M2 Study Guide Flashcards
1
Q
what are neurotransmitters synthesized by
A
neurons
2
Q
where are neurotransmitters stored
A
synaptic vesicles in presynaptic axon terminal (knobs)
3
Q
what are neurotransmitters released from
A
vesicles that are fused to the membrane of the synaptic knob secondary to the actions of Ca2+, synaptotagmin, and SNAREs
4
Q
what do neurotransmitters bind to
A
receptor on postsynaptic neuron (or effector)
5
Q
what do neurotransmitters trigger
A
physiological response downstream by initiating graded excitatory or inhibitory postsynaptic potential (EPSPs and IPSPS)
6
Q
agonist
A
mimic action of neurotransmitter
7
Q
antagonist
A
block action of neurotransmitter
8
Q
facilitator
A
enhance effect of neurotransmitter
9
Q
inhibitor
A
reduce effect of neurotransmitter
10
Q
what binds to an ionotropic receptor
A
ligand
11
Q
what does the ligand do after binding to an ionotropic receptor
A
opens the channel and allows an influx of that ion through the channel into the postsynaptic cell (and therefore, altering mem. potential)
12
Q
what binds to a metabotropic receptor
A
water-soluble ligand (1st messenger)
13
Q
what happens after a water-soluble ligand binds to a metabotropic receptor
A
triggers a G-protein-second messenger mechanism which activates the opening of ion channels of another integral protein within cell membrane, allowing for an influx of ions into the postsynaptic cell (therefore, altering mem. potential)
14
Q
cholinergic
A
neurons that utilize ACh
15
Q
where is ACh found
A
CNS and PNS
16
Q
what does ACh act on
A
nicotinic receptors located in spinal cord, autonomic ganglia, and neurotransmitter junction.
muscarinic receptors located in remainder of CNS
17
Q
what do nicotinic receptors utilize
A
utilize ion channels = ionotropic receptors
18
Q
what do muscarinic receptors utilize
A
G-proteins/second messengers = utilize metabotropic receptors
19
Q
where is ACh degraded and by what
A
degraded in synaptic cleft by acetylcholinesterase
20
Q
what does acetylcholinesterase degrade ACh into
A
acetate and choline
21
Q
how does ACh correlate to Alzheimer’s
A
cholinergic neurons degenerate = loss of ACh as neurotransmitter synthesize within these neurons (synaptic knob).
Loss of postsynaptic neurons that would have responded to ACh exacerbate disease
22
Q
clinical signs of Alzheimer’s
A
declining language
memory loss
23
Q
what are catecholamines derived from
A
amino acid tyrosine
24
Q
what do catecholamines include
A
dopamine
norepinephrine
epinephrine
25
what is parkinson's disease characterized by
loss of dopamine-releasing neurons within substantia nigra of the basal nuclei (basal ganglia) deep within brain
26
what are the basal ganglia responsible for
motor control
27
what are the effects of Parkinson's
loss of motor control including abnormal (involuntary) body movements, muscle tone, and posture.
increased severity of the movements is indicative of greater loss of neurons.
28
what is Parkinson's initially treated with
L-dopa to treat symptoms only (NOT the disease).
this intermediate is able to cross the blood-brain barrier vs. dopamine
29
what do norepinephrine and epinephrine bind to
alpha- and beta-adrenergic receptors
30
are alpha- and beta-adrenergic receptors ionotropic or metabotropic
metabotropic - utilize G-protein mechanism
31
pathway from starting amino acid (tyrosine) and downstream products
Tyrosine --tyrosine hydroxylase--> L-Dopa --dopa decarboxylase--> dopamine --dopamine beta-hydroxylase --> norepinephrine --phenylethaolamine N-methyltransferase --> epinephrine
32
what do MAO inhibitors degrade
enzymatic degradation of catecholamines
33
what do MAO inhibitors increase
the amount of catecholamines in the synapse
34
what are MAO inhibitors used to treat
mood disorders and various classes of depression by increasing motivation and pleasure
35
what is serotonin derived from
amino acid tryptophan
36
what is the 'sleepy' amino acid
tryptophan
37
what does serotonin regulate
sleep and emotions
38
what are selective-serotonin reuptake inhibitors (SSRIs) utilized for
treating mood disorders
39
what is histamine derived from
amino acid histidine
40
most common neurotransmitter in CNS
glutamate
41
what do AMPA ionotropic receptors conduct and how
fast EPSPs by rapid influx of Na+ into the postsynaptic cell
42
what do NMDA ionotropic receptors open and how
open in response to membrane depolarization secondary to the opening of the of AMPA receptors by bumping Mg2+ plug in this receptor.
opening of this receptor triggers a chain of events that will ultimately signal presynaptic cell to continue synthesizing and releasing glutamate to allow for longer-lasting response.
