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Types, Blood Vessels - Coggle Diagram

- - - - Resistance Vessels
    - - Conducting (large) Arteries
        
        Biggest arteries
        
        Order:
        
        Lumen
        
        Tunica Interna:
        
        Endothelium
        
        Basement Membrane
        
        Elastic Lamina
        
        Tunica Media
        
        1 more item...
        
        During Systole:
        
        Expand
        
        During Diastole:
        
        Recoil
        
        Distributing (Muscular/Medium) Arteries
        
        Distribute blood to specific organs
        
        Order:
        
        Tunica Internal
        
        Endothelium
        
        Basement Membrane
        
        Internal Elastic Lamina
        
        Tunica Media
        
        1 more item...
        
        Resistance (small) Arteries
        
        Arteriole
        
        Order:
        
        Tunica Interna
        
        3 more items...
        
        smallest of resistance arteries
        
        Metarterioles (thoroughfare channels)
        
        short vessels that link arterioles directly to venules in some places
        
        provide shortcuts to bypass capillaries
        
        thicker tunica media in proportion to lumen than large arteries and very little tunica externa
        
        smooth muscle layers make up 3/4ths of wall thickness
    - - weak point in artery or heart wall
        
        forms thin-walled bulging sac that can rupture at any time
        
        rupture causing hemorrhage
      - Dissecting Aneurysm
        
        blood accumulates between tunics of artery and separates them
      - common sites:
        
        abdominal aorta
        
        renal arteries
        
        Circle of Wilis
      - results from congenital weakness of blood vessels, trauma, bacterial infections, atherosclerosis, hypertension
    - - Carotid Sinsuses
        
        Baroreceptors in walls of internal carotid artery
        
        monitor blood pressure, transmit signals thru glossopharyngeal nerve, allow for baroreflex
      - Carotid bodies
        
        Chemoreceptors
        
        oval bodies near branch of common carotids
        
        moniter blood chemistry, transmit singal to gloospharyngeal nerve to brainstem respiratory centers
        
        adjust respiratory rate to stabilize pH, CO2, O2
      - Aortic bodies:
        
        1-3 bodies in walls of aoritc arch
        
        same structure/function as carotid bodies, but uses vagus nerve
- - - - Capacitance Vessels
    - - 10mm Hg with little fluctuation
    - - smallest (10-20 mm diameter)
      - more porous than capillaries (exchange fluid with surrounding tissues
      - Tunica Interna only has few fibroblasts around it (no muscle)
      - Muscular Venules
        
        Medium Veins
        
        Venous Sinuses
        
        Large Veins
        
        10mm diameter
        
        smooth muscle in all 3 tunics
        
        thin tunica media with moderate amount of smooth muscle
        
        Tunica Externa thickest layer
        
        thin walls, large lumens, no smooth muscle
        
        can't vasoconstrict
        
        Dural Sinuses, Coronary Sinuses, etc.
        
        thin Tunica media and thick tunica extrema
        
        Tunica Interna forms venous valves
        
        failure of these valves may cause
        
        Varicose Veins
        
        3 more items...
        
        Skeletal muscle pump propels venous blood back to heart
        
        up to 10 mm diameter
        
        up to 1 mm diameter
        
        1-2 layers smooth muscle in tunica media
        
        thin tunica externa
      - Leukocytes leave bloodstream thru venule walls
    - - Pressure gradient
        
        BP is most important force in venous return
        
        7-13 mmHg venous pressure toward heart
        
        Venules (12-18 mm Hg) to central venous pressure: point where vena cavae enter heart (5 mm Hg)
      - Gravity
        
        drains blood from head and neck
      - Skeletal muscle pump
        
        Contracting limb muscles squeezes blood out of compressed part of vein
        
        valves keep moving towards heart
      - Thoracic pump
        
        Inhalation expands thoracic activity
        
        thoracic pressure on inferior vena cava decreases
        
        abdominal pressure on IVC increases
        
        blood flows upward toward heart
        
        Central venous pressure
        
        direct measurement of BP in Right Atrium and Vena Cava
        
        fluctates while breathing
        
        Inhaling (2mm Hg)
        
        Exhaling (6 mm Hg)
      - Cardiac suction
        
        Ventricle contract -> valves pulled downward and atrial space expands
        
        slight suction draws blood from vena cavae to atria and pulmonary veins
      - Physical Activity
        
        Exercise increases venous return
        
        heart beasts faster and harder, increasing CO2 and BP
        
        vessels of skeletal muscles, lungs, heart, dilate and increase flow
        
        increase respiratory rate, increased action of thoracic pump
        
        inactivity causes venous pooling
        
        venous pressure not enough to force blood upward
        
        prolonged standing, CO may be low enough to cause dizziness
        
        prevented by tensing leg muscles, activiting
        
        Jet Pilots wear pressure suits
- - - - Endothelium
      - Basal Lamina
    - - Continuous Capillaries
        
