Mod 2: Histology Flashcards
1
Q
Innate immunity: passive vs active
Adaptive immunity: passive vs active
A
INNATE
Passive: mom ANTIBODIES move across placenta (IgG to fetus)/in breast milk (IgA to infant)
Active: ANTIBODIES for neutralization, opsonization, precipitation of toxin or pathogen (antidotes)
ADAPTIVE
Passive: immunization WITH BACTERIAL/VIRAL EPITOPES
Active: real-life exposure TO PATHOGEN
2
Q
Differences b/w innate and adaptive immunity
A
Innate: both active and passive – Ab introduced to person
Adaptive: both active and passive – exposure to actual pathogen
Innate: no memory cells produced
Adaptive: memory cells produced
3
Q
Initial vs repeat exposure timeline
A
More efficient and specific antibody molec during repeat exposure
Initial:
1. Innate immune sys EARLY inflammation (0-4 hrs)
2. Innate immune sys LATE inflammation (4-5 days)
3. Adaptive immune sys (14 days)
4. Pathogen removal/tissue repair
Repeat
- Innate immune sys EARLY inflammation (0-4 hrs)
- Innate immune sys LATE inflammation (2-3 days) SHORTER
- Adaptive immune sys (5-7 days)
- Pathogen removal/tissue repair
4
Q
MHC I vs MHC II
A
MHC I: on all nucleated cells of body
MHC II: on phago WBC that have been activated (engulfed a pathogen)
5
Q
Where are MHC I molec synthesized?
A
RER TGN (trans golgi network) membrane embedded in plasma membrane **MHC I always produced by our cells**
6
Q
PRR
What cells are they located on?
A
Toll receptors -- recognize PAMPs located on: neutrophils periph tissue macrophages periph tissue NK
7
Q
PAMPs
A
surface molec with repeated/identical protein (glycoprotein) subunits on pathogens
8
Q
Proinflammatory cytokines
A
histamine (basophils, mast cells) – vasodilation, inc cell permeability
prostaglandin (damaged cells) – smooth muscle in blood vessel wall contracts, vasodilation, inc cell permeability
9
Q
Bonds that hold light chains to heavy chains
heavy chains to heavy chains
A
disulfide
10
Q
Structure of heavy and light chains of Ab
A
Heavy and light chains both have variable and constant region
2 heavy and 2 light chains per antibody
variable region is where antigen epitope binds
11
Q
Functions of antibodies – initial binding
A
Neutralization: Ab covers biologically active part of microbe/toxin
Agglutination: Ab cross-links cells – forms clump
Precipitation: Ab cross-links circulating particles to form an insoluble complex
enhance recognition and diminish disease-causing properties
12
Q
Antibody functions – after binding
A
Complement fixation: Fc region of antibody binds complement proteins, complement is activated
Opsonization: Fc region of antibody binds to receptors of phago cells, triggering phagocytosis
Activation of NK cells: Fc region of antibody binds to NK cell, triggering release of cytotoxic chemicals
facilitate removal of pathogen
13
Q
Functions of immune-lymphatic sys
A
Transport medium (moves WBC and immunesignalling molec b/w blood, periph tissues, immune sys organs)
Circulation of digested/absorbed lipids (from GI tract to heart)
Recognition, degradation, and removal of antigens
14
Q
MBL vs classic pathway
A
MBL: day 1, does not require Ab
classic: day 5-7, REQUIRES Ab
15
Q
Where are complement proteins produced?
A
liver (they are soluble plasma proteins)
16
Q
What are the pro-inflammatory cytokines?
A
C3a
C5a
17
Q
What opsonizes the pathogen?
A
C3b
18
Q
When do monocytes become macrophages?
A
when exit bloodstream and enter periph tissue
19
Q
Unique resident pop of macrophages
A
Langerhan’s: skin/epidermis
Kupfer: liver
Microglia: brain/SC
20
Q
Cells involved in innate vs adaptive response
A
Innate:
- -neutrophils
- -monocytes/ macrophages/ dendritic cells
Adaptive:
- -B cells
- -T cells
21
Q
PAMP – PRR interactions result in…
A
inflammatory cytokines released
increased numbers of phago cells
number of pathogens dec
22
Q
CD4+
CD8+
A
CD4+ on helper T cell
CD8+ on cytotoxic (killer) T cell
23
Q
NK cells as a “tweaker”
A
intermediate in specificity
bridge b/w innate and adaptive immune responses
24
Q
Describe flow of lymph fluid
A
unidirectional away from periph tissue toward lymph node toward heart returned to blood at brachiocephalic vv
25
Describe structure of lymphatic vessels
thin walls of smooth muscle (1-2 layers)
| valves
26
Most lymph fluid drains to...
