Organ Histo Final Flashcards
Elastic arteries aka? Give 5 examples of these elastic arteries. Where are they typically found?
aka conducting arteries; common iliacs, carotid, aorta, brachiocephalic, subclavian arteries (ccabs); largest arteries typically found closest to heart)
In which type of arteries, elastic or muscular, is there a common & well-developed internal elastic lamina of the tunica intima? Which tunica media is mostly composed of many fenestrated elastic laminae? Which tunica intima has a thin/incomplete internal elastic lamina? Which tunica media is mostly smooth muscle and richly innervated w/sympathetics for pinpoint control of lumen size for blood flow?
muscular; elastic; elastic; muscular
Comment on the tunica intima of elastic arteries (conducting).
-attenuated epithelium w/rounded nuclei, thin or incomplete internal elastic lamina, thicker CT including collagen I, elastic fibers, smooth muscle cells & fibroblasts
Which layer of both elastic & muscular arteries is typically most dominant? Which layer contains the endothelium & is closest to the lumen? Which layer typically contains the vasa vasorum, small blood vessels that supply nutrients & O2 to the larger blood vessels?
tunica media; tunica intima; tunica adventitia
In the elastic arteries, what is the tunica media mainly comprised of? What is its’ function? What else is found in the tunica media of these conducting arteries?
many fenestrated elastic laminae; function-for expansion & recoil; there also is found a thin external elastic lamina, and vasa vesorum are common in the outer portions of the tunica media of elastic arteries
Which layer of the elastic arteries is composed of loose fibroelastic CT w/numerous vasa vasorum?
tunica adventitia
Muscular arteries aka? What are 4 examples of these?
aka distributing arteries; brachial, radial, renal, femoral arteries (BRRF)
Which layer of the muscular arteries has a common, well-developed internal elastic lamina w/endothelium & a few smooth muscle cells possible?
tunica intima
The tunica media of muscular arteries (distributing) is primarily composed of? It is richly innervated w/? Is an external elastic lamina possible? name some other structures found in the tunica media.
primarily circular smooth muscle; richly innervated w/sympathetics to control blood flow; an external elastic lamina is possible (more often found in elastic arteries); also found gap junctions btwn. smooth muscle cells & elastic fibers, reticular fibers, & chondroitin sulfate
What is found in the tunica adventitia of muscular arteries?
fibroelastic CT w/sulfated GAG’s, fibroblasts, & vasa vasorum
Name the 3 different types of arteries we discussed.
- elastic arteries (conducting)
- muscular arteries (disbruting)
- arterioles (small muscular arteries)
In arterioles, lumen size is relatively equivalent to what?
the wall width
Arterioles are considered a smaller version of?
muscular arteries
T/F: In arterioles, there is a well-developed external elastic lamina.
False; no external elastic lamina
Name 2 of the blood vessels that have an internal elastic lamina possible, but not well-developed in most cases.
elastic arteries, arterioles
These arteries see an increase in width into their 20’s where the wall gets thicker, especially the tunica media (increased # of elastic laminae).
elastic arteries (conducting)
These arteries see collagen I & various proteoglycans increasing in their wall, decreasing their flexibility (which is particularly a problem in which vessels)? What age bracket do they do this?
muscular arteries (distributing); particularly a problem in coronary vessels; typically occurs into middle age
With hypertension, typically around the 50’s in age, elastic fibers break down & are not sufficiently replaced; collagen I & proteoglycans end up accumulating in the tunica _, resulting in an increase in _ BP?
media; systolic
Arteriosclerosis aka? Primarily occurs in which arteries? which layer becomes infiltrated w/soft lipids, causing lumen diameter to decrease? Which layer can have collagen I & sulfated GAG’s build up?
aka atherosclerosis or “hardening of the arteries”; primarily occurs in elastic arteries; tunica intima causes decreased lumen diameter; tunica media can have collagen I & sulfated GAG’s accumulate
What is the main problem w/elastic arteries and atherosclerosis that causes the tunica intima to have trouble surviving?
blood is moving very fast
With blood moving so fast in atherosclerosis, which layer is prone to injury, irritation & infection? If there is an accumulation of lipid-loaded macrophages that have surrounded large amounts of a fatty substance, typically cholesterol, what type of cell is it called? With this lipid accumulation full of macrophages, platelets, smooth muscle cells, collagen & proteoglycans, there is an increase in the tunica intima _, and therefore a decrease in _ size?
tunica intima; “foam cells”; width, lumen
Metarterioles aka? found how often in capillary beds? the flow into a metarteriole is preceded by a _ _?
aka “overflow prevention system”; found w/ALL capillary beds, usually there are multiple metarterioles; preceded by a precapillary sphincter
This “bypass system” is NOT found within all capillary beds? If not found there, where is it typically found?
AVA=arteriovenous anastomosis (AV shunt); found in dermis of skin, stomach wall, & the erectile tissues of penis & clitoris
The overflow prevention system aka? the bypass system aka?
metarterioles; arteriovenous anastomosis (AVA or AV shunt)
Name 4 things that controls/influences the amount of blood flow into capillaries.
- metarterioles
- AVA’s in some locations
- precapillary sphincters
- diameter of the terminal arteriole
In the general capillary structure, there is a single layer of flattened _ cells? What form transient channels through the cytoplasm to move larger molecules like hormones & allergens? Comment on the typical cell junctions and their functions.
endothelial; pinocytic vesicles; typical cell junctions have spotty fasciae occludens between the endothelial cells for a) movement of larger molecules and b) to allow cell movement
Name the 3 types of capillaries. Which one is most common? Which one is located in the pancreas, intestines, and endocrine organs?
