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59 Cards in this Set
- Front
- Back
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Digestive System Overview
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Layers:
1) Mucosa -Epithelium -Lamina Propria - Cellular tissue, has lymphocytes, plasma cells, lymphatics, small blood vessels -Muscularis Mucosa (mostly smooth muscle) 2) Submucosa - Large blood vessels and nerves. Dense irregular CT 3) Muscularis Externa - Broken into a oblique, circular, and longitudinal layer. Mostly smooth muscle 4) Serosa or adventitia - If it's attached it's a adventitia, if it's loose it's serosa |
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Esophagus
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1. Mucosa
-Epithelium is non-keratinized stratified squamous -Lamina Propria - has connective tissue papillae -Muscularis mucosa 2. Submucosa 3. Muscularis Externa - The initial 1/3 is skeletal muscle, then next 1/3 is mixed, the final 1/3 is smooth. Has peristaltic activity 4. Adventitia/Serosa - Adventitia until after the diaphragm then serosa Gland - It has submucosal glands in alveoli. The glands are in the submucosa for the middle 1/3 and mucosa for the initial and final 1/3 -Leading into the stomach it has a esophageal sphincter |
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Cardiac Stomach
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1. Mucosa
-Epithelium changes to simple columnar mucus-secreting cells. This is called the secretory sheet. only in the stomach -Lamina propria has short infoldings called gastric pits that lead to long twisted cardiac glands that produce mucus-secreting cells. Can tell difference because cardiac gland cell have flat nuclei and the cells that make up the gastric pit are slightly elongated -Muscularis Mucosa 2. Submucosa - The submucosa and mucosa come together to make folds called rugae. Within the rugae are circular divisions called mammilated areas 3. Muscularis Externa 4. Serosa - Thick |
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Fundic Stomach
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Notable: Has short gastric pits that lead into long, straight fundic glands. At the intersection, the cells that go up are mucus cells and those that go down make up the fundic gland cells.
-2 main types, the parietal cell makes HCl and the chief cell makes pepsinogen 1. Mucosa - Contains the fundic glands are gastric pits 2. Submucosa - Has blood vessels and nerves 3. Muscularis Externa 4. Seroa |
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Pyloric Stomach
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Notables: They have longer gastric pits and short and curve pyloric glands in the mucosa which have mucus-secreting cells
-There is a thick muscularis externa circular layer which is the gastroduodenal sphincter |
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Duodenum
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Mucosa - Switch from mucus-secreting columnar cells to a adsorptive epithelium
-Epithelium - Luminal surface has fixed fold called plicae circularis with villus protrusions and submucosa in it -Instead of gastric pits there are Crypts of Liberkuhn or intestinal glands. These glands produce mucus-secreting goblet cells and the adsoprtive cells with microvili called enterocytes or adsorptive cells. Also has endocrine cells like argentaffin cells, paneth cells (secrete lysozyme), and APUD cells. -Lamina propria and muscularis mucosa normal. LP may have neutrophils in addition to the usual Submucosa - Has special duodenal glands called Brunner's Glands which secrete a alkaline mucus to neutralize the acidic stomach chyme. They dump directly into the COL -Typical muscularis external and serosa |
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Parietal vs. Chief Cells
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Parietal - Stain orange with esosin and secrete HCL. Have nuclei in center of the cell
Chief - Stain blue/purple with basophilic stain because of lots of rough ER. Nuclei is the in the cell center |
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Brunner's Glands and Gland's in General
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- When glands are in the mucosa, they are usually intermixed with the lamina propria which is cellular
-Paneth cells stain red |
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Jejunum
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Notable: The jejunum is similar to the duodenum but the plicae circularis begin to disappear and there are no Brunner's Glands
-The villi show a different shape with the crypt and gland the same length and straight |
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Ileum
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Notable: There is a continued shrinkage of the plicae circularis, they are shorter and fingerlike here
-The major difference is groups of lymphatic nodules in the submucosa and mucosa called Peyer's patches. Their location coincides with a smooth lumenal surface and few COL -In the submucosa is the submucosal plexus (Meissner's Plexus) and between the externa layers are the Myenteric Plexus (Auerbach's Plexus) -The Myenteric Plexus is prominent here and it has several parikarya or parasympathetic ganglion cells |
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Appendix
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-Fingerlike and arises from the cecum with a small lumen
