Exam 1 Flashcards
(462 cards)
1
Q
Function of epithelial tissue
A
covers body surfaces & lines hollow organs, body cavities, ducts, & forms glands
2
Q
Function of connective tissue
A
protects, supports, & binds organs; stores energy as fat, provides immunity; selective transport
3
Q
Characteristics of epithelial tissue structure
A
surface specialization, arrangement of cells, & cell junctions
4
Q
Describe microvilli
A
finger-like extensions of plasma membrane; increase SA; most developed in absorptive cells (ex: intestinal epithelium, kidney tubules)
5
Q
Describe cilia
A
motile surface projecions of cells involved in transport of materials over epithelial surface (ex: respiratory tract & oviduct)
6
Q
Structure of cilia
A
2 centrally placed microtubules surrounded by 9 doublets of microtubules; provides the scaffold for various proteins
7
Q
Stereocilium definition
A
enormous microvilli; ex: auditory sensory cells of organ of Corti; vestibular sensory cells of vestibular organ; epididymis
8
Q
Alveolus has what type of epithelium
A
simple squamous; functions for the rapid passage of substances (O2 & CO2)
9
Q
Bronchioles have what type of epithelium
A
simple cuboidal; secretion, includes Club cells & Bronchiolar exocrine cells that release substances
also has simple columnar w/ cilia; transport of trapped particles
10
Q
Bronchus, trachea, & nasal cavity have what type of epithelium
A
pseudostratified columnar epithelium w/ microvilli; also has mucus-secreting goblet cells, columnar cells w/ cilia, & basal cells
11
Q
Functions of pseudostratified columnar epithelium
A
secretion (mucus/serous) & transport of trapped materials
12
Q
Nostril & nasal plane have what type of epithelium
A
stratified squamous; protection
13
Q
Urinary system has what type of special epithelium
A
transitional epithelium
14
Q
Function of transitional epithelium
A
designed to distend & return to its normal size, as it does in the lining of the urinary bladder; provides distensibility; prevents urine from diffusing back into the body; variable appearance (relaxed state, cuboidal, stretched state, squamous)
15
Q
Lateral cell junctions connect with what
A
specialized areas of cell membrane; membrane proteins acting as adhesion molecules
16
Q
Types of cell junctions
A
tight (occluding junction), anchoring junction, communicating junction
17
Q
Tight junction location
A
lateral
18
Q
Anchoring junction location
A
lateral & basal
19
Q
Describe tight junctions
A
web-like strands of transmembrane proteins that fuse cells together & are unique to epithelial cells; completely surrounds cell
20
Q
Function of tight junctions
A
forms a barrier preventing diffusion of water-soluble molecules b/w adj cells & lumen; maintains cell polarity
21
Q
Function of anchoring junctions
A
resist separation of cells by connecting cytoskeletal elements of one cell to neighboring cells/ extracellular matrix
22
Q
3 types of anchoring junctions
A
Zonula adherens, desmosome, & hemidesmosome
23
Q
Describe zonula adherens
A
below the tight junction, surrounds cells in a belt-like fashion; transmembrane glycoproteins (Cadherin); plaque (intracellular link protein); cytoskeleton (actin filaments)
24
Q
Describe desmosome
A
binding spot b/w cells; transmembrane glycoprotein; plaque; cytoskeleton (intermediate filaments)
25
Describe hemidesmosome
resemble half desmosome; anchor epithelial cells to underlying basement membrane (extracellular matrix); contains transmembrane glycoprotein (integrin); integrin attach to plaque/intermediate filaments & the protein laminin present in the basement membrane
26
What is pemphigus
autoimmune blistering skin disease; autoantibodies bind to transmembrane glycoproteins disrupting cell adhesion (fluid-filled sacs & cysts); widespread blistering & loss of extracellular fluid
27
Define glands
exocrine cells that make & secrete a substance
28
What are exocrine glands
secretory cells derived from the surface epithelium; secrete product onto external or internal epithelial surfaces; generally have ducts
29
What are endocrine glands
hormones into bloodstream travel to target organ; no ducts
30
How are exocrine glands classified
of cells, arrangement of duct/ secretory segment; secretory product; secretory release method
31
Describe unicellular glands
single secretory cell (ex: intestinal & respiratory epithelim)
32
Describe multicellular gland
many secretory cells
33
Words to describe the arrangement of duct/ secretory segment
simple or compound; acinar or tubular
34
Simple glands
no branching for duct
35
Compound gland
duct branches
36
Acinar gland
looks like a berry
37
Tubular gland
secretory segment/ unit
38
Ex of a simple tubular gland
large intestine
39
Ex of a branched tubular gland
stomach
40
Ex of a simple coiled tubular gland
sweat gland (foot pad)
41
Simple branched acinar gland
enlarged, spherical secretory unit opens to the surface by a duct; ex: sebaceous gland
42
Serous glands secrete what
watery product enriched w/ proteins
43
Ex of serous glands
exocrine pancreas (amylase, trypsin, lipase); parotid gland, sweat gland (foot pad), lacrimal gland
44
Mucous glands secrete what
thick & viscous substance rich in mucin (glycoproteins)
45
Function of mucous glands
lubricant, protects cell layers, & traps foreign particles/ bacteria
46
Ex of mucous glands
goblet cells, sublingual salivary gland
47
Name for a gland consisting of mucous & serous cells
