Exam 1 Flashcards
Three general functions of epithelium
Provide a barrier
Absorption
Secretion
Three specialized functions of epithelium
Transport molecules across epi.
Prevent transport of material across epi. selective permeability
Sensory (taste buds, retina)
What are two things that various types of epithelium that are basic characteristic they share?
Cells are adjacent to each other
Associated with a complete or partial basement membrane
Avascular - obtain nutrition by diffusion
Associated with vascular CT
Held together by cell junctions
What is the difference between a complete basement membrane and partial?
Complete - basal lamina and reticular lamina
Partial - basal lamina only
What type of cells produce basal lamina?
Reticular lamina?
Epithelial
CT
Three functions of basement membrane
Provide surface for cell attachment
Filter
Limits stretch
What are the four type of cell junctions?
Zona Occludens
Zona Adherens
Macula Adherens
Gap Junctions
Describe Zona Occludens
2 functions
AKA Tight junction
Share intrinsic membrane proteins between adjacent cells
Strong attachments
Blocks materials from moving between cells
Describe Zona Adherens
2 functions
Adhesion Belt
Cadherins lining adjacent cells in presence of Ca
Strong attachment
Marginal Bands contribute to cell stability
Describe Macula Adherens
Function
Demasomes
Strong attachment
Describe Gap Junction
Function
Describe Junctional Complex
6 proteins arranged in cylinder shape
Strong attachment
Sharing or movement of materials
Sonula occludens - sonula adherens - macula adherens
What two things hold the epithelium to the basement membrane?
Hemidesmosomes and focal point contacts
What does simple epithelium mean and what are the types?
Single layer thick
Squamous
Cuboidal
Columnar
Ciliated Pseudostratified Columnar
Simple squamous locations
Description
Functions
Lung, Parietal layer of Bowman capsule in kidney, serosa outside organs
Single layer flat cells
Provide barrier, Living filter
Simple Cuboidal locations
Description
Functions
Exocrine ducts, thyroid follicular cells, kidney tubules
Single layer of cube cells, nucleus occupies much of cell cytoplasm, looks like square on slide
Secretion, Barrier, Absorption
Simple Columnar location
Description
Function
Stomach, SI, gallbladder, larger exocrine ducts
Singel layer, height, more cytoplasm than cuboidal, rectangle on slides
Barrier, Absorption, Secretion
Ciliated Pseudostratified Columnar epithelium (respiratory epi) location
Description
Trachea, respiratory region of nasal cavity, bronchi
Three cell types of various heights to look stratified
Ciliated Columnar Cells
Columnar that contain cilia anchored in the apex of the cell by basal bodies
Move mucus
Goblet cells
Modified columnar cell
Produce release mucus
Basal cells
Short pyramidal and does not reach surface
Act as stem cell before forming goblet cell or ciliated columnar
Describe Microvili and their function and location
Finger like projections at apical surface on some epithelial cells. Called brush border or striated border
Increase surface area for absorption
Kidney tubule cells, SI
Sterocilia describe
Function
Location
Extremely long microvilli, not related to true cilia
Increase surface area
Epididymis, chochlear hair cells
Cilia describe
Function
Location
Thin apical hair like extensions of cytoskeleton
Move something over a surface
Trachea and fallopian tube
Do Cilia have many mitochondria?
Do their basal bodies absorb and secrete?
Yes
No
Describe Glycocalyx
Produced by?
Function?
Location
Surface layer of glycoproteins and carbs that cover epithelium
Epithelium cells
Protection and cell recognition
Stomach and SI
Definition of stratified epithelium
What is it named after per type?
What do ALL types have a common function of?
Epithelium that is two or more cell layers thick
Shape of its superficial cells
Protective function
Stratified Squamous location
Describe
Function
Problems limitations (2)
Esophagus, oral cavity, tongue, vagina
Multp layers tend to flatten out from basal layer to superficial which are flat and alive
Protect from abrasion
No protection from drying
Limited thickness
Kertanized Stratifed Squamous location
Describe
Function
Skin
Multiple layers tend to flatten from basal to superficial which is covered by nonliving layer of keratin
Protection in dry environment
What are the 5 layers of epithelium of the skin?