-Similar to the small intestine except the plicae circularis are gone, the lumen surface is smooth, and the villi protrusions are gone -The mucosa and submucosa are infiltrated with lymphatic nodules, with diffuse collections of lymphocytes spread throughout the lamina propria -The COL are striaght and tubular lined by simple columnar epithelium, goblet cells, no paneth, has endocrine cells -The circularis externa is elongated nuclei with the longitudinal are round |
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Colon
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-Is used to reabsorb electrolytes and water
-Has a smooth surface because no villus protrusions or plicae circularis -Similar to the rest of the intestine with the COL but these have no paneth, instead they have goblet (more than the rest of the intestine), absorptive (similar to enterocytes) and endocrine cells -The COL are long and tubular and close together -The longitudinal muscularis externa have expansions called teniae coli all along the colon -The lamina propria has lymphocytes, plasma cells, lymphatics, small blood vessels |
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Anal Canal
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-The rectum is similar to the rest of the colon
-As the anal canal approaches the simple columnar epithelium turn into stratified keratinized epithelium -There are sebacous glands and hair follicles -The muscularis mucosa ends and the smooth muscle of the circular layer becomes the internal anal sphincter while the external sphincter is the pelvic floor or perineum -The COL eventually disappear and the mucosa and submucosa are directly attached -Lots of lymphocytes in the LP during this transition |
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Liver
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Portal Triad - portal vein, hepatic artery, and bile ducts. These structures have CT branches that help define liver lobule
1) Blood comes in the portal vein from GI with toxins 1b) Blood comes in hepatic artery to feed blood cells 2) Blood percholates from portal vein through hepatic sinusoids (lines by endothelial cells). At sinuoids it is filtered by Kupper Cells and Hepatocytes 3) Clean blood reaches central vein and goes back to heart from hepatic vein -Human liver lobule is not very filled with connective tissue -Blood comes into the portal canal (portal triad) and percholates down the hepatic sinusoids which are surrounded by hepatic cords composed of endothelial cells, hepatocytes, and Von Kupffer Cells. As it goes down the hepatic sinusoid toxins are removed -Within the portal canal is a bile duct -Hepatocytes are connected by tight junctions and the space between them forms bile canaliculus -Bile travels through the canaliculus to a bile ductules and then bile duct which empties into the hepatic ducts and goes to the gall bladder -The size goes in decreasing order: portal vein, bile duct, hepatic artery -The portal canal leads to hepatic cords of hepatocytes, and inbetween them are sinusoids of endothelial cells and von kupffer |
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Gallbladder
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-pear shape and attach to the liver, receive and concentrates bile
-Lined by columnar absoprtive cells which concentrate bile -Partially covered in serosa and some adventitia -The cell layers is similar to the colon - mucosa with prominent mucosal folds, muscularis with smooth muscle (muscularis mucosa and submucosa are not present, call this externa and it's thin), and a adventitia/serosa with the blood vessels and nerves -Gallbladder has epithelial outpouches called Rokitansky-Aschoff sinuses (R-A) -Mucosa has columnar absoprtive cells and mucus-secreting glands. Lots of lymphocytes in the LP and highly vascularized |
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Pancreas
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-Double gland. Exocrine is a serous gland (dark stain) and endocrine is scattered islets of langerhands (light stain)
-The pancreas is is surrounded by a thin capsule and divided into lobules by a CT septa -The majority of each lobule are 5-8 pyramidal serous secreting acinar cells that empty contents into a central lumen. In the central lumen are centroalveolar cells which are part of the intralobular duct system -Within the lobule in a small percentage are acini islets that produce peptides and hormones (A-cell on outside, B-cell on inside) -Has a perenchymal structure with small villi and Brunner's Gland (similar to duodenum) -Has lots of ducts lined by simple columnar epithelium with goblet cells coming out. At surface has pseudostratified/stratified columnar epithelium Pancreatic Ducts 1) Duct starts with a acini with 5-8 pyramidal serous cells around a central lumen 2) In the lumen are centroacinar/centroalveolar cells which create the intercalated ducts which are squamous 3) Intercalated drain to the intralobulae (not striated) which are round, simple cuboidal 4) Intralobular unit to form the interlobular, have lots of CT around a simple cuboidal to columnar epithelium 5) These drain to the pancreatic duct |
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Tooth Development (1)
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1) Bud Stage - primary epithelial band goes into the ectomesenchyme with basement membrane between them. Condensation of ectomesenchyme is transition between stages
2) Cap Stage - Ectomesenchyme condenses to form the dental papilla and dental follicle. The enamel organ forms with the outer enamel epithelium (cubodial), inner enamel epithelium (cubodial to low columnar), the stratum intermedium (squamous) and the stellate reticulum (bound by desmosome, star shape with GAG and mucoid substance). This step is the transition between cap and bell -The dental organ is here (follicle, papilla, enamel organ) -Enamel knot which directs cust formation appears and cells will die by apoptosis 3) Bell Stage - Crown assumes its final shape. Odontoblast and ameloblast differentiate. The dental lamina fragments and degrades. Due to a difference in differentiation the cells at the cusp will fold up creating the final crown shape and -note: refer to the enamel organ as the dental organ with outer/inner dental epithelium. Dental organ, dental follicle, and dental papilla make the tooth germ |