mixed gland
48
Ex of seromucous gland
mandibular salivary gland; esophagus, duodenum, respiratory airway
49
3 kinds of release secretory methods for glands
exocytosis, pinching off apical cell cytoplasm w/ cell product, whole cells
50
Name for glands that use exocytosis
merocrine gland (ex: pancreas, sweat gland (foot pad))
51
Name for glands that pinch off apical cell cytoplasm w/ cell product
apocrine gland (ex: sweat gland (haired skin))
52
Name for glands that release whole cells
holocrine gland (ex: sebaceous gland)
53
Describe myoepithelial cells
present in some glands; share the basal lamina of the acinar cells; share some properties of smooth muscle (contractility)
54
Other names for muscle cells
myocyte, muscle fibers, or myofibers
55
Structure of muscle cells
long axis parallel to direction of contraction; full of long protein fibers
56
Name for cells located b/w myocytes
satellite cells
57
What leads to very long myocytes w/ many nuclei
prenatal fusion of myoblasts
58
Location of nuclei on myocytes
cell periphery
59
What appears as dots in cross sections
myofibrils
60
Name for thin filaments & level of movement
actin- moves
61
Name for thick filaments & level of movement
myosin- stationary
62
What causes striations in muscle
overlap of filaments
63
Name for the structural unit of a myofibril
sarcomere; gets shorter as muscle contracts
64
Z line is what
boundaries b/w adj sarcomeres; attachment of actin filaments
65
A band is what
dark band; corresponds to myosin filaments (darker parts are where actin & myosin overlap)
66
H zone is what
lighter zone inside of A band; contains only myosin filaments
67
I band is what
light area on each side of Z line; where actin does not overlap myosin
68
Components of a thin filament
actin, tropomyosin, troponin
69
Function of myosin
binds actin & ATP; hydrolyses ATP
70
Cross bridges function to do what
generate force
71
Cycle of cross bridge formation
ATP split into ADP & Pi to cock the myosin head; myosin cross bridge attaches to the actin myofilament; working stroke- myosin head pivots & bends as it pulls on the actin filament, sliding it towards the M line; as new ATP attaches to the myosin head, the cross bridge detaches
72
At rest, what prevents myosin from binding to actin
tropomyosin
73
How does myosin bind to actin
Ca2+ binds to troponin & pulls on tropomyosin, exposing myosin binding site on actin
74
Method to affect force production of muscle
level of overlap b/w actin & myosin; affects cross bridges formed
75
Plasma membrane of myocyte
sarcolemma
76
Invagination of plasma membrane of myocyte
T-Tubules
77
Internal membrane compartment of myocyte that stores Ca2+
sarcoplasmic reticulum
78
In a neoromuscular junction, does the neuron physically touch the sarcolemma
no; relies on neurotransmitters to jump the gap
79
Excitation contraction coupling of neuromuscular junction
action potential generated is propagated along the sarcolemma & down the T tubules; action potential triggers Ca2+ relase from terminal cistemae of SR; calcium ions bind to troponin, troponin changes shape & removes the blocking action of tropomyosin, exposes active sites; contraction as myosin cross bridges alternately attach to actin & detach, pulling the actin filaments towards the center of the sarcomere, release of energy by ATP hydrolysis powers the cycling process; removal of Ca2+ by active transport into the SR alter the action of potential ends; tropomyosin blockage restored blocking actin active site, contraction ends & muscle fiber relaxes
80
Definiton of motor units
1 motor neuron & all the muscle fibers it innervates
81
Small motor units
low force, high precision
82
Large motor units
high force, low precision
83
Order of motor unit recruitment
small then to large
84
Describe red muscle fibers
slow oxidative; smaller than white ones; more extensive blood supply; more myoglobin; more mitochondria; more intracellular lipid; contract & fatigue slowly
85
Describe white muscle fibers
fast glycolytic; more extensive sarcolemma; more rapid Ca2+ release & contraction; more glycogen; faster ATPase; recruited last
86
Describe myogenesis
myoblasts proliferate & fuse together to become myocytes/ myofibrils
87
What happens when myocytes undergo atrophy
myonuclar loss; decrease in myofibrillar proteins; decrease in myofiber CSA
88
What happens when myocytes undergo hypertrophy
myonuclear addition; increase in myofibrillar proteins; decrease in myofiber CSA
89
2 types of muscle contractions
isotonic (concentric or eccentric) or isometric
90
Describe isotonic muscle contractions
muscle moves in 2 phases- concentric & eccentric
91
Concentric phase
more heat, less force
92
Eccentric phase
muscle lengthening; less heat, more force, more damage; rhabdomyolysis (muscles ripping apart)
93
Cardiac myocyte description
single centrally-located nucleus; fibers branch & anastomose; more mitochondria than cells of skeletal muscle; intercalated discs
94
Define desmosomes
mechanical link b/w cells
95
Define gap junctions
electrical link b/w cells
96
Layers of the heart
pericardium, epicardium, & endocardium
97
Reticular fibers of cardiac muscle cells are analogous to what
endomysium
98
Groups of cardiac myocytes are divided by thick bundles of connective tissue, which is analogous to what
perimysium
99
Features of cardiac muscle
striated; same banding pattern made by myofibrils
