Epithelial Tissue Part 2, Cellular Pathology, CT (Exam 1) Flashcards
Where do glands develop from?
covering epithelia
____________ glands remain connected to the surface epithelia
Exocine
_____________ glands lose the connection to their original epithelium and therefore lack ducts
Endocrine
(endocrine glands synthesize, store, and secrete, BUT they do not have a free surface)
Endocrine glands attract blood vessels to the surface. Capillaries are the smallest vessels and are the exchange vessels. This results in the hormones/chemical messangers going on a systemic trip through the body. What is the attraction of blood vessels called?
angiogenesis
What are the 2 big categories from structural classes of exocrine glands?
1) simple glands (ducts do not branch)
2) compound glands (ducts from several secretory units converge into larger ducts)
What are the 5 types of simple exocrine glands?
1) simple tubular
2) branched tubular
3) coiled tubular
4) acinar (or alveolar)
5) branched acinar
What are the 3 types of compound exocrine glands?
1) tubular
2) acinar (alveolar)
3) tubuloacinar
What are the 2 types of glandular epithelia?
endocrine glands and exocrine glands!
Endocrine glands secrete/release hormones into the blood, which is systemic and causes wide spread effects into the ______________. This is because endocrine glands have no ducts.
interstitial fluid
Exocrine glands produce secretions onto epithelial surfaces through ducts. The secretions are released ___________ onto a surface
locally
What are the 3 main mechanisms of how cells release contents onto surface for exocrine glands?
1) merocrine
2) holocrine
3) apocrine
Merocrine secretion releases products, usually containing proteins by the means of ___________ at the apical end of the secretory cells
exocytosis
(release contents w/o a membrane)
Are most exocrine glands merocrine, holocrine, or apocrine glands?
most are merocrine glands!
Exocrine glands with merocrine secretion can be further categorized as either _________ or _________
serous (water contents), mucous (opaque contents of solids, proteins, lipids, carbs, etc)
Holocrine secretion is produced by the __________________ of the secretory cells themselves as they complete their terminal differentiation, which involves becoming fluid with product. Sebaceous (oil) glands of hair follicles are the best example of holocrine glands
disintegration
Apocrine secretion involves loss of ___________________________________, usually containing one ore more lipid droplets. Products accumulates at the cells apical ends, portions of which are then pinched off to release the product surrounded by a small amount of cytoplasm and cell membrane.
membrane enclosed apical cytoplasm
What 2 types of secretion are both seen in mammary glands?
apocrine and merocrine secretion
Where is apocrine secretion usually found?
mammary glands, axillary region, groin region
What is pathology?
study of disease
What are the 4 adaptations we went over in class for cells?
-hyperplasia
-hypertrophy
-atrophy
-metaplasia
Changes to a cell can be either physiologic or pathologic. What is the difference?
physiologic= cells will adapt to stay alive (functional change)
pathologic= lead to disease state (disease causing change)
What is hyperplasia?
increase in the number of cells
What is physiologic hyperplasia?
increase in the number of cells
occurs due to a normal/functional stressor/demand
ex: increase in the size of breasts due to pregnancy or increase in thickness of endometrium during menstrual cycle
What is pathologic hyperplasia?
increase in the number of cells
occurs due to abnormal stressor
ex: growth of adrenal glands due to production of adrenocorticotropic hormone (ACTH) by a pituitary adenoma, or proliferation of endometrium due to prolonged estrogen stimulus
Only cells that can divide will undergo hyperplasia, therefore, hyperplasia of the ____________ in the heart and neurons in the brain does not occur
myocytes
What is hypertrophy?
increase in the size of a cell
What is physiologic hypertrophy?
increase in the size of a cell
occurs due to normal stressor
ex: enlargement of skeletal muscle with exercise (weight training)
What is pathologic hypertrophy?
increase in the size of a cell
occurs due to an abnormal stressor
ex: increase in the size of the heart due to aortic stenosis. Aortic stenosis is due to a change in the aortic valve, which obstructs the orifice, resulting in the left ventricle working harder to pump blood into the aorta (ventricular hypertrophy will occur and cause walls to thicken to pump more)
What is atrophy?
decrease in the size of a cell that has at one time been of normal size
What is physiologic atrophy?