- continuous capillaries-most common
- fenestrated capillaries-located in pancreas, intestines, endocrine organs
- sinusoidal capillaries
Where are continuous capillaries usually found? What are the residual mesenchyme cells found in continous capillaries that are numerous in capillaries and venules?
muscles, CT, many organs; pericytes
Residual mesenchyme cells aka? they are numerous on which 2 structures? they secrete what? are they mitotic? what are they very good at changing into? name 2 functions of these cells.
pericytes; numerous on capillaries & venules; secrete basement membrane & matrix components; they are mitotic; very good at changing into smooth muscle cells, fibroblasts, & endothelial cells; functions: 1) healing of damaged capillary, 2) perhaps contract capillaries & help regulate blood flow?
Where would one find a modified continuous capillary? Why is it considered modified? it has a barrier regulation by endothelium but is influenced by which cell type?
in the CNS; modified because it has a zonula occludens instead of fasciae occludens; influenced by astrocytes
Locations of fenestrated capillaries? Their structure includes pores w/_ __ containing 8 fibrils. What is the function of fenestrated capillaries?
pancreas, intestines, endocrine organs (PIE); pores w/thin protein diaphragm containing 8 fibrils; function: to allow greater movement of molecules & cells for rapid nutrient absorption
Which type of capillaries are found in the bone marrow, endocrine organs, liver, lymphatic organs, and spleen (bells)? What is structure and function?
sinusoidal capillaries (sinusoids); structure is an enlarged diameter w/many large fenestrae, gaps, and NO protein diaphragm; function is to enhance material movement
Of the 3 types of capillaries, which one has no protein diaphragm and enhances the movement of materials w/its gaps? which one is for the healing of damaged capillaries? which one has a protein diaphragm? which one has pericytes?
sinusoidal capillaries; continuous capillaries; fenestrated capillaries; continuous capillaries
How are veins similar to arteries? How are they different?
similar because both have the 3 major wall layers (tunica intima, media, adventitia); Veins are not as uniform in structure or number (higher # of veins in the body and their placement in the body is more variable), they usually have a larger lumen than arteries, and they have valves
These structures in veins have two flaps of tunica intima & fibroelastic CT to keep blood moving in the right direction.
valves
What are the 2 functions of valves? which blood vessel are they found in?
- prevent backflow from damaging the capillaries
- work w/skeletal muscle in extremities to keep blood moving back to the heart
- valves found in veins
Name the 3 types of Venules. Venules are determined by _, not diameter?
- postcapillary venules 2. collecting venules 3. muscular venules; venules are determined by tunics, not diameter
This type of venule has endothelium, a small amount of CT and numerous pericytes in the tunica intima, but NO tunica media or tunica adventitia?
postcapillary venules
This type of venule has endothelium and small amounts of CT, NO tunica media, and some CT, fibroblasts, & pericytes in the tunica adventitia?
collecting venules
This type of venule has some endothelium & small amounts of CT in the tunica intima, an incomplete layer of smooth muscle for the tunica media, and the tunica adventitia is present, but has a few pericytes.
muscular venules
Comment on the pattern of pericyte numbers as we increase in venule size?
Pericytes decrease in # as we get into larger venules
Which vessel is similar to venules except that it has a complete tunica media?
small veins
What is the dominant layer in arteries? in veins?
arteries=tunica media
veins=tunica adventitia
T/F: Medium veins have an internal elastic lamina in their tunica intima?
False. They sometimes have an elastic fiber network, but it doesn’t contain an internal elastic lamina (whereas large veins have an elastic network a little thicker that resembles an internal elastic lamina)
In large veins, such as the superficial veins of the legs, comment on the tunica media.
It is very well developed so pooling of blood doesn’t occur.
Name the 2 types of venules that have NO tunica media.
postcapillary venules, collecting venules
These 2 types of large veins have tunica adventitia that includes some cardiac muscle as it transitions closer to the heart?
pulmonary veins & vena cava
This large vein has some longitudinally-arranged smooth muscle for structure/support in its’ tunica adventitia.
inferior vena cava
What is the name of the enlarged & superficial veins in the legs? What are some possible causes of them?
varicose veins; 1. loss of skeletal muscle tone around the veins 2. degeneration of the vessel wall 3. valve incompetence
What are varicose veins in the lower esophagus called? who are they common in?
esophageal varices; common in alcoholics, caused by portal hypertension
What are varicose veins at the end of the anal canal?
hemorrhoids
What are 3 functions of lymphatic vessels?
- drain excess ISF
- transport lymph to lymph nodes; foreign antigen detection in lymph nodes
- transport lymph to blood stream
T/F: Lymphatic vessels are more similar to veins in structure than arteries?
TRUE
Lymphatic capillaries structurally resemble what?
continuous blood capillaries
How are lymphatic capillaries different from continuous blood capillaries?
Lymphatic capillaries are blind ended (suddenly begin), they don’t have pericytes, their endothelial walls can overlap but create clefts between cells (allowing for easy movement of materials into & out of cells), the don’t have fenestrae or tight junctions between endothelial cells, and they contain bundles of lymphatic anchoring filament that support endothelial walls so capillaries can stay open
Small lymphatic vessels resemble what?
venules
What empty into the venous system at the junction of the right internal jugular and subclavian veins?
lymphatic ducts
What are the 2 lymphatic ducts?
- short right lymphatic duct
2. thoracic duct (much more widespreading)
Whose tunica media has longitudinal and circular layers of smooth muscle, several layers of collagen & elastic fibers in the tunica intima, and vasa vasorum-like vessels in the tunica adventitia?
lymphatic ducts
What are 5 functions of the Respiratory system?
- oxygen/CO2 exchange (respiratory portion)
2. olfaction 3. phonation 4. provide defense 5. condition air (conducting portion is 2-5)
What is an example of the large particle filter in the filtration system? medium particle filter? small particle filter?
vibrissae in the vestibule (bugs); mucociliary apparatus in respiratory region (dust, pollen); small particle filter is seromucus glands
This portion of the Respiratory system transports air to the respiratory portion?
Conducting portion
Name the 3 parts of the nasal cavity of the conducting portion.