100
Are atrial or ventricular myoctyes smaller
atrial
101
Atrial myocytes contain what granules
Atrial Natriuretic Peptides
102
Atrial Natriuretic Peptides stimulate the kidney to do what
excrete Na+ & water
103
Atrial Natruiuretic Peptides promote relaxation of what
smooth muscle in blood vessel walls
104
Why are ventricular myocytes larger than atrial myocytes
operate against pressure/ require force
105
What are purkinje fibers
modified cardiac myocytes/ impulse conducting fibers
106
How are purkinje fibers different from other cardiac tissues
impulse conducting fibers; more cytoplasm & fewer myofibrils (cytoplasm more pale); sarcoplasmic reticulum present; T tubules absent
107
Describe contraction of cardiac muscles
Ca2+ released from sarcoplasmic reticulum; myosin & actin form cross-bridges; unstable resting membrane potential
108
Electrical coupling b/w cardiac muscle cells results in
spread of action potential
109
Interaction of actin & myosin do what in cardiac muscle cells
shorten sarcomeres
110
Describe a smooth muscle myocyte
single centrally-located nucleus; spindle shaped; surrounded by reticular fibers; tissue rich in blood vessels & nerves; no striations
111
Smooth muscle is present in hollow organs such as
uterus, gallbladder, stomach, urinary bladder, intestines
112
What filament is smooth muscle lacking compared to skeletal muscle
troponin
113
Dense bodies in smooth muscle do what
anchor myofilaments to extracellular matrix & other cells
114
What is the contraction of smooth muscle dependent on
phosphorylation of mysoin
115
What happens when myosin is phosphorylated in smooth muscle (after Ca2+ & calmodulin)
myosin binds to actin & the muscle shortens
116
Cause of myosin phosphorylation in smooth muscle
increase in intracellular Ca2+ that binds to calmodulin which activates it; calcium-calmodulin phosphorylates mysoin light-chain kinase (MLCK); MLCK phosphorylates mysoin & phosphorylated myosin binds actin
117
How does calcium come into smooth muscle
stretch activated cation channel; voltage-dependent calcium channel; ligand-gated cation channel; GPCR
118
Contraction of smooth muscle differs from skeletal or cardiac how
slower & more sustainable
119
Involuntary movement of smooth muscle is under the control of
autonomic nervous system
120
Cells of unitary smooth muscle are linked by
gap junctions
121
All cells in a unitary smooth muscle do what
act as a unit
122
Cells of multi-unit smooth muscle are linked by
nothing
123
Individual cells of a multi-unit smooth muscle get what
their own innervation
124
Multi-unit smooth muscle allows for what
precise contraction
125
Types of connective tissue
embryonic; connective tissue proper (loose & dense); specialized connective tissue (blood, cartilage, & bone)
126
Functions of connective tissue
3D framework supporting epithelium & other tissues; heat regulation; storage; preserve organ structure; protection
127
Connective tissue characteristics (not including blood)
sparse cells & extensive extracullar matrix (ECM)
128
What is the ECM composed of
fibers & ground substance
129
Fibers in ECM of CT
collagen & elastin
130
Ground substance of CT consists of what
Glycosaminoglycans & Proteoglycans
131
Characteristics of collagen
high tensile strength (especially type I)
132
Collagen is secreted as what & assembled where
procollagen; extracellularly
133
Type I collagen
skin, vessels, tendon, organ capsule, bone
134
Type II collagen
cartilage
135
Type III collagen
reticular fibers
136
Type IV collagen
basement membrane
137
Type V collagen
hair & placenta
138
Describe shape of Type III (reticular) fibers
thinner than other fibrils
139
Type III (reticular) fibers can be stained w/ what color
silver
140
Function of Type III (reticular) fibers
provide a supporting framework for soft organs
141
Describe properties of elastin
stretch & recoil
142
Elastin is secreted as what & assembled where
proelastin; extracellularly
143
What are Glycosaminoglycans (GAGs)
chains of sugars w/ a repeating disacchaide unit
144
Ex of GAGs
hyaluronic acid, chondoirtin sulfate, dermatan sulfate, keratan sulfate, heparan sulfate
145
What are Proteoglycans
GAGs linked to a protein core
146
Proteoglycans can be linked together by what
a core molecule
147
Resident cells in connective tissue proper
fibroblasts/fibrocytes, adipocytes, mast cells, macrophages, pericytes, & pigment cells
148
Transient cells in connective tissue proper
lymphocytes/plasma cells & leukocytes
149
Function of fibroblasts
produce ECM in proper connective tissue (fibers- procollagen/prelastin & ground substance- GAGs & proteoglycans)
150
Function of fibrocytes
less active than fibroblasts, may become stimulated to become more fibroblastic
151
Mast cells shape
ovoid; large
152
Granules in mast cells
basophilic
153
Function of mast cells
chemical mediators (histamine); responsible for allergic symptoms
154
Function of macrophages
professional phagocytes; engulf & destroy; patrol tissues for foreign objects & dead tissue
155
Macrophages are derived from what
myocytes
156
Appearance of macrophages when inactive
large & appear oval/spherical
157
Apperance of macrophages when active
very large & multinucleated
158
Functions of loose/ areolar connective tissue
support, tissue repair, & defense activation
159
Loose connective tissue is more common than dense; where is it found