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Tooth Development (2)
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Differentiation
1) IDE undergo reverse polarity and signal for the dental papilla to do the same. These are free ameloblast. Space between preameloblast and preodontoblast is cell free zone 2) Dental papilla secrete pre-dentin which breaks down the basemental membrane and which triggers the ameloblast to secrete enamel. The cells are now in the secretory phase -The reduced dental epithelium is formed by 2 events 1) The ameloblast at the cusp and cervical loop will prof/diff at different rates creating the cusp shape. After the ameloblast form the immature enamel they will undergo a transition phase and then a maturation phase. The resorbed ameloblast, statum intermedium, what's left of the stellate reticulum, and ODE make the reduced dental/enamel organ 2) As the hard mineral is laid down the nutrient supply will be low. BV will invaginate from above the ODE and this combination of a loss of the reticulum and thinning of the dental organ creates the reduced dental organ. |
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Tooth Development (3) - Root Formation
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-Epithelial cells of the inner/outer enamel epithelium proliferate from the cervical loop to form a double layer Hertwig's epithelial root sheath. The shealth is a continuation of the reduced enamel epithelium
-This layer will extend around the dental pulp within the follicle and the apical surface will become the primary apical foramen or epithelial diaphragm -As the Hertwig sheath is formed, it will will not become ameloblast but will secrete enamel products that help ectomesenchyme cells to differentiate to odontoblast of the root -As the root forms, the crown grows away from the tooth base and this stretches the root sheath cells. As the stretching continues the sheath will fragment to form clusters of epithelial cells called the cell rests of Malassez -The rests of Malassez remain through adult life within the periodontal ligament Edit Formation of Supporting Tissue -During the cap stage the supporting tissues of the tooth form from the fibrocellular dental follicle layer -As the shealth's fragment, the dental follicle cells migrate between the epithelium, contact the dentin, and differentiate into cementoblast -These cells make a organic matrix with mineralizaes and anchors collagen fiber bundles of the PDL -In all the dental follicle contributes to cementoblast, periodontal ligament fibroblast, and alveolar bone osteoblast |
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Development Time Points
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Primary Epithelial Band - 5 weeks
Bud Stage - 6-8 weeks (ingrowth) Cap - 8-12 weeks (morphogenesis) Bell - 12-16 weeks (differentiation) Crown - 18 weeks - mineral forms |
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Picture Notes
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Slide 9 - Immature and mature enamel stain different colors. Immature is 30% calcified and mature is 95% calcified. Even in immature you can see developmental incremental lines (Straie of Retzius)
Slide 11 - Pre-dentin and dentin stain different colors. Dentin is a darker stain, more mineralized Slide 12 - The cementocytes first lay down cementoid before it is mineralized. Slide 15 - Best way to study tooth is a ground section where mineral remains but soft tissue in the pulp disappears. Enamel cannot grow during adulthood but the secondary/teriary dentin and cementum will increase with age |
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Tooth Structures in the Slides
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1. Straie of Retzius - Developmental incremental lines due to metabolism during growth. Can be seen as reaching DEJ to cusp (perikymata) or parallel ot the DEJ
2. Enamel Tuft - Featherlike inorganic section from the DEJ to 1/3 enamel. They are swirling so different planes show different directions 3. Enamel Lamellae - Area of hypomineralization from the DEJ to the cusp 4. Neonatal Line - A prominent Retzius that forms as enamel mineralization transition from fetus (better calcification) to after birth 5. Enamel rods usually run perpendicular to the cusp. However, as they get to the cusp their pattern becomes more S-shaped until it reaches spiraling gnarled enamel 6. Cross Striations - Incremental lines seen by the 4um deposit of enamel per day. 7. Hunter Schreger Bands - Usually seen on the sides of enamel. Optical illusion caused by ameloblast changing the direction of the rods so it takes a wavy course. Dark bands are diazones caused by transverse section, longitudinal section cause light bands called parazones |
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Teeth: 2nd Projection Slides
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-two types of bone preparation. Decalcified where the inorganic matrix is removed, and ground where the mineral stays