43
inhibitory amino acids
gamma-aminobutyric acid (GABA) and glycine
44
excitatory amino acid
glutamate
45
what is the most common inhibitory neurotransmitter
GABA - dampens brain's neural activity
46
what is nitric oxide (NO) a major player in
blood vessel dilation (vasodilation) via smooth muscle relaxation
47
how is NO synthase triggered and what does it activate
G-protein/second messenger cascade triggers enzyme (NO synthase) to activate NO, which activates another cascade in the adjacent smooth muscle causes relaxation (therefore, vasodilation)
48
how is NO different from other neurotransmitters
not stored in vesicles and synthesized only on an as-needed basis in the postsynaptic cell and it acts on the presynaptic cell (retrograde communication)
49
what can too much NO cause
proinflammatory, therefore, cytotoxic
50
what lipids are neurotransmitters
those derived from arachidonic acid (eicosanoids) and include prostaglandins, thromboxanes, and leukotrienes
51
what are endocannabinoids derived from
arachidonic acid
52
what are endocannabinoids released from and act on
released from the postsynaptic cell (like NO) and act antagonistically on the presynaptic cell in response to a neurotransmitter binding to the postsynaptic receptor.
overall result is modulation of the signal in the postsynaptic pathway that dampens 1. transmission of pain signals in the CNS and 2. inflammatory response in many tissues
53
neurotransmitters of interest
nitric oxide (NO)
lipids
carbon monoxide
hydrogen sulfide
ATP/adenosine
54
what do g-proteins serve as
a 'switch' to couple a receptor to an ion channel in the cell membrane
55
general steps of g proteins
1. ligand binds to transmembrane receptor ('first messenger') and changes its conformation (ex. shape).
2. change in receptor conformation allows for binding of the g protein subunit where GDP bound to the g protein is replaced with GTP, 'activating' g protein.
3. activated GTP-bound g protein binds to an enzyme that is embedded in the cell membrane, activating/inhibiting this enzyme.
- once enzyme/ion channel has been activated, GTP on the g-protein alpha subunit is cleaved into GDP and phosphate; g-protein is now inactivated.
4. specific second messenger is activated by the enzyme when bound by the g-protein:
- cyclic AMP (cAMP)
- cyclic GMP (cGMP)
- diacylglycerol (DAG)
- inositol triphosphate (IP3)
- Ca2+
- arachidonic acid
5. second messenger activates particular protein kinase which will stimulate (or inhibit) signal pathways within that cell
56
what does inactive g protein within the postsynaptic cell's cytoplasm bound to
guanosine diphosphate (GDP)
57
what happens after ligand (ex. first messenger) binds to the receptor
g protein binds to the receptor protein as well but on the intracellular side
58
what does GTP activate
g protein
58
what is GDP replaced with
guanosine triphosphate (GTP)
59
what does g protein bind to on the intracellular side
another transmembrane protein that is an enzyme, which catalyzes ATP into a second messenger
60
what does the second messenger activate
another enzyme, a kinase, which triggers modifications of the numerous activities taking place within the cell
61
will the binding of one ligand to a receptor significantly amplify the number of final products
yes.
these ligands are very potent in a response
62
what are extracellular matrix components secreted by
resident cells
63
what is the collagen precursor and what is comprised of
procollagen and it is comprised of 3 identical polypeptide strands in a helix.
ends are capped to prevent degradation and packaged within vesicles by golgi complex and is transferred out of the cell by exocytosis.