around nerves & skeletal muscle bundles; b/w most epithelia
160
Describe the appearance of loose connective tissue
cells & fibers separated by large areas filled w/ ground substance
161
Describe the general appearance of dense connective tissue
fibers (mainly collagen) are more abundant than ground substance
162
Explain strength of dense regular connective tissue
strong in one direction- parallel to orientation of the fibers
163
Explain strength of dense irregular connective tissue
strong in many directions
164
Ex of dense regular connective tissue
tendons/ ligaments
165
Ex of irregular connective tissue
dermis
166
Components of the blood
cells (erythrocytes/leukocytes); cell fragments (platelets); plasma (water+)
167
Blood components can be separated through
clotting & sedimentation
168
Sedimentation occurs when
clotting is prevented
169
3 layers of sedimentation
erythrocytes (PCV or hematorcrit- volume of RBCs compared to total blood volume); buffy coat (leukocytes & platelets); plasma
170
Substances found in plasma include
salt, ions, large molecules (albumins, globulins, fibrogen), organic compounds
171
Define serum
plasma minus fibrinogen & other clotting factors
172
How do you get serum
allow blood to clot, then centrifuge
173
Another name for platelets
thrombocytes
174
Platelets are fragments of what
megakaryocytes
175
Platelets are essential for what
hemostasis (blood clotting)
176
Describe platelet formation
megakaryocytes in bone marrow project cytoplasm into a blood vessel; fragments break off & become platelets
177
Type of activation for platelets
receptor mediated activation
178
Steps of platelet activation
morphology change; degranulation; aggregate
179
When a platelet is activated, this means that
it is helping to clot blood
180
Two broad categories of leukocytes
granulocytes & agranulocytes
181
Describe a general feature of granulocytes
segmented nucleus
182
Describe a general feature of agranulocytes
mononuclear
183
Types of granulocytes
eosinophils, basophils, & neutrophils
184
Types of agranulocytes
monocytes & lymphocytes
185
Describe erythrocytes in mammals
non-nucleated & biconcave disks
186
Erythrocytes are rich w/ what
hemoglobin
187
Special feature of neutrophils compared to other granulocytes
granules do not stain
188
Functions of neutrophils
early responders to bacterial/fungal infections; phagocytize microbes & foreign particles
189
Describe the plasma components & the substances in each
salts, ions, organic compounds, large molecules (albumins, globulins, & fibrinogen)
190
Special feature of eosinophils compared to other granulocytes
granules stain red to reddish-orange w/ eosin
191
Functions of eosinophils
combat parasites; source of inflammation in an allergic rxn; non-phagocytic
192
Special feature of basophils compared to other granulocytes
granules stain blue w/ basophilic stain (hematoxylin)
193
Function of basophil
source of inflammation in allergic rxn (histamine)
194
Which cell is the largest leukocyte
monocyte
195
Monocytes enter different tissues; what are 4 examples of the names & where they are found
macrophages- many tissue
langerhans cells- skin
osteoclasts- bone
microglia- brain
196
In the majority of species, what WBCs are the most common
neutrophils (most) & lymphocytes (2nd most)
197
Appearance of lymphocytes
little cytoplasm w/ a large nucleus; smallest leukocytes
198
Types of lymphocytes
T-lymphocytes & B-lymphocytes
199
Define hematopoiesis/hemopoiesis
formation of blood cells
200
Where does hematopoisesis occur in mammals
yolk sac -> prenatally
liver -> youth
bone marrow -> adults
201
Extramedullary hematopoiesis occurs where
liver & spleen
202
Hematopoietic stem cells include what kinds
pluripotent & multipotent (blood stem cells- myeloid & lymphoid)
203
Vascular space in bone marrow is continous w/
cardiovascular system
204
Extravascular space in bone marrow is where what occurs
hematopoiesis
205
What kinds of factors guide the ultimate differentiation of blood cells
local & systemic origin
206
Hematopoietic stem cells give rise to what cells
common myeloid progenitor & common lymphoid progenitor
207
Common myeloid progenator gives rise to what cells
megakaryotcyte/erythroid progenitor & granulocyte/macrophage progenitor
208
Megakaryocyte/erythroid progenitor gives rise to what cells
RBCs & megakaryocytes
209
Megakaryocytes give rise to what cells
platelets
210
Granulocyte/macrophage progenitor give rise to what cells
monocytes, neutrophils, eosinophils, basophils, & mast cells
211
Monocytes give rise to what cells
macrophages & dendritic cells
212
Common lymphoid progenitor gives rise to what cells
B cells, T cells, & NK cells
213
B cells give rise to what cells
plasma cells
214
What is the most active component of hemopoiesis
erythropoiesis
215
What are erythrocytes called in the stage prior to maturation
reticulocytes
216
Features of reticulocytes
still have RNA but no nucleus
217
Erythropoietin (EPO) is secreted by the kidney & does what
acts at all stages of maturation of erythrocytes
218
Last nucleated stage in RBC maturation
metarubricytes
219
As the RBC matures, what changes occur
size decreases, basiophilia decreases, nuclear size decreases, & hemoglobin increases
220
How many days does it take to produce a granulocyte
6-9 days
221
Last step before maturation of a granulocyte is what
band cell
222
Some mature granulocytes are stored where until they are needed