Stratum basale (germinativum)
Stratum Spinosum
Stratum granulosum
Stratum lucidum
Stratum Corneum
Multiple layers of “spiny shaped” keratinocytes that produce lipids and keratohyalin vacuoles. Thickness varies
Stratum Spinosum
Uppermost 1-2 layers of flattened living keratinocytes that contain flattened condensed keratohylan vacuoles
Stratum Granulosum
1-2 layers which are mitotic and closest to the dermis
Stratum Basale (germinativum)
Layer of dead cells, keratin and lipids. thickness of this layer varies but has three functions….
What are three
Stratum corneum
Prevent water loss
Provide barrier to micronbes
Protect from abrasion
Thin layer of recent dead or dying keratinocytes present only in thick skin. This is not easy to see
Stratum lucidum
How do epidermal pegs (rete ridges) and dermal papillae contribute strength to Stratum Corneum?
Increasing surface area for attachment of the epithelium to the ct below
What is the duration of a cell life cycle?
28 days
What do Melanocytes do?
Layer found in?
How they function?
Protect against UV
Stratum Basale
Melanosomes (with pigment they produced) pinch off ends of cytoplamsic projections - > taken up by karatinocytes
What 4 things influence skin color?
Size of melanosomes
Number of melanosomes
Placement of melanin within cell
Eumelanin vs. pheomelanin
(brown/black) vs. (reddish)
What do langerhan cells do?
Layer found in?
Also can be found in?
Recognize external foreign antigens
Stratum spinosum
Esophagus and vagina - stratified squamous
Merkel cells function
found layer?
Associated with?
Provide touch receptors
Stratum basale
Associated with free nerve endings
What happens to number of melanocytes when exposed to uv light repeatedly?
Langerhand cells?
Increase
Decrease
Stratified cuboidal location
description
Function
Larger ducts in sweat and salivary glands
Two layers, basal layer flattened, superficial cuboid. Not common
Barrier and protection/structure
Strratified Columnar location
Description
Function
Large ducts in pancreas, part of male urethra, conjunctiva of eye
Two layers, basal flat to cuboid, superficial is columnar. Very rare
Protection/structure
Barrier
Transition to another epithelium type
Transitional (Urinary) = Urothelium location
Describe
Function
Most of urinary tract
Multiple layers
Protection that stretches
Barrier
Specializations of Transitional (Urothelium)
Why important?
Fenestrated basment
Larger rounder superficial cells
Well developed zone occludens
Fenestrated basement - not much for cells to attach to
Barrier to nitrogenous waste
Unusual superficial cell feature of Urothelium?
Cells obtain more O2 why?
Some are bi-nucleate
When stretched, diffusion distance decrease
Patchy skin lesions
Accelerated keratinocyte life cycle
Cells accumulate in stratum corneum
Inflammation in dermal papillae
Cyclic and etiology unknown
Psoriasis Vulgaris
Spots with extra pigment, fair skin especially
Increase in melanin without increase in melanocyte numbers
Tend to fade in winter and darken in sun
Freckles
Patches which lack melanocytes
Unknown cause but associated with systemic disease
Vitiligo
Discoloration due to Proliferation of melanocytes
Moles (naevi)
Melanocytes become mitotically active and invade dermis
Very invasive and metastatic
Treatment : surgery and chemo
Malignant Melanoma
What are the two categories of epithelial glands?