ends are cleaved from procollagen molecules and a series of mostly unknown steps convert to mature collagen
64
what is the function of collagen
provides tensile strength to tissue (structural role)
65
what are the major types of collagen
1
2
3
66
what is soluble tropoelastin secreted from
fibroblasts into extracellular matrix where it undergoes posttranslational modification to form insoluble elastin
67
what makes up microfibrils and what do they do
fibrillin serves as the scaffold for elastin deposition that forms an inner core
68
characteristics of ground substance
transparent, viscous, semi-fluid gel
69
what do the high viscosity and osmotic pressure of ground substance help
high viscosity helps resist compression.
high osmotic pressure helps maintain fluid balance between interstitial fluid and intracellular environment and vasculature - significant enough drop in tissue osmotic pressure can result in edema due to influx of fluid into the tissue
70
function of ground substance
influence fluid transport and metabolic exchange
71
what makes up proteoglycan
GAG + core protein (binds to GAG) + linker protein (binds core protein and GAG to hyaluronic acid backbone)
72
what make sup proteoglycan aggregate
proteoglycan + hyaluronic acid + some collagen
73
what makes up extracellular matrix (ECM)
collagen
tropoelastin
microfibrils
ground substance
74
what are the 3 types of cartilage
hyaline
elastic
fibrous (fibrocartilage)
75
what does the outer fibrous layer of cartilage contain
fibroblasts and comprised of fibrous connective tissue; contain vasculature
76
what does the inner chondrogenic layer contain
mostly chondrogenic progenitor cells and chondroblasts.
some chondrocytes
77
what are the cells of cartilage proper
chondroblasts
chondrocytes
78
function of chondroblasts
main producer of extracellular matrix
79
function of chondrocytes
secrete substances to prevent blood vessel formation, so cartilage is avascular
80
do chondroclasts exist in carilage
no
81
what is lacunae
space occupied by a cell
82
where is hyaline cartilage and perichondrium not found
articulating surface of joints because you want to keep growth to a minimum
83
does hyaline cartilage have elastic fibers
no
84
what type of collagen is predominant in hyaline cartilage
type 2 collagen.
type 1 in outer fibrous layer of perichondrium - fibroblasts are in the perichondral sublayer and they secrete type 1 collagen
85
location of hyaline cartilage
tracheal bands.
bronchi.
nasal septum.
articulating bone surfaces in long bone.
growth (epiphyseal) plates of long bones.
site of initial bone repair following a fracture.
embryonic template for long bone formation.
86
what is the 2nd type of cartilage
elastic
87
what is the difference between elastic and hyaline cartilage
elastic cartilage has elastic fibers, which provides some additional flexibility compared to hyaline cartilage
88
what type of collagen is predominant in elastic cartilage
type 2 collagen predominant.
type 1 in outer fibrous layer of perichondrium
89
location of elastic cartilage
external ear (lobe).
epiglottis.
pharyngotympanic/auditory tube (Eustachian tube).
90
what is the 3rd type of cartilage
fibrous cartilage (fibrocartilage).
91
does fibrous cartilage have perichondrium
no
92
what is fibrous cartilage great at withstanding
compression
93
location of fibrous cartilage
intervertebral discs (specifically, outer annulus fibrosis).
symphyses (ex. joints between bones of breastbone as well as joint between right and left pubic bones in hip).
foramen lacerum 'filler.'
menisci of joints.
temporomandibular joint (TMJ).
94
true or false: cartilage growth is limited
true
95
where does appositional growth occur
width.
at the external edge of the cartilage where there are more chondroblasts and more area for these cells to secrete extracellular matrix
96
where does interstitial growth occur
lengthwise.
occurs at center of cartilage
97
what is the fibrous and osteogenic periosteum
outer and inner layers on most external portion of bone
98
what does the fibrous layer of bone contain
fibroblasts
99
what does the inner osteogenic layer of bone contain
mostly osteogenic progenitor cells and differentiated osteoblasts but can also contain osteocytes
100
what are sharpey (penetrating) fibers
'extensions' of the fibrous periosteum into compact bone
101
what do sharpey fibers allow for
better 'adherence' of the periosteum to the underlying bone given that the periosteum serves as attachment sites for tendons and ligaments
102
what cells are in bone
osteoblasts
osteocytes
osteoclasts
103
what are osteoblasts
main builder of bone by secreting osteoid into extracellular matrix
104
what are osteocytes
secondary builder of bone.
