Exam 2 Flashcards
(161 cards)
1
Q
Simple squamous epithelium
A
thin, flat layer of cells
found in endothelium of blood vessels, mesothelium that lines body cavities, alveoli, Bowman’s capsule, & loop of Henle
2
Q
Simple cuboidal epithelium
A
single layer of square-shaped cells
found in kidney/renal tubules, rete testis, small ducts of exocrine glands, surface of ovary, bronchioles
3
Q
Simple columnar epithelium
A
single layer of tall rectangular cells, can be ciliated
found in stomach, small intestine, gall bladder
ciliated in fallopian tubes
4
Q
Stratified squamous epithelium
A
multiple layers of thin flat cells, keratinized (skin) or non-keratinized (esophagus, lining of oral cavity, epiglottis, anus, cervix, vagina, vulva, glans penis, cornea)
5
Q
Stratified cuboidal epithelium
A
multiple layers of square-shaped cells
found in larger ducts of exocrine glands
6
Q
Stratified columnar epithelium
A
multiple layers of tall rectangular cells
found in large ducts of glands
7
Q
Pseudostratified columnar epithelium
A
layers of cells that are all attached at basal lamina but may not reach the surface/lumen/apex
ciliated
found in respiratory tract including nose, sinuses, trachea
8
Q
Transitional epithelium
A
urothelium
similar to pseudostratified
found in urinary tract (renal pelvis, ureters, bladder, urethra)
9
Q
Simple glandular epithelium
A
found in colon, stomach, eccrine sweat glands
10
Q
Compound glandular epithelium
A
found in sebaceous sweat gland, Brunner’s glands of duodenum, small salivary glands, breast, prostate
11
Q
Exocrine glands (solid organs)
A
major salivary glands, liver, pancreas (acinar)
12
Q
Endocrine glands (solid organs)
A
thyroid, anterior pituitary, adrenal, pancreas
13
Q
Epithelial polarity - apical domain
A
exposed to lumen or external environment
specialization - cilia (move mucous and fluid out, sperm motility), microvilli (increased surface area/absorption), stereocilia (inner ear, epididymis; sense changes in position orientation/pitch)
14
Q
Epithelial polarity - lateral domain
A
facing neighboring cells, linked together by junctional complexes and cell adhesion molecules
15
Q
Epithelial polarity - basal domain
A
associated with basal lamina and connective tissue
basement membrane
16
Q
Functions of epithelia
A
protection (skin), absorption (intestines), secretion (glands), excretion (kidney), gas exchange (lung), gliding between surfaces (mesothelium)
17
Q
Endocrine vs. exocrine glands
A
endocrine glands release products directly into the blood
exocrine glands release their products onto the surface
18
Q
Simple vs. compound (branched) glands
A
simple glands have ducts that do not branch, can still have glandular portions that do branch
compound (branched) glands have ductal structures that do branch
19
Q
Serous secretions
A
secreting cells have large spherical nucleus, basal region in which rough ER predominates, and apical region with red-stained zymogen granules (secretory vesicles with enzyme precursors)
20
Q
Serous secreting glands
A
secreting cells have large spherical nucleus, basal region in which rough ER predominates, and apical region with red-stained zymogen granules (secretory vesicles with enzyme precursors)
21
Q
Mucous secreting glands
A
glands often pail staining due to high content glycoproteins and glycolipids, nuclei flattened against basal portion of secretory cells
22
Q
Merocrine secretion
A
secretory vesicle approaches apical domain of epithelial cell, vesicular membrane fuses with plasma membrane to release its contents into ECM, fused plasma membrane can be taken back into cell by endocytosis and recycled
23
Q
Apocrine secretion
A
some of apical cytoplasm is pinched off with contained secretions
24
Q
Holocrine secretion
A
cell produces and accumulates secretory product in cytoplasm (such as sebum in sebaceous glands) then disintegrates to release secretory material
25
Adaptive cellular changes
experienced by cells in response to physiological or pathological stimuli
26
Non-adaptive cellular changes
random
including genetic drift, mutation, and recombination
27
Metaplasia
changing differentiation of cell type (phenotype & function)
ex: normal mucosal epithelium of pseudostratified columnar w/ cilia to stratified squamous w/ no cilia in response to irritation from smoke inhalation
ex: vitamin A deficiency in geckos causing lacrimal gland to secrete keratin instead of tears causing blindness
28
Ubiquitin-proteasome pathway