```
thoracic duct
(drains into left subclavian v/ brachiocephalic v)
```
27
Right arm and head lymph fluid drains to...
right lymphatic duct
| drains to right subclavian v/ brachiocephalic v
28
Higher number of lymph nodes in...
```
Cervical
Axillary
Breasts
Abdominal
Inguinal regions
(at major intersections in body where there are aa and vv/ areas where there is direct access to outside world)
```
29
Size of lymph nodes
1-25 mm in diameter
30
Hilum of lymph node
entry/exit point of lymph node
entry for arterial blood
exit for venous blood
exit for filtered lymph fluid (EFFERENT lymphatic vessels)
31
Afferent vs efferent lymphatic vessels
Afferent: to
Efferent: away (efferent becomes afferent as passes to next node)
32
Structure of lymph node
covered by thin, fibrous capsule
subcapsular space (filled with lymph fluid)
collagen fibers from capsule invaginate to form trabeculi in stroma of node
lymph fluid moves through trabecular sinuses toward central region (which is filled with lymph fluid)
medullary sinus
33
Residents of subcapsular sinus
follicular dendritic cells (these are the best macrophages/APCs)
- -pathogen debris or APC presents to follicular dendrites
- -pathogen material attaches to follicular dendritic cells --> activate WBC for specific response
34
Functions of respiratory sys
```
Main site of gas exchange
--conduct, warm, moisten air
--exchange air from environment with CO2 produced by cells of the body
Acid-base balance of body
Phonation (larynx)
Pulmonary defense (thick lamina propria with immune cells)
Metabolism
Olfactioin
```
35
Components of conducting portion of resp sys
- -nasal cavity
- -nasopharynx
- -larynx
- -trachea
- -primary bronchi
- -terminal bronchioles
36
Features of conducting portion of resp sys
Passages that deliver air to lung
No alveoli
Warm, moisten, and filter air b/f reaches resp portion
37
Components of resp portion of resp sys
Resp bronchioles
Alveolar ducts
Alveolar sacs
Alveoli (primary site of gas exchange)
38
Upper resp sys structures
Sphenoidal sinus
Frontal sinus
Nasal cavity
Pharynx
39
Lower resp tract contents
Larynx
Trachea
Bronchi
Lungs
40
Amount of mucous removed by beating cilia per minute
10 mm per minute
41
Purpose of lysozymes, IgA in secretions from Bowman's glands
prevent pathogens from gaining intracranial entry
42
Functions of the larynx
Close trachea during swallowing (epiglottis is in the larynx)
Produce sound -- true vocal cords
43
Ventricle
| Ventricular folds
Ventricle: elongated space that separates TRUE vocal cords and FALSE vocal cords (ventricular folds)
Ventricular folds: FALSE vocal cords
44
Vestibule of larynx
area above the vocal cords
45
Functions of trachea
conduit for air
| remains open
46
Cell types at bronchioalveolar duct junction
clara cells
| cuboidal cells
47
ACE
Angiotensin converting enzymes (ACE, CD143)
transmembrane ectopeptidase
angiotensin I --> II
Inactivates kinins
Important for regulation of vascular tone and BP
48
What kind of immunity is occurs in lymph nodes?
Adaptive immunity
| --specific cells become activated and mobilized against single pathogen
49
Residents of subcapsular sinus
follicular dendritic cells
(pathogen debris or APC present to follicular dendritic cells)
(pathogen material attaches to follicular dendritic cells --> activate WBC for specific immune sys)
50
Bacterial infection pathway in lymph node
Activate APC
Activates Th2
Th activates B cell --> plasma cell produces Ab
51
Viral infection pathway in lymph node
Th1 activates cytotoxic (killer) T cells
Killer T cell leaves lymph node --> goes through venous blood to site of infection
Release perforin at cells with MHC I displaying viral epitope
52
What is the difference b/w action of plasma cells of bacterial infection and cytotoxic T cells of viral infection?
Plasma cells do not leave the node, only Ab produced by plasma cell leave the node
Cytotoxic T cells leave the node
53
HEV
high endothelila venules -- where gas and nutrient exchange occurs in lymph node
54
Some of the fluid in the lymph node is absorbed directly back into the blood stream -- why is this important?