Endocrine and Exocrine
Components directly involved with primary function
Ex biceps- skeletal ells
Parenchyma
Components providing mechanical and metabolic support
Ct, Nerve, Blood vessels, Lymphatics
Stroma
What are the three methods of subclassifiying Exocrine secretion
Morphology
Secretion Method
Product secreted
Describe Options for Morphology
Secretory : tubular vs acinar (avelolar)
Duct arrangements - Ubranched or branched
Describe options for Secretion method
Merocrine (eccrine)
Holocrine
Apocrine
Name and examples
Most common method of
secretion
Secretion by exocytosis so no cytoplasm or membranes in secretory product
No cell damage or odor
Merocrine (eccrine)
Goblet, salivary, pancreas, sweat glands
name and examples
Cell matures and dies
Secretory product - intact vacuoles and parts of cell
Odor
Holocrine - Sebaceous glands, tarsal glands of eye lid (meibomian glands)
Cell damage is minimal
Secretory product - intact vacuoles and some cell cytoplasm and membrane
Odor
Apocrine
Lactating mammary glands, some adult sweat glands, ceruminous glands in external auditory canal Ciliary glands (molls) glands in eyelid
Options for classifying based on Product Secreted
Acinus - smallest division of gland, group surrounding cavity
Serous Demilune - Small group of serous cells attached to mucus acinus
Myoepithelial cells - cells with epithelial origin that are contractile, cells wrap around acini and ducts may become exocrine glands - found in salivary sweat lacrimal and mammary glands!
These glands produce proteins
Pancreas, parotid gland, chief cells
Often produce enzymes
Trapezoid cells
Nucleus usually round
Cellspick up stain
Serous Glands
These cells produce mucus
Goblet cells, mucus cells, minor salivary glands in tongue and palate
Stain light
Nucleus usually perish and flat in cell
Mucus glands
Glands produce serous and mucus
Sublingual, submandibular, salivary
See above
Serous demilunes are possible
Mixed glands
Three parts of Exocrine Regulation
Myoepithelial cells - each has an ANS fiber
Hormonal
Blood supply = increase flow, increase O2, increase secretion
opposite if low blood flow
Functions of CT 4?
Provide structural support
Provide medium for exchange
Defense/Protection
Storage of adipose - energy source
4 Characteristics of CT
Most derived from mesenchyme
Support cells separated by matrix
Support cells produce matrix
Cells adhere to matrix
Important general trait of Glycosaminoglycans (mucopolysaccharides)
Hydrophilic
Sulfated GAGS like keratin sulfate, chondrotin sulfate, heparin and dermatin sulfate two points of interest
Smaller molecules
Convalently bonded to proteins
Three points of interest of non-sulfated GAGs like Hyaluronic Acid (HA or Hyaluronan)
Larger molecules
Forms dense molecular network
Hold Much H20
2 positive aspects of inflammation
one negative
Increased fluidity which aids cell movement
Increase number of defensive cells
Swelling can damage vessels/lymphatics and nerves and cells
Four types of Ground Substance
Glycosaminoglycans = mucopolysaccharides
Proteoglycans = protein core with many sulfated GAGs attached
Adhesive Glycoproteins like laminin and fibronectin
Other
Three types of fibers
Collagen
Elastic
Reticular
Collagen many types or few?
Most common?
Type 1 Account for __ percent of total body
collagen
C1 is knowns for tensile strength but…
Serious pathologies can occur from what?
Many
yes
90
no stretch
Improper production of Collagen 1
As you age what happens to Collagen fiber production?
If not enough Vit C?
Slows and weaker fibers produced
Weaker coll 1 more rapid fiber breakdown
Elastic fibers composed of __ and ___
Can stretch by ___ percent of resting length
Important in blood vessels and ___
Commonly produced by ___ and smooth muscle cells
Simpler fiber than C1 so easier to make
More or less fibers as you age?
Greater or fewer pathologies with this type of fiber?
Elastin and microfibrils
150%
Lungs
Fibroblasts
Less
Fewer
Hereditary condition of CT bones muscle ligaments and skeletal structures where undeveloped elastic fibers result in
Irregular unsteady gate
Tall lean body long extrems
Abnormal joint flexibility, flat feet stoop shoulder and dislocation of optic lens
4th important one?
Marfan’s Syndrome
Aorta usually dilated and may become weakened allowing aneurysm to develop
Reticular fibers same as…
Easy or hard to produce
Last __ days
Pathologies?
Aging effects?