molecular pathway involved in cellular atrophy
proteins enter proteasome and get chewed up into peptides that are recycled
causes cells to shrink from loss of proteins & cell membrane
lipofuscin
"ultimate recycling pathway"
29
Disuse atrophy
relatively slow
ex: osteoarthritis, lameness
30
Neurogenic atrophy
rapid onset
ex: mass in brain compressing cranial nerve
31
Two basic pathways for hepatic lipidosis
overload of cells (metabolic alterations) - fat/energy mobilized to liver causing build-up
decreased function of cells (especially lysosomes) - cell injury, diabetes
32
Intravascular hemolysis
breakdown occurs in circulation
hemoglobin filtered out in kidneys before macrophages can detect
hemoglobinuria is major clinical sign
ex: copper toxicosis in small ruminants, bacterial toxemia, sepsis
33
Extravascular hemolysis
breakdown occurs in macrophages
hemoglobin breaks down to hemosiderin and bilirubin (yellow/brown pigment)
icterus (jaundice) is major clinical sign
ex: IMHA, trauma
34
Icterus formation
phagocytosis of RBCs by macrophages releases hemoglobin that gets broken down into heme and iron to form bilirubin and hemosiderin to be secreted and absorbed by tissues
bilirubin = yellow = jaundice/icterus
implies severe extravascular hemolysis
35
Lysosomal storage disease
lysosomes incapable of breaking down protein/lipid/carbohydrate causing build-up of partially digested metabolites in cells and eventually cell death
brain/liver/muscle primarily affected due to rapid turnover of organelles and high energy demand
36
Primary amyloidosis
overproduction of light chain of immunoglobulins
defect in plasma cell production
rare in veterinary medicine
37
Secondary amyloidosis
overproduction of serum amyloid A (SAA) produced in liver
upregulated during inflammation
38
Islet cell amyloid
IAPP produced by pancreatic beta-cells
common in cats
39
How hepatic amyloidosis interferes with liver function
amyloid build-up in liver blocks hepatocytes from being able to "filter" blood
hepatocytes atrophy and entire liver looks grossly big because of amyloid accumulations
results in liver failure
40
Dystrophic calcification/mineralization
local deposition of calcium in injured/dying/dead tissue
unrelated to serum Ca:PO4 balance
can be anywhere in body where there are dead cells, old abscesses/granulomas, dead parasites
41
Metastatic calcification/mineralization
systemic deposition of calcium in connective tissues and basement membranes
when there is hypercalcemia or hyperphosphatemia, and solubility product of Ca:PO4 is exceeded
etiologies: kidney disease, vitamin D toxicosis, parathyroid disorders, neoplasia
can be located in stomach, lungs, heart, kidney, parietal pleura
42
Karyolysis
nuclear fading
chromatin dissolution due to action of DNAases and RNAases
43
Pyknosis
nuclear shrinkage
DNA condenses into shrunken basophilic mass
44
Karyorrhexis
nuclear fragmentation
pyknotic nuclei membrane ruptures and nucleus undergoes fragmentation
45
Why is cellular eosinophilia a sign of cell injury/death?
hematoxylin stains nucleic acid (RNA, ribosomes) blue
injured cells appear pinker due to denatured protein (lost ribosomes) and loss of blue staining
46
Apoptosis
orderly cell death
"clean"
no inflammation
47
Necrosis
disorderly, sloppy death
leaks a lot of inflammatory molecules resulting in secondary inflammation
48
Reversible cell injury
some cells may develop "fatty change"
usually occurs in liver and muscle cell
apoptosis
49
Irreversible cell injury/cell death
necrosis
cell size enlarges and plasma membrane/organelles/nucleus break down
leakage of contents attracts neutrophils = inflammation
50
Coagulative necrosis
maintains overall shape of organ
pallor, shrunken
may still look similar in shape, function is decreased/absent
commonly identified in ischemic, metabolic, or toxic injury
51
Liquefactive necrosis
pus
loss of tissue architecture
tissue is liquified or paste-like
commonly identified in extracellular bacteria (neutrophils)
52
Caseous necrosis
"cheese crumbles"
loss of tissue architecture
dry and crumbly
commonly identified in intracellular bacteria (macrophages)
53
Fat necrosis/saponification
specific to coagulative necrosis of adipocytes
fat within cells are saponified (precipitated with calcium soaps)
54
2 ways to initiate apoptosis
extrinsic - activation of cell death receptors
intrinsic - injury to mitochondria
culminates in common "execution" pathway
55
What enzymes mediate apoptosis?