Less fluid moving through the lymph node allows for SLOWER flow through node -- so WBC can better examine pathogen debris
55
Afferent and efferent lymph vessel valves
both afferent and efferent lymph vessels have valves -- except in the head and neck
56
```
Cells in:
subcapsular sinus
paracortex
lymphatic nodules
medullary cords
```
subcapsular sinus: dendritic cells
paracortex: Th cells
lymphatic nodules: B cells
medullary cords: macrophages, Th and killer T cells, plasma cells
57
Cells in parts of the lymphatic nodule
Primary follicle
Germinal center of secondary follicle
Plasma cells move to...?
Primary: resting B cells
Germinal center of secondary follicle: activated/dividing B cells
Plasma cells move to medullary cords
58
CD4+ vs CD8+ cells
CD4+: Th1 and Th2
| CD8+: cytotoxic killer T cells
59
Primary lymphoid organ
Primary: give rise to or help mature lymphocytes (red bone marrow and thymus)
60
Structures formed from lateral plate/splanchnic mesoderm in 3 week old embryo
Pericardial sac (fibrous CT)
Cardiac muscle (contractile, conducting, neuroendocrine)
Fibrous skeleton (fibrous CT)
--AV valves, semi lunar valves, tendinous cords
Blood vessels of heart
Blood cells to circulate
61
In what week are there rudimentary organs of every sys?
week 8
62
RBC begin development where? What time? Features?
| Then start production in embryo...where? time? features?
Day 21: RBC with NUCLEUS produced in extraembryonic meso covering yolk sac
Week 5: RBC WITHOUT nucleus produced in embryo in splanchnic meso near organs
63
Vasculogenesis vs angiogenesis
Vasculo: formation of NEW blood vessels
Angio: formation of new blood vessels FROM EXISTING blood vessels
BOTH REQUIRE VEGF
64
Receptors for vasculogenesis
Flk-1: vasculogenesis --> hemangioblasts (clusters of MSCs)
| Flt-1: vasculogenesis --> capillary tube formation
65
Locations of blood cell development during embryonic/fetal life
yolk sac
liver/spleen
bone marrow
66
Due to the embryology of the development of the heart and diaphragm...
heart attached to skeletal muscle of diaphragm via fibrous connection
67
Mesothelium
single layer of simple squamous epithelium with underlying aerolar CT found in one of the closed ventral body cavities (thoracic, abdominopelvic)
68
Purkinje fibers are what kind of cell
modified cardiac m cells
69
Intecellular junctions in cardiac muscle
```
fascia adherens = zonula adherens (belt desmosome)
macula adheres (spot desmosome)
Gap junctions at longitudinal portion of intercalcated discs
(gap junctions on steps, adherens on risers)
```
70
Myofilaments arranged in what shape?
hexagonal arrangement
71
Fascia adherens of cardiac muscle are the same as...
zonula adherens
72
every cell in the body is ... cell widths from blood supply
2 cell widths
73
Capillaries follow the ... axis of cardiac myocytes
long axis
74
All conducting cells in heart linked by what kind of junctions?
gap junctions
75
SA node location
```
right atrium (superiorly on back wall of right atrium)
Where R nodal a comes in and disperses oxy blood to right atrial wall (from R coronary a)
```
76
Parasym ganglion in SA node comes from what nerve?
Vagus CN X (postganglionic neurons here)
| Ach released -- slow HR
77
Contractile vs conducting cells in cardiac muscle
Contractile: parallel rows of mito, organized sarcomeres
Conducting: lack organized sarcomere arrangement -- conduction of ions to surrounding contractile myocytes
78
Bundle of His located...
embedded in interventricular septum AKA atrioventricular bundle
79
Do purkinje fibers extend into what kind of muscles in the ventricles?
Papillary muscles
| cusps of AV valves -- cause papillary muscles to contract
80
Type of stimulation that inc cardiac output
Dec cardiac output
Also NT involved?
