Histology-summary - Images of slides from the practicals and how to identify them PDF

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Summary

System Tissue Information Image Nervous Cerebrum  Dura (dense fibrous CT), pia (few cells thick, not largely noticeable, covers every tiny cleft) and arachnoid mater (loose, highly vascular, dips into clefts, most noticeable of the meninges)  Large cells – neurons (owl eye)  Glial – 10x more abun...

Description

System Nervous

Tissue Cerebrum

Information  Dura (dense fibrous CT), pia (few cells thick, not largely noticeable, covers every tiny cleft) and arachnoid mater (loose, highly vascular, dips into clefts, most noticeable of the meninges)  Large cells – neurons (owl eye)  Glial – 10x more abundant, small  Oligodendrocytes – small and round w/ clear halo surrounding  Astrocytes near blood vessels  Smallest fusiform cells are microglia (macrophages)  Grey (cortex)  neurons  White (medulla)  processes

Spinal Cord

 Posterior grey matter is sensory  Ventral grey matter is motor  White matter ascending or descending from brain  Central canal lined by ependymal cells  Multipolar neurons  Nucleus almost obscured by Nissl substance (Nissl also extends into dendrites)  Ependymal cells look like simple columnar epithelium

Peripheral Nerve

 White spaces around nuclei = axoplasm of individual neurons  Surrounding nerve is CT layer of epineurium  Surrounding axon is perineurium  Surrounding nerve fibre is endoneurium  Nuclei are from Schwann cells

Image

Resp

Trachea

 Respiratory epithelium containing goblet cells  Epithelium + loose CT under it are the tracheal mucosa  Submucosa underneath contains many seromucous glands and blood vessels  Hyaline cartilage ring  End of rings = bands of smooth trachealis muscle to adjust diameter of trachea  Outermost = CT & muscle comprise the adventitia  Oesophagus is posterior

Lung

Lymph

Lymph Node

 Basically air & vascular space  Bronchi > bronchioles > resp bronchioles > alveolar ducts > alveoli  Air flow structure w/ cartilage = bronchus  W/out cartilage = bronchiole  Smallest air space = alveoli  Air space that is a common vestibule for several alveoli = alveolar duct  Bronchus = ciliated epithelium  Respiratory bronch = cuboidal  Alveolar duct/alveoli = squam  Red regions in alveolar wall = capillaries  Wall also has pneumocytes and macrophages  Type 1 = small, spindly and comprises capillary wall  Type 2 = “foamy” contain surfactant (look like mesothelial cells)  Clara cells in bronchioles contain surfactant  Fibrous capsule – fibroblasts and collagen  Space under = sub-capsular sinus  Sinus connects to efferent lymphatics  Sinuses extend along sides of trabecular down into medulla  Follicles (nodules) in cortex, medullary sinuses (pale staining) and cords (darker) of lymphocytes in medulla  Lymphocytes have very little cytoplasm  99% of cells are lymphocytes  Larger nucleus = macrophages  Blood vessels and collagen present to form trabeculae  No epithelium present (if present it is likely carcinoma)  Vessels similar to blood vessels but without blood are likely lymphatic vessels  Most vessels are afferent (in), only 1 is efferent (coming out) but histologically identiical

MALT

Palatine Tonsil

Lingual

Pharyngeal

GIT

Oesophagus

Stomach

 Largest  Where soft palate meets tongue  Dark lymphocytes at periphery, middle = pale germinal centre (more cyto)  Diagnostic feature  squamous epithelium forming clefts between groups of lymphoid tissue – tonsular crypts  Involutes with old age  At back of tongue  Occurs w/in framework of mucinous and serous glands  Intermittently joined with squamous epithelium of surface  Skeletal muscle in varying orientations (b/c tongue is nearby)  Mucosa of tongue is stratified squamous, and dips into tonsil  Slight crypt, but not as defined as palatine crypts  Nasopharynx  At periphery there is columnar mucosa b/c it is located in the nasal cavity (epithelium similar to respiratory epithelium