caspases - activated by calcium release, catalyze all aspects of apoptosis
results in cleavage of membranes, DNA, proteins, etc.
cell falls apart but remains membrane bound
56
Reperfusion injury
tissue damage caused when blood supply returns to tissue after period of ischemia
lots of calcium/potassium/lactic acid build up suddenly gets dumped into circulation
ex: great dane with GDV, equine colic
57
Embryonic connective tissue
fills spaces between developing tissues and organs
large number of stellate multi-potential mesenchymal stem cells
develops into connective tissues
58
Adult loose (areolar) tissue
supports epithelia, mucosa (gut), stroma of organs, surrounds blood vessels and nerves
contain collagen bundles and elastin fibers
59
Adult dense irregular tissue
many fibers arranged randomly
dermis of skin, capsules of organs, sheaths of nerves and muscle
60
Adult dense regular tissue
collagen fibers regularly arranged/running in same direction
tightly bundled, cells squished
tendon and ligament
61
Specialized connective tissue
adipose, cartilage, bone, hematopoietic tissue (bone marrow)
62
Cells found in connective tissue
Fibroblast - ECM
Macrophage - phagocytic, turn over old ECM
Mast cell - histamine
Plasma cell - antibodies
63
Collagen type I
major fibrillar collagen that provides tensile strength
found in bone, tendon, ligament, skin
(90% of body collagen)
64
Collagen type II
cartilage collagen
thinner fibrils than type I
65
Collagen type III
picks up silver (reticular) stains, often called reticular fibers
in many organs and basement membranes
provide supportive framework (skin, blood vessels, internal organs)
66
Collagen type IV
major collagen in basal lamina
67
Elastin
produced by fibroblast, smooth muscle cell, or chondrocyte
Fibroblast - skin, ligament, tendons
Smooth muscle cell - large blood vessels
Chondrocyte - elastic cartilage
68
Glycosaminoglycans
unbranched polysaccharide chains, repeating disaccharide units
highly negatively charged (carboxyl/sulfate groups on sugars), hydrophilic
long/stiff chains
69
Proteoglycans
glycosaminoglycan (GAG) + protein
aggregates form by axial hyaluronan molecule (core proteins attached by linker protein)
resist compressive forces in tissues and joints, mechanical support
70
Glycoproteins
fibronectin and laminin
cell matrix adhesion
71
Skeletal muscle
voluntary, striated
multinucleate, peripheral nuclei
t-tubules, triads (t-tubule + 2 expansions of rough ER)
72
Smooth muscle
involuntary, non-striated
spindle-shaped cells of variable size, arranged in single/multiple layers
dense bodies
caveolae - depressions in plasma membrane, gap junctions
one centrally placed nucleus
innervated by autonomic nervous system
(wall of gut, bile duct, ureters/urinary bladder, respiratory tract, uterus, blood vessels)
73
Cardiac muscle
involuntary, striated
branched cylinders, organization similar to skeletal muscle
single central nucleus
cells joined end to end by intercalated discs
diads rather than triads
larger t-tubules, gap junctions, purkinje fibers - conduct stimuli faster
autonomic nervous system
mitochondria more abundant/larger
74
Erythrocytes (RBCs)
biconcave discs
very flexible, squeeze through capillaries
transport oxygen and carbon dioxide to and from the tissues
75
Neutrophils
most common granulocyte (40-60% WBC total)
pale pink cytoplasm, nucleus stains dark blue and usually segmented into 3-5 indented lobes
inflammation, bacterial infection, environmental exposure, cancer, first responder
76
Eosinophils
granulocyte (1-4% WBC total), dark-pink/red granules
defense against parasitic infections, defense against intracellular bacteria, modulation of immediate hypersensitivity reactions
77
Basophils
least common granulocyte (0.5-1% WBC total), dark purple/blue granules
defense against parasitic infections, asthma, modulation of allergic reactions
