.
Cardiac Conduction
Cardiac Conduction: The heart’s electrical system begins with the sinoatrial (SA) node, spreading impulses through the atria, to the atrioventricular (AV) node, and down the bundle branches and Purkinje fibers to coordinate contraction.
Lower Limb Arteries Anterior Posterior
Lower Limb Arteries Anterior Posterior: The anterior and posterior tibial arteries, along with the femoral and popliteal arteries, supply oxygenated blood to the muscles and skin of the leg and foot.
The Location Structure and Histology of the Thymus
The Location Structure and Histology of the Thymus: The thymus is located in the anterior mediastinum, made of lobules containing cortex and medulla, and supports T cell maturation, especially in childhood.
Ventricular Muscle Thickness
Ventricular Muscle Thickness: The walls of the left ventricle are thicker than the right due to the higher pressure needed to pump blood throughout the body, compared to the lower resistance in the pulmonary circulation.
Gallbladder
Gallbladder: The gallbladder stores and concentrates bile produced by the liver, releasing it into the small intestine to aid in the digestion and absorption of fats.
Muscular and Elastic Artery Arteriole
Muscular and Elastic Artery Arteriole: Elastic arteries (like the aorta) buffer pressure from the heart, muscular arteries distribute blood to organs, and arterioles regulate blood flow into capillary beds via vasoconstriction and vasodilation.
Complement Cascade and Function
Complement Cascade and Function: The complement system is a group of plasma proteins that, once activated, enhance immune responses by promoting inflammation, opsonizing pathogens for phagocytosis, and directly lysing microbial cells through the membrane attack complex.
Bone Marrow
Bone Marrow: Bone marrow is the primary site of blood cell production, including red and white blood cells and platelets, and contains stem cells that support hematopoiesis.
Arteries of the Brain
Arteries of the Brain: The brain is supplied by the internal carotid and vertebral arteries, which form the Circle of Willis, ensuring consistent cerebral blood flow.