storage pool in bone
223
Most common granulocyte in production
neutrophil
224
Once post-mitotic, granulocyte cells undergo maturation & storage until they are what
released into blood
225
Interesting feature about the origin of monocytes
produced along granulocytes (even though they are an agranulocyte)
226
Monocytes do not fully mature until when
they enter tissues & become macrophages
227
How do megakaryocytes become multinucleated
nucleus divides but cytoplasm does not
228
Hemostasis definition
process that causes bleeding to stop
229
Hemostasis is a finely regulated process w/ what 3 main players
endothelial cells, platelets, & coagulation factors
230
Describe primary hemostasis
1) contraction of vessel smooth muscle (vasoconstriction)
2) platelet activation, adhesion/aggregation at site of injury
3) endothelial cells & platelets release factors that facilitate plug formation
231
After a tear in the endothelium, endothelial cells help pull the endothelium back together & release what to make it easier to stick to the defect
von Willebrand factor
232
Steps of primary hemostasis
1) platelet adhesion
2) shape change
3) granule release (ADP & TXA2)
4) recruitment
5) aggregation (hemostatic plug)
233
Describe secondary hemostasis
coagulation to form a fibrin meshwork
234
In secondary hemostasis, thrombin does what
converts fibrinogen (soluble) to fibrin (insoluble)
235
Fibrin production is the end result of several rxns involving what
coagulation factors, nonenzymatic cofactors, calcium, & phospholipid membranes
236
Steps of secondary hemostasis
1) tissue factor
2) phospholipid complex expression
3) thrombin activation
4) fibrin polymerization
237
Pathways of the coagulation cascade
extrinsic & intrinsic pathways that meet up at the common pathway
238
What is an important cofactor in clotting (coagulation cascade)
Ca2+
239
Ca2+ does what (coagulation cascade)
makes thrombin; which converts fibrogen -> fibrin
240
Function of coagulation cascade
to amplify the signal so it doesn't get washed away
241
Clotting factors are activated where
at the site they are needed/ point of injury
242
Anticoagulant activity involves what
antithrombin III
243
Antithrombin III is produced where
liver
244
Antithrombin III is activated by
heparin, present in normal epithelial cells
245
Disseminated Intravascular Coagulation (DIC) can result from
endothelial damage (heat stroke); platelet activation (parasite); release of tissue procoagulants
246
Where is cartilage found
fetal skeleton; supporting framework; on articulating surfaces
247
Describe properties of cartilage
strong & pliable connective tissue
248
Special features of cartilage
non-vascular & not innervated
249
Cells in cartilage
chondroblasts & chondrocytes (few in #)
250
Components in cartilage
fibers (collagen/elastin) & ground substance (GAGs/proteoglycans)
251
The cartilage structure is surrounded by what
perichondrium (outer fibrous & inner cellular layers)
252
Chondrocytes are surrounded by matrix & fibers but located in what
lacunae
253
3 types of cartilage
hyaline, elastic, & fibrocartilage
254
Hyaline cartilage is the most common cartilage & is found where
articulating surfaces, nose, larynx, connects ribs to sternum, & tracheal rings/bronchi; fetal skeleton & epiphyseal plates
255
Elastic cartilage is flexible & is found where
epiglottis & ear canal
256
Fibrocartilage is for mechanical stress & is found where
intervertebral disks & menisci
257
Major components of articular (hyaline) cartilage
water, collagen, GAGs, & proteoglycans
258
Articular (hyaline) cartilage is dependent on what
diffusion from synovial fluid for nutrients & waste removal
259
Why is articular (hyaline) cartilage dependent on diffusion
does not have a perichondrium
260
Articular (hyaline) cartilage has what characteristic regarding growth
slow remodeling/healing in the adult
261
Matrix of articular (hyaline) cartilage includes what
type II collagen, hyaluronic acid (HA), & proteoglycans (PGs)
262
Matrix of articular (hyaline) cartilage does what
attracts water (PGs(GAG))
263
The well hydrated matrix of articular (hyaline) cartilage is crucial to what
shock absorbing properties
264
Why do the PGs (GAG) help to attract water
negative charge
265
Phase of articular cartilage where it is under a load
creep
266
Phase of articular cartilage where it is compressed fully
equillibrium
267
Why does articular cartilage not function well long-term if it is not being used
compression of the joint allows for diffusion of water-> brings nutrients
268
Superficial layer of articular cartilage has what features
more water, more collagen, more cells, less PGs
269
Deep layer of articular cartilage has what features
less water, less collagen, less cells, more PGs
270
Why does the deep layer of articular cartilage have more PGs
to help draw fluid down to the deeper layer
271
Define perichondrium
layer of dense irregular connective tissue that surrounds the cartilage of developing bone (except articular cartilage)
272
Muscle lengthens in eccentric or concentric
eccentric
273
Muscle shortens in eccentric or concentric
concentric
274
Function of T tubules
conduct impulses from the surface of the cell (sarcolemma) down into the cell and, specifically, to another structure in the cell called the sarcoplasmic reticulum
275
Intercalated disks are what
cell junctions- includes desmosomes & gap junctions