___ fiber produced during wound healing
Collagen 3
Easy
3 days
None
Not affected
First
7 Cells in CT
Fibroblast Fibrocyte Myofibroblast Adipocytes Plasma cell Macrophage (histiocyte) Mast Cell
Fibroblast usually derived from…
Very important in ordinary CT?
Generally a ___ cell but can move about a little
May occasionally divide and primary during….
May change into other cell types under special conditions explain
Mesenchyme cells
Yes
Fixed
Wound healing
Adipocytes
Chondrocytes during cartilage formation
Osteoblasts during some pathologies
Describe Fibroblast structural functions
What type of cells?
When mature are almost ___ and contain fibrocytes
___ percent as strong as original tissue
Produce and maintain matrix by making GAGs, fibers etc
Healing by producing cytokines and enzymes (collagenase)
Avascular
70
2 Defensive functions of fibroblasts
Produce cytokines and enzymes
Can phagocytize
Fibrocyte mature less active so they appear…
__ lived cell with ___ energy and oxygen requirements
Can do what…
Cant do what…
Flatter
Long/ lower
Make ground substance, GAGS, reticular fibers
Make collagen 1 and elastic fibers
Myofibroblasts possess features of ____ and ____
Functions 2
Fibroblasts and smooth muscle cells
Wound closure
Tooth eruption
Adipocytes do or do not divide/change into other cell types
Derived from….
Function in lipid storage and…
D not
Mesenchyme
Produce other factor and hormones
Plasma cells do or do not divide?
Long or short lived
Found in CT and _____
Found in blood?
Derived from ___ lymphocytes
Large cells with a spherical ___ nucleus
Function?
NOT
Short
Lymphatic tissue/organs
no
B
Clock faced
Produce antibodies
Macrophages (Histiocytes)
Large cells with kidney bean shape nucleus often contain ___ in cytoplasm
Divide?
Derived from…
Very important ___cell
Party of what system?
All members arise from common ancestor in ____ ____ and are able to phagocytize and display particular receptors
Example Memnbers
Residual bodies
Yes
Mesenchyme
Defensive
Monuclear Phagocyte or Reticulendothelial system (RES)
Bone Marrow
Kupffer cells, alveolar macrophages, monocytes, microglia, langerhan cells, osteoclasts
Four functions of Macrophages
Phagocytosis of debris and microorganisms
Act as APC, present info about foreign antigen to helper t cells
Create foreign body giant cell = permeant fusion of many macrophages. This forms in response to sizable foreign object, and some pathogens
Release cytokines and other products
Mast cells large contain…
Found in ____ by small blood vessels under epithelium
Divide?
Lifespan?
Derived from…
Once thought to be derived from?
cytoplasmic ganules
CT proper
Occasionally
days to months
bone marrow precursor
Basophils
Three functions of Mast cells?
Mediate Inflammation, Immediate hypersensivity response, Anaphylaxis, Asthma
Release primary mediators Histamine, Heparin, and Eosinophil Chemotactic Factor (ECF) and Nutrophil Chemotactic Factor (NCF
Produce and release secondary mediators Leukotrienes
Effects of Histamine
Increase permeability of capillaries and venules
Cause vasodilation of small arteries, increasing blood to affected area
Cause contraction of any visceral smooth muscle in area
Effects of Heparin
Counteracts effects of Histamine
Which is on switch and off switch?
Histamine = Flash on
Heparin = slow off
Efects of ECF and NCF?
ECF - attracts eosinophils
NCF - attract neutrophils for phagocytosis
What inhibits leukotrienes, produces factor that inhibits mast cell degranulation, Phagocytize IgE and secretes Histaminase?
Therefore they will help to ___ effects of histamine and leukotrienes
Eosinophils
Limit
Leukotriene effects
Same as histamine but 1000s of times stronger. Amplifies and prolongs the effect of histamines.
What three things will activate mast cells?