Inc: sym -- more rapid and forceful contraction
--epinephrine/norepinephrine (postgang)
Dec: parasym -- back to normal HR
--Ach (pre and postgang)
81
Normal HR
60-100 bpm
82
Bradychardia
| A-fibrillation
Bradychardia: abnormally slow HR
| A-fib: no atrial contraction (no P wave)
83
How does heart demonstrate auto-rhythmicity
SA nodal cells -- resting membrane potential more pos than other excitable cells in body
Leaky Na+ channels allow slow creep towards threshold potential
Nodal cells have a long refractory period (compared to contractile m cells in atria and ventricles)
84
3 internodal pathways from SA --> AV nodes
Ant
Middle
Post
*internodal cells histologically similar to purkinje fibers (smaller in diameter --> conduction velocity is slower)
85
Resting HR w/ and w/o sym stimulation
w/ sym stimulation: 80 bpm
w/o sym stimulation: 60 bpm (freq rate of SA node)
freq rate of AV nodal cells: 40-60 bpm
freq rate of bundle/purkinje fibers: 15-40 bpm
86
Sympathetic neurons that transmit en passant neuronal impulse
What NT involved?
Where is this used?
multiple bulbous enlargements along length of axons where NT stored/ released
more rapid stimulation/ more coordinated contraction
sym post-gang neuron --> norepinephrine
Important in heart and GI tract
87
Fibrous skeleton of heart is what kind of tissue?
dense irregular CT with SSqE
88
Histology of heart valves
fibrous CT
collagen (mostly)
some elastic fibers
generated from endocardial cushions
89
Describe layers of tissue of heart valve
```
Endothelial lining (simple squamous)
Spongiosa (loose CT/aereolar)
Fibrosa (dense irreg CT)
Ventricularis (dense irreg CT)
Endothelial lining (simple squamous)
```
90
Layers of chordae tendinae
endothelium on outer surface
| dense regular CT at core (no blood supply)
91
Simple pathway
Arteriovenosus shunt
Portal sys (arterial vs venous)
Simple: artery --> capillary bed --> vein
Arteriovenosus: artery --> vein (bypasses capillary bed)
--used in distal extremities when exposed to large drop in ambient temp
--vasoconstriction -- dump blood back to heart
Portal sys: 2 capillary beds in between artery and vein
--ARTERIAL portal sys: 1st capillary bed has no gas or nutrient exchange, just collect molec from surrounding cells --> artery --> 2nd capillary bed where molec can diffuse out and gases and nutrients are exchanged here
--VENOUS portal sys: gases and nutrients exchanged in 1st capillary bed --> vein --> more waste products and CO2 picked up in 2nd capillary bed, nutrients that were picked up in 1st can now diffuse out
92
Arteries vs veins
aa: thicker walls, narrower lumen, deep to vv
vv: thinner walls, wider lumen, more superficial than aa -- protection
- -blood in vv at lower pressure/lower resistance
93
Edema vs hypertension -- ICF, blood plasma, ECF balance
Edema: lower blood plasma, higher extracellular fluid
Hypertension: higher blood plasma, lower extracellular fluid
94
Layers of arteries and veins
Tunica intima/endothelium: simple squamous/basement membrane with thin aerolar layer just below surface lining
Tunica media: smooth muscle
Tunica externa/adventitia: fibrous connective tissue (vascularized in larger blood vessels)
95
Compare histology of aa and vv
**all aa and vv have same 3 layers
**vasa vasorum in both aa and vv
Tunica media thicker in aa
Adventitia thinner in aa
Tunica media thinner in vv
Adventitia thicker in vv
vv have valves
96
blood vessels from heart and aorta, proximal to aorta (large aa) are ... aa due to ...
blood vessels distal to aorta (medium aa) are ... aa
proximal to aorta (large): elastic aa due to high pressure of AV pump
--intima has internal elastic layer + endothelium
distal to aorta (medium): muscular aa
--intima only endothelium
97
Where are elastic fibers in elastic aa?
Tunica media
| Embedded b/w smooth muscle
98
Muscular aa -- describe tunica media
| Elastic aa -- describe tunica media
Muscular: single sheet of elastic fibers sandwich tunica media
--internal and external elastic lamina
Elastic: elastic fibers embedded in tunica media
99
Larger vv in extremities -- how move blood
valves (thin flaps of simple sq epithelium)
skeletal muscles
100
Valves derived from what layer of bv?
tunica intima (extensions of simple squamous epithelium/endothelium)
101
Glomus bodies/carotid bodies
embedded in wall of common carotid a (elastic a)
chemoreceptive (changes in O2, CO2, H+) --> release NT onto dendrites of sensory afferents of CN IX --> medulla oblongata
102
What junctions hold simple squamous epithelial cells of capillaries together?
zonula adherens (belt desmosome)
103
External lamina
"basement membrane" surrounding anything in periph tissues
collagen IV
located b/w skeletal m, smooth m, adipocytes, indiv simple squamous endothelial cells
104
Components of ECM
| Function of components?