bone maintenance/remodeling
105
what are osteoclasts
maintenance/remodeling --> dissolve bone
106
what do osteoclasts secrete to break down organic component of the osteoid
enzymes
107
what are the organic components of the osteoid
collagen
GAGs
glycoproteins
108
what do osteoclasts secrete to break down inorganic salts
hydrochloric acid (HCl)
109
what are the inorganic salts of bone
hydroxyapatite
110
what is liberated when organic components of the osteoid and inorganic salts are broken down
calcium and phosphorus
111
what is calcium vital for
muscle contraction
neurotransmitter release
blood clotting pathway
112
what is phosphorus utilized in
forming ATP and the phospholipids that contribute to the cell membrane
113
what ions are incorporated into the hydroxyapatite crystals
sodium
chloride
magnesium
114
what are the organic components of the extracellular matrix of bone
collagen
GAGs
glycoproteins
115
what do organic components contribute to
bone's tensile
116
what do low quantities of inorganic components in bone make it
excessively flexible (taffy like)
117
what are the inorganic components of extracellular matrix of bone
mainly of calcium phosphate (Ca3(PO4)2 and calcium hydroxide (Ca(OH)2 that incorporate to form hydroxyapatite Ca10(PO4)6(OH)2
118
what do inorganic components contribute to
increase bone's rigidity while also allowing for a small amount of flexibility
119
what do low quantities of organic components in bone do
make it brittle
120
what are the different structures of Haversian system/osteon
concentric lamellae
haversian (central) canal
volkmann (perforating) canal
canaliculi and lacunae
121
what do lacunae contain
space-occupying osteocytes
122
what is found within canaliculi
the cell membrane extensions of osteocytes.
extend towards a canal containing vasculature
123
what are outer and inner circumferential lamellae comprised of
compact bone surrounding the bone's external (adjacent to the periosteum) and internal (adjacent to the endosteum and inner core, the medullary cavity) periphery
124
what are interstitial lamellae comprised of
compact bone between osteons
125
what are trabeculae
spicules of bone within medullary cavity
126
what are howship lacunae
cavities occupied by an osteoclast
127
what does the innermost medullary cavity contain
vasculature
lymphatics
nerves
marrow (red or yellow)
128
what is intramembranous ossification
formation of flat bones (ex. skull, facial bones)
129
what is endochondral ossification
formation of long bones (ex. arm and leg bones).
derived from a miniature hyaline cartilage template
130
why is the bone collar formation special
bone collar formed initially is intramembranous ossification.
bone that is developed is forming around the hyaline cartilage template
131
where is the epiphysis
located at the ends of long bone
132
what is the epiphysis the location of
secondary ossification center that forms after the primary ossification site where cartilage is calcified and then chondrogenic cells are replaced by osteogenic cells that begin producing osteoid (organic component of ECM)
133
what type of bone marrow does the epiphysis contain and what is it a common site for
contains red bone marrow within the spongy region and serves as the most common site for hematopoiesis
134
what is the metaphysis
small, transitional region between epiphyses and diaphysis
135
what is the metaphysis the location of
the growth plate (at the metaphyseal/epiphyseal border).
plate decreases in size with age prior to closing at adolescence due to its ossification to become the epiphyseal line
136
what are the zones of the growth plate
zone of reserve (resting) cartilage.
zone of proliferation cartilage.
zone of maturation/hypertrophy.
zone of degeneration (calcified) cartilage.
zone of ossification.
137
zone of reserve (resting) cartilage
typical hyaline cartilage with chondrocytes in small clusters
138
zone of proliferation cartilage
mitotic activity of chondrocytes increase, extracellular matrix rich in proteoglycans
139
zone of maturation/hypertrophy
mitosis has ceased and chondrocytes increase in size.