- vestibule
- respiratory region
- olfactory region
What type of surface epithelium is in the vestibule? What type of glands are there? Support from which cartilage? What are the large particle filters?
same as skin-keratinized stratified squamos epithelium; sebaceous & sweat glands in the CT; hyaline cartilage for support; vibrissae (nose hairs for large particle filters, like bugs)
Which portion of the nasal cavity is between the limen nasi and superior & middle nasal concha?
Respiratory region
What are the functions of the respiratory region of the nasal cavity? What is the largest portion of the nasal cavity?
fxns: 1)warm air 2)clean air 3)humidify air 4)provide defense; largest portion of the nasal cavity is the respiratory region
What is the surface epithelium of the respiratory region of the nasal cavity, and what type of cells are found there? What is the medium particle filter found here?
respiratory epithelium w/basal cells (for mitosis), goblet cells (making mucus for collecting debris), & ciliated columnar cells (to move the mucus from the goblet cells); medium particle filter (dust, pollen) = mucociliary apparatus, which consists of the goblet & ciliated columnar cells
What type of glands are found in the respiratory region of the nasal cavity, and which layer are they found in?
seromucus glands (small particle filter); found in the lamina propria
In the seromucus gland of the LP of the resp. region of the nasal cavity, what is the mucus portion contributing mucus for?
- mucociliary clearance (combines w/mucus from goblet cells)
- more watery than goblet cells’ mucus, so humidifies the air
In the seromucus gland of the LP of the resp. region of the nasal cavity, what are the serous products that are produced?
- lysozymes (antibacterial product)
- various interferons (antiviral)
- cytokines, which stimulate defensive cells
As a serous product of the seromucous glands, what are lysozymes used to combat? what about interferons? what do cytokines do?
lysozymes-antibacterial product; interferons-antiviral; cytokines-stimulate defensive cells
Name 2 things found in the lamina propria of the respiratory region of the nasal cavity.
seromucous glands, cavernous plexus
What is found in the lamina propria of the resp. region of the nasal cavity that is composed of many large (muscular) venules and is typically partially filled w/blood?
cavernous plexus
What are the functions of the cavernous plexus? Where is it located?
- warm air 2. humidify air
- provide defense: example-inflammation, leading to…
a. increase in blood flow-venules enlarge-increase LP size-increase lumen-stuffy nose
b. increase in blood flow-increased oxygen-stimulates seromucus secretion-makes way to lumen-runny nose
-cavernous plexus located in lamina propria of resp. region of nasal cavity
What is the support for the resp. region of the nasal cavity?
hyaline cartilage more anteriorly, and bone more posteriorly
Broadly name the parts of the Olfactory Region.
- olfactory epithelium w/sustentacular, basal, & olfactory cells
- Bowman’s glands
- bone for support
When air enters the Respiratory system, name the order of body parts it encounters.
- Nasal cavity 2. paranasal sinuses 3. pharynx 4. larynx 5. trachea 6. extrapulmonary bronchi 7. intrapulmonary bronchi 8. bronchioles 9. alveolar ducts 10. alveolar sacs 11. alveoli
What is found in the ethmoid, sphenoid, frontal & maxilla bones, and connect to the nasal cavity through the sinal ostia (small openings)?
paranasal sinuses
What is the name of the small openings that connect the paranasal sinuses to the nasal cavity?
sinal ostia
What type of epithelium is found in the paranasal sinuses? Does it have a lamina propria? What is a possible problem in the paranasal sinuses?
respiratory epithelium; the lamina propria is thin, but has seromucus glands and is quite vascular; a possible problem is if there are small ostia, inflammation can lead to LP swelling, blocking the ostia, creating a warm, dark, moist environment for bacteria to thrive=sinus infections
What are the 3 subdivisions of the pharynx from superior to inferior?
- nasopharynx
- oropharynx
- laryngopharynx
In the pharynx, what are the 2 parts of the mucosa? Why isn’t there a 3rd layer, like usual?
- surface epithelium
- lamina propria
- The muscularis mucosa is ABSENT (much like a majority of the resp. system), hence no 3rd layer
Name the surface epithelium of the nasopharynx. Oropharynx? Laryngopharynx?
nasopharynx-respiratory epithelium w/mucociliary clearance (medium particle filtration); oropharynx & laryngopharynx both have stratified squamos epithelium (like tongue & esophagus)
Name something unusual that is found in the lamina propria of the pharynx.
Pharynx has tonsils in the LP
Name the tonsils found in the nasopharynx LP.
pharyngeal tonsils (adenoids) & tubal tonsils
Name the tonsils found in the oropharynx LP.
palatine tonsils (tonsilitis) & lingual tonsils
Name the tonsils found in the laryngopharynx LP.
No tonsils found
T/F: The muscularis mucosa in the pharynx is very thick.
False. There is NO muscularis mucosa in the pharynx.
Name the surface epithelium & type of tonsils found in the nasopharynx.
respiratory epithelium w/mucociliary clearance; pharyngeal tonsils (adenoids) & tubal tonsils
Name the surface epithelium & type of tonsils found in the oropharynx.
stratified squamos epithelium; palatine tonsils (tonsilitis) & lingual tonsils
Name the surface epithelium & type of tonsils found in the laryngopharynx.
stratified squamos epithelium; NO tonsils found
The submucosa of the pharynx aka? What is the function of this region?
submucosa aka pharyngobasilar fascia b/c the collagen in the periosteum of the basilar portion of the occiput blends into wall of pharynx “pharynx hangs suspended by the skull”; fxn: helps in support of the curve of the pharynx
Name 2 reasons why the muscularis externa of the pharynx is a bit abnormal.