Dentin Tubules -Near the pulp chamber where the OBP sharply curves is considered the beginning of secondary dentin. S-shaped tubule reflects path OB took due to a reduction in pulp. Usually straight at cusps and apex though. In additional to major S-shape, their are minor waves in the dentin that reflect OB motion. In a cross section you can see the tubule surrounded by a light stained richly mineralized area (peritubular) and lightly stained less mineralized (intertubular). The tubules also have a lot of lateral branching -The tubules have more lateral branching near the root, also branching at the DEJ. Their width is greater near in the pulp Enamel Spindles: Extension of OBP into the enamel. Either percendicular to DEJ or at a slight angle. Appear dark because ground section removes organic material Contour Lines of Owen - Visible lines in dentin due to metabolic changes during formation. Example are birth, illness, and injection of tetracycline which is incorporated into the HAP |
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Dentin
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1) Mantle Dentin - 10um layer near DEJ. Formed by globular calcification. Appears red and collagen is perpendicular to DEJ
2) Circumpulpal Dentin - Majority of primary dentin, forms by heterogenous or linear calcification. Collagen is parallel to DEJ and it appears blue. Has peritubular dentin near tubules and intertubular 3) Interglobular Dentin - Near the DEJ, it's areas where globular dentin didn't come together and mineralize completely. Dentin tubules run through it normally 4) Tomes Granular Layer - Along the dentin-cementum junction, areas of hypomineralization around the dentin tubules in root formation |
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Dentin (2)
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1) Secondary Dentin - Forms after the apical foramen is completed. A continuation of primary dentin but the tubules change direction. This is deposited slowly. The odontoblast are usually crowded at this point and appear as a pseudostratified layer
2) Tertiary/Reparative Dentin - Forms over time in response to age, stimuli, caries. Has few and more irregular tubules. Doesn't mineralize with DSPP and secondary/tertiary interface has a low mineralization area. Dead Tracts - When caries affect the tubules the odontoblast are sealed off by reparative dentin. After the OBP disappears all is left is a residual dead tract that appears black in slides. Sclerotic Dentin - Either due to dead tracks or age, the tubules or tubule space can fill with calcium salts and appear transparent Lines of Von Ebner - Incremental growth lines in dentin, parallel to the DEJ. Reflect 5 day or 20um dentin growth cycles |
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Cementum
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1) Acellular - Forms near the apex and first laid down. Has mineralized matrix with collagen fiber bundles (sharpy's fibers). Deposited slowly
2) Cellular - Mixture of cementocytes in lacunae and less mineralized but still trapps Sharpy's fibers. Deposited quickly and continual over life. Found in the apical and interraddicular pulp areas. Thicker than acellular cementum -Cementocytes have canaliculi pointed towards periodontal ligament where the nutritional source comes from Cementum Lamellae - Incremental lines in cementum reflecting periods of inactivity and growth |
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Pulp
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-Function of the pulp is to maintain the dentin over life
-Contains cells of NNC (ectomesenchymal origin) like fibroblast and neural and vascular components. No large veins/arteries, just smaller ones -Has a odontoblast layer, cell-free zone of Weil, cell rich zone (has cells used for reparative dentin), and the pulp core -Early in life it has many proteoglycans, later on these are replaced from reticular or collagenous fibers -Nerve supply in pulp is mostly unmyelinated and has the plexus of Raschkow running through the cell-free zone. Can innervate the odontoblast in a few ways |
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Periodontium
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Ligament - The width varies with age and between teeth. Made of fibroblast that secrete collagen fiber bundles (Sharpy Fiber) connecting the cementum to the alveolar bone
-Also has epithelial rests of Malassez Gingiva - Reduced enamel epithelium and oral epithelium combine during eruption to form the junctional epithelium around the enamel. Also has sulcular and oral epithelium. -These are statified squamous, with the oral epithelium being keratinized -Junctional epithelium has two basal laminas, connect to enamel by desmosomes, and is permeable. Has neutrophils under normal conditions. Has rete pegs into the gingiva connective tissue under abnormal conditions Gingiva Connective Tissue - Has blood vessels and nerves which supply the oral epithelium. The GCT has folds in the OE called papilla, and the OE has folds into the GCT called rete pegs. Normal in the OE -The GCT has fiber bundles forming dentinogingival connections and dentinoperiosteal connections with cementum and bone -Stippling in the OE is normal. The depressions are called by rete peg formation, and the humps are caused by the connective tissue papilla |
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Larynx
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Function - Production of sound and passage of air between oropharynx and trachea
Structure 1) Cartilagenous framework with intrinsic muscles that move cartilage that changes vocal cord tension. Extrinsic muscle move larynx up or down during swallowing. 2) The superior space is the ventricular fold (false vocal cord), followed by the ventricle (makes resonance), and then the inferior vocal fold (true vocal cord) 3) Layers a) Mucosa - Epithelium is stratified squamous until trachea and then pseudostratified ciliated columnar. Has lamina propria b) Submucosa - Mucoserous glands (mostly mucus) in the ventricular fold submucosa. Glands mostly serous in vocal folds submucosa c) Has cartiagenous layer followed by skeletal muscle 4) Vocal Fold - Has elastic vocal cords to produce sound. Has clear areas where cords use to be. Major muscle is the vocalis muscle which is skeletal |