 Non-keratinized stratified squamous mucosa  Muscularis mucosa under BM  Loose CT/fat in submucosa  Variation of smooth muscle layers  Adventitia (b/c it is not intraperitoneal)  CT of adventitia  loose collagen  loose irregular; some fat and blood vessels  Some skeletal muscles present in the posterior portion b/c swallowing is voluntary  Start of GIT  Surface epithelium not

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 GastroDuodenal Junction

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defined in a papillary array like small intestine Glands pit down rather than grow up (gastric pits) Surface epithelium very mucoid Parietal cells – fried eggs Cells that do not look like that are mucoid – chief cells Chief cells more abundant towards base of mucosa Muscularis mucosa normal Submucosa normal 3 muscle layers, 2 longitudinal, 1 circular Intraperitoneal – mesothelial cells present  serosa Dark layer = epithelium of mucosa, underlying tissues are pale staining and CT/muscle Squam-columnar junction Sphincter is not well defined Stratified squamous (oesophagus), simple columnar (cardiac region of stomach) Muscle underlying mucosae of oesophagus gets thicker  forms sphincter (not obvious) Usually do not see acid secreting cells in this portion of stomach  mucosal glands are present (chief cells) Loose lamina propria between glandular pits in stomach Transition zone – smooth muscle layer (circular) is very thick True serosa in bulb of duodenum Loose CT of submucosa is obscured by Brünner’s Basal glands in duodenum

Duodenum

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Jejunum

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Ileum

Colon

Delicate array of mucosal villi Plentiful loose CT between Majority of cells absorptive Many lymphocytes, plasma Thin rim of muscularis mucosa Abrupt transition from submucosa into muscle layers Ganglion between circular and muscular layer Mainly adventitia except for at gastro junction Plicae circulares Lack of lymphoid tissue in submucosa Developed villi Little CT Serosa Relative lack of goblet cells Looser CT in lamina propria Lacteals (similar to venules) present Red granules in cells at basal surface of mucosa  Paneth

 Serosa (intraperitoneal  Mucosa has papillary arrangement – goblet and absorptive cells  More goblet cells than jejunum  Many lymphocytes  Lymph nodes  Serosa  Extension of submucosal muscle tissue to form plicae circulares (increases SA)  4 distinct layers  Mucosa does not form into papillary structures  Glands dip in to form colonic crypts  2* Lymphoid follicles present in mucosa  Loose CT, adipose and large blood vessels in submucosa  Submucosal ganglion present  Muscle layers normal

Endo

Liver

 Fibrous CT capsule  Intraperitoneal  Central vein – no CT, endothelium lined  Portal vein – CT (bile duct and small artery can be present)  Sinusoid open into central vein  Spindly nuclei  Kupffer  Round nuclei  hepatocyte  Serosa

Pancreas

 Lobules separated by CT  Ducts can be w/in lobes or ducts outside of it (intra/inter)  Ducts outside lobules surrounded by CT, ducts w/in lobules surrounded by acini  Ducts have simple cuboidal  Islet of Langerhans – no ducts or granules, abundant cyto  Exocrine portion (acinar) contains zymogen granules in cells, nuclei on periphery  Fried egg cells w/ no granules = centro-acinar (beginning of duct system)  Adipose throughout pancreas  Nerve tissue present

Gall bladder

 Simple columnar epithelial layer on surface  Lamina propria between mucosa (which is papillary)  Wall of smooth muscle  Loose CT on the outside  Chiefly peritoneum CT rather than adventitia  At edge of CT – mesothelium  Highly geometric epithelia

