List of abbreviations

Vocabulary of micros- copic anatomy specialist terms explained in English + German

Every attempt was made to provide correct information and labelling, however any liability for eventual errors or incompleteness is rejected!

dieser Seite Editor: Dr. med. H. Jastrow

Conditions of use

differential diagnosis	striated		smooth
characteristics:	skeletal muscle	heart muscle	smooth muscle
sample image (for more images  click the name above the image, please)
nuclei	very many, close to cell membrane	1-2, rarely more located centrally	only 1 in the centre of the cell
nuclear diameter and form	8-10 µm, lens-like	~ 12 µm, ovoid	10-25 µm, rod-like, corkscrew-like when contracted
order of filaments	exactly parallel (striation)	exactly parallel (striation)	net-like (no striation)
Cohnheim fields	yes	yes	no
cell form and length	cylindric, up to 15 cm	Y-like branched, 50-120 µm	spindle-like, 50-200 µm, in uterus maximal 700 µm
tubular system	Triads: L-T-L tubules	Dyads: L-T or T-L tubules, rarely triads	none
sarkoplasmatic reticulum = L-tubules	very many	many	not present but caveolae
mitochondria	small, electron-dense, many	very large, electron-dense, very many	small, less electron-dense, rare, only close to nuclei
power	very strong	moderate	small, shorten about 20 % of total length
duration	only some minutes of full power	never ending change of contraction & release	contraction for hours possible
innervation	controlled by mind	autonomous	autonomous, low frequency of own activity
stimulation	controlled by motor neurons	influenced by autonomic nerves (& hormones)	influenced by autonomic nerves & hormones
motor end plates	present	none, stimuli conducted by gap-junctions	none, stimuli conducted by gap-junctions
regeneration	possible thanks to satellite cells	none in practice (no satellite cells)	easy by mitosis
specialities:	Type 1 fibres = red fibres higher endurance, much myoglobin, thinner Type 2 fibres = white fibres faster, less myoglobin, thicker	striated discs	caveolae, dense plaques, dense bodies,  synthesis of prostacycline and elastic fibres

All muscle cells derive from myogenic stem cells (Terminologia histologica: Cellulae myogenicae precursoriae) which only in case of skeletal muscle begin to fuse in order to from a large syncythium. Only a small portion of these stem cells is maintained as attached satellite cells. In heart and smooth muscle practically all myogenic stem cells further differentiate to become mature myocytes. This is the reason for no efficient regeneration of these muscle tissues in case of damage.

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