Cardiac MuscleMyocardiumMyoendocrine Cells from the Right Atrium 1
Myoendocrine cells have a typical morphology. The endocrine secretory apparatus, for example, exists only in the Golgi region in or close to the sarco-plasmic cones , which is rich in sarcoplasm and poor in myofibrils. Golgi complexes 2 can be located either close to or further away from the nucleus. Secretory granules 0 occur mainly in the Golgi regions, but sporadically there are also secretory granules in the rest of the cytoplasm. They often form lines of vesicles in the space between...
Striated MusclePsoas Muscle Mwv
Longitudinal section through several sarcomeres in a skeletal muscle fibril cf. Fig. 230 . The space between two adjacent Z-bands 1 is called sarcomere. By this definition, a sarcomere consists of an A-band and the two halves of the adjacent I-band 2 on each side. The Z-band is electron-dense. It runs through the center of the I-band 2. The somewhat lighter stained H-band goes through the middle of the A-band 3. In the center of the H-band is the M-band or M-line center membrane cf. Fig.230 ....
Elastic LigamentLigamentum Nuchae Nuchal Ligament
The elastic ligaments are considered dense regular connective tissue stretch-resistant parallel fibers . Their interconnecting bundles of elastic fibers vary in thickness cf. Fig. 191 . In this preparation, the elastic fibers are stained bright red cf. Fig. 190 . The network of collagen fibers and reticular fibers stained green-blue contains fibrocytes and small blood vessels. The smooth muscles, which can raise the neck hair arrector muscles of the hair , have elastic end-tendons. Bovine neck...
Soft Palate and Uvula 1
Muscle fibers from the velum extend into the uvula. Some clusters of mucous glands of the uvula are located in this web of muscle fibers. Sporadically, there are also small tonsil-like structures in the uvula. The striated muscle fibers of the uvula muscle of the uvula branch out in an almost regular pattern. Circumferential muscles are also found cf. Fig.237 . Longitudinal section through the uvula with striated muscle fibers U and mucous glands 2. The connective tissue is stained blue. This...
FibroblastsFibrocytes Oil
Fibrocytes from the connective tissue of a human amnion. Some of the oval or spindle-shaped fibrocytes have long processes, which will make contact with processes from other fibroblasts. Whole-mount preparation. Stain Heidenhain Iron hematoxylin magnification x 50 100 Fibrocyte from the epineurium of the median nerve with arcuate, slender processes 0 of different lengths. Fibrocytes tend to have the shape of a spindle and consequently, their nuclei are elongated and often lobed H. The...
Reticular FibersAmnion 1
The amnion Greek sheep skin, membrane covering the embryo is a transparent, shiny embryo sac. The outer amnion layer consists of the amnion connective tissue, which attaches to the chorion connective tissue see textbooks of embryology . The inner surface is smooth and lined by the single-layered amnion epithelium. The amnion connective tissue has several distinct layers. Immediately underneath the epithelium are reticular fibers, which run in different directions and cross over each other,...
SingleLayered Pseudostratified Columnar Cylindrical EpitheliumRenal Papilla
Cross-section through the kidney papilla at the height of the ductus papil-lares H. The ducts are lined with single-layered pseudostratified epithelium cylindrical epithelium, columnar epithelium cf. Figs. 106, 505 . The epithelial nuclei light red are located in the basal portion of the cell. The cytoplasm contains few organelles and shows only faint staining. The cell borders are a prominent detail. Between the ductus papillares are blood-filled capillaries 2. The connective tissue components...
Membranous OsteogenesisParietal Bone
Multinucleated giant cells, osteoclasts, soon appear on the scenes of osteogenesis. They are part of the hematopoietic macrophage-monocyte system and are able to systematically degrade the basic bone substance bone resorption and phagocytose the products of this degradation. Osteoblasts have irregular shapes. They are branched and may contain as many as 50 or more nuclei. Osteoblasts are located close to the newly formed osteoid lamellae. When they degrade osteoid material, they create small...