decrease in the size of a cell that has at one time been of normal size
occurs due to normal stressor
ex: decrease in the size of the uterus after pregnancy
What is pathologic atrophy?
decrease in the size of a cell that has at one time been of normal size
occurs due to an abnormal stressor
atrophy is due to the loss of stimulus to the organ such as loss of blood supply or nerve innervation, loss of endocrine stimulus, disuse, mechanical compression, decreased workload, aging, or starvation
Atrophy occurs in a once normally developed organ, If the organ was never a normal size because it did not develop properly, the condition is called….
hypoplasia
Is there a physiologic reason for metaplasia?
no, it is only pathologic!!!
What is metaplasia?
change of epithelium at a site, or location, from one type of epithelium to another type
the epithelium is normal in appearance but is in an abnormal location
In metaplasia, the epithelium normally present at a site cannot handle the new environment so it converts it to a type of epithelium that can adapt. What are the 2 examples we talked about in class?
1) barrett esophagus is due to reflux of gastric contents into the esophagus, which causes the epithelium type to convert from stratified squamous to simple columnar or glandular (this is almost always a precursor for stomach cancer)
2) squamous metaplasia in the lungs is due to exposure of respiratory epithelium to toxins in cigarettes or other smoke (lungs are simple squamous but can change into simple cuboidal and eventually stratified)
What is cell injury?
when cells cannot adapt to their new environment
What are some causes of cell injury?
-hypoxia (decreased oxygen)
-ischemia (decreased blood flow)
-physical and chemical agents
-trauma
-infectious agents
-radiation
-toxins
-metabolic abnormalities (genetic or acquired)
-immune dysfunction (autoimmune)
-aging
-nutritional imbalances
note: you do not need to memorize all of these, the first 2 are most important
What are the 2 most common sources of cellular injury?
Hypoxia and ischemia
Is hypoxia or ischemia more damaging?
ischemia
ischemia is more damaging bc it involves hypoxia PLUS a lack of other nutrients and an accumulation of toxic cellular metabolites
In general, decreased oxygen results in decreased production of….
ATP
What is normally required by the Na+/K+ pump and Ca+2 pump? What happens when levels decrease?
ATP
When ATP levels decrease, these pumps fail and sodium along with water enters the cell, causing swelling
cells switch to anaerobic respiration to produce ATP, which results in accumulation of lactic acid (this decreases the cellular pH)
decreased pH causes disaggregation of ribosomes from ER and can cause the enzyme to denature
What is apoptosis?
programmed cell death
this is where the cellular process ends at the nucleus and results in a clean self destruction
when apoptosis is happening, the nucleus will be condensed and fragmented w/ no inflammatory reaction will be elicited as long as the cell undergoes the programmed cell death
examples:
-during growth and development, some cells serve a function in the growth phase but need to be removed after their purpose is fulfilled
-when DNA sustains irreparable damage such as after low dose radiation exposure, the cell must be destroyed so that mutations that have been developed will not be propagated. In this manner, apoptosis serves as a safety step by removing damaged cells from the body
There are multiple pathways by which apoptosis is initiated. What are the 2 pathways we talked about in class?
extracellular and intracellular pathways
both share similar endpoints, culminating w/ the use of caspases and prevention of inflammatory reactions
Necrosis is a term used to describe uncontrolled death of cells due to one of various causes of cellular injury. Does necrosis have a local or systemic effect?
starts off locally and can lead into systemic if not treated properly
What are the 2 main types of necrosis?
1) coagulative necrosis
2) liquefactive necrosis
Is this coagulative or liquefactive necrosis?
protein denaturation is more prominent than enzymatic breakdown
coagulative necrosis
Is this coagulative or liquefactive necrosis?
occurs in situations in which enzymatic breakdown is more prominent than protein denaturation or in organs that lack a substantial protein rich matrix (lipid rich organs such as the brain)
liquefactive necrosis
Substances can accumulate in cells as a result of damage to the cell, or they can accumulate in the cells as the result of an ____________ abnormality in metabolic functions
intrinsic
Substances that commonly accumulate in cells are….