- It is composed of ALL skeletal muscle (voluntary control over swallowing)
- It has a reversed pattern where it goes inner longitudinal muscle, then outer circular muscle (also occurs in the ureter)
Name the 2 organs where there is a reversal of muscle pattern in the muscularis externa.
pharynx & ureter
The adventitia of the pharynx aka? Why is it called this?
buccopharyngeal fascia; the epimysium of the buccinator muscle blends into the adventitia of the pharynx
What is the surface epithelium in the trachea? Name the types of cells found there, and their proportion & function.
respiratory epithelium; 1. goblet cells-30% of tracheal cells-produce mucus 2. ciliated columnar cells-30% for moving mucus 3. basal cells-30% for support 4. brush cells-3%: associated w/sensory nerve endings? 5. serous cells-3%: fxn. is secretion of a product into/onto the lumen but serous product is unknown 6. DNES (diffuse neuroendocrine system) cells- aka small granule cells or Kulchitsky cells: 4% that secrete in LP to likely influence other cells in the resp. epithelium
Comment on the lamina propria (LP) & muscularis mucosa of the trachea.
The LP has loose CT w/seromucous glands that is quite vascular. There is NO muscularis mucosa, just like the pharynx
The submucosa of the trachea contains _ cartilage _ and blends w/the LP. The muscularis externa is composed of the individual _ muscles? There is _ for CT on the outside of the muscularis externa?
hyaline cartilage C-rings; trachealis; adventitia
Name the organs that have serosa on their outside?
JIGS- jejunum, ileum, gallbladder, stomach (sometimes colon)
Concerning the structural trends in bronchi, name 4 things that decrease. Name 2 things that increase.
Decrease:
1. amount of cartilage in the wall
2. # of seromucus glands in LP
3. # of goblet cells 4. height of epithelium
Increase:
1.smooth muscle
2. amount of elastic CT below the epithelium
Which bronchi includes the secondary and tertiary bronchi?
intrapulmonary bronchi
Which part of the lung is characterized by NO seromucous glands, NO cartilage in the wall, a complete layer of smooth muscle, simple epithelium that decreases in height, and has Clara cells?
bronchioles
Name the secretory cells that are found in the surface epithelium of bronchioles that have short microvilli. What are the functions of these cells?
Clara cells; 1. secrete product to protect epithelium 2. produce enzymes which degrade toxins 3. regenerate bronchiolar epithelium, & MAYBE produce a pulmonary-like surfactant
These are the last part of the conducting portion of the respiratory system. There is NO gas exchange that occurs here, simple columnar/cuboidal epithelium w/Clara cells, fibroelastic CT in the LP, and 1-2 layers of smooth muscle.
Terminal Bronchioles
These are the first region of the respiratory portion of the respiratory system. They are similar to terminal bronchioles in structure, but they have some simple squamos epithelium to allow for some gas exchange.
Respiratory bronchioles
Name the 4 structures, in order it proceeds through, that there is gas exchange.
- respiratory bronchioles
- alveolar ducts
- alveolar sacs
- alveoli
What are the 3 types of cells found in the Alveoli?
- alveolar type 1 cells, aka type 1 pneumocyte
- alveolar type 2 cells, aka type II pneumocyte
- alveolar macrophages
This type of alveolar cell covers 95% of the alveolar surface, is a squamos type cell w/zonula occludens btwn. cells, and the general function is for gas exchange (more specialized cell for this reason).
alveolar type I cell
This type of alveolar cell covers 5% of the alveolar surface, but is made of cuboidal cells and therefore has NO gas exchange.
alveolar type II cells
What are the 2 functions of the alveolar type II cell?
- produce pulmonary surfactant for alveoli
2. stem cells for alveolar types I & II
This type of alveolar cell is derived from monocytes and its general function is to clean septal walls using phagocytosis.
alveolar macrophage
What is the region between two alveoli that includes both alveolar type I and type II cells? It requires a good blood supply (numerous continuous capillaries for this reason), has a basal lamina, and small amounts of CT w/lots of elastic fibers.
interalveolar septum
This is the region where oxygen and carbon dioxide pass between the air and the blood, and we want it as thin as possible for the minimum diffusion distance/barrier.
Blood-Gas barrier aka “diffusion barrier”
Name the order of structures that gases diffuse through starting from the air and ending in the blood.
- pulmonary surfactant 2. alveolar type I cell 3. fused basal lamina btwn. alveolar type I & endothelial cell of the capillary 4. the flat endothelial cell
If there is a chronic exposure to irritants & metaplasia in the upper respiratory tract, what happens to: goblet cells numbers? ciliated columnar cell numbers? seromucus glands? If there is much coughing, what develops?
goblet cells will increase, resulting in more mucus being produced; ciliated columnar cells will decrease, resulting in a mucus buildup and more congestion; seromucus glands will increase in # & size to deal w/irritants, equaling more fluid & coughing; if there is much coughing, then areas of stratified squamos epithelium will develop in the trachea
*this can be reversible if the irritant is removed (smokers quit smoking)
Respiratory Distress Syndrome of the Newborn (RDS) aka? Who is it especially found in? what is the cause of RDS?
RDS aka hyaline membrane disease; especially in premature babies; cause of RDS is a lack of alveolar type II cells, meaning not enough pulmonary surfactant
Name 2 treatments for RDS.
- artificial surfactant
2. glucocorticoids given before birth will induce surfactant production
This disease is irreversible, has a reduced surface for gas exchange, and a decrease in the elastin, which decreases the elasticity of the alveoli.
Emphysema
What are 2 common causes of emphysema?
- inflammation from an infection, irritants, or smoking
2. genetic problem where hepatocytes can produce alpha1-AT but cannot release it
Walk through the process of inflammation in emphysema.
Inflammation from infections, irritants, or smoking attracts defensive cells, such as macrophages or neutrophils, which secrete elastase, an enzyme which damages elastic fibers.
- alpha1-AT (antitrypsin) is a protein that protects elastic fibers
- alpha1-AT is produced by hepatocytes in the liver
- ROS in smoking disables alpha1-AT, meaning the elastic fibers are degraded, & the alveoli lose their elasticity, making it harder to breathe
Name the 3 functions of the Digestive System.