Corpus of the StomachGastric Glands
The corpus and fundus of the stomach corpus and fundus ventriculi contain the gastric glands .The glands are about 1.5-2.0 mm long, rarely branched tubules, which will split in two shortly before they reach the lamina muscu-laris mucosae. The tubules are densely packed. Their lumina are only 3-6 im wide. Chief or zymogenic cells, parietal or oxyntic cells, neck mucous cells and enteroendocrine cells form the lining of the secretory tubules cf. Fig.405-410 . The parietal cells stained red are...
Spleen
0 The spleen is the largest lymphatic organ in the human body. It is enveloped by a collagen fiber capsule J, which has a covering of peritoneal epithelium qq top of the figure . Irregularly arranged connective tissue cords traverse the organ, starting at the outer capsule. They are named splenic trabeculae 2 almost unstained in this preparation and contain the trabecular blood vessels. Richly vascularized reticular connective tissue occupies the space between splenic capsule and trabeculae....
qq302 Capillaries
Capillaries with fenestrated endothelium see Fig. 299 must be distinguished from fenestrated, discontinuous sinusoidal capillaries. Their endothelial layer shows gaps 2. The figure shows a section of a liver capillary sinusoids of the liver lobule . The endothelium displays 0.1 to 1.0 im-widegaps Exchanges between capillary lumen and the Disse space 3 spatium perisinu-soideum proceed via this discontinuous endothelium. There is no basal membrane. The surfaces of the liver cells hepatocytes next...
AirFilled Ground Dental Section Unstained
Figure a shows osteocytes in the fibrous bone of the tooth enamel. The oste-ocytes feature long cytoplasmic processes. Figure b depicts the ground section of the crown of a tooth with the enamel top and dentine bottom . There is a clear border between both the hard substances. Dentine is traversed by air-filled, parallel dentine canals H .Their ends may branch and fan out like bushels. The dentine canals cause a radial striation of the dentine. The long odontoblast processes are located in the...
PigmentsPurkinje Cells
The enzymatic degradation of endocytosed material is often incomplete. Vesicles and vacuoles with such material are called residual bodies. Lipofus-cin is a membrane-enclosed, indigestible residue that is left over after lysoso-mal degradation. Lipofuscin-loaded residual bodies are called lipofuscin granules. In long-lived muscle and nerve cells, lipofuscin granules become more abundant with age. Lipofuscin is therefore known as an aging or wear-and-tear pigment. Lipofuscin granules in Purkinje...
KinociliaTuba Uterina
Kinocilia are motile, membrane-enclosed cell processes. They emerge from small bodies basal bodies or kinetosomes under the cell membrane see Fig.84 . Cilia are usually 2-5 im long and have diameters of about 0.2-0.3 im. That makes them considerably longer than microvilli and easily discernible using light microscopy. Kinocilia are often abundant cilia border and form very dense groups at the cell surface. Such cells are called cilia cells. This figure shows single-layered columnar epithelial...
g 358 Thyroid Gland
- In contrast to other endocrine glands, the thyroid gland stores large amounts of its hormone-containing secretory product in the extracellular space. Consequently, the ultrastructure with its irregular lobes and follicles looks more like that of an exocrine gland. The follicles of the thyroid gland are round, ovoid or tube-like hollow organs with a diameter between 0.1-0.8 mm. Their walls consist of a single-layered epithelium see Fig.362 .The height of this epithelium depends on the...
Odontogenesis
Enamel and dentine can be particularly well demonstrated showing an incisor in the 5th fetal month. At the end of development, dentine is a 1-5-nm wide layer between stellate reticulum and enamel, and between stellate re-5 ticulum and dental cement. The following tissues are seen in this figure 1 Loosely arranged mesenchyme cells and the connective tissue fibers of the dental sac. 2 A layer of densely packed cells of the stellate reticulum stratum stellate, stratum intermedium . C 3...
Chondral OsteogenesisFinger Bqe
Proximal phalanx from the finger of a fetus. Section from the zone of cartilage degradation and endochondral osteogenesis. In the right upper corner, the figure shows the largest cells of the column cartilage. The cells in the subsequent layer are the large voluminous cartilage cells of the initiation zone. The center image shows calcified cartilage ground substance , which contains islands of primary bone marrow. Young bone tissue stained light red is layered onto this perforated layer...