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Trachea
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Function - Conduit for air. Goes from the larynx to the middle thorax and divides into 2 primary bronchi
4 Major Layers 1) Mucosa - Ciliated pseudostratified epithelium with goblet cells and a elastic, fiber-rich reticular lamina propria 2) Submucosa - Has seromucous glands and dense irregular CT 3) A C-shaped hyaline cartilage which keeps trachea open. Surrounded by the perichondrium. Open in the back 3b) Connecting the C-shaped ring is fibroelastic tissue and smooth muscle trachealis muscle that divides mucoserous glands 4) Adventitia -Trachea usually surrounded by endocrine organ thyroid and parathyroid glands |
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Lung
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Function: Air conduit and sight of gas exchange with pulmonary vessels
Breakdown: Primary bronchus divides into smaller secondary and tertiary bronchi. This leads to bronchiole and a terminal bronchiole. This leads to a respiratory bronchioles. Once alveoli increase it becomes a alveolar duct which terminates in a alveolar sac surrounded by alveoli Bronchus - Ciliated Pseudostratified columnar epithelium with goblet cells in the mucosa. Loose CT and mixed glands in the submucosa. Muscularis with smooth muslce followed by cartilagenous plates Bronchiole - simple columnar epithelium followed by thick muscularis mucosa, no cartilage or submucosal glands or goblet cells. Becomes simple cubodial. Goes from simple ciliated columnar to simple ciliated cubodial but not all ciliated Terminal Bronchiole - Simple ciliated cubodial |
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Lung - 2
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Alveoli - sites of gas exchange between air and blood
Respiratory Bronchiole - Has cubodial cells with alveoli recesses in the mucosa. Also has muscle layer Alveoli Duct - Mostly a thin epithelium with a bit of smooth muscle. Starts with interalveolar septum with CT, collagen, elastic fiber, fibroblast, and macrophages which remove inhaled matter Alveoli Sac - Only a thin epithelium Alveoli - Has type I and type II pneumocytes. Type I is squamous alveolar cell and type II is great alveolar cell. Thinnest part of spetum has a pulled pulmonary capillary for gas exchange -Type I - squamous and line majority of surface - Type II - cubodial and secrete surfactant to keep alveoli open. Divides and replenishs both type I and type II Septum - Surrounded alveoli duct, sac, and alveolus. Varies in thickness. Thickest parts has fibroelastic tissue, macrophages, and type I/II cells. Thin parts has capillary fused with epithelial cells which are squamous at this point |
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Kidney - Greater Structure
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Function: Conserve body fluids and electrolytes, remove metabolic waste in the blood, modify filtrate. Hydroxylates vitamin D and make renin, involved in blood volume and pressure (produced by cells of distal tubule and adjacent afferent arteriole)
1. Outer thin connective tissue is the capsule 2. Cortex - Contains the renal corpuscles and cortical labyrinths with the convoluted tubules. Also has medullary rays has straight tubules. 3. Medulla - Composed of collecting tubules for the urine. Composed of medullary rays and inverted pyramids known as medullary pyramid whcih are a group of collecting tubules. The tip is called a medullary pyramid and it dumps urine into the renal pelvic 4. Renal Pelvis - Lined by transitional epithelium, funnel shaped and passes urine from the medulla to the ureter and then bladder. Runs through the kidney hilum. It is a double walled cup and has renal artery and vein. |
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Kidney - Tubules Structure
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-Blood enters the nephron through the renal corpuscle. The corpulse has a capillary glomerus and a double walled bowman's capsule which filters the blood into the proximal tubule (convoluted), loop of henle, and distal tubule (convoluted) and into the collecting tubule
1. Bowman's Capsule - The glomerus endothelial cells is in contact with the capsule inner called wall (visceral layer). They have a fused basal lamina which the filtrate passes through between visceral podocytes. The filtrate enters Bowman's space and is passed to the outer layer which is the parietal layer (simple squamous) 2. Proximal Tubule - Has large cells and a non clear defined cell boundary. Has a brush border to help of reabsorption of filtrate back to the outside. The lumen is star shaped. The cells are cubodial with lots of mitochondria for pumping. 3. Distal Tubule - A larger lumen and smaller cells, still not a clear cell boundary distinction. The brush border isn't as extent. Lumen is circular, fairly smooth, cells are low cubodial. 4. Collecting Tubule - In the medullary rays and pyramid, they have mound shaped cells with a clear junction. No brush border. If asked, they are cubodial. Merge, collect, and grow in size as they pass from the cortex to the medulla. End in the apex of the medullary pyramid, the renal papilla |
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Kidney Tube System and Filtration
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1. Proximal Tubule (Convoluted Portion)