extracellular matrix begins to calcify, trapping chondrocytes in the lacunae
140
zone of degeneration (calcified) cartilage
chondrocytes degenerate and die secondary to the calcifying extracellular matrix from increase mineralization
141
zone of ossification
spaces in the walls of the lacunae once occupied by chondrocytes now allow for the invasion of osteogenic cells into the lacunae in addition to vasculature that also invades this zone
142
what is the diaphysis
bone shaft
143
what is the diaphysis the location of
primary ossification center with the process of ossification being the same as previously mentioned for the secondary ossification center
144
what do the growth plates contribute to
the bone's interstitial growth (or its length)
145
what happens during appositional bone growth
bone is added to the external surface while bone is removed simultaneously internally, which widens medullary cavity as well as the bone's overall diameter (its width)
146
is the first bone of development (or after fracture) unorganized or organized?
unorganized
147
when is primary bone tissue present
during development of bone or when a fracture is being repaired
148
what does fracture cause
destruction of bone matrix and death of bone cells
149
what do damaged blood vessels form
a clot
150
what are removed from macrophages
the clot, cells and damaged matrix
151
what do the periosteum and endosteum respond with
intense proliferation, surrounding the fracture and penetrating the fracture
152
what is the process of bone formation
primary bone is formed as hyaline cartilage is formed, then replaced with bone, as well as connective tissue is formed and replaced.
these form irregular trabeculae or bone calluses
153
what is the callus replaced by
secondary bone tissue from remodeling
154
what type of gland is the thyroid gland
butterfly-shaped, bi-lobed endocrine gland located in the next ventral to the lower cervical vertebral column
155
what are thyroid parafollicular cells responsible for
synthesis and secretion of the peptide hormone calcitonin in response to elevated blood plasma Ca2+ concentration
156
what does calcitonin do to blood Ca2+ levels
lowers blood Ca2+ levels by inhibition of bone resorption .
ex. inhibition of osteoclast activity
157
normal function of calcitonin in normal day to day
no real function of calcitonin in normal day-to-day Ca2+ regulation
158
hypercalcemia
when plasma Ca2+ concentrations are extremely high due to over-secretion of parathyroid hormone by a parathyroid gland tumor (parathyroid adenoma)
159
what is calcitonin vital in
bone formation
160
size and location of parathyroid glands
small, paired (superior and inferior) ovoid-shaped endocrine structures on dorsal surface of thyroid
161
where are chief (principal) cells most numerous and what do they do
most numerous within the parathyroid.
secrete parathyroid hormone (PTH) in response to decreased blood Ca2+ levels (antagonist to calcitonin)
162
what does PTH act directly/indirectly on
bone
kidneys
gastrointestinal tact
163
how does PTH increase plasma Ca2+ levels
1. increasing Ca2+ resorption from bone via osteoclast activity.
2. increasing reabsorption of Ca2+ from kidneys (less Ca2+ excreted in urine).
3. activation of an enzyme (1-hydroxylase) in the kidneys that converts Vitamin D (obtained from diet or sunlight and first metabolized in the liver) to calcitriol [1,25-(OH)2D]. calcitriol increases Ca2+ and phosphate absorption from the small intestine into the blood
164
does PTH increase or decrease bone growth
while PTH has an opposing effect on plasma Ca2+ levels compared to calcitonin, both promote bone growth along with calcitriol
165
composition of special CT: blood
plasma
buffy coat
formed elements
166
what are the components of plasma and the approximate fractions for each
Plasma makes up 55% of blood volume.
Water: 91%.
Proteins: 7%.
Salts, sugars, and lipids: 2%.
167
what is the buffy coat
very thin, grayish layer of white blood cells mostly sandwiched between plasma and formed elements in a centrifuged blood sample
168
what makes up the formed elements
red (erythrocytes) and white (leukocytes) blood cells along with platelets (thrombocytes)
169
what is much of the formed element fraction
red blood cells (hematocrit) given the sheer number of these cells compared to platelets and leukocytes
170
volume of blood in males
5-6 L
171
volume of blood in females
4-5 L
172
shape of erythrocytes
biconcave and anuclear
173
what is hemoglobin comprised of
4 polypeptide (globin) chains with iron-containing heme groups associated with each globin chain
174
what does O2 bind to in hemoglobin
binds weakly to iron of iron-containing heme group
175
what does CO2 bind to in hemoglobin
binds to globin
176
does CO have a higher or lower affinity to the iron-containing heme group than O2
several hundred times greater
177
what do macrophages do with damaged or old erythrocytes and where
macrophages in the spleen and slightly in the liver digest damaged or old erythrocytes and recycle many components, including much of the hemoglobin molecule.