- nutrient breakdown, both physical & chemical
- absorption
- elimination of wastes
What are the 3 types of Salivary glands? which one is the largest? which one is smallest? which one secretes the most amount of salivary output?
- parotid gland-largest
- submandibular gland-secretes most amount of salivary output
- sublingual gland-smallest salivary gland
This gland is the largest salivary gland but only produces about 30% of the total salivary output. It is most affected by _ because the facial nerve passes through this gland. As one ages, this gland commonly becomes infiltrated w/adipose. It is 100% serous producing.
parotid gland
What products do all the salivary glands produce?
- salivary amylase (mainly for carbs) & salivary lipase (for fats) in the oral cavity (weaker than pancreatic enzymes)
- lysozymes
- secretory IgA
This is a mixed gland producing mucus and serous products, but primarily (80-90%) is serous producing. It produces about 60% of the total salivary output, & can have fatty infiltration by midlife.
submandibular gland
This is the smallest salivary gland, and only produces about 5% of the total salivary output. It is a mixed gland producing mucus and serous products, but is about 80% mucus-producing. All the serous products come from serous demilunes.
sublingual gland
Name the gland that is 100% serous producing. Name the gland that is primarily (80%) mucus producing. Name the gland that is primarily (80-90%) serous producing.
parotid gland; sublingual gland; submandibular gland
In general, what is found in the mucosa of organs? What about the submucosa? What is the next major lumenal wall layer after the submucosa? What typically surrounds the outside of these organs?
mucosa-surface epithelium, LP, muscularis mucosa
submucosa-glands & larger blood vessels;
muscularis externa; typically serosa or adventitia surrounds the outside of these organs
Whose function is to transfer the bolus from the oropharynx to the stomach?
esophagus
What is the surface epithelium of the mucosa of the esophagus? What does it contain? What other organs have epithelium like the esophagus?
stratified squamos epithelium found lining the lumen (mucus membrane); found here are Langerhans cells, which are antigen-presenting cells that function in food allergies; other organs w/stratified squamos epithelium include the tongue, oropharynx, laryngopharynx, then the esophagus
Name the type of glands that can be found in the LP (loose areolar CT) of the esophagus. What is their function? What 2 locations are they found?
esophageal cardiac glands (seromucus glands); function-produce mostly mucus to protect the epithelium; 2 locations: 1. upper 1 inch near the pharynx 2. lower 1 inch near the stomach
The muscularis mucosa of this organ is a discontinuous layer of longitudinal smooth muscle that is thinner distally (by the pharynx) & thicker proximally (by the stomach).
esophagus
The esophageal proper glands are found in which layer of the esophagus? What is their function & location?
submucosa; they are scattered along the length of the esophagus. they produce mucus to lubricate & stick the bolus together. They also produce very little serous products such as lysozymes & pepsinogen
The esophageal cardiac glands & esophageal proper glands are found in which layers of the esophagus? What is their main product produced?
esophageal cardiac glands = LP
esophageal proper glands = submucosa
*both primary product is mucus
What is the pattern of the muscularis externa of the esophagus?
Normal pattern: inner circular, outer longitudinal layers
*abnormal pattern found in ureter, pharynx
The upper 1/3 of the esophagus is what type of muscle? middle 1/3? lower 1/3?
upper-all skeletal muscle
middle 1/3- mixture of skeletal muscle & smooth muscle
lower 1/3- all smooth muscle
T/F: The outer layer of the esophagus is only adventitia?
False. It is primarily adventitia except for the last 1-2 inches closest to the stomach AFTER it passses under the diaphragm, then it becomes serosa.
Serosa=JIGS (jejunum, ileum, gallbladder, stomach) & sometimes colon
Name the 2 physiological sphincters. Which organ are they found?
- Pharyngoesophageal sphincter
- gastroesophageal sphincter (lower esophageal sphincter)
* found in the esophagus
Name the sphincter found between the oropharynx & the esophagus. What about between the esophagus & the stomach? These 2 sphincters are known as what?
Pharyngoesophageal sphincter; gastroesophageal sphincter; known as the 2 physiological sphincters
The lower esophageal sphincter (gastroesophageal sphincter) control involves four complimentary forces. What are they?
- diaphragm contraction
- greater intra-abdominal pressure than intra-gastric pressure being exerted upon the abdominal part of the esophagus
- peristalsis
- maintenance of correct anatomical arrangements of structures
What are the 2 characteristics of the physiological sphincters? What are the 2 physiological sphincters?
- NO thickening of the circular muscle in the muscularis externa of the physiological sphincters
- the pressure gradient aids the movement from the esophagus into the stomach (as well as gravity)
* the 2 physiological sphincters are the pharyngoesophageal sphincter & the gastroesophageal (lower esophageal sphincter)
What are the 2 functions of the stomach?
- primarily for storage of food, which then allocates the amount of food passing to the small intestine
- some nutrient breakdown (primarily chemical as mechanical occurred in the mouth already)
T/F: The stomach is great at absorbing nutrients.
False. There is hardly any absorption, if any, taking place in the stomach.
Which portion of the stomach is the domed region that is often filled w/gas? Which are the longitudinal folds that allow for distension? What is the narrow region by the gastroesophageal sphincter? What are the tiny depressions in the stomach’s surface?
fundus; rugae; cardia; gastric pits
What is the surface epithelium of the stomach? Which type of cells are found here?
simple columnar epithelium; 1. surface mucus absorptive cells that produce thick, visible mucus which doesn’t mix w/chyme, and 2. regenerative stem cells at the bases of the pits
These types of cells found in the simple columnar epithelium of the stomach are located at the bases of the pits and serve as stem cells? These cells produce a thick, visible mucus (cloudy in appearance) that doesn’t mix w/chyme & is highly numerous in bicarbonate ions.
regenerative cells; surface mucus absorptive cells
The muscularis mucosa of the stomach is a smooth muscle layer that is often arranged in how many layers?