2. Loop of Henle - In the medulla, near the medullary ray. Little filtration -Descending Loop is a proximal tubule straight portion -Loop is the thin segment. Filtrates water only -Ascending loop is the distal tubule straight portion. Impermeable to water but allows ions to come through 3. Distal Tubule Convoluted Portion |
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Kidney Pictures
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1. Renal Lobe = Cortex and Medulla (medullary pyramid). Medullary rays are continuation of medulla into cortex, contains collecting tubules, pars recta (straight proximal tubule), ascending thick loop of henle (distal tubule) and blood vessels
2.Two types of neurons depending on where renal corpuscle is. Typical is juxtamedullary and other is cortical (hypertonic urine made) 3. Renal Lobule - Centered between medullary rays 4. Poles - The renal corpuscle of Malphigian Corpuscles have a vascular and urinary pole. Vascular pole receives afferent/efferent arterioles and glomerular capillaries. It is where the ultrifilate or glomerular plasma filtrate collects. The other end is the urinary pole which passes filtrate to the proximal tubule |
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Ureter
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Function: Takes urine from the renal pelvis to the urinary bladder. Passaged assisted by smooth muscles in the wall
Layers: 1. Mucosa -Transitional epithelium of basal cubodial/columnar cells, intermediate cubodial cells, and surface dome-shape or squamous depending on ureter state -Dense connective tissue - Sometimes divided to LP and submucosa. Contains several capillaries 2. Muscularis Externa - Smooth muscle of 2-3 layers. Inner longitudinal and middle circular always present. Outer longitudinal present near bladder 3. Adventitia - Rich in fibroelastic connective tissue and adipose tissue |
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Urinary Bladder
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-Receives urine from two ureters and stores until neural stimulation sends it to the urethra
Mucosa - Has a transitional epithelium (similar to ureter) and a layer of dense connective tissue of the LP and submucosa Muscularis - Muscularis externa is thick with three irregularly arranged layers, hard to make them out Serosa/Adventitia of loose connective tissue -can often see the ureter within the urinary bladder. Space between the two has several medium blood vessels |
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Testes - Large Structure
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Function - Male reproduction. Seminiferous tubules lead to epididymis and vas deferens. accessory glands are prostate, bulbourethral gland and seminal vesicle
-The outside is thick connective tissue fibroelastic tunica albunginea. Epithelium is simple subodial -The rest of the testis are seminiferous tubules held in a CT layer known as the tunica vasculosa -Between the seminiferous tubules are the Leydig Cells which make testosterone -The seminiferous epithelium is made of fibroblast which produce a collagenous layer, and a few layer of myoid cells that create peristaltic movement |
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Inside the Seminiferous Tubule
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-The main cell of the tubule are Sertoli cells which attach basement membrane to the lumen. They are tall columnar with pyramidal nuclei and a dense nucleolus. They phagocytize extra spermatid cytoplasm. They give metabolic and strcutural support to developing sperm
-Between the Sertoli the sperm develop 1) Attach to basement membrane is the spermatogonia or sperm stem cell. Divide to produce another spermatogonia or a primary spermacytes 2) Primary Spermatocyte has 4N DNA and granular nucleus. It divides meiotically to make a short lived secondary spermatocyte 3) Secondary spermatocyte divides meiotically to make a spermatids which are 1N. These are around the lumen and go from circular to elongated DNA 4) Spermatids grow a tail and become final spermatozoa which are released to lumen and stored in the epididyis (mature) and then vas deferens. They are nonmotile until leaving epididymis and only able to fertizile after capacitation |
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Prostate
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Function - Largest accessory sex gland. Produces secretion involved in semen and has smooth muscle contraction during ejaculation
Structure: Outer fibroelastic capsule and inner prostatic glands which are tubulo-alveolar (3 layers 1) Mucsal - mucosal glands and pseudostratified columnar epithelium 2) Submucosa (stroma) - Has smooth muscle interspersed with fibroblast secreting collagen, so it is called fibromuscular 3) Main prostatic gland - has aggregations of dead epithelial cells and precipitated secretory products which make the prostatic concretion |
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Penis
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Outer: This elastic dermis and stratified squamous epidermis
Middle: Dense connective tissue of the deep and superficial fascia Inner: Has three erectile bodies, the corpus cavernosum and a single corpus spongiosum which has the urethra -Cavernosum - Has a thick fibrous tunica albuginea and lots of vascular channels surrounded by smooth muscle. Upon parasympathetic impulse there is vasoconstriction, blood enters, and penis becomes erect. The interstittum or corpus cavernosum trabeculae (CCT) is filled with fibrous tissue, blood vessels, and nerves -Corpus Spongiosum - Has the urethra in it with pseudostratified columnar epithelium. Has a thinner and fibroelastic tunica albuginea. It is filled with vascular spaces surrounded by smooth muscle and a interstitum of fibrous tissue -Where the 3 tunica albuginea come together is the pectidaform septum |
