Skip to main content
Indietro

Blood Vessels - Anatomy & Physiology

I pulsanti di controllo sono stati cambiati in modalità "navigazione".
1/28

Termini in questo insieme (28)

  • What are the three tunics of a blood vessel from the lumen outward?

    Tunica intima, tunica media, and tunica externa.

  • What is the main function of the tunica intima?

    Provides a smooth, low-friction surface next to the blood, composed of endothelium.

  • What is the role of the tunica media in blood vessels?

    Contains circular smooth muscle that controls vessel diameter via vasoconstriction and vasodilation; it is the thickest layer in arteries.

  • What does the tunica externa do?

    Protects, strengthens, anchors the vessel, and nourishes the outer wall; contains longitudinal connective tissue fibers and vasa vasorum in large vessels.

  • What is the lumen of a blood vessel?

    The central, blood-filled space inside a vessel.

  • What are elastic arteries and their function?

    Largest conducting arteries with abundant elastin; they smooth the pressure surge from ventricular ejection (e.g., aorta, pulmonary trunk).

  • How do muscular arteries differ from elastic arteries?

    Muscular arteries are distributing arteries with a thick tunica media and distinct elastic membranes; they supply most named arteries.

  • What is the primary function of arterioles?

    Smallest arteries that regulate blood flow into capillary beds by changing diameter in response to local and sympathetic signals.

  • What happens during vasoconstriction and vasodilation?

    Vasoconstriction: smooth muscle contracts, narrowing lumen.
    Vasodilation: smooth muscle relaxes, widening lumen.

  • What are the three types of capillaries and their permeability?

    Continuous: least permeable, tight junctions.
    Fenestrated: pores for rapid exchange.
    Sinusoid: wide gaps, very leaky for large molecules and cells.

  • Where are continuous capillaries typically found?

    Most organs; special tight form creates the blood–brain barrier.

  • What is the function of pericytes in capillaries?

    They stabilize capillaries, regulate permeability, and contribute to new vessel formation.

  • How do veins differ structurally from arteries?

    Veins have thinner walls, less elastin, larger lumens, and a relatively thick tunica externa; they carry blood toward the heart at lower pressure.

  • What mechanisms assist venous blood return to the heart?

    Venous valves prevent backflow, skeletal muscle pump compresses veins, and respiratory pump uses breathing pressure changes.

  • What is the difference between pulmonary and systemic circulation?

    Pulmonary: right ventricle to lungs, lower pressure.
    Systemic: left ventricle to body tissues, higher pressure.

  • What is an arterial anastomosis?

    A connection between neighboring arteries providing collateral routes around blockages, common near joints and in the heart and brain.

  • Name the three branches of the aortic arch in order from right to left.

    Brachiocephalic trunk, left common carotid artery, left subclavian artery.

  • Trace the arterial blood flow from the subclavian artery to the fingers.

    Subclavian → axillary → brachial → radial and ulnar → palmar arches → digital arteries.

  • What is the hepatic portal system?

    A portal system connecting two capillary beds: GI tract capillaries absorb nutrients, then blood passes through liver sinusoids for processing before returning to the heart.

  • What are the three major fetal shunts and their adult remnants?

    Foramen ovale → fossa ovalis; ductus arteriosus → ligamentum arteriosum; ductus venosus → ligamentum venosum.

  • Why do pulmonary arteries carry oxygen-poor blood and pulmonary veins carry oxygen-rich blood?

    Because vessel names reflect direction relative to the heart: pulmonary arteries leave the heart; pulmonary veins return to it.

  • What is the function of the foramen ovale in fetal circulation?

    Shunts blood from the right atrium to the left atrium, bypassing the non-functioning fetal lungs.

  • What causes the closure of fetal shunts at birth?

    First breaths expand lungs, lowering pulmonary resistance; increased left atrial pressure closes foramen ovale; ductus arteriosus constricts; umbilical vessels close.

  • What is an aneurysm?

    A localized ballooning or dilation of a weakened vessel wall that can rupture and cause life-threatening hemorrhage.

  • What is deep vein thrombosis (DVT)?

    A clot in a deep vein, often in the lower limb; a detached clot can travel to the lungs causing pulmonary embolism.

  • What is the difference between the great and small saphenous veins?

    Great saphenous empties into the femoral vein; small saphenous empties into the popliteal vein.

  • What is the primary site where leukocytes leave the bloodstream during inflammation?

    Postcapillary venules.

  • What is the function of the vasa vasorum?

    Small vessels that supply blood to the outer walls of large blood vessels.