Striated MusclePsoas Muscle 1
This cross-section shows striated muscle fibers about 10-100 im thick. Size and morphology depend on muscle function and workload. The nuclei HI are clearly located in the periphery of the cells. The plasmalemma envelops the cytoplasm sarcoplasm . The crevices between the muscle fibers contain the loose connective tissue of the endomysium, which consists mostly of reticular fibers. The even, dense and only softly stained dots in this cross-section reflect the even distribution of myofibrils cf....
Multilayered Stratified Nonkeratinizing Squamous EpitheliumEsophagus
In multilayered stratified epithelium, there are always many stacked cell layers. Only one layer, the basal layer, is in contact with the basal membrane. 3 In the multilayered stratified nonkeratinizing squamous epithelium, the surface cells are flattened, while the cells of the basal layer are seemingly prists matic. In reality, cells of the basal layer have quite irregular shapes. The cells .2 in layers following the stratum basale 1 have polyhedral geometry and are generally larger. In...
Multilayered Stratified Nonkeratinizing Squamous EpitheliumPlica Vocalis
The plica vocalis vocal fold is also lined with a multilayered stratified non-keratinizing squamous epithelium . It forms a rigid attachment to its support. There are no glands in this area. As before, notice the changes in cell shapes in the different layers. The basal cells are between isoprismatic and columnar and border on the basal membrane 2. In the following layers, the cells have polyhedral shapes. Closer toward the free surface, they are more and more flattened until their longest...
Pharyngeal Tonsil
In contrast to the palatine and lingual tonsils see Figs. 335-339 , the epipharyngeal tonsil has a multilayered ciliated epithelium 0. Islands of multi-layered squamous epithelium may interrupt it. This nonciliated epithelium may contain lymphocytes cf. Fig.337 as well. The mucous membrane forms sagittal folds, i.e., the surface is enlarged not by invaginations and tonsillar pits, but by the formation of microfolds. As in the palatine tonsil, there is a layer of lymphoreticular tissue 0 with...
Multilayered Stratified Nonkeratinizing Squamous EpitheliumCornea
Vertical section through the human cornea with Bowman membrane H and substantia propria corneae 2. The anterior corneal epithelium is a typical multilayered stratified nonkeratinizing squamous epithelium 3 cf. Figs. 633-636 . It consists of only a few epithelial cell layers. Several epithelial cells are densely layered one over the other. The resulting layers contain basal cells, intermediary cells or superficial cells, respectively. The basal layer consists of prismatic cells only these are in...
Blood Smear
cu a Neutrophilic granulocyte with banded nucleus. b Neutrophilic granulocyte with banded nucleus and beginning segmenta- tion of the nucleus. The cytoplasm is stained light pink and contains azuro-E philic granules with a diameter of about 0.5 im. -q c Two neutrophilic granulocytes with segmented nuclei. Fine threads cong nect the three segments in each of the nuclei. The coarse, heavily stained -Q chromatin bodies are located at the peripheral nuclear membrane. d Neutrophilic granulocyte,...
J2 1 Spinal Ganglion Cells
Human and animal cells are dedicated to specialized functions within the or-vJ ganism, and their sizes, shapes and structures vary accordingly. Spinal ganglion cells are mostly pseudounipolar neurons and can be spherical, ellipsoid, or pear-shaped, with diameters between 20 and 120 m. The round cell nuclei, up to 25 im in size, contain little chromatin H. The nuclei always have a clearly visible nucleolus 2-4 im . Glial cells form a layer around the spinal ganglion cells. Therefore, they are...
Thrombocytes
At about 3 im, thrombocytes are the smallest of the blood cells. They are created as the megakaryocyte disintegrates see Fig.309e . Thrombocytes do not have a nucleus. In streaming blood, thrombocytes have the shape of biconcave disks. In vascular endothelium, they attach to damaged structures and in this way seal the vessels. In the process, thrombocytes are activated, change their shape and release secretory products 2, 3. One important sign of this activation is the formation of pseudopodia....