3: inner circular, outer longitudinal, outermost circular sometimes is present
This region of the stomach is highly vascular (lots of larger blood vessels), has AVA’s located there, and contains Meissner’s plexus.
submucosa of stomach
The function of these in the submucosa of the stomach is to quickly shut down mucosal activity if there’s energy/blood needed elsewhere.
AVA (arteriovenous anastomosis)
This plexus in the stomach submucosa is next to the inner circular layer of muscle, and functions to influence the mucosa via secretions, blood flow, & movements of the muscularis mucosa (although limited ability).
submucosal (Meissner’s) plexus
In the muscularis externa of the stomach, name the order of muscle layers possible. Which one can be absent? Which one is typically most well-developed? Which is thin?
- innermost oblique-sometimes absent
- middle circular-usually most well-developed & always present
- outer longitudinal-always present, but often thin
Which plexus located in the muscularis externa of the stomach is located between the circular & longitudinal layers of muscle which functions to stimulate the muscularis externa?
myenteric (Auerbach’s) plexus
In the stomach, which type of CT is found outside of the muscularis externa?
Serosa-ALL
*Serosa=JIGS-jejunum, ileum, gallbladder, stomach (sometimes colon as well)
What are the 3 regions of the stomach, and which is the largest?
- cardiac
- gastric (includes both fundus & body)-largest
- pyloric
Which region in the stomach includes shorter pits that lead to cardiac glands w/a coiled base?
cardiac region
The cardiac region of the stomach contains which types of cells?
primarily surface mucus cells, some neck mucus cells, a few DNES & parietal cells. NO chief cells
Which type of glands extend from the gastric pit to the muscularis mucosa?
gastric glands
Name the 3 regions of a gastric gland (zymogenic gland).
- Isthmus
- Neck
- Base
In the isthmus of the gastric gland of the stomach, name the 2 types of cells found.
- surface mucus cells
2. DNES cells (diffuse neuroendocrine cells)
How long do the surface mucus cells of the stomach live? What is their function?
3-5 days; produce that thick, visible mucus
Diffuse neuroendocrine cells aka?What are the 3 types?
DNES or enteroendocrine cells; type D, type EC, type G
The type D DNES cells produce somatostatin, which _ release of hormones by nearby DNES cells?
inhibits
The type EC DNES cells produce _ & _, which inrease peristalsis in the small intestine?
serotonin & substance P
The type G DNES cells produce gastrin (stimulated by stretching of the stomach & certain foods like caffeine, amino acids, & alcohol), which stimulates _ & _ secretion, gastric motility, & regenerative cells in the body of the stomach.
HCL & pepsinogen
Name the 4 types of cells found in the Neck of the gastric gland.
- neck mucus cells
- regenerative cells
- parietal (oxyntic) cells
- DNES cells
These cells in the Neck of the gastric gland produce a more soluble mucus that does mix w/chyme & lubricates stomach cells. They live approx. 6 days.
neck mucus cells
How long do the parietal cells live? Where are they found in the gastric gland? Name 2 products they produce.
Parietal cells are odd columnar cells w/intracellular canaliculi (allowing for lots of acid production) that live 150-200 days; they are found in the Neck of the gastric gland; they produce HCL (initial pH around 1, then buffered to pH of 2-4) & gastric instrinsic factor (IF), which is necessary for Vit. B12 absorption later on in the ileum
This product of parietal cells is necessary for Vitamin B12 absorption, which is important for RBC maturation.
gastric intrinsic factor (IF)
Chronic gastritis can lead to pernicious _. Why?
pernicious anemia; the decrease in # of parietal cells (or less intrinsic factor) decreases Vit. B12 absorption, which is necessary for the RBC maturation
Name the 3 types of cells found in the Base of the gastric gland.
- chief (zymogenic) cells
- some parietal cells
- some DNES cells which live 60-90 days
The chief cells produce what 2 products? Where are they found in the gastric gland? How long do they live?
chief cells produce pepsinogen, which becomes pepsin that aids in protein digestion, and also some weak gastric lipase; they are found in the Base of the gastric gland; live 60-90 days
This region of the stomach has deeper pits and has very twisted & branched glands. The cells include some surface mucus cells, parietal cells, DNES cells, & some neck mucus cells that also produce lysozyme.
pyloric region
This is an anatomical sphincter btwn. the pylorus of the stomach & the duodenum.
pyloric sphincter
What are the 2 characteristics of an anatomical sphincter? How is this different from the physiological sphincters? what were the 2 physiological sphincters?
- well developed inner circular layer of muscle in the muscularis externa
- inner circular layer in muscularis externa can be independently controlled so it can be closed off voluntarily
- physiological sphincters don’t have the thickening of the muscular layer because they utilize pressure gradients & gravity to move digestion forwards; pharyngoesophageal sphincter & gastroesophageal sphincter
Whose functions are Digestion, absorbing nutrients, and producing intestinal hormones using DNES cells?
small intestines
Three surface adaptations increase surface area 400x in the small intestines. What are they?
- villi 2. microvilli on the luminal cell surface 3. plicae circulares (valves of Kerckring)-permanent folds affecting the mucosa & submucoa; found throughout duodenum, jejunum, & proximal ileum
What is the surface epithelium of the small intestine?
simple columnar (just like stomach)
What are the cell types found in the small intestine?
surface absorptive cells, goblet cells, DNES cells, Regenerative cells, Paneth cells
These cells in the mucosa of the small intestine contain microvilli. Their main functions are to absorb water/nutrients and terminal digestion in glycocalyx.
surface absorptive cells
These types of cells are fewest in the duodenum, most in the ileum. (in mucosa of small intestine)
goblet cells
How many different types of DNES cells are there in the small intestine? What examples did she give?