276
Describe appearance of articular (hyaline) cartilage
chondrocytes/blasts are random; cannot distinguish collagen from ground substance
277
Describe appearance of fibrocartilage
chondrocytes in parallel rows w/ collagen in b/w
278
Describe appearance of elastic cartilage
abundant & large chondrocytes; collagen blends in w/ ground substance; visible elastic cartilage
279
Fibers in hyaline/ elastic cartilage
collagen
280
Fibers in fibrocartilage
collagen
281
Fibers in elastic cartilage
collagen & elastin
282
Perichondrium has what layers
outer fibrous & innter cellular layer
283
Where is the perichondrium absent
hyaline articular cartilage & fibrocartilage
284
Role of hyaluronic acid in hyaline articular cartilage
lubrication & viscoelasticity of synovial fluid
285
Location of appositional growth of cartilage
underneath periosteum
286
Location of interstitial growth of cartilage
located around chondrocytes in lacunae
287
Functions of bone
hematopoeisis; support; protection (against mechanical stress); storage (of minerals); attachment; lever system
288
Describe osteoprogenitors
make osteblasts
289
Describe osteoblasts
immature bone cells; no lacunae; make tissue; found lined up along edges of growing bone
290
Describe osteocytes
mature bone cells; have lacunae; maintain bone; found trapped in bone
291
Describe osteclasts
cut edges of bone (under endosteum); multinucleated (differentiate from monocytes)
292
(Periosteum is the outer covering of bone) Outer fibrous layer of periosteum does what
makes collagen
293
(Periosteum is the outer covering of bone) Inner cellular layer of periosteum does what
osteogenesis
294
Describe compact bone
osteon functional units (includes central canal, cone rings of osteocytes in lacunae, & canaliculi); in diaphysis
295
Other names for compact bone
cortical or dense bone
296
Describe calcullous bone
large open spaces surrounded by thin anastomosing plates of bone; lines w/ endosteum (squamous cells & osteblasts/clasts); in epiphysis
297
Other names for calcullous bone
spongy or trabecular
298
Explain the organization of calcullous bone
lamella organized as trabeculae w/ osteocytes in lacunae; canaliculi open at trabecular surface below the endosteum & fluid nutrients are exchanged; no osteon
299
Central canals are located parallel to bone and contain what
blood & nerve supply
300
Perforating canals are located perpendicular to bone and do what
connect central canals to periosteum
301
What is the canaliculi
paths to central canal for fluid, waste, & nutrients to be exchanged
302
Concentric rings of compact bone are from what
lamina of osteocytes in lacunae
303
Function of bone marrow
make RBCs & is important in the lymphatic system
304
Describe red bone marrow
hematopoetically active; present at birth; gradually converts to yellow
305
Describe yellow bone marrow
inactive; primary adipocytes; in severe blood loss, can convert back to red
306
Intramembranous ossification occurs where
flat bones & fracture sites w/ blood supply
307
Endochondral ossification occurs where
long bones & fracture sites w/out blood supply
308
What happens in intramembranous ossification
connective tissue ossifies
309
What happens in endochondral ossification
cartilage is replaced w/ bone
310
Describe structure of lamellar bone
organized matrix of collagen fibers
311
Describe structure of woven bone
irregular arrangement of collagen fibers
312
Longevity of woven bone
not permanent, replaced w/ lamellar bone
313
Characteristics of lamellar bone
slow to make, layered, & stronger
314
Characteristics of woven bone
quick to make, single layer, & weaker
315
Steps of intramembranous ossification
1) mesenchyme condenses
2) cells produce collagen fibrils & thicken matrix
3) osteoblasts differentiate & form mesenchymal cells
4) osteoblasts secrete collagen for matrix (centers of ossification that form trabeculae of bone - add layers - then fuse w/ other trabeculae)
5) organization is poor at first (woven bone)
316
Steps of endochondral ossification
1) mesenchymal cells become chondroblasts
2) hyaline cartilage starts being replaced by bone
3) bone collar forms on outside of cartilage
4) chondrocytes in center hypertrophy, calcify matrix, & die
5) vessels invade cartilage matrix
6) osteoblasts invade & start making new bone
317
Explain resting cartilage cells (epiphyseal plate)
chondrocytes in storage
318
Explain proliferating cartilage cells (epiphyseal plate)
chondrocytes line up
319
Explain hypertrophic cartilage cells (epiphyseal plate)
chondrocytes enlarge & burst
320
Explain zone of calcifies cartilage (epiphyseal plate)
cartilage turns to bone
321
Explain vascular invasion & primary bone formation (epiphyseal plate)
last phase of epiphyseal plate growth
322
Summary of epiphyseal plate growth
chondrocytes proliferate, hypertrophy/ calcify matrix, then die; osteoblast invade & secrete matrix; growth plates eventually close
323
Bone remodeling occurs when
throughout life
324
Bone remodeling involves what
bone repair; Ca2+ homeostasis; shape changes after mechanical stress; increasing diameter
325
Name the phases of bone fracture healing
reactive phase, reparative phase, & remodeling phase
326
Describe reactive phase of bone fracture healing
fracture, hematoma, & inflammation; granulation type tissue formation; new CT & blood vessels fill the wound
327
Describe reparative phase of bone fracture healing