Wolfgang Kuehnel MD Professor
Institute of Anatomy Universit t zu Luebeck Luebeck, Germany Library of Congress Cataloging-in-Publication Data is available from the publisher. 1st English edition 1965 2nd English edition 1981 3rd English edition 1992 1st German edition 1950 2nd German edition 1965 3rd German edition 1972 4th German edition 1978 5th German edition 1981 6th German edition 1985 7th German edition 1989 8th German edition 1992 9th German edition 1995 10th German edition 1999 11th German edition 2002 1st Italian...
Parathyroid Gland
cu The parathyroid glands glandulae parathyroideae consist of epithelial cell clusters that are about as big as a wheat kernel. They are richly vascularized. q Fat cells and an occasional colloid-containing follicle interrupt the parathy-o roid tissue organization. Based on their affinity to dyes, three cell types can uu be distinguished in light microscopy 1, clear chief cells lightly stained cells 2, dark chief cells and 3, oxyphilic cells chromophilic cells, Welsh cells . The parathyroid...
Palatine Tonsil 1
. Longitudinal section of the tonsillar crypt U. In the center of the figure, the structure of the multilayered nonkeratinizing squamous epithelium 2 of the oral mucous membranes is completely obliterated by lymphocytes 3. It now has the structure of a sponge. The underlying lymphoreticular tissue HI follows without clear demarcation. The multilayered squamous epithelium to the right and left is for the most part intact. Only a few small, heavier stained lymphocytes reside in this part of the...
Thrombocytes 1
y The equatorial section shows the array of organelles. Particularly prominent are the many a-granules H as well as the sections through the open tubular systems 2. The latter consist of many tubules and vacuoles, which intercon- c nect with each other and the extracellular space. This system influences the release of secretory products from stored secretory granules and is instrumental in the activation of thrombocytes. The peripheral layer also attracts attention. It contains a bundle of...
Dense Irregular Connective TissueRenal Capsule
In some organ capsules, the taut, fiber-rich connective tissue shows a woven structure. The fibers are densely packed in layers, running in the direction, in which the tissue is pulled. In other cases, as in this example, the coarse fiber bundles are tightly interwoven, which explains the name matted or felted connective tissue. Intermingled with the coarse bundles of collagen fibers, there are also delicate reticular fibers cf. Figs. 161,180,181,183 . This preparation does not show the...
Peripheral NerveMyelin Sheath
The myelin sheath is formed from Schwann cell processes. The plasmalemma processes encircle the myelinated nerve fibers. The myelin structure is based on a lipid-protein system membranes , in which lipid and protein lamellae are stacked in concentric layers. The myelin sheath can be stained using osmium tetroxide cf. Figs. 260, 261, 265, 266, 269 . It can also be stained blue-violet with Luxol fast blue. Electron microscopy shows that the myelin sheath is made up of stacked membranes. The...
Thymus
Large Hassall corpuscle in the medullary thymus from a child. The figure shows the concentric layering of the reticulum cells particularly well cf. Fig.317 . Note the somewhat larger epithelial reticulum cells in the medulla, which interconnect via their cell processes and form a meshwork. There are fewer lymphocytes in that area. The sectioned blood vessels 2 are filled with erythrocytes. The thymus is equipped with a blood-thymus barrier, which is restricted to the cortex. Stain alum...
Sciatic Nerve
Peripheral nerves consist of bundles of either myelinated or unmyelinated nerve fibers that are held together by connective tissue. This cross-section shows numerous fibers of a sciatic nerve U enclosed by the perineurium 2 see Fig. 263 . The perineurium is composed of very flat fibrocytes and collagen fibrils. Dense regular connective tissue covers the entire nerve. 1 Fascicle nerve fiber bundle Stain alum hematoxylin magnification x 10 Fiber bundle fascicle from the sciatic nerve nervus...