seen in viral infections/inflammatory conditions (arthritis)
78
Lymphocytes
from common lymphoid progenitor (20-40% WBC total)
B cells, T cells, natural killer (NK) cells
immune response
79
Monocytes
from common myeloid progenitor, largest leukocyte (2-8% WBC total)
precursor to macrophages
inflammation (cytokine production), phagocytosis, antigen presentation
80
Platelets
anucleate cells derived from bone marrow megakaryocytes
required for normal hemostasis
play role in inflammation, thrombosis
81
Plasma
anticoagulant
contains albumin, FIBRINOGEN, immunoglobulins, lipids (lipoproteins), hormones, vitamins, salts
82
Serum
NO anticoagulant
protein-rich fluid LACKING FIBRINOGEN but contains albumin, immunoglobulins, and other components
blood clot contains fibrin network trapping blood cells
83
Red marrow
located in spongy bone
forms RBCs --> WBCs --> leukocytes, blood platelets
decreases with age
84
Yellow marrow
located in medullary canal
stores mostly adipose tissue
increases with age - conversion begins centrally and extends peripherally and axially
85
Mesenchymal stem cells (MSC)
multipotent stem cells
osteoblasts, osteocytes, adipocytes, chondrocytes, neurocytes, hepatocytes, myocytes, keratinocytes
86
Hematopoietic stem cells (HSC)
self-renewal, form blood cells
myeloid or lymphoid stem cells
myeloid --> RBCs, platelets, or myeloblasts to WBCs
lymphoid --> lymphoblast --> B cells, T cells, NK cells
87
Spleen (components and structure)
connective tissue framework: capsule, trabeculae, reticular stroma (fibers)
parenchyma: white and red pulp
88
Red pulp
splenic circulation
splenic cords (Billroth's cords) - T-cells/B-cells/macrophages/plasma cells/RBCs/etc.
sinusoids
function as filtration organ for removal of old/damaged RBCs/platelets, blood storage, support extramedullary hematopoiesis
rapid release in spleens of cats/horses/ruminants due to larger trabeculae and more smooth muscle
innate response by activation of macrophages, adaptive response by plasma cell migration from white pulp after antigen-specific differentiation in follicles
89
White pulp
periarterial lymphatic sheath (PALS) - T-cells
marginal zone - macrophages, innate response by production of natural antibodies
germinal center - B-cells
immune function: macrophages, B/T cells, dendritic cells, neutrophils
adaptive response (antigen-specific) consequent to interaction between antigen-presenting cells and B/T cells
90
Open circulation
slow "open" circulation - blood cells move out of capillaries and into splenic cords then filter into sinuses
venule (horses) - faster
sinuses (dog) - slower
91
Closed circulation
fast "closed" circulation - shunted directly from the capillary to the sinus (dog, human) or venule (horse, cat, cow)
92
Hydrostatic pressure
pushing fluid out, from blood pressure
higher blood pressure = higher hydrostatic pressure
93
Colloidal oncotic pressure
pulling fluid in, from solutes in blood (concentration gradient)
94
How hydrostatic pressure and colloidal oncotic pressure can form edema
1. increased hydrostatic pressure - may arise from arterial or venous sources
2. decreased colloidal oncotic pressure - failure to "hold in" fluid; hypoalbuminemia: albumin is major colloidal protein
95
Ascites
abdominal effusion, fluid accumulation in abdomen
96
Pitting edema
peripheral edema/subcutaneous edema
97
Hydrothorax
thoracic effusion (clear fluid)
98
Chylothorax
leakage of lymphatic fluid (chyle) into chest cavity (thorax)
may arise from blockage or rupture of thoracic duct
often idiopathic in cats
99
Hemoabdomen
blood in thoracic cavity
100
Virchow's triad disease processes
1. endothelial injury: hypercholesterolemia, inflammation
2. abnormal blood flow: stasis (atrial fibrillation, bed rest, etc.) vs. turbulence (atherosclerotic vessel narrowing, etc.)