-lipofuscin (wear and tear pigment)
-calcium
-protein
-iron
-fat
-cholesterol
-glycogen
-pigments
What tissue is the most widespread throughout the body?
connective tissue
What tissue connects the epithelium to the rest of the body (basal lamina)?
connective tissue
What tissue provides structure with bones?
connective tissue
What tissue stores energy through fat (adipose tissue)?
connective tissue
What tissue transports materials through blood?
connective tissues
What tissue has no contact with the outside environment (during homeostasis)?
connective tissue
What are the 3 rules/characteristics of connective tissue?
1) specialized cells (named cells)
2) solid extracellular protein fibers (between the cells, no cell-cell contact)
3) fluid extracellular ground substance
What makes up the matrix in connective tissue?
protein fibers and ground substance (extracellular components)
What is the major constituent of connective tissue?
the extracellular matrix
The matrix in connective tissue consists of different combinations of protein fibers (collagen and elastic fibers) and ground substance. Ground substance is a complex of anionic, hydrophilic proteoglycans, glycosaminoglycans (GAGs), and multi-adhesive glycoproteins (__________)
laminin
What determines specialized function in connective tissue?
the matrix
What are the 3 types/classifications of connective tissue?
1) connective tissue proper (connect and protect)
2) fluid connective tissues (transport)
3) supportive/structural connective tissues (structural strength)
Which connective tissue type are the fibers very prominent and can be seen in pictures/on microscope as lines?
connective tissue proper
What are the 2 subcategories of connective tissue proper?
loose CT and dense CT
What CT type has more ground substance and less fibers? For example, fat (adipose tissue)
loose CT proper
What CT type has more fibers and less ground substance? For example, tendons (connect m. to b.)
jam-packed fibers= dense CT proper
What are the 9 cells types within CT?
1) fibroblasts
2) fibrocytes
3) macrophages
4) adipocytes
5) mesenchymal cells
6) melanocytes
7) mast cells
8) lymphocytes
9) microphages
What cells are found in CT proper?
-fibroblasts
-fibrocytes
-macrophages
-adipocytes
-mesenchymal cells
-melanocytes
-mast cells
-lymphocytes
-microphages
(all 9 of the cells types in CT!)
What is the most abundant cell type found in all connective tissue proper?
fibroblasts
What cells secrete proteins and hyaluronan (cellular cement)?
fibroblasts
Fibroblasts are young, active cells that differentiate into….
fibrocytes
Fibroblasts synthesize and secrete proteins and hyaluronan (cellular cement) from the surface. What is being made here?
the matrix!
What is the second most abundant cell type found in all connective tissue proper?
fibrocytes
What cells maintain the matrix fibers of connective tissue proper?
fibrocytes
Which cells are phagocytic?
macrophages
Macrophages are large, amoeba-like cells of the immune system that eat pathogens and destroy cells. What are fixed macrophages? What are free macrophages?
fixed macrophages= stay in the tissue
free macrophages- migrate
What do adipocytes store in each cell?
a single large fat (lipid) droplet
Stem cells produce 2 cells. For what?
1 cell to differentiate, and the other for self-renewal
Stem cells are capable of _____________
self renewal
What are the stem cells of CT?
mesenchymal cells
Mesenchymal cells are stem cells that respond to ____________ or ____________
injury, infection
Mesenchymal cells differentiate into what cells?
fibroblasts or macrophages (usually)
What cells synthesize and store the brown pigment melanin?
melanocytes
Where is melanin found in the body?
the epidermis and in the iris of eyes
What cells stimulate inflammation after injury or infection by releasing histamine and heparin (leading to systemic effects)?
mast cells (they travel in blood)
note: basophils are leukocytes (WBCs) that also contain histamine and heparin but these are not found in CT
What cells are specialized immune cells in the lymphoid/lymphatic system?
lymphocytes
for example, lymphocytes may develop into plasma cells (plasmocytes) that produce antibodies
Microphages are smaller than macrophages but are more specific. They are phagocytic blood cells that respond to signals from who?
macrophages and mast cells
for example, neutrophils and eosinophils are microphages
What fibers are the most common protein fibers in CT proper?
collagen fibers
Which fibers are long, straight, and unbranched protein molecules?
collagen fibers (they’re also packed tightly)
Which fibers are very strong and flexible?
collagen fibers