idealised cell Dr.Jastrows electron microscopic atlas

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

idealised mammal cell with organelles, junctions etc. (sheme)	index of drawn structures: Terminology name (English name; linked to page providing images & information)
Please click here for image in higher resolution	This drawing of an idealised cell with small original images of structures
	1 = Nucleus (nucleus) 1a = Euchromatinum (euchromatin) 1b = Heterochromatinum (heterochromatin) 2 = Nucleolus (nucleolus) 3 = Membrana nuclearis (nuclear membrane; consists of inner membrane, perinuclear space + outer membrane with attached ribosoms) 4 = Porus nuclearis (nuclear pore) 5 = Ribosoma (ribosome) aggregated in form of plyribosomes 6 = RER = Reticulum endoplasmicum granulosum (rough endoplasmic reticulum; with attached ribosoms) 7 = SER = Reticulum endoplasmicum nongranulosum (smooth endoplasmic reticulum; lacks ribosoms) 8a = Mitochondrion (Mitochondrion: crista-type; longitudinal & cross-sectioned) 8b = Mitochondrion (Mitochondrion: tubular-type; longitudinal & cross-sectioned) 8c = Mitochondrion (Mitochondrion: saccular-type) 9 = Centriolum (Centriole; longitudinal & cross-sectioned) 10 = Complexus golgiensis - Apparatus golgiensis (Golgi complex; Golgi apparatus) 11 = Vesicula golgiensis (Golgi vesicle) 12 = Vesicula pinocytotica (pinocytotic vesicle) 13 = Lysosoma (lysosome; fuses with 12 to 14) 14 = Heterolysosoma (secondary lysosome = [auto]phagolysosome) 15 = Telolysosoma (lipofuscin body = residual body) 16 = Corpusculum multivesiculare (multivescular body) 17 = Corpusculum lamellare (lamellar body) 18 = Peroxysomum (peroxisome = microbody) 19 = Vesiculae secretoriae (secretory vesicles) 20 = Microtubuli (microtubules) 21 = Microfilamenta; Filamenta actinia (microfilaments; actin filaments) 22 = Filamenta intermedia (intermediate filaments e.g., on desmosomes) 23 = Trama terminalis (terminal web) 24 = alpha-Granula glycogeni (alpha-glycogen granules) 25 = Gutta adipis (Fat droplet) 26 = Synapsis (synapse) 27 = Fasciolus synapticus (synaptic ribbon with attached neurotransmitter vesicles) 28 = Membrana cellularis; Plasmalemma (cell membrane; plasma membrane) covered with glycocalyx 29 = Spatium intercellulare (intercellular space) 30 = Canaliculus bilifer (bile canaliculus) 31 = Zonula occludens (tight junction) 32 = Zonula adhaerens (adhesive belt; belt desmosome) 33 = Fascia adhaerens (fascia adherens; adhesive strip ) 34 = Punctum adhaerens (punctum adherens) 35 = Macula adhaerens (macula adherens; spot desmosome) 36 = Hemidesmosoma (hemidesmosome) 37 = Macula communicans; Nexus (gap junction; macula communicans; nexus) 38 = Microvilli (microvilli) covered with Glycocalyx (glycocalyx) 39 = Cilia; Kinocilia (cilia; kinocilia) 40 = Corpuscula basalia; Kinetosomae (basal bodies; kinetosomes) 41 = Radices basales (Rootlet fibres) 41 = Stereocilia; Stereovilli (stereocils; stereovilli; about 3x longer than 38) 42 = Lamina basalis (basal lamina) 43 = Junctio intercellularis digitiformis (digitiform intercellular junction)

Cells are the smallest components of the body that are able to live. They are the basis for all living creatures. Cells are surrounded by a unit membrane an contain a fluid with small organellss called cytoplasm. With the exception of red blood cells all cells of humans and animals contain at least one nucleus limited by a nuclear membrane with pores. Cell nuclei contain the genetic information nesessary for regulated protein synthesis which is the basis for all living processes. The cytoplasm contains water, electrolytes, thousands of different proteins and other molecules as well as organised larger structures visible in the electron microscope as can be seen above. The content of a cell depends on its function and may change in reaction to outer influences. Cellular function is depending on the genes which are active, i.e. which are copied and translated in protein sequences. Gene activation again depends on messenger substances, e.g. hormones or neurotransmitters that come from other cells or blood via intercellular fluid. Examples for the differentiation (spcialisation of cells for certain purposes) of cells are: generation and conduction of stimuli (sensory and nerve cells); movement (muscle tissues); destruction of bacteria and viruses (cells of the immune system), reproduction (sperms and ovum cells), synthesis and destruction of filling or stabilising connective tissue e.g., bone-, fat-, cartilage- and other immotile cells of the connective tissue; production of secretions (gland cells); resorption and digestion of food (epithelial cells of the gut).
A human adult is comprised of about 10.000.000.000.000 (10 Trillion or 10¹³) celles. The size of cells has a certain range. The smallest cells are lymphocytes and microglial cells with diameters of 5 µm (1 micrometer [µm] is the thoudsandth part of a millimeter = 10^-6m), the largest cells are femal ovum cells with maximal diameters of 130 - 150 µm.
The life time of cells is quite different and depends on function. e.g., white blood cells and epithelial cells of the gut normally live just for a few days, red blood cells about 120 days, nerve cells, that may not devide after birth mostly live until death of the individuum.
Free cells like those of the blood have a more or less spherical shape. All cells are stabilised by a cytoskeleton and their morphology is mostly determined by requirements of the tissues they belong to. Cells may form processes that may have a length of over 1000x of their diameter e.g., neurons. In case cells are on inner or outer surfaces, i.e. belong to epithelia, they often show surface specialisations like kinocilia, microvilli oder stereovilli. Free, mobile cells are quite rare. They mostly migrate slowly through connective tissue using mobile processes called pseudopods. Only male sperm cells may move quickly thanks to their cilia. Resting cells in tissues (associations of cells) especially those in epithelia (groups of cells without notable amounts of intercellular substances) are often dirctly connected to each other by different cell-to cell contacts. Some of these connections are stable e.g., interdigitations or desmosomes, others serve for exchange of small molecules and ions and propagate stimuli (gap-junctions). The substances secrected by cells into the intercellular space in connective tissue are responsible for biomechanic functions like elasticity (tendons) or stability (bones).
Any living cell has a more or less intense metabolic activity. Liver cells are very active others like chondrocytes have only low metabolic parameters. Most important metabolic activities are the exchange of substances with surrounding tissues realised by endo- and exocytosis. Further synthesis or destruction of substances, oxigen and carbondioxide exchange (cellular breathing) and communication processes are of major importance for life.

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