Embryonal Connective TissueGelatinous or Mucous Tissue
Gelatinous connective tissue exists in the skin of embryos and, particularly well defined, as Wharton's jelly in the umbilical cord. The cells of the gelatinous tissue are flattened fibroblasts and fibrocytes with branched cell processes, which interconnect and form a wide-meshed network. Light microscopy shows that the interstices are filled with a homogeneous gelatinous ground substance with embedded densely interwoven bundles of reticular and collagen fibers. When boiled, these fibers yield...
Descending Thoracic Aorta Paa
_o This parallel section shows the fiber network of the tunica media. It features strong lamellae, homogeneous layers of 2-3- im thick elastic membranes as well as singular elastic fibers. They form tight concentric layers. The webbed membranes leave openings in different shapes and sizes and in this way, form fenestrated elastic membranes. The number of these fenestrated elastic membranes increases with age 35-40 for a newborn, 65-75 for an adult cf. Figs. 164-166, 277, 278 . The wall muscles...
Adipose Tissue
There are two types of adipose tissue unilocular white and multilocular brown adipose tissue. Adipose tissue arises from the pluripotent mesenchymal cells and later from cells of the reticular connective tissue, which can produce grape like fatty tissue lobes also. The reticulum cells store fat droplets that will finally coalesce to one large drop. In the process, the cells become rounder. This often creates remarkably large, about 100 im wide, vacuole cells. Their nuclei and cytoplasm are...
Purkinje CellsCerebellar Cortex 1
Purkinje cells J.E. Purkinje, 1787-1869 are neurons with characteristic attributes They exclusively occur in the cerebellum cf. Figs. 5, 681, 682 . Arranged in rows, Purkinje cells are found in the stratum neuronorum pirifor-mium stratum gangliosum, Purkinje cell layer in the cerebellum cortex cerebelli . The pear-shaped cell bodies are 50-70 im high and mostly free of pigments. Each cell extends one axon toward the granular layer 2 and projects two, rarely three dendrites 3 toward the...
Cardiac MuscleMyocardiumLeft Ventricle 1
Longitudinal section through the myocardium of the left ventricle. Note the branching of the cardiomyocytes. The in part terrace-like arranged struts 0 disci intercalares are very noticeable because they stain heavily. Fibril-free sarcoplasm surrounds the nuclei like a cap . 2 Branching of the cardiomyocytes 4 Intercalated discs disci intercalares 5 Network lamella of the cardiac muscle cell 6 Interstitial connective tissue 7 Cardiac muscle cell with nucleus 9 Endothelial nucleus 172 10 Nucleus...
Bone TissueCompact Bone Kwp
Decalcified bone tissue can be processed like any other tissue. It can be cut using a microtome and stained. The cytoplastic processes of osteoplasts occupy bone canals in the extracellular space and connect with each other via nexuses. The exchange of materials probably proceeds via these cytoplasmic processes. Osteocytes and their cytoplasmic processes projections are clearly visible in thin sections of compact bone substance from the femur after decalcification and Schmorl staining. Stain...
Cell Nucleus Lck
Cell nucleus and adjacent cytoplasm from an enterocyte jejunum in a freeze-fracture plane cryofracture, freeze-etching , which renders a profile view of the nuclear membranes. The view is on the inner side of the inner lamella of the inner nuclear double membrane . The white fracture line in this figure corresponds to the perinuclear cisterna Fig. 11 . The lower plane 2 gives a view of the inner side of the inner lamella of the outer nuclear double membrane. Note the abundance of nuclear pores...
Capillaries
cu Continuous capillary not fenestrated from the stratum moleculare of the feline cerebellar cortex. A strong basal membrane separates the endothe- lium from nerve tissue 2 and glial cells, respectively. The pericyte 3 is also completely enveloped by a separate basal membrane. Pinocytotic vesicles in o the endothelium of brain capillaries are rare. Note the sickle-shaped endo- Electron microscopy magnification x 10 000 Capillaries are lined by a single-layered simple endothelium cf. Figs....
Extraepithelial GlandsHolocrine Sebaceous Glands
Sebaceous glands consist of bulbous multilayered epithelium cones, termed sebaceous bulbs or sacs, which lack a luminal space cf. Figs. 612, 613 . The neck of the main bulb opens to the hair shaft. The cells inside the bulb grow larger, produce sebum and consequently, change into sebum cells 2. Their nuclei then die apoptosis . In the usual preparations used for teaching purposes, the fat droplets are removed. This leads to more and more vacuoles in the cells at the center. While producing the...