callus formation; bone deposition (endo/intra ossification)
328
Describe remodeling phase of bone fracture healing
many years to convert woven -> lamellar
329
Does thin or thick skin have hair follicles
thin skin
330
Sweat glands in thick skin
merocrine
331
Sweat glands in thin skin
apocrine
332
Layers of thick skin
stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, & stratum corneum
333
Layers of thin skin
thin stratum corneum; stratum lucidum/ granulosum difficult to define
334
Which type of skin is glabrous
thick (thin is nonglabrous)
335
Describe stratum basale
situated on top of basement membrane; stem cells give rise to keratoncytes; melanocytes & merkel cells
336
Describe stratum spinosum
cells attached by desmosomes; membranes coating granules; start of keratinization
337
Describe stratum granulosum
last layer where cells have nuclei; keratohyaline granules
338
Describe stratum lucidum
(not always present) no organelles or nuclei; keratin filaments
339
Describe stratum corneum
deep layer has desmosomes while superficial layer has desmosome breakdown & desquamated (sloughed off)
340
Where are melanocytes found
epidermis basal layer; external root sheath & matrix of hair
341
Function of melanocytes
source of melanin for keratinocytes
342
Where are dendritic (Langerhans cells) found
all layers of epidermis
343
Function of dendritic cells
antigen-presenting cells
344
Where are merkel cells found
epidermis basal layer
345
Function of merkel cells
slow adapting light touch receptors
346
Layers of the dermis
papillary layer & reticular layer
347
Describe papillary layer
dermal ridges; loose CT; anchoring fibrils from basal lamina of epithelium
348
Describe reticular layer
dense irregular CT (collagen & elastin); sweat glands; hair follicles/ arrector pili; mechanoreceptors; blood & lymph nodes
349
Thin skin of dermis has what characteristics
only have a reticular layer that can be divided into superficial & deep
350
Describe the hypodermis
loose CT; anchors dermis to underlying muscle/bone; has adipose tissue
351
1st degree burn
epidermis
352
2nd degree burn
dermis
353
3rd degree burn
hypodermis
354
4th degree burn
muscle
355
Describe what sebacous glands secrete
sebum for water-proofing & antibacterial
356
Describe what sweat glands secrete
viscous secretions that contain scent
357
Type of secretion for sebacous glands
holocrine secretion
358
Type of secretion for sweat glands
apocrine & merocrine secretion
359
Where does apocrine secretion of sweat glands occur
into hair follicles; in all haired skin
360
Where does merocrine secretion of sweat glands occur
onto cell surface; foot pads of cats/ dogs
361
Define hair
flexible keratinized structure
362
Function of a hair follicle
produces hair
363
Hair follicles are embedded in what
dermis
364
Layers of hair
medulla (inner), cortex (hair color), & cuticle (outer)
365
Components of external root sheath
epidermis & dermis
366
Internal root sheath produced by what & ends where
inner matrix; b4 sebacous gland
367
What is at the base of a growing hair follicle
hair matrix & dermal papilla
368
Hair matrix has what
cells that produce keratin
369
Dermal papella is for what
support & nutrition
370
Describe simple hair follicles
single hair from one external orifice
371
Describe compound hair follicles
one/few primary hair(s) & several/many secondary hairs all from one external orifice
372
Arrangement of hair follicles is dependent on what
species, breed, & age
373
How does age affect hair follicles
animals born w/ simple hair follicles that then turn into compound follicles as they age; humans always have single hair follicles
374
Other names for whiskers
sinus or tactile hairs
375
Special features of whiskers
blood-filled cavity b/w inner & outer dermal sheath; innervated by sensory nerve bundles
376
Anagen hair growth
active growth
377
Catagen hair growth
growth slows & stops; bulb keratinizes & starts moving to sebacous glands
378
Telogen hair growth
resting phase; club hair on bulb
379
Renewed anagen hair growth
new hair pushes out old one
380
Hair growth is under the control of what
hormones, day length, temperature, & nutrition
381
Describe the epidermis of the claw
keratinized; dorsal ridge on top; wall on side; sole on bottom
382
Describe dermis of the claw
not keratinized; blood supply -> called quick
383
Another name for the dermis of the claw
corium
384
Compare structure of horns to antlers
horn = hollow; antlers = solid
385
Are horns found in both males & females
yes -> antlers are not (usually)
386
Species that have horns
cattle, sheep, goats
387
Species that have antlers
cervids
388
Are horns permanent
yes -> antlers are shed seasonally
389
Boney core of a horn is what
corneal process from frontal bone
390
Dermis of horn
dermal core covering corneal process
391
Epidermis of horn
outer layer is keratinized
392
Antlers are a bony outgrowth from what
frontal bones (pedicle)
393
Dermis & epidermis in antlers
velvet
394
Other names for mammary glands
tubuloalvelar/ modified sweat gland
395
Components of mammary glands
alveoli, ducts, & interstitial tissue
396
Merocrine part of mammary gland
protein & carbs
397
Apocrine part of mammary gland
lipids
398
What is involution
process of converting from active to inactive (vice versa)
399
Over time, involution of mammary glands leads to what