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Ovary - Function and large sections
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Function: Produce female gametes (oocytes) and steroid hormones
-Divided into a cortex and medulla Cortex - Has thousands of primordial follicles arrested in 4N first prophase and others in different phases. -Outer is germinal epithelium (cubodial) and a thick CT of tunica albuginea Medulla - highly vascularized with loose CT |
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Ovary - Cell Stages
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1) Primordial Follicle - Has a primary oocyte surrounded by a layer of squamous follicular cells bound to a basal lamina
2) Growing Follicle (early or late primary) - The follicle cells divide and form a stratum granulosa (follicle cells now cubodial) attached to the zona pellucida immediately around the oocyte. Additionally, stomal cells around the follicle develop into the htheca folliculi 3) Secondary or Mature Follicle - Between primary/secondary follicle the cell goes from prophase I to metaphase II. As granulosum thickens fluid filled cavities will appear and coalesce to make antrum. The layer of the cells immediately around the oocyte is the corona radiata. The next layer away from the antrum is the cumulus oophorus, and the rest of the statum granulosum. All these structures appear as the oocyte is pushed to one side by the antrum. The theca folliculi is still at the outside. |
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Corpus Luteum
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Function - Produce progesterone and estreogen to stimulate growth and differentiation of uterine endometrium is prep for implantation
Structure -Develops from leftover stratum granulosum and theca folliculi -During lutinization these cells form glandular clumps called luteal cells. The granulosum form large cubodial granulosa lutein cells, and the theca folliculi form smaller cubodial theca lutein cells -The antrum (central cavity of the corpus luteum) decreases in size, immediately surrounded by granulosa lutein cells, and then the theca lutein cells -On the outside blood vessels from the ovarian stoma penetrate to the central cavity (flattened cells) to carry hormones away |
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Uterus Overview
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Function - Site of fetus implantation
Structure - hollow, pear shaped muscular organ 1) endometrium (mucosa) - simple columnar outside. Around glands is LP which is cellular and vascularized 2) myometrium (muscularis) - outer longitudinal, middle randomly interdigitating smooth muscle bundles, inner circular. Layers separated by connective tissue and BV 3) Perimetrium or seroa. Extends laterally to form broad ligament of the uterus, attach uterus to pelvic sides and has nerves, BV, and lymphatic. Is a loose CT |
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Uterus Menstrual Cycle
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3 phases: proliferative, secretory, and menstrual
-The basement layer of the endometrium is the stratum basale which remains throughout the whole event -During proliferation thse cells proliferate to create the endometrial or uterine glands (straight) which secrete mucus, and the stroma CT and BV also proliferate. All under the influence of estrogen. The glandular cells are simple columnar 2) Secretory - Glands have a corkscrew shape and form sacculations of filled mucus 3) Menstrual - Spiral arteries constrict and this new layer created from the basale, the stratum functionale, degenerates and sloughes off |
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Mammary Gland
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-They are branched tubulo-alveolar glands that lie in subcutaneous tissue. Become mature mamary glands at puberty due to estrogen
-Get lots of adipose tissue -Each mammory gland is divided into lobes and lobes are divides into lobules -At rest lobules have terminal ductules which compose a terminal duct lobular unit (no secretions until pregnancy) -When activated they have secretory alveoli that enlarge and make most of the lobule tissue. The alveolar epithelium is low cubodial and has milk -Tubes go from either alveoli or terminal ductules to intralobular duct (loose CT), interlobular duct (dense CT) and then lactiferous sinus below nipple |
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Mammary Gland Proliferative
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-estrogen acts on ductal system and progesterone on the alveolar development
1) Terminal ductule branch and elongate 2) Mammory gland enlarge, alveoli differentiate from end of terminal ductules. Myoepithelial cells between BL proliferate 3) Alveoli mature and the glandular epithelium becomes cubodial. Interlobular CT becomes a thin fibrous capsule around th elobule. Secretory endings apparent |
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Pituitary Gland
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-endocrine gland at brain base
-has a infundibulum that connects it to the hypothalmus and passes the median eminence -split into 2 lobes 1) anterior adenohypophysis - glandular tissue -pars distalis - majority, has cells arranged in cords, rich capillary network -pars intermedia -pars tuberalis - sheath around the infundibular stalk 2) posterior neurohypophysis is a neural secretory tube -pars nervosa and infundibular stalk which have unmyelinated neural secretory axons and special glial cells which are pituicytes |