        Endothelial cells w/ tight junctions
        
        Pericytes wrap around capillaries and contain contractile protein (like muscles do) to contract and regulate blood flow
        
        allow passage of solutes such as glucose
      - Fenestrated Capillaries
        
        Endothelial cells riddled with holes called
        
        filtration pores (fenestrations)
        
        spanned by very thin glycoprotein layer
        
        allows for only small molecules to pass through
        
        proteins + larger particles stay in bloodstream
        
        organs need rapid absoprtion and filtration
      - Sinusoids
        
        in Liver, Bone Marrow, Spleen
        
        irregular blood-filled spaces with large fenestrations
        
        let proteins (albumin), clotting factors, blood cells to enter circulation
    - - networks of 10-100 capillaries
        
        usually supplied by single arteriole/metarteriole and drain into venule/distal end of metarteriole
        
        at any given time 75% of body's capillaries are shut down
        
        Precapillary shincters
        
        control flow in capillary beds by relaxing (allowing blood into capillaries) and contracts (constricting entry)
    - - 3 routes Chemicals take to pass thru capillary wall:
        
        Endothelial cell cytoplasm
        
        Intercellular clefts between endothelial cells
        
        filtration pores (fenestrations) of fenestrated capillaries
      - Mechanisms:
        
        Diffusion
        
        most important form
        
        Glucose + O2 diffuse out of blood
        
        CO2 + other waste diffuse into blood
        
        occurs when either:
        
        Endothelial cell membrane is permeable to the solute
        
        Lipid-Soluble substances
        
        Steroid Hormones, O2, CO2
        
        solute can find passages large enough to pass through (fenestrations + intracellular clefts)
        
        Water-soluble substances
        
        Glucose, Electrolytes
        
        Transcytosis
        
        Vesicle-mediated transport moving materials accross endothelial
        
        pinocytosis or receptor-mediated endocytosis pick it up
        
        transport vesicles move across epithelial cell
        
        discharged by exocytosis
        
        only small fraction uses this, but is important for:
        
        fatty acids, albumin, some hormones (insulin)
        
        Filtration + Reabsorption
        
        Capillary filtration (arterial end), Capillary absoption (venous end)
        
        delivers materials to cell + removes metabolic wastes
        
        not always the case:
        
        Glomeruli of kidneys
        
        devoted to filtration
        
        Alveolar capillaries in lungs
        
        devoted to absorption
        
        activity/trauma
        
        increase filtration
        
        Opposing Forces
        
        drives fluid out of capillary
        
        Blood Hydrostatic pressure
        
        high on arterial end of capillary, low on venous end
        
        blood pressure in vessels is hydostatic pressure
        
        draws fluid into capillary
        
        Colloid Osmotic Pressure
        
        results from plasma proteins (albumin)
        
        Oncotic Pressure = Net COP = blood COP - tissue COP
        
        Capillaries reabsorb about 85% of fluid they filter
        
        other 15% is absorbed by lymphatic system, returned to blood
        
        Edema
        
        Accumulation of excess fluid in tissue because filtration becomes faster than absorption
        
        3 Primary Causes:
        
        Increased capillary filtration
        
        Kidney failure
        
        Histamine
        
        Old Age
        
        Poor Venous Return
        
        Reduced capillary reabsorption
        
        Hypoporteinemia
        
        Liver Disease
        
        Dietary protein deficiency
        
        Obstructed lymphative drainage
        
        Surgical removal of lymph nodes
        
        Consequences
        
        Tissue necrosis
        
        O2 delivery and Waste removal impaired
        
        Pulmonary edema
        
        Suffocation threat
        
        Cerebral edema
        
        headaches, nausea, seizures, coma
        
        Severe edema
        
        excess fluid in tissue spaces causes low blood volume and low blood pressure
- - - - 5.25 L/min
        
        equal to Cardiac Output:
        
        Heart Rate X Stroke Volume
        
        Stroke Volume = End Diastolic Volume - End Systolic Volume
  - - - F = Blood Flow
      - ΔP = difference in pressure difference between 2 points
        
        greater = greater F
      - R = resistance
        
        greater = lesser F
        
        Peripheral Resistance
        
        opposition to flow that blood encounters in vessels away from heart
        
        based on 3 things:
        
        Blood Viscosity
        
        stems from plasma proteins (albumins) and erythrocytes --> raise vicosity
        
        thickness
        
        Vessel Length
        
        the father liquid goes thru tube, the more cumulative friction it encounters
        
        Vessel Radius^4
        
        viscosity and length dont change in short term of person, but vasoconstriction and vasodilation can
        
        vasoconstriction from smooth muscle of tunica media contracts, vasodilation when it relaxes
        
        2 more items...
        