Vegetative Ganglion Cell
Large vegetative ganglion cell from the Auerbach plexus plexus myentericus from cat duodenum. A collateral branches from the upward extending axon. The downward-pointing cell processes are dendrites. Note the large nucleus cf. Figs. 432-437 . Stain Cauna silver impregnation magnification x 650 lo The nucleus is the center for the genetically determined information in every eukaryotic cell. The nucleus also serves as a command or logistics center for the regulation of cell functions. There is a...
c 184 Dense Regular Connective TissueTendon
c Cross-section through a tendon. Each of the fiber bundles in the tendon are encased by loose, fibrous, vascularized connective tissue peritendineum in-ternum H, which subdivides the tendon into secondary bundles. The tendon tj cells winged cells extend thin, wing-like cytoplasmic processes in all directs tions. The cell processes adhere closely to the collagen fibers. The light cre- vices are technical artifacts shrinkage due to fixation cf. Figs. 183, 185-U 189 . The tendon surface is...
Annulate Lamellae
Annulate lamellae are a specialized form of smooth endoplasmic reticulum membrane They articulate from the nuclear membrane and form concentric layers of lamellae or, as seen here, membrane stacks The cisternae show po-recomplexes H, which are identical to those of the nuclear pore complexes cf Fig-11 Osmiophilic material is more abundant in the pore regions. Annulate lamellae are prevalent in cells with a high membrane turnover, such as tumor cells, testicular Sertoli cells and gametes This...
Basal Plasmalemma InfoldsBasal Labyrinth Basolateral Interdigitations
Epithelial cells, which are involved in an extensive transport of ions and liquids, have deep, often complex, vertical involutions of the basal plasmalemma. In earlier descriptions, they were known as the basal labyrinth 2. Involutions of the plasmalemma obviously serve to enlarge the basal cell surface area. Involutions exist in different variations. Separating curtains of membrane folds create high, narrow cytoplasmic spaces, which contain large, mostly oval crista-type mitochondria 3....
Multicellular Intraepithelial Glands
Several secretory cells can combine to small groups in the surface epithelium. This creates multicellular intraepithelial glands H, which can be found in the multilayered stratified columnar epithelium of the nasal cavities as well as in the epithelium of the urethra and the conjunctiva of the eye goblet-cell groups . This vertical section through the ciliated, multilayered stratified columnar epithelium of the nasal cavity shows goblet cells 2 and a multicellular intraepithelial gland. The...
Granular Rough Endoplasmic Reticulum rERErgastoplasm
The endoplasmic reticulum ER is a continuous system of cell membranes, which are about 6nm thick. Dependent on cell specialization and activity, the membranes occur in different forms, such as stacks or tubules. The ER double membranes may be smooth or have granules attached to their outer surfaces. These granules are about 25 nm in diameter and have been identified as membrane-bound ribosomes. Therefore, two types of ER exist the granular or rough form rER, rough ER and the agranular or...
Tonofibrils
oo Strings of several different filament networks span the cytoplasmic matrix of l cells to form the cytoskeleton. These networks are a dynamic system. There are three distinct networks with morphologically different structures microfilaments, intermediary filaments and microtubules. Among others, there are desmin, vimentin and spectrin filaments, also neurofilaments in neurons, glial filaments in glial cells and keratin filaments in epidermal epithelium. Each of these networks is built from...
Lysosomes Fef
Telophagolysosome residual body in a human cell from the submandibular gland, with heteromorphic content. Lipofuscin granules, which are seen in some cell types see Fig. 66 , represent tertiary permanent lysosomes residual lysosomes, telolysosomes . In contrast, the rod or disk-shaped granules in neutrophil granulocytes see Fig.351 and the discus-shaped granules with crystalloid content in eosinophil granulocytes see Fig. 143 are primary lysosomes. Electron microscopy magnification x 30 000