*excludes heme group without the iron ion which is excreted from the body via the urine and feces as a form of bilirubin + bile
178
what is erythropoietin (EPO)
hormone secreted by kidneys that drives red blood cell proliferation and differentiation in red bone marrow
179
what are the types of leukocytes
granulocytes and agranulocytes
180
structure of granulocytes
multi-lobed
181
what do granulocytes contain and how are they named
stain different colors.
named based on the histological dye that stains the granules (eosin or hematoxylin)
182
what are granulocytes comprised of
neutrophils
eosinophils
basophils
183
structure of agranulocytes
single-lobed
184
what are agranulocytes comprised of
monocytes/macrophages
lymphocytes
185
blood cell precursor
hematopoietic stem cell
186
myeloid stem cell
precursor to progenitors that form all blood cell types except agranular lymphocytes (T and B cells) and natural killer (NK) cell
187
blood cell types formed by myeloid stem cells
erythrocytes
thrombocytes (platelets)
granulocytic leukocytes (basophils, eosinophils, neutrophils)
agranular monocyte (macrophage precursor)
188
what formed T and B lymphocytes and NK cells
lymphoid stem cells
189
3 phases of hemostasis
1. smooth muscle spasm
2. platelet plug formation
3. clotting
190
is the hemostasis clotting mechanisms complex or simple and what does it involve
very complex process
involves cascade of factors
191
steps of hemostasis clotting mechanism
1. thrombin drives conversion of fibrinogen to fibrin
2. fibrin is product in clot formation
3. plasmin dissolves the clot
192
A blood
can accept blood from A and O blood types from a donor
193
B blood
can accept blood from B and O blood types from a donor
194
AB blood
can accept blood from A, B, AB and O blood types from a donor
195
O blood
can only accept O blood
196
what blood is most common in the population
O+ blood (1/3rd of population)
197
what type of blood does emergency transfusion typically involve
O blood (centrifuged and washed to remove antibodies) from a donor even though using same blood type is optimal
198
Rh factor
either positive or negatie
199
is Rh+ or Rh- most common
Rh+
200
rarest blood type
AB- (<0.5%)
201
types of blood cancers
leukemia
lymphoma
myeloma
202
characteristics of leukemia
originates in bone marrow.
acute and chronic forms.
can be of myeloid or lymphoid origin (WBC).
circulates in blood
203
characteristics of lymphoma
originates in lymph node (T or B cells).
lymphoid origin.
Hodgkin's vs. non-Hodgkin's lymphoma: (+) Reed-Sternberg cells present with Hodgkin's
204
characteristics of myeloma
originates in bone marrow.
plasma cell origin.
typically slow-growing
205
how are cells laid together in epithelia
laid together tightly in sheets - avascular and innervated
206
what does epithelia line
internal and external surfaces:
- epidermis
- mucous membranes - conjunctiva and oral cavity
- endocrine and exocrine glands
207
what directionality does epithelia possess
apical/basal/lateral (polarity)
208
what does epithelial tissue form
boundaries between different environments - nearly all substances must pass through
209
functions of epithelial tissue
Protection for underlying tissues from radiation, desiccation, toxins, and physical trauma.
Absorption of substances in digestive tract lining with distinct modifications.
Regulation and excretion of chemicals between underlying tissues and body cavity.
Secretion of hormones into blood vascular system.
Detection of sensation
210
where do the secretion of sweat, mucus, enzymes, and other products that are delivered by ducts come from
glandular epithelium
211
how are epithelial cells classified
shape:
- squamous (flattened)
- cuboidal (width and length same)
- columnar (elongated vertically)
212
what can the apical surface of epithelial cells have
cilia or microvilli
213
what is epithelial tissue classified as
- simple: single layer of cells
- stratified: >1 layer of cells
- pseudostratified: one layer of cells that gives appearance of more than one layer being present in vertical section. simple tissue bc all cells are in contact with basal lamina
214
how many layers of cells does simple epithelium consist of
single layer
215
in what type of epithelium does absorption, secretion, and filtration occur
simple epithelium - the thinness of the epithelial barrier facilitates these processes
216
what contains simple epithelium
lungs
kidneys
mesothelium
endothelium
217
simple squamous
very thin tissue.