3. hypercoagulability: inherited or acquired, chronic renal failure (loss of anti-clotting factor AT-III in urine)
disruption results in thrombosis - blood clot
101
Petechiae
pinpoint hemorrhage
often present in skin/epithelia, oral cavity/mucous membranes, conjunctiva
only 2 ways to get: vasculitis (inflammation of blood vessels) or thrombocytopenia (low platelets)
102
Ecchymoses
often looks like blending of petechiae into larger hemorrhage
causes could be vasculitis, thrombocytopenia, trauma, bleeding disorders (clotting factors)
implies more significant bleeding disorder than petechiae
103
Hematoma
local collection of blood
caused by vessel rupture/damage, clotting factor depletion, coagulopathy, NOT thrombocytopenia
104
Primary hemostasis
platelet plug
platelets attracted to exposed collagen, become activated when aggregated
secrete granules (ADP, TxA2) that cause more vasoconstriction, "grows" platelet plug
105
Secondary hemostasis
platelet plug already present
"cements" plug with fibrin
fibrin is formed on platelet membrane and forms supportive latticework (glue)
106
Von Willebrand's factor and deficiency
mediates platelet adhesion
mutation in vWF causes it to not work as well - clotting disorder seen more often in Dobermans
107
Fibrin vs. fibrosis
Fibrin = scab = acute inflammation, disorganized, acellular protein exudation, very pink on histology
Fibrosis = scar = chronic inflammation, organized, fibroblasts, collagen (dense regular/irregular), contractile
108
Breakdown of thrombi (blood clots)
fibrinolysis - degradation of fibrin meshwork, allows "holes" to form in large plug, endothelium will migrate into holes
recanalization - restoration of blood flow through a thrombus
109
White infarct
arterial obstruction
blockage of blood delivery --> tissue hypoxia --> necrosis --> pallor
blood NOT present in lesion
110
Red infarct
venous obstruction
blockage of blood drainage --> blood backup --> blood stasis --> hypoxia --> necrosis
blood present in lesion
111
White infarct vs. chronic infarct
white infarct: acute - bulging/swelling
chronic infarct: healed by fibrosis over time --> scarring, contraction (shrinking)
112
Lymph node organization
- capsule: dense irregular connective tissue, afferent lymphatic vessels, subcapsular sinus
- parenchyma: reticular fibers
- outer cortex: B-cell rich follicles
- inner cortex: CD4+ T-cells, high endothelial venules, trabecular sinuses
- medullary sinusoids: efferent lymphatic vesicle, blood vessels
- medullary cords: type III collagen, macrophages, DCs, lymphocytes
113
How do T-cells exit the vasculature to enter the lymph node?
through high endothelial venules (HEV) using L-selectin (protein on T-cell surface binds receptors on endothelial surface)
receptor-ligand interactions in HEV
114
What is associated with the lymph node capsule?
dense irregular connective tissue, afferent lymphatic vessels, subcapsular sinus
115
Thymus-blood barrier
thick/prominent basal lamina prevents/restricts antigens in the blood from gaining access to the thymus
116
Nodular lymphoid tissues generally contain
B-cells
117
Tunica externa (adventitia)
connective tissue surrounding the vessel
contains nerves and vessels supplying the vessel (vasa vasorum)
118
Tunica media
some smooth muscle (more in arteries than veins, some arteries also have elastin)
119
Tunica intima
endothelium creates a smooth lining (prevent turbulence)
endothelial cells are on basement membrane
also contains elastic fibers in arteries
120
Arteries (components and vessel layers)
thick wall with small lumen, round
intima: wavy endothelium, internal elastic membrane (large vessels)
media: thickest layer, mostly small reticular fibers, collagen
adventitia: thinner than media
121
Veins (components and vessel layers)
thin wall, larger lumen, flattened
intima: smooth endothelium, lacks internal elastic membrane
media: smaller or equal to adventitia, interspersed with collagenous and few elastic fibers
adventitia: thicker than or equal to media
122
Capillaries (components)
have special modifications
generally involve alterations in permeability
- endothelium: cell-cell junctions
- basement membrane: under endothelium
123
Vasculogenesis
initiated by coalescence of free & migratory vascular endothelial progenitors (angioblasts) during embryogenesis to form primitive vascular network in yolk sac and trunk axial vessels
essential for embryonic survival
124
Angiogenesis
initiated in preexisting vessel and observed in embryo and adult
adult - occurs during uterine menstrual cycle, placental growth, wound healing, inflammatory responses
tumor angiogenesis is specific form with important clinical implications
125
Principles of immune system
recognition: detection of substances that are "non-self"
effector function: contain infection and eliminate
regulation: need ability to turn processes "off", lack of regulation can cause disease
memory: develop long-term protective immunity
126
Innate immunity
response triggered to conserved structural patterns/motifs (PAMPs, DAMPs)
genetically encoded receptors
immediately available
by itself will not confer protective immunity (no memory)
127
Adaptive immunity
specific immune response to an antigen
antigen receptors can detect lots of different molecules
adaptation to infection, protective immunity
takes time to develop
128
Primary lymphoid organs
bone marrow and thymus
129
Secondary lymphoid organs
lymph nodes and spleen
130
T-cell development requires...