GAGs, proteoglycans -- trap water
105
Attributes of all endothelial cells
1. Microvilli: inc SA -- rely on diffusion for cell viability
2. Pinocytic vesicles: "sampling of local lumen contents" -- detect chem changes in local environment
3. Weibel-Palade bodies: storage for von Willebrand clotting factor
4. ICAMS (P and E selectins)
5. Cell-to-cell adhesion complexes
106
Weibel-Palade bodies
store von Willebrand clotting factor
--binds to factor VIII prevents degradation
VIII --> X --> prothrombin --> thrombin --> fibrinogen --> fibrin
107
How can water/water soluble substances move through capillary?
```
intercellular cleft (b/w endothelial cells)
transcytose from inside cell to periph EC fluid
```
108
Endothelial cell properties and functions
1. Prostacyclin/Prostaglandin I2 (PGI2): inhibits platelet activation and inc vasodilation --> non-thrombogenic surface (smooth surface)
2. Synthesis of local/transient mediators of blood flow (factors cause vasodilation/constriction)
3. Synthesis of blood clotting transporter proteins (tissue factors and von willebrand's factor)
4. Synthesis of P and E selectins (WBC diapedesis during inflammation)
109
3 major types of capillary networks
Continuous (most) -- tight junctions (occluding)
Fenestrated: in portal sys (CONTINUOUS external lamina with THINNING in certain regions of phospholipid bilayer creates small pores which allow for more rapid diffusion of particles)
Sinusoids/discontinuous: larger spaces b/w adj cells; DISCONTINUOUS external lamina (in liver)
110
Pericytes
capillary-associated cells
firmly attach/contribute to basement membrane
repair dmaged bv -- remodel during angiogenesis
ensheathed in external lamina
contribute to:
--embryonic development of vasculature (MSCs)
--neurovascularization (after menstruation, pregnancy)
--regulation of blood flow
--tumor vasculature (upregulation of metabolic activity in cells -- bv grow in this area)
111
Autonomic regulation of blood flow controlled by what div of NS?
```
Sym
vasomotor reflexes change diameter of periph blood vessels
myogenic tone (smooth m cells in tunica media)
--usually slightly contracted -- can relax these m cels or restrict them more
```
112
Precapillary sphincters
| Controlled by what NS div?
can close off capillary branches to direct blood through thoroughfare to more metabolically active tissues
SYM div
113
Pre-Capillary sphincters open/closed when there is low/high metabolic demand
Low metabolic demand: sphincters CLOSED -- blood moves only through thoroghfare channel
High metabolic demand: sphincters OPEN -- blood moves through entire plexus
114
Pathway for prostacyclin?
| NO?
prostacyclin: PKA pathway
NO: PKG pathway
115
MALT
| 2 div of MALT
MALT: mucosa-associated lymphoid tissue (interactions of WBC that respond to pathogens occur here)
- -O-MALT: organized (lingual, palatine, and pharyngeal tonsils; Peyer's patches in ileum)
- -D-MALT: diffuse
116
Organized WBC clusters in lamina propria/submucosa include:
Naive and activated macrophages/dendritic cells/B and T cells
Plasma cells
Th and Tc cells
117
DMALT in diff organs
| WBC located here?
```
GALT (gut)
BALT (bronchus)
NALT (nose)
CALT (conjunctival)
VALT (vulvo-vaginal)
***B cells and macrophages
```
118
Primary lymphoid organs
| Secondary lymphoid organs
Primary: red bone marrow, thymus (WBC produced and mature here)
Secondary: spleen and lymph nodes (mature WBC sequestered to ensure optimal interactions for pathogen recognition and WBC activation to occur)
119
B cells and T cells derived from what precursor?
| Neutrophils, basophils, eosinophils, monocytes?
Lymphoid: B and T cells
Myeloid: neutro, baso, eosinophils, monocytes
--granulocytes include neutro, baso, eosino
--agraunolcytes include monocytes
120
Mast cells
cells that are similar to basophils and are derived from the same lineage but are localized to PERIPH tissues (loose CT)
121
Germinal center
sites where activated B cells (plasma cells) are producing Ab
122
Primary vs secondary lymphoid nodules
Primary: do NOT have germinal centers
Secondary: HAVE activated germinal center
123
Peyer's patches
lymphoid nodules that extend from lamina propria --> submucosa
(primary: w/o germinal center or secondary: w/ germinal center)
124
Tonsils
organized aggregates of WBCs inthe submucosa
125
Waldeyer's ring and its components w/ locations
lymphoid nodules form a ring of lymphoid tissue at the opening of the pharynx
Include:
--pharyngeal tonsil/adenoid (nasopharynx)
--palatine tonsils -- paired (oropharynx)
--tubal tonsils -- paired (oropharynx)
--lingual tonsils (tongue)
126
Describe change in thymus from child --> adult
dec in size after puberty
| involution complete by middle age -- adipose replaces most of specialized glandulr epithelium and deeper lymphoid tissue
127
Lymph fluid is derived from...
