2.4 Anatomy of Circulation - HISTOLOGY Flashcards
3 LAYERS of the HEART:
(inner? middle? outer?)
Inner: ENDOCARDIUM
Middle: MYOCARDIUM
Outer: EPICARDIUM / VISCERAL PERICARDIUM
the VISCERAL LAYER of SEROUS PERICARDIUM is also known as
EPICARDIUM
Inner ENDOCARDIUM (inner lining) is composed of which CELL TYPE
SIMPLE SQUAMOUS ENDOTHELIAL CELLS
& supporting CONNECTIVE TISSUE
MYOCARDIUM is the THICKEST LAYER, and THICKER in the…
LEFT VENTRICLE WALL
MYOCARDIUM consists of..
CARDIAC MYOCYTES (muscle cells)
CELL TYPE in the EPICARDIUM (VISCERAL serous pericardium)
SIMPLE SQUAMOUS MESOTHELIUM
supported by a thin layer of connective tissue, containing blood vessels and nerves
what does the EPICARDIUM contain to help CUSHION the HEART
EPICARDIAL FAT - adipose tissue
also helps produce serous fluid for lubrication
CHARACTERISTICS of CARDIAC MUSCLE
voluntary/involuntary?
INVOLUNTARY
(autonomic nervous system)
CHARACTERISTICS of CARDIAC MUSCLE
striations or no striations?
STRIATED
CHARACTERISTICS of CARDIAC MUSCLE
nucleus:
UNINUCLEATE
- CENTRAL
CHARACTERISTICS of CARDIAC MUSCLE
branched or unbranched?
BRANCHED
SKELETAL MUSCLE characteristics
- Voluntary (somatic nervous system)
- Striated
- Multinucleate (peripheral)
- Unbranched
SMOOTH MUSCLE characteristics
- Involuntary
- No Striations
- Uninucleate
- Unbranched
can CARDIAC MUSCLE REGENERATE?
NO produces scar tissue
(although skeletal and smooth muscle can regenerate)
CARDIAC CELLS are CONNECTED by…
INTERCALATED DISCS
3 types of CELL-CELL JUNCTIONS (INTERCALATED DISCS) between CARDIAC CELLS are
- FASCIA ADHERENS (‘adherence / anchoring junctions’)
- DESMOSOMES
- GAP JUNCTIONS
what do FASCIA ADHERENS between cardiac cells help
Help to TRANSMIT CONTRACTILE FORCES between cells
also sites of ATTACHMENT and insertion of Thin filaments of MYOFIBRILS
what do DESMOSOMES between cardiac cells provide
STRUCTURAL SUPPORT and MECHANICAL STABILTY
by binding myocytes together to prevent separation during contraction
what do GAP JUNCTIONS between cardiac cells help
ELECTRICAL COMMUNICATION
(direct communication between cardiac muscle cells)
via CONNEXONS (intracellular channels / central pores that are aligned to connexons of adjacent cells)
which INTERCALATED DISC / CELL-CELL JUNCTION type allows WAVES of DEPOLARISATION to SPREAD RAPIDLY ACROSS entire HEART (passing from cell to cell) and so coordinating action of muscle cells
GAP JUNCTIONS
via CONNEXONS
which INTERCALATED DISC / CELL-CELL JUNCTION type is for STRUCTURAL SUPPORT and MECHANICAL STABILITY
DESMOSOMES (strong)
which INTERCALATED DISC / CELL-CELL JUNCTION type help to TRANSMIT CONTRACTILE FORCES
FASCIA ADHERENS