the thymus
2-step selection process
some self-reactivity
131
B-cell development requires...
stromal cell production of chemokines, adhesion molecules, and cytokines
homing and retention of progenitor cells
removal of self-reactive B-cells
132
Zona glomerulosa
angiotensin and ACTH stimulate synthesis of mineralocorticoids (aldosterone)
regulates ions
SALT
133
Zona fasciculata
ACTH stimulates synthesis of glucocorticoids (built from cholesterol, adipose tissue)
Androgens
SUGAR
134
Zona reticularis
ACTH stimulates synthesis of glucocorticoids (?) and mostly androgens
SEX
135
Adrenal medulla
preganglionic fibers stimulate liberation of epinephrine/norepinephrine (catecholamines)
fight or flight
136
Cushing's disease (hyperadrenocorticism)
can be caused by ACTH-secreting tumor in pituitary gland
hypertrophy of adrenal cortex, particularly the zona fasciculata
extremely large cortex, large adrenal gland
137
Addison's disease (hypoadrenocorticism)
entire cortex is destroyed and atrophied by unknown mechanisms (idiopathic)
wiping out production of all cortex derived hormones
need to supplement glucocorticoids & aldosterone
138
Cell receptors that mediate the innate immune response include
toll-like receptors
139
TLR signaling typically activates ___ mediated gene transcription
NF-kappaB
140
Dendritic cells present
after homing to lymph nodes
to T-cells
peptides
141
TLR signaling can cause increased expression of
chemokines and cytokines
142
DAMPs are...
analogous to PAMPs, but with different ligand and receptor
ATP, HMGB1
technically self-derived
143
What are the 4 layers of the gut wall
mucosa
submucosa
muscle
serosa (serous membrane/mesentery)
144
Mucosa components
epithelium, lamina propria, muscularis mucosa
145
Submucosa components
loose connective tissue
nerve plexus
larger blood vessels
submucosal glands
146
Muscularis (muscle) components
2 layers
circular (thicker) and longitudinal
147
Serosa
mesentery
outermost layer
148
What is lamina propria made up of?
loose connective tissue
immune cells
blood vessels
lymphatics
nerves
149
How is the gut epithelium a proliferative structure?
stem cells that originate at the base of crypts and migrate up crypt-villus axis to differentiate
takes 3 days
150
Components of epithelial barrier
extracellular barrier
cellular component (membrane, paracellular pathway, transcellular pathway)
commensal bacteria
151
Paneth cells
secrete antimicrobial peptides
152
Transcellular pathway
enterocytes (absorptive cells) transport macromolecules from lumen to lamina propria
antigens/bacterial toxins/viruses can enter enterocytes through this mechanism
153
Paracellular pathway
apical junctional complexes
tight junctions most studied and best understood, important part of barrier and determinant of mucosal permeability
154
Esophagus
mucous glands
smooth and striated skeletal muscle
moves material form mouth to stomach
155
Stomach
"dilation" of tube
storage and mixing
low permeability
release of acid (protons) for digestion
156
Small intestine
tube with large surface area for digestion and absorption
157
Colon (large intestine)
absorption of water and ions
fermentation
158
2 main drainage pathways
hepatic portal system (gut to liver)
intestinal lymphatic system (gut to circulation)
159
Accessory glands of GI tract
exocrine pancreas
liver
salivary glands
160
Submucosal glands of GI tract
tubuloacinar structures with main body of gland in submucosa and ducts leading to the gut lumen
duodenum
esophagus
161
Mucosal glands of GI tract
crypts - invagination of epithelial layer
stomach
small intestine
colon