        Radius has big impact on Flow, as it is r^4
        
        1 more item...
  - - - Systole = peak arterial BP (ventricular contraction)
      - Diastole = minimum arterial BP (ventricular relaxation
    - - Under 120/Under 80
    - - 120-139/80-89
        
        weaken arteries, cause aneurysms, promote atherosclerosis
        
        as opposed to to
        
        Hypotension
        
        chronic low resting BP caused by blood loss, dehydration, anemia
    - - 160/>100
    - - 180/>110
    - - arteries = pulses (blood spurts intermittently from open artery)
      - capillaries + veins = steady speed (vein bleeding is slow and steady)
      - with age:
        
        Arteriosclerosis
        
        stiffening of arteries due to deterioration of elastic tissues of artery walls
        
        Atherosclerosis
        
        build up of lipid deposits that become plaques
  - - - Edema
      - Fainting
      - Kidney failure
- - - - inadequate heart pumping (MI)
    - - cardiac output low because too little blood returns to heart
      - 3 Principle Forms of LVR shock
        
        Hypovolemic Shock
        
        most common
        
        loss of blood volume
        
        trauma
        
        burns
        
        dehydration
        
        Obstructed Venous Return Shock
        
        Tumor or Aneurysm compresses vein
      - Venous Pooling (vascular) Shock
        
        long periods of standing, sitting, or widespread vasodilation
    - - Loss of vasomotor tone, vasodilation
    - - bacterial toxins trigger vasodilation and increased capillary permeability
    - - severe immune reaction to antigen, histamine release, generalized vasodilation, increased capillary permeability
    - - Several homeostatic mechanisms bring about spontaneous recovery
        
        person faints and falls to floor, gravity restors blood flow to brain
    - - when compensation fails
        
        life-threatening positive feedback loops causing cradic and brain tissue damage
  - - - 0.5 mL of air in coronary artery can cause cardiac arrest
        
        small bubbles in system circulation cut off blood flow to brain, lungs, etc.
        
        air accumaltes in heart chambers
  - - - pressure backs up into spleen, which enlarges and weeps serous fluid
    - - Alcoholism (most common)
      - Malnutrition
      - Heart Failure
      - Chronic Hepatitis
  - - - damages heart by increasing afterload, mycardium enlarges until overstretched and insuffient
      - renal arterioles thicken in response to stress
        
        drop in Renal BP leads to falt rention (aldosterone) and worsens hypertension
    - - obesity, sedentary behavior, diet, nicotine (90% of cases)
    - - increased BP caused by other disease (10% of cases)
        
        Kidney disease
        
        atheroscleorsis
        
        hyperthyroidism
        
        cushing syndrome
- - - - 4-5 minutes causes irreversible brain damage
    - - autoregulated by brain
  - - - CO2 + H2O
        
        H2CO3
        
        H+ + HCO3-
      - Hypercapnia
        
        CO2 levels increase, pH decreases
        
        triggers vasodilation
      - Hypocapnia
        
        CO2 levels decrease pH increases
        
        stimulates vasoconstriction
        
        occurs with hyperventiliation
        
        may lead to ischemia, dizziness, syncope
  - - - Atherosclerosis
      - Thrombosis
      - Ruptured aneurysm
- - - - Arteries
        
        Capillaries
        
        Venules
        
        Veins
  - - - Heart -> Intestines -> Liver -> Heart
      - Kidneys
      - Hypothalamus and Anterior Pituitary
  - - - Artery -> vein, (bypassing capillaries)
    - - Most common
      - vein -> vein
        
        this is why vein blockage is less serious than arterial blockage
    - - 2 arteries merge
      - common around joints, provides alternative routes
- - - - pulmonary capillaries absorb fluid (almost no filtration)
      - prevents fluid accumaltion in alveoli
  - - - redirects flow to better ventilated region
- - - - Tunica Interna
        
        lines blood vessel (touches blood)
        
        Simple Squamous Epithelium
        
        Secretes chemicals for vasodilation or vasoconstriction
        
        usually repels blood cells and platelets to prevent clotting
      - Tunica Media
        
        Consists of: Smooth Muscle, Collagen, Elastic Tissue
        
        strengthens vessels and prevents blood pressure from rupturing them
        
        Contraction of muscle controls blood vessel diameter
      - Tunica Externa
        
        Consists of loose connective tissue that can merge with neighboring vessels, nerves, organs
        
        anchors vessel and provides passage way for nerves, lymphatic vessels
        
        Vaso Vasorum
        
        small vessels that supply blood to outer part of larger vessels
- - - - arterioles constrict
      - most capillary beds shut fown
      - total flow (1L/min)
    - - arterioles dilate in response to lactate, CO2, H+
      - Flow can increase 20fold, diverted from digestive and urinary organs