Adrenal

Thyroid

Urinary

Kidney

 Clear definition between cortex and medulla  Fibrous capsule that dips into cortex at some points  Clusters of glomeruli-like cells in most superficial layer of cortex – zona glomerulosa (mineral-corticoids aldosterone) SALT  Linear streaks extending through majority of cortex – zona fasciculata (gluco corticoids  cortisol) SUGAR  Mesh of reticular cells – zona Reticularis (androgens) SEX  Microscopically – cells of 3 zones look quite similar  Medulla is highly vascular - Synth of epinephrine - Majority of cells are ganglia  Medulla may have very large veins  central veins  Epithelial lined spaces filled with uniform pink colloid  Variation of size of follicle  Every follicle lined by simple cuboidal epithelium  Inter-follicular CT is highly vascular  Parafollicular cells that make calcitonin are found in spaces b/w follicles in CT  pink cyto, larger round nucleus, usually clustered together  Glomeruli in cortex  Tubules in medulla  At apex of medulla is renal papilla which dips into urinary space lined with transitional epithelium (minor calyx)  Fibrous capsule  Glomeruli are surrounded by tubules  tubules that have full lumens = proximal (90%), empty tubules = distal (10%)  Glomerular: Podocytes (form around inside of capillary), parietal Bowman’s epithelium (outer), mesangial cells  Medulla has pyramidal shape

Repro

Ovary

Testes

Uterus

 When oocytes have developed enough they will have a flat squamous epithelial lining  primordial oocyte  Cuboidal epithelium  primary follicle  Clear zona pelucida around follicle lined by granulosa cells  secondary  Separation of granulosa cells to form antrum  Graaffian follicle  Spindly stromal cells between follicles  Fibrous capsule  Outermost layer = mesothelial  parietal tunica vaginalis  Tunica albuginea (bulk of capsule)  fibrous tissue, collagen, fibroblasts, some blood vessels in the deepest part (tunica vasculosa)  Parenchyma  seminiferous tubules separated by thin bands of CT  Maturation of sperm goes from base to lumen  Round dark nuclei at base of tubule  spermatogonia  1* spermatocytes further up, dense, dark nuclei  Spindly nuclei = Sertoli cells  Spermatids still have significant amount of cyto  Mature sperm have tail and very small nuclei  Important cell in CT between tubules  Leydig cell  Rete testis  network - Epithelium is low cuboidal  Tubules lined entirely by Sertoli = straight tubules  90% smooth muscle  True serosa on upper portion  Adventitia near cervix  Muscle arranged in several orientations  Highly vascular  Endometrium is glandular  Glands extend to myometrium

Fallopian Tube

Cervix

 Connects lumen of uterus through abdominal cavity  Ends near surface of ovary with papillary fimbriae  Where lumen is dilated – has papillary projection in mucosa  Ampullary portion = area of fertilisation,columnar epithelia  Cilia for transportation  Large amount of smooth muscle surrounding tube  Ciliated simple columnar to stratified squamous epithelium  Chiefly fibrous/muscular CT  Deeper portion is chiefly smooth muscle  Mucous glands  Stroma mainly smooth muscle  Vascular  Lymphatic tissue, some of which penetrates through epithelium

LAYER Serosa

Stomach Serosa continuous with peritoneum of cavity

Muscularis externa

Outer longitudinal Middle circular Inner oblique

Submucosa

Rugae to allow expansion No crypts

Brünner’s glands Crypts of Lieberkühn

Normal Crypts

Muscularis mucosae

Contains glands & pit Parietal (HCl, IF), Chief (Pepsin), Mucous Normal

Thin layer of epithelial cells Normal

Large folds

Lamina propria Epithelium Villi

Simple columnar, goblet cells. None

Duodenum 1st part – serosa 2nd to 4th parts adventitia

Jejunum Normal

Ileum Normal

Longitudinal and circular layers Auerbach’s (Myenteric) plexus between

Normal

Peyer’s Patches extend into the submucosa Crypts Normal

Large Peyer’s Simple columnar. Contains goblet and Paneth cells Normal Plicae Very short circulares

Colon Adventitia

Outer Longitudinal Middle circular Inner oblique Transverse rectal folds Crypts persist

Many goblet cells to lubricate faeces Normal Many goblet cells None...