rapid diffusion.
ex:
- alveolus within lung
- bowman's capsule in kidney
- endothelium within a venule (very small vein)
218
simple cuboidal
single layer.
central nucleus.
absorption and secretion.
kidney.
ovary.
ex:
- tubules in kidneys
- follicular cells in thyroid
219
what do simple columnar cells possess
organelle density and energy reserves to engage in the most complex and efficient secretory or absorptive functions
220
where are simple columnar epithelia with microvilli found
lining the small intestine
221
where does 90% absorption from the digestive tract occur
small intestine
222
where are ciliated types of simple columnar found
in small bronchioles of the respiratory tract and in fallopian tubes of female reproductive tract.
cilia aid in the movement of mucous or reproductive cells
223
what is the unicellular gland or goblet cell
specialized columnar cell of mucous membranes that secretes mucous for protection
224
locations of simple columnar
stomach.
small intestine.
large intestine.
bronchioles of the lungs.
exocrine ducts and large ducts of kidney
225
where is pseudostratified epithelia most prevalent
in upper or lower respiratory tract as ciliated types
226
what do all pseudostratified cells reach / not reach
all cells reach basement membrane but not apical surface
227
where are non-ciliated pseudostratified epithelium found
in ducts of larger glands or male urethra.
these may be transition zones between epithelial types
228
what do cilia of respiratory pseudostratified epithelia do to propel mucous along the surfaces of cells
beat in a rhythmic manner --> ciliary escalator
229
ciliary escaltor
resultant movement of mucous from the lower respiratory tract via ciliary movements
230
how many layers/surfaces do stratified epithelium have and what are they
multiple layers of epithelial cells.
apical and basal layers, along with apical and basal surfaces for each epithelial cells within the tissue
231
what are the 2 types of stratified epithelium and where are each found
Stratified squamous keratinized (SSK): epidermis - outer layer of skin.
Stratified squamous non-keratinized (SSNK): mucous membrane tissues - oral cavity, palpebral conjunctiva, corneal epithelium, esophagus, rectum.
232
difference between SSK and SSNK
apical layers of tissue in SSNK are nucleated unlike SSK.
keratin granules will be seen in mid-layers of tissue in SSK, but not in SSNK.
233
qualities of stratified cuboidal
glandular epithelium.
two-layered tissue
234
qualities of stratified columnar
rare in human body - only found in isolated locations (ex. bulbar conjunctiva)
235
where is transitional found
urinary epithelium - bladder, ureter, portion of urethra
236
qualities of transitional
ability to stretch: squamous appearance when distended, cuboidal when not.
dome-shaped apical surface of apical layer of cells when not distended.
looks like stratified cuboidal tissue when non-distended, but has more than 2 layers
237
qualities of H & E stains
Hematoxylin: basic stain that stains acidic structures a purple color.
Eosin: acidic stain that stains basic structures reddish-pink color.
238
what is the external layer of the basement membrane
basal lamina - consists of outer lamina lucida and inner lamina densa
239
what does the basement membrane serve as
anchor for hemidesmosomes found in basal cell membrane of basal epithelial cell layer, as well as an anchor to deep, connective tissue
240
tight junctions (zonula occludens)
later surface nearest apical surface.
anchoring junction
241
belt junctions (zonula adherens)
overlapping transmembrane proteins.
anchoring junction
242
gap junctions
utilizes connexons that allow for direct cell-cell communication
243
desmosomes
overlapping transmembrane proteins anchored into plaques in cell membrane.
anchoring junction
244
hemidesmosomes
on basal surface of epithelial call and anchors epithelium to underlying basal lamina
245
types of exocrine glands
merocrine/eccrine
apocrine
holocrine
246
merocrine/eccrine
most common.
least destructive as secretions
247
apocrine
part of cell membrane forms vesicle to contain secretant and is lost.
sweat gland sin axillary, groin, breast
248
holocrine
most destructive to cell as cell membrane ruptures.
meibomian glands of eyelids and sebaceous associated with hair follicles in skin --> lipid-based secretion.
