The Vascular System Part 1 Flashcards
(63 cards)
definition of BLOOD VESSELS
the DELIVERY SYSTEM of DYNAMIC STRUCTURES that BEGINS and ENDS at the HEART
definition of ARTERIES
blood vessels that carry BLOOD AWAY FROM THE HEART
- carries OXYGENATED BLOOD (with the EXCEPTION of PULMONARY and UMBILICAL VESSELS)
definition of ARTERIOLES
smaller ARTERIES that ENTER our TISSUE
- begin to BRANCH OFF to make CAPILLARIES and begins to SUPPLY TISSUE CELLS–serves cellular needs
definition of VENULES
small VEINS that come from GROUPS OF CAPILLARIES
- collects blood from the CAPILLARY
definition of VEINS
blood vessels that carry BLOOD BACK to the HEART
- carries DEOXYGENATED BLOOD
describe the HISTOLOGICAL STRUCTURE of BLOOD VESSEL WALLS/ what are the 3 TUNICS of our BLOOD VESSEL WALLS?
WALL LAYERS/TUNICS:
- TUNICA INTIMA
- TUNICA MEDIA
- TUNICA EXTERNA
describe the TUNICA INTIMA
- includes the ENDOTHELIUM
- begins to LINE THE LUMEN–moves simultaneously to the ENDOCARDIUM
- has an INTERNAL ELASTIC TISSUE
- has the SUBENDOTHELIAL LAYER–has CONNECTIVE TISSUE
describe the TUNICA MEDIA
- contains SMOOTH MUSCLE and ELASTIC FIBERS/ELASTIN –makes our vessels STRETCHY
- controls VASOCONSTRICTION and VASODILATION begins to INFLUENCE B
- has an EXTERNAL ELASTIC MEMBRANE
describe TUNICA EXTERNA
- composed of ELASTIC CONNECTIVE TISSUE
- contains COLLAGEN FIBERS–very important for ANCHORING and PROTECTION
- contains LYMPHATIC VESSELS
- contains the VASO VASORUM
describe the VASO VASORUM
- often is a PART OF ALL LARGE VESSELS
- begins to NOURISH EXTERNAL VESSELS–helps with SUPPLYING NUTRIENTS and REMOVES WASTE
describe the LUMEN
the area where blood passes through
- helps with the transportation of blood; a certain CAVITY
what are the THREE DIVISIONS of ARTERIES?
- have THREE DIVISIONS for ARTERIES–all based on SIZE AND FUNCTION
- ELASTIC ARTERIES
- MUSCULAR ARTERIES
- ARTERIOLES
describe ELASTIC ARTERIES/CONDUCTING ARTERIES
- thick walled with LARGE LOW-RESISTANCE LUMEN
- often known as CONDUCTING ARTERIES–ex. the AORTA and other MAJOR BRANCHES
- important for CONDUCTING BLOOD–transports from HEART to MEDIUM-SIZED VESSELS
describe the SIGNIFICANCE of ELASTIN
- protein that is found in ALL THREE TUNICS (most in TUNICA MEDIA)
- contains SUBSTANTIAL SMOOTH MUSCLE (this is INACTIVE in VASOCONSTRICTION)
- acts as specific PRESSURE RESERVOIRS
- begins to ABSORB PRESSURE for minimization as blood MOVES DOWNSTREAM
describe the MUSCULAR ARTERIES
- rose from origin of ELASTIC ARTERIES
- also known as DISTRIBUTING ARTERIES–begins to DELIVER BLOOD TO BODY ORGANS
- has a broad range of DIAMETER; can be size of as pinky to a pencil
- they have the THICKEST TUNICA MEDIA–sandwiched between ELASTIC MEMBRANES
- have greater amount of ELASTIC TISSUE
- ACTIVE IN VASOCONSTRICTION–helps with MAINTAINING VESSEL PRESSURE
describe ARTERIOLES
- the SMALLEST OF ALL ARTERIES
- known as RESISTANCE ARTERIES–changing of DIAMETERS begins to have CHANGES OF RESISTANCE to BLOOD FLOW
- have a controlled flow into CAPILLARY BEDS (via VASO DILATION) and the VASOCONSTRICTION of SMOOTH MUSCLE
what is the DIFFERENCE between LARGE and SMALL ARTERIOLES? what is the METARTERIOLE?
LARGE ARTERIOLES:
- contains all THREE TUNICS
SMALLER ARTERIOLES:
- contains only a SINGLE LAYER OF SMOOTH MUSCLE that begins to SURROUND ENDOTHELIAL CELLS
METARTERIOLE:
- the VERY END of the CAPILLARIES
- the GAS EXCHANGE SITE
definition of CAPILLARIES
- provides access to ALMOST EVERY CELL and ALMOST ALL TISSUES
- exceptions: CARTILAGE, EPITHELIA, CORNEA, and EYE LENS
what are PERICYTES?
spider-shaped STEM CELLS that help
- stabilizes CAPILLARY CELLS
- controls PERMEABILITY
- plays a role in VESSEL REPAIR
what is the FUNCTION OF CAPILLARIES?
- helps with the exchange of GASES + NUTRIENTS + WASTES + HORMONES between blood and interstitial fluid–known as VASOMOTION (just means INTERMITTENT CONTRACTION and RELAXATION)
- released by ENDOTHELIAL CELLS–NITRIC OXIDE
what are our 3 TYPES OF CAPILLARIES?
- CONTINUOUS CAPILLARIES
- FENESTRATED CAPILLARIES
- SINUSOID CAPILLARIES
describe CONTINUOUS CAPILLARIES
- found ALL OVER THE BODY (within SKIN, MUSCLES, LUNGS, and CNS)
- quite UNIQUE to see in BRAIN–have own BRAIN CAPILLARY ENDOTHELIAL CELLS with TIGHT JUNCTIONS in formation of BLOOD BRAIN BARRIER
- often have associated PERICYTES and PINOCYTOTIC VESICLES
describe FENESTRATED CAPILLARIES
- has typical LARGE FENESTRATIONS or aka PORES that aid in INCREASING PERMEABILITY
- often seen in AREAS OF ACTIVE FILTRATION (ex. the KIDNEYS), areas of ACTIVE ABSORPTION (ex. the SMALL INTEST), and AREAS OF ACTIVE SECRETION (ex. the ENDOCRINE GLANDS)
- can also be seen in the DIGESTIVE TRACT–have a greater number of FENESTRATIONS (due to ACTIVE ABSORPTION OF NUTRIENTS)
- FENESTRATIONS have a THIN DIAPHRAGM made up of GLYCOPROTEINS
describe SINUSOID CAPILLARIES
- often seen in LIVER, BONE MARROW, SPLEEN, and the ADRENAL MEDULLA
- have LARGER INTRACELLULAR CLEFTS and FEW TIGHT JUNCTIONS
- larger clefts allow for LARGER MOLECULES and CELLS to PASS THROUGH–slower process of blood entering
- have INCOMPLETE BASEMENT MEMBRANES
- are IRREGULARLY SHAPED and have LARGE LUMENS