11 different types; Type I, K, S, VIP
Cholecystokinin secreted from the DNES cells in the small intestine has what effects?
stimulates gallbladder contraction, stimulates pancreas secretion of enzymes from the pancreatic acini
GIP (gastric inhibitory peptide) has what function? Where is it produced?
inhibits HCl; GIP produced in the DNES cells in small intestine
What is the function of secretin produced from DNES cells in the S.I.?
secretin stimulates pancreas secretion from the pancreatic ducts, which make bicarbonates
Which two hormones directly stimulate pancreas secretion?
cholecystokinin (CCK) & secretin
This hormone produced by the DNES cells in the S.I. increases peristalsis in the small and large intestines.
VIP-vasoactive intestinal peptide
These types of cells in the mucosa of the small intestine live only 5-7 days and are found in the crypts.
regenerative cells
Where are paneth cells found? What is their function? How long-lived are they?
found in bases of crypts of mucosa; produce lysozyme; long lived-20 days
In the lamina propria of the S.I., what are lymphatic capillaries responsible for lipid absorption, found mostly in the villus core?
lacteals
If villi are irritated in the small intestine, what is the result?
If villi are irritated, the longitudinal smooth muscle contracts, which shortens the villi. If this is chronic, it leads to nurtional deficiences.
What glands are found in the submucosa of the duodenum of the small intestine? What is important about this?
Brunner’s glands, which are seromucus glands; they produce an alkaline mucus to deal w/the acidic chyme coming from the stomach
Where is urogastrone found? What effect does it have?
found in the submucosa of the duodenum; increases mitosis of epithelial cells, and inhibts HCl production in the stomach
What is found in the submucosa of the jejunum?
no significant structures
What is found in the submucosa of the ileum?
Peyer’s patches-groups of regularly occuring large lymph nodules
Which plexus of the muscularis externa in the small intestine is stimulating peristalsis?
myenteric (Auerbach’s) plexus
Explain where serosa and adventitia are found in the small intestine.
Serosa=all jejunum & ileum, 1st & last cm of the duodenum
Adventitia=vertical portion of duodenum
What is the example of a physiological & anatomical sphincter found between the final part of the small intestine & the cecum of the colon?
ileocecal valve
This organ is a blind puch, on the right side of the body, that extends from the cecum. What is its’ surface epithelium? Does it have a lamina propria?
appendix; simple columnar epithelium (like stomach & SI); yes, it does have a LP
T/F: In the appendix, there are NO villi, and infrequent to no paneth cells.
TRUE
In the appendix, what are the notable structures in the submucosa?
numerous lymph nodules
Serosa or adventitia in the appendix?
Serosa (JIGS-jejunum, ileum, gallbladder, stomach), now appendix & horizontal parts of the colon
What are some supposed functions of the appendix?
- Quite a few lymph nodules, so humoral immunity
2. reservoir for good bacteria
The functions of this organ are the (re) absorption of water, some vitamin production as a byproduct of bacterial activity, and the compaction, lubrication, & elimination of feces.
Colon
What is the surface epithelium of the colon? What does the mucosa of the colon LACK? What makes the muscularis externa of the colon abnormal?
simple columnar (w/stomach, SI, & appendix); colon LACKS villi & paneth cells (similar to appendix); muscularis externa of the colon is abnormal b/c the outer longitudinal muscle layer is gathered into bands called teniae coli & is discontinuous.
What is constant tonus of teniae coli resulting in sacculations called? Which organ is this found?
haustra; colon
Name the parts of the colon that have serosa and the parts that have adventitia. What are the fat-filled pouches called created by serosa?
serosa=transverse & sigmoid colons
adventitia (CT w/collagen I)= vertical portions, so ascending & descending colons
-appendices epiploicae are the fat-filled pouches created by serosa
What are 2 general causes of a Peptic Ulcer Disease?
- insufficient protection from HCL (from parietal cells in stomach) & pepsin-either from a damaged mucus coat, or too much HCl & pepsin produced
- Helicobacter pylori (as well as aspirin)
If luminal acidity is _, damaged tissues can repair in 1-2 months.
decreased
Name 5 factors that delay healing of Peptic Ulcer Disease.
- cigarette smoking
- alcohol consumption
- coffee & caffeine (stimulates parietal cells, making more HCl)
- calcium (stimulates parietal cells, making more HCl)
- aspirin & other drugs
What else can aggravate an ulcer, but cannot technically be the outright cause of an ulcer?
stress & spicy foods
The cause of this is stomach chyme backing up into the lower esophagus. Possible causes of chyme backup are: 1. chronic gastritis: inflammation of the stomach lining 2. hiatal hernia 3. pregnancy 4. incompetent lower esophageal sphincter 5. subluxations-problems w/myenteric plexus?
Gastroesophageal (esophageal) reflux
What are some good ways to reduce esophageal reflux?
keep a food diary, limit amount eaten @ one time, don’t eat less than 3 hours before bed
What are problem foods for esophageal reflux?
spices (pepper, garlic, onion, peppermint, cinnamon), acidic foods like tomatoes and citrus fruits, acidic beverages like fruit juices, carbonated drinks, coffee, & tea, fatty foods, & alcohol
In Barrett’s esophagus, the typical stratified squamos epithelium undergoes metaplasia due to a chronic problem & is replaced by mucus-secreting _ _ epithelium?
simple columnar epithelium; a precursor to cancer, but can be reversed if chronic problem is removed
Name the very thin-walled organ inferior to the liver that is prone to rupture because of an absent submucosa.
Gallbladder
What is the bulk of the gallbladder? What connects to the neck of it?
bulk is the body; a cystic duct connects to the neck
Name the 2 functions of the gallbladder.
- stores bile-can hold about 70 ml
2. concentrates bile
What are the 2 types of bile?