CT/ adipocyte content increasing & milk production decreasing
400
Describe structure of mammary gland cells inactive vs active
low cuboidal when inactive to tall cuboidal/ columnar when active
401
Anal sacs are what
paired diverticular opening into the anal canal at the anocutanous junction
402
Describe dog anal sacs
apocrine glands in wall; sebacous glands near duct
403
Describe cat anal sacs
apocrrine & sebacous glands in wall
404
Primary lymphoid organs are the sites for what
lymphocyte development; B & T cell education
405
Secondary lymphoid organs are the sites for what
lymphocytes respond to antigens
406
Primary lymphoid organs include what
thymus, bursa, peyer's patches, & bone marrow
407
Secondary lymphoid organs include what
tonsils, spleen, lymph nodes, peyer's patches, & bone marrow
408
Primary lymphoid organ of T cells
thymus
409
Primary lymphoid organ of B cells
bursa, peyer's patches, & bone marrow
410
What occurs in the cortex of the thymus
T lymphocytes replicate; positive selection for MHC I & II recognition
411
Epithelial reticular cells help w/ what
+/- selection in cortex of thymus
412
What happens in corticomedullary junction of thymus
negative selection for self antigen recognition
413
Primary lymphoid organ of birds
bursa
414
Ruminants, pigs, horses, dogs, & cats have what for their primary lymphoid organ
large peyer's patches
415
Primates & rodents have what for their secondary lymphoid organ
small peyer's patches
416
As the thymus age (more involutions) what happens
size decrease & adipose tissue increases
417
Parts of thymus
cranial part, craniocervical isthmus, cervical part, cerviothoracic isthmus, & thoracic part
418
Function of lymph node
proceess lymph (interstitial fluid); filter lymph when it returns
419
Parts of a lymph node
stroma, cortex, paracortex, & medulla
420
Describe stroma
contains a capsule, trabeculae, reticular fibers, & sinuses
421
Capsule of stroma has what
dense irregular CT
422
Trapeculae of stroma is formed from what
CT from capsule diving into lymph nodes
423
Describe the cortex
lymphoid nodules w/ B cells & follicular dendritic cells
424
Describe the paracortex
T cells, APCs, & high endothelial venules
425
Describe the medulla
medullary cords & medullary sinuses
426
What is in the medullary cords of the medulla
plasma cells, T cells, & macrophaages
427
High endothelial venules allow for what
passage of naive lymphocytes into lymph nodes
428
Afferant lymphatic vessels allow for what
passage of primed lymphocytes into lymph nodes
429
Efferant lymphatic vessels allow for what
passage of primed & naive lymphocytes out of lymph nodes
430
Typical lymph nodes have what
two afferent lymph vessels & one efferant lymph vessel
431
Pig lymph nodes have what
one afferant lymph vessel & two efferant lymph vessels
432
High endothelial venules are found where
tonsils, lymph nodes, Peyer's patches, & bone marrow
433
High endothelial venules are NOT found where
spleen
434
What are high endothelial vessels
blood vessels adapted for lymphocyte trafficking
435
Describe primary lymphatic nodules
stromal network of connective tissue & immature follicular dendritic cells
436
What type of lymphocyte does primary lymphatic nodules have
naive recirculating B cells
437
What type of lymphatic nodule has germinal centers
secondary lymphatic nodules
438
What occurs in the dark zone of secondary lymphatic nodules
B cells replicate when they find their antigen
439
What occurs in the light zone of secondary lymphatic tissue
when mature, B cell immune response is tested; if B cells do not match their antigen, they are destroyed
440
Where are lymphatic nodules found
cortex of lymph node, spleen, tonsils, & Peyer's patches
441
Function of spleen
blood filtration, blood storage (species-specific), hematopoiesis, & mounting an immune response to bloodborne pathogens
442
Components of spleen
capsule w/ trabeculae, reticular fibers, red & white pulp
443
What is the capsule of the spleen made out of
fibroelastic tissue w/ smooth muscle
| dense irregular CT
444
Red pulp has what
splenic sinuses, vascular spaces, macrophages, & PAMS
445
Species that have splenic sinuses
dog, rat, & human
446
What are splenic sinuses
disconintous endothelium & basal lamina
447
PAMS are what
Periarticular Macrophage Sheath
448
White pulp has what
PALS, nodules, marginal zones
449
PALS are what
Periarticular Lymphoid Sheath
450
PALS have what cell
T lymphocytes
451
Nodules in white pulp has what
B lymphocytes
452
Marginal zones in spleen have what
plasma cells, APCs, macrophages, & circulating B & T lymphocytes (leave blood & contact APCs)
453
MALT is what
Mucosa-Associated Lymphatic Tissue
454
What does MALT consist of
lymphatic nodules & diffuse lymphatic tissue
455
Special feature of MALT
no afferant ducts
456
MALT is found where
tonsils, Bronchus-ALT (BALT), & Gut-ALT (GALT)
457
Describe hemal node
black structure w/ unkown function
458
Species that have hemal nodes
ruminants
459
Besides the lymphatic vessels being different, what else is weird about the pig lymph node
the inside layer is the cortex, the middle is paracortex, and the outside is the medulla
460
What is the organization of a typical (not pig) lymph node
the inside layer is the medulla, the middle is paracortex, and the ouside is the cortex
461
Sarcomeres in series
fast contractions, but less force
462
Sarcomeres in parallel
slow contractions, but more force