Direct mast cell trauma
Phagocytosis
IgE-allergin complex
Describe what happens at first and second exposure for primary and secondary immune response
1 - Elicits IgE formation which binds to mast cells
2 - Allergin binds to “sensitized” mast cells and mast cells degranulate
Describe the Mast cell mediated event of a basic inflammatory reaction - cut in the skin
Stimulus - direct trauma and phagocytosis
Mast cells degranulate
Histamine reacts fast and increases permeability of capsules and venules, also vasodilates arterioles
Leukotrienes extend and amplifies histamine
Heparin and ECF react last to counteract histamine, attract eosinophils
Describe the Immediate Hypersensitivy response of Simple allergy
Stimulus
Mast cells degranulate and produce various substances
Localized inflammatory response at sight of allergen contact
Describe steps of Anaphylaxis
Stimulus
Systemic mast cell and basophil degranulation and secretion
Systemic inflammatory response
Anaphylactic Shock = Circulatory shock -> cardiovascular collapse caused by blood loss
Describe two types of asthma
Stimulated by
Extrinsic - allergen known, childhood onset
Intrinsic - adult onset, often allergen unknown
IgE allergen complex
Fatigue mental and physical, emotions, endocrine, etc.
Primary problem with asthma
seccondary difficulties caused by
Leukotriene release –> smooth muscles in bronchioles can completely close
Inflamm in lungs can interfere with gas exchange
Leukocytes which ones?
Become macrophages
Similar to mast cells
Humoral and cell mediated immunity
Phagocytosis
Can destroy parasitic worm/ allergin
Monocytes
Basophils
Lymphocytes
Neutrophils
Eosinophils
Mesenchyme cells are adult __ cells
Have sparse pale staining cytoplasm with ____ shape nucleus
Functcion?
Divide?
Exist in adults?
Stem cells
Oval
To change into another cell type
Yes but numbers decrease as you age
Reticular cells are derived from ___ cells
Function?
Mesenchyme cells
Make reticular fibers.
When needed on temp basis - fibroblasts make IE wound healing
Permanent basis - reticular fibers made by ret cells
4 characteristics of Loose Connective Tissue
(1) Large number of cells and many cell types
Fewer fibers
More ground substance
Quite vascular
Two types of Lose Connective tissue
Loose areolar - greater and lesser omenta “fillers”
Loose irregular - Dermis - papillary layer; often directly beneath epithelium in organs
4 characteristics of Dense connective tissue
Many fibers
Fewer cells and cell types
Less ground substance
Less vascular
4 types of Dense CT
Dense Irregular - dermis reticular layer nerve sheath organ capsule
Dense Regular - Tendon, ligament, aponeuroses
Reticular CT - lymphatic and endocrine organs
Adipose - around kidney and heart, hypodermic and bone marrow
What are the two general CT rules?
1 - greater number of cell types therefore greater healing potential
2- Increased vascularity therefore increased healing potential
Three types of Specailized CT
Cartilage
Bone
Blood
Three mechanisms of protection are…
Surface protection - skin, mucus, acidic vagina
Acute Inflammation - non specific process ; neutrophils macrophages and eiosinophils
Immune Response - Two main types
What are the two main types of Acquired Immunity (adaptive immunity)
Humoral and Cell mediated
Usually a response to invading bacteria
Mediated by B cells and plasma cells with T involvement
Involves antibody production
Humoral Immunity
Usually responds to viruses, fungi, or foreign cells
Mediated by T cells
Does not depend on B cell participation
Cell Mediated Immunity
Three functions of the Immune System
Storage of Lymphocytes
Increase numbers of lymphocytes
Provide a favorable environment for establishing immunity
What are the characteristics of Diffuse Lymphatics?
Lymphatic Organs?
No or incomplete capsule
Humoral Immunity
Has a capsule
Humoral and Cell mediated
Provide an environment where lymphocytes become immunocompetent (ex Thymus and bone marrow)
Provide environment where lymphocytes can contact foreign antigens and interact with each other (lymph nodes and spleen)
Primary Lymphoid Organ
Secondary
What does MALT stand for?
Located?
Mucosal-Associated Lymphatic Tissue
GI tract, Respiratory and Urogenital tracts
Where is secretory IgA secreted onto?