- hepatic (non-concentrated) bile: directly from the liver
2. cystic bile (concentrated): concentrated to emulsify fats better
Bile release is controlled by which 2 factors?
cholecystokinin (CCK from DNES cells in the SI mucosa) & the vagus nerve
What is the surface epithelium of the gallbladder? Name the sublayer of the mucosa that is absent. Name the major luminal wall layer that is very unusually absent in the gallbladder. Why is the muscularis externa an abnormal pattern? Serosa or adventitia?
simple columnar (w/stomach, SI, appendix, colon); muscularis mucosa absent; submucosa absent; muscularis externa is abnormal as it consists of a smooth muscle layer w/a disorganized muscle arrangement; mostly serosa (edge of squamos cells), along w/jejunum, ileum, stomach, part of the colon (transverse & sigmoid colons), & the appendix
Name the 2 types of pancreas. Which one has the Islets of Langerhans producing hormones. Which one has serous acini producing digestive enzymes (strongest of the enzymes)?
- endocrine pancreas-islets of Langerhans
2. exocrine pancreas-enzymes
What is the largest portion of the pancreas?
exocrine portion
In the serous acini of the exocrine pancreas, the secretion is controlled by what 2 things?
cholecystokinin (CCK) & ACH from parasymp. nerves
In the pancreatic ducts of the exocrine pancreas, the secretion is controlled by which 2 things?
secretin & ACH from parasymp. nerves
Name the cells in the exocrine pancreas that produce an alkaline fluid w/large quantities of bicarbonate ions that are released into the duodenum to buffer stomach chyme. Which part of the exocrine pancreas produces them?
centroacinar cells; pancreatic ducts produce them
In the exocrine pancreas, what provides extra protection from the possible leaking of digestive enzymes?
collagen-rich CT wrapping the pancreatic ducts
Name the largest gland in the body with both endocrine & exocrine functions.
Liver
What are the general functions of the liver listed in class?
- metabolism of lipids, carbs (glucose to glucagon for storage), and proteins
- production of blood proteins (albumin, fibrinogen), factors, & non-essential vitamins
- detoxify blood
- produce hepatic bile
- store certain vitamins
- mostly hepatocytes doing these functions
Why are the hexagonal-shaped lobules that we saw in lab of the pig liver difficult to distinguish in humans?
the lack of CT between lobules
Name the 4 types of cells found in the liver.
hepatocytes, Kupffer cells, lipocytes, & pit cells (& possibly hepatic progenitor cells as well)
The function of these cells is possibly as natural killers?
pit cells
The functions of these cells are to store lipids for immediate use, possibly store some Vitamin A, & produce collage IV typically and collagen I & III in certain circumstances.
lipocytes (fat storing cells of Ito)
T/F: Lipocytes in the liver are associated w/cirrhosis of the liver.
False. lipocytes are NOT associated w/cirrhosis or fatty liver, but hepatocytes are associated w/these diseases
Kupffer cells are resident _ that develop from _? What is their function?
macrophages; monocytes; function is the phagocytosis of debris
T/F: Bile & blood are always kept separate in the liver.
TRUE
These most numerous cells of the liver are microvilliated cuboidal cells (on 2 sides) possessing lateral bile canaliculi between adjacent cells.
hepatocytes
What do bile canaliculi do?
collect bile
Bile moves from the hepatocytes towards the bile duct branch in the _ _?
portal triad
What 4 things do portial triads have?
- hepatic artery
- portal vein
- bile duct
- lymph vessels
These are dilated, fenestrated thin walled vessels found between the rows of hepatocytes; they carry a mixture of blood made up of _% venous blood & _% arterial blood.
hepatic sinusoids; 75% venous blood, 25% arterial blood
This is a fenestrated thin-walled vessel that collects blood from the hepatic sinusoids. Blood flows from the portal triad towards it.
central vein
What is the space between the hepatocytes & the fenestrated hepatic sinusoids where blood can directly contact the microvilliated surfaces of the hepatocytes?
Space of Disse (perisinusoidal space)
Which organ can take over functioning for the spleen in 24-48 hours, and also is the only known organ to significantly regenerate if it’s been damaged?
liver
Name the 2 organs w/the reversal pattern of the muscularis externa.
ureter & pharynx
Name all the organs that have simple columnar epithelium.
duodenum, jejunum, ileum, stomach, colon, gallbladder, appendix, Barrett’s esophagus (mucus-producing simple columnar epithelium)
Name all the organs with respiratory epithelium. What is the other name for this epithelium?
nasopharynx, trachea, respiratory region of the nasal cavity; respiratory epithelium aka ciliated pseudostratified epithelium
Name all the organs with stratified squamos epithelium.
tongue, esophagus, oropharynx, laryngopharynx
Name the area where keratinized stratified squamos epithelium is found.
vestibule of nasal cavity
Name the area where olfactory epithelium is found.
olfactory region of the nasal cavity
Name the organs that have mostly or all serosa.
jejunum, ileum, gallbladder, stomach, last 1-2 inches of the esophagus closest to the stomach AFTER it passes the diaphragm, 1st & last cm of duodenum, appendix, transverse & sigmoid colons
In general, which type of organs is adventitia found?
vertical organs; ascending & descending colons, pharynx (buccopharyngeal fascia), trachea, most of esophagus, vertical portion of duodenum
Name the 2 physiological sphincters. Name the anatomical sphincter. Name the “sphincter” that is both a physiological & anatomical sphincter.
physiological: 1. pharyngoesophageal sphincter 2. gastroesophageal sphincter
* anatomical- pyloric sphincter
* ileocecal valve is both anatomical & physiological sphincter
“1. tunica intima- endocardium (connecting blood)
- tunica media-myocardium (muscular)
- tunica adventitia- visceral pericardium aka epicardium (CT layer)”
What are the 3 major luminal wall layers found in all but the thinnest & smallest of blood vessels, and what are they a continuation of from the heart’s histological layers?