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Pituitary Gland Secretions
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Adenohypophysis -
1) Growth Hormone 2) Lactogenic Hormone or Prolactin for mammary gland development 3) Adrenocorticotrophic hormone (ACTH) stimulates the adrenal gland 4) Follice-stimulating hormone - ovarian follicles develop and sertoli cells develop 5) Luteinizing Hormone (LH)/ Interstitial Cell Stimulating Hormone - causes corpus luteum to form and secrete estrogen and leydigs to produce testosterone 6) Thyroid Stimulating Hormone Neurohypophysis - Oxytocin and ANtidiuertic Hormone (ADH) or Vasopressin - released through portal vein which goes through adenohypophysis (come from rathe's pouch) |
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Thyroid Gland
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-lower part of neck, has 2 lobes connected by isthmus
-thin CT capsule and septa divide it into lobes -2 types of secretory cells, follicular cells and large parafollicular or C-cells -Cubodial/Columnar/Squamous follicle cells form a follicle filled with colloid, inactive thyroglobulin. Upon stimulation by TSH they take up iodine and secrete thyroxin (T4) and triiodothyronine (T3) -C-cells are in the basement membrane of the follicular cells, they secrete calcitonin for Ca2+ take up by cells |
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Parathyroid Gland
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-CT capsule
-4 of them near or embedded in thyroid gland -2 cell types 1) Chief Cells - darker stain, more numerous, closesly packed together. Produce PTH which releases calcium in blood 2) Oxyphil Cells - lighter stain, usually in a group, wider dispersion, larger |
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Adrenal Gland
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-paired, right above kidney with lots of fat. Has a capsule, cortex, and medulla
1) Cortex - has 3 layers - Zona Glomerulosa - cubodial cells in ovoid groups with spherical closesly packed nuclei, basophilic. Secrete mineralocorticoids like aldosterone which target kidney and regulate electrolytes 2) Zona Fasciculata - large vacuolated cubodial cell (spongiocyte) in long straight cords separated by sinusoidal capillaries. Lightly stained cause have lipid droplets. Secrete glucocorticoids like cortisol 3) Zona Reticularis - small cells in anastomosing cords. Have sex steroids like androgens and glucocorticoids Medulla -have pale cells, medullary cells that produce norepineprine or epinephrine -Vein drains the capillaries of the cortex and medulla to medullary vein |
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Eye Overview
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-Eye has 3 concentric layers, reina, vascular coat, corneoscleral coat
-Cornea and lens concentrate and focus light on the retina -Iris betwen cornea and lens regulates the size of the pupil through which light can enter -Photoreceptors (rods and cones) in the retina detect the intensity and color Inner: retina -Between inner and middle is retinal pigment epithelium Middle: Vascular choroid has ciliary body with ciliary muscles which adjust the lens and zonular fibers to suspend the lens. Connected to iris Outerlayer: Clear cornea and opaque sclera which extrinsic muscles attach to. -In cavity of eye is vitreous cavity with vitreous body. Also has anterior and posterior chambers with aqueous humor |
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Retina
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-attached to the forebrain
1. Tapetum (not in humans) 2. Retinal Pigment Epithelium - 3. Photosensitive receptor of rod/cone - first nerve impulse 4. Outer Nuclear Layer - Has nuclei of rods and cones 5. Outer Plexiform Layer - has synpase between rods/cones and horizontal cells 6. Inner Nuclear Layer - has nuclei of horizontal cells 7. Inner Plexiform Layer - Has synapse between horizontal and ganglion cell 8 Ganglion Cell Layer - Cell bodies and nuclei of ganglion cells 9. Canglion Cell Axon - Axons take impulse to forebrain |
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Ear
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-system of chambers and canal called bone labyrinth and mebraneous labyrinth (endolymph). Perilymph between membraneous and bony labyrinth
-Has cochlead which has receptor for hearing, the organ of Corti - cochlead sits on a bony stem called the modiolus and have spiral ganglion and the cochlear nerve |
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Cochlea
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-has hair cells with stereo cilia to convert mechanical E to electrical and transmit to vestibulocochlead nerve
-Made of several bony canals -Bony canals lined by spiral crest (ligament) -Bony canal divided by membraneous spiral lamina which has basilar lamina and vestibular membrane to make scala vestibuli, scala tympani, and cochlear duct (scala media) -Vestibuli and tympani are perilympthatic spaces while scala media has endolymph -Endolymph made by cells in spiral ligament called stria vascularis -Osseous spiral lamina extends from modiolus to basilar membrane and cochlear nerve runs along it. Above the osseous is the spiral limbus which supports elevation of cells -Tectorial membrane is a extension of the spiral limbus and contacts hair cells -THe hair cells rest upon the spiral lamina |
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Olfactory Epithelium
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-has short basal cells, spindle-shaped olfactory cells (neurons), columnar-shaped supporting cells with cilia
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