Found where?
__ important line of defense agains infection
__ specific
Free epithelial surfaces
Tears, saliva, gut lumen, nose, vagina
First
Antigen
Igas can neutralize what two things?
Also do what to microbial adhesion to host cell?
Viruses and bacterial toxins
Decrease
What is GALT?
BALT?
Gut-Associtated Lymphatic Tissue
Bronchial-Associated Lymphatic Tissue
Explain the types of Tonsils
A.With epithelial folds = Pleated tonsils
- Pharyngeal Tonsils (inflammed callled adenoids
B. With Tonsilar Crypts
- Palatine Tonsils (Faucial Tonsils) - boundary of oral cavity and oropharynx
- Lingual Tonsils
Advantages and Disadvanteages for Palatine Tonsils
A - more area for antigen detection. Lymph nodule formation
D - Decripts - > bacteria thrive - > Inflammative tonsillitis
Tonsillar ring around openings to the Digestive and respiratory systems are called?
Waldeyer’s Ring
Two major functions of Lymph Nodes
Filtration of Lymph using phagocytosis
Establish humoral and cell mediated immunities
5 major parts of lymph node
Capsule
Afferent lymphatics
Efferent lymphatics
Hilum
System of sinuses
Sinuses that pass through
Marginal sinus…
Cortex region…
Deep cortex (paracortex)
Medulla region
Subcapsular sinus
Cortical sinus
Deep cortical sinus
Medullary sinus
Three regions of a lymph node
Cortex
Paracortex (Thymus dependent zone)
Medulla
Cells within all regions and sinuses of lymph node are supported by system of…
Reticular fibers that are produced by reticular cells
List lymph node cortex cells
Primary cell type in region?
Activity in region
Macrophages, reticular cells, dendritic, T, plasma cells
B cells
Phagocytosis and Humoral immunity
Lymph nodules which one?
Without germinal centers, older nodule with no B cell division, Naive B cells or B memory cells hanging out
With germinal centers, formed in response to particular antigen, active B cell division. Lite center is germinal and dark periphery is mantle
Primary Lymphoid Nodule
Secondary Lymphoid Nodule
List cells in Paracortex (Thymus Dependent Zone) of Lymph node
Primary type
Activity
Macrophages, reticular, dendritic, Some B and plasma
T cells
Long term storage for T cells
Cell mediated immunity
Phagocytosis
What important structures are lined with cuboid cells, function to facilitate passage of B and T cells from blood to lymph node, and The paracortex thins with its infection
HEV - High Endothelial Venules
Medulla Cell list
Primary cell type
Activity
Macrophages, dendritic cells, some b and T
Plasma cells
Humoral immunity and Phagocytosis
Medullary sinus vs cord
Numerous and lower cell density
Areas of higher cell density
Medullary sinuses
Meduallary cords
How many lobes of the thymus extend over the great heart vessels?
It is the primary ___ organ
When does involution begin?
Little functioning thymus let by age
Function?
Two
Lymphoid
first few years of life, speeds up at puberty
25
Establishment of immunocompetent T lymphocytes - recognize foreign antigen properly, develop self tolerance
Epithielioreticular cells
Produce reticular fibers?
Offer support using….
Secrete….
Function…
NO
Long cytoplasmic processes
Thymic hormones and cytokines
Influence T cell maturation, division, and activities
Epithelioreticular cells form thymic corpuscles (hassal’s bodies)
Always in the…
Size and number ___ a lot
Size number ___ w age
Function
Medulla
Vary
Increase
Secretion of cytokines that influence local cells
Blood thymic barrier consist of what 4 things
Continous capillary
Thick basal lamina
Macrophages
Epithelial reticular cells
Why does the Cortex stain more dark than the medulla in the thymus?
Larger number of T cells
Lymphocytes produced in bone marrow
Enter thymus as immunoincompent T cells
Leave blood at corticomedullary line
Migrate to periphery of cortex
Migrate back toward medulla
T cells enter medulla & finish final stages of testing
????
