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Phase 1 Histology COPY > CV > Flashcards

Flashcards in CV Deck (24)
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1
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A

CARDIAC MUSCLE (MYOCARDIUM)

  • branching chains of cardiac myocytes
  • striations (myofibrils and repeat sarcolemmas)
  • dark intercalated discks (myocyte junctions)

differ from skeletal -

  1. structural - branched, mononuclear (central), no stem cells
  2. physiological - contract/relax without rest, secrete hormones (ANP- when stretched excessibely, increases water/Na+/K+ excretion, inhibits RAAS)
2
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INTERCALATED DISC

  • w/ desmosomes + adherent junctions (stick)
  • w/ gap junctions (electrical coupling)

disc = black

myofibrial = blue/black

function:

desmosome - anchor one cardiac muscle to next by immediate cytoskeleton filaments

gap junctions - allow ion transfer between cardiac smooth muscle

electrochemical coupling - not cardiac conduction

3
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PURKINJE FIBRES (WITH PAS PROCEDURE - MAGENTA)

  • large modified muscles
  • large vacuoles
  • few myofibrils therefore pale H&E
  • stores of GLYCOGEN (PAS)

CARDIAC CONDUCTION

4
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ARTERY - LEFT, VEIN - RIGHT

  • 3 layers
  1. intima (innermost) - endothelial cells on loose connective tissue w/ occasional myo-intimal cells (contractile potential)
  2. media (middle) - thicker in arteries than in veins - smooth muscle, elastic, collagen
  3. adventitia (outermost) - dense collagen and elastic
5
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MUSCULAR ARTERY

  • well defined medial layer (smooth muscle in concentric rings)
  • medial layer interspersed with elastic
  • media-intima divide = wavy internal elastic lamina (condensed perforated elastic)
  • adventitia-media divie = external elastic lamina only in large muscular
6
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ARTERY WITH PLAQUE AND THROMBUS (WITH IRON HAEMATOXYLIN)

  • elastic/nucleus = black
7
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ELASTIC ARTERY (WITH MALLORY’S STAIN)

  • elastic - red / collagen & muscle - blue
  • = aorta and GT vessels close to heart
  • medial layer thick w/concentric sheets of elastic interspersed w/smooth muscle
  • as vessels large - contain own blood supply vasa vasorum

at top = intima then internal elastic lamina, then vascular endothelial cells on BM

8
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ARTERIOLES

  • 3 layers or fewer of muscle @ media
  • no internal elastic lamina - therefore amy completely close when muscle contracts
  • poor adventitia - mainly collagen and elastin

function: highly responsive to vasoactive stimuli - regulation of TPR

9
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A

CAPILLARIES

  • sometimes have contractile pericytes along bed
  • continuous or fenestrated (gut, kidney glomerulus, endocrine glands)
  • diameter is size of RBC

this slide - mature adipose

10
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ENDOTHELIAL CELLS (EM)

  • specialised - release vasoactive substances
  • capillary @ centre

function:

  1. active transport of molecules across cytoplasm
  2. influence muscle tone
  3. coagulation
  4. produce cell adhesion molecules - influsence lymphocyte/neutrophil migration
11
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A

VENULES

  • thin walled
  • pericytes alongside them
  • pericytes become continuous as vessel gets bigger
  • in veins no pericytes, replaced by smooth muscle
  • irregular outline
12
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VEINS (TOP LEFT x2)

  • same layers as arteries, but thinner and poor boundaries
  • irregular outline, large lumne (therefore same blood at lower pressure)
  • wider lumen than arterioles (but slower flow) therefore same volume/sec
13
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LARGE VEINS

  • thick wall
  • distince intima/media and internal elastic lamina
  • medial layer w/ longitudinal smooth muscle
  • adventitia - thick w/ longitudinally arranged muscle fibres
14
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A

LYMPH VESSELS

  • w/ pink staining blood plasma and valves
  • small = like capillaries
  • large = like veins
  • walls = connective tissue with some muscle
  • less pressure than venules
  • sometimes lymphocytes
  • transports antigens and activated lymphocytes from tissue to lymph nodes (and resident macrophage)
  • drains excess fluid fro tissue (hydrostatic/oncotic pressure imbalance)
  • no blood
15
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A

RBC (LEISHMAN’S STAIN - TYPE OF ROMANOVSKY SMEARS)

  • 44% of blood
  • anucleate - leads to biconcavity
  • 120 day lifespan
16
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RETICULOCYTES

  • mature RBC loses cytoplasm and nucleus
  • reticulocytes = immature RBC w/ some visible ribosomes, ie. some dark staining granules
  • increased number with increased RBC produciton
17
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EOSINOPHILS (ROMANOVSKY/LEISHMAN’S)

  • 2-3 lobe nucleus
  • bright pink granules
  • acidophils
  • circulate for a few hours
  • diurnal - highest in morning
  • phagocytose antigen/antibody complexes, associated w/ parasitic infection
  • neutralise histamine

GRANULOCYTES

18
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NEUTROPHILS - POLYMORPHONUCLEAR LEUKOCYTES (LEISHMAN’S STAIN)

  • multi-lobar nucleus
  • most numerous
  • phagocytic
  • engulf and destroy bacteria
  • leave blood stream to enter tissue @ infection site

fine granules = GRANULOCYTES

  1. primary - lysosomes, acid hydrolases, antibac and digest
  2. secondary - neutrophil specific, regulation of inflammation response
  3. tertiary - facilitate insertion of proteis to cell membrane

lobes = 2-4, number increases with age

19
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BASOPHILS - BASOPHILIC LEUKOCYTES

  • not multi-lobar
  • dark blue granules which appear to fill cell
  • least common
  • similar role to MAST cells
  • secrete HISTAMINE and other vasoactive substances - increased blood flow locally
20
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LYMPHOCYTES

  • small cells with dark stained nucleus and little cytoplasm
  • B and T are indistinguishable
  • immature are bigger than RBC, smaller than granulocytes
  • mature roughly equal size to granulocyte
21
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A

MONOCYTES

  • kidney-shaped nucleus
  • no granules
  • pale blue cytoplasm
  • immature cells which differentiate to one of various forms when leave blood and enter connective tissue
  • many to macrophages (fixed marcophage @ liver = Kupffer, and @ spleen)

in blood and alveolar air spaces

macrophage phagocytotic, actute inflammation, arrive after neutrophils

22
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PLATELETS

  • smaller than red cell
  • anucleate
  • fragements
  • from multinuclear megakaryocytes
  • blue
  • 4 types of granules:
  1. alpha - clotting
  2. dense
  3. lysosomes
  4. peroxisomes - elimination of oxygen radicals
23
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MUSCULAR ARTERY 2

  • circumferential sm @ media
  • when this contracts reduces diameter of vessel
24
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ELASTIC TISSUE (ELASTIC VAN GIESON’S WITH IRON HAEMATOXYLIN COUNTER STAIN

  • elastic tissue in tube like sheets - elastic lamina
  • elastic = black
  • sm = mushroom
  • collagen = pink