blood plasma
128
Superficial vs deep lymph nodes
Superficial: embedded in subcutaneous adipose/superficial fascia and the parietal membranes of closed body cavities
Deep: embedded in deep fascia --b/w skeletal muscles in extremities and neck (also closely asociated with NAV bundles in closed body cavities)
129
Clonal expansion
after WBCs activated, undergo rapid mitosis -- this is clonal expansion
130
Th1 cells activate...
| Th2 cells activate...
Th1 activate CD8+ (killer T cells)
| Th2 activate B cells
131
Spleen has lobes -- T or F?
False, spleen does NOT have lobes
132
What types of muscle cells use gap junctions?
| Where are gap junctions located in these muscle types?
cardiac (longitudinal part of intercalcated discs)
| smooth (densely clustered in plasma membranes b/w adj smooth muscle cells)
133
What aa are elastic?
Aorta
left common carotid
left subclavian
brachiocephalic
134
How is blood vessel diameter regulated?
sym div of NS or
local chemical regulation produced by simple sq epithelial cells of bv (endothelin-1 -- vasoconstriction and NO -- vasodilation)
135
Vasa vasorum
blood supply to muscular layer of bv
136
Nervi vascularis
autonomic nerve supply to muscular layer
137
Locations where 3 types of capillaries are found
```
Continous:
--muscle
--lung
--skin
--CNS
Fenestrated:
--ant pituitary gland
--glomerulus of kidney (filtration)
--intestinal villi (nutrient absorption)
Discontinuous/sinusoids:
--lymph nodes
--spleen
--red bone marrow
--liver
```
138
Terminal bars
tight junctions + belt desmosomes
| adhere 2 intestinal cells together
139
Plicae of jejunum vs duodenum and ileum
pliacae more well defined and larger than plicae in duodenum and ileum
140
Distinguish recto-anal junction from esophageal-cardiac junction
recto-anal: no glands in lamina propria or submucosa
| esophagus: both esophageal and esophageal cardiac glands
141
Lower esophageal sphincter
function
from what muscle layer
```
regulates rate of bolus of food enters stomach
usually closed (prevents reflux of gastric contents into esophagus)
thickening of inner circular layer of muscularis externa
```
142
Pepsinogen activated to...by...
| Pepsinogen stored in...which are located in....
Activated to pepsin by low pH in gastric juices
| Stored in chief cells which are located in the fundus/body of the stomach
143
Gastric acid
facilitates digestion (of proteins and absorption of Ca, Fe, vit B12)
suppresses bacterial growth
prevent GI tract infections and bacterial overgrowth in SI
**present in all vertebrates
144
glands in what part of the stomach have the deepest pits?
pyloric stomach
145
Stem cells in stomach vs intestine
stomach: neck of gland
intestine: base of crypt
146
What is the advantage of the digestive and absorptive functions of enterocytes in SI?
end products of digestion closer to site of absorption
| **terminal digestion via enz in microvilli
147
Protein degradation stomach vs duodenum
Stomach: pepsin
Duodenum: trypsin
148
GALT
diffuse lymphatic tissue and lymphatic nodules
Immunological barrier
Throughout length of GI tract
149
Peyer's patches
in ileum
OMALT
lamina propria, submucosa
extensive aggregates of nodules
150
Peyer's patches organized into 3 parts
Follicle associated epithelium: M cells, enterocytes
Domes: B cells, macrophages, plasma cells
Germinal centers: plasma cells and B cells
151
Valve b/w SI and LI
ileocecal valve
152
Functions of LI
absorption (of electrolytes, fluids, water)
houses bacteria (vit B12 and K production)
produces mucus
compact feces
153
Key features of colon
```
no villi
no plicae circulares
no paneth cells
MANY goblet cells
MANY crypts
```
154
Tenia coli from what muscle layer?
outer longitudinal
155
Liver is from what germ layer?
Glisson's capsule?
Kupffer cells?
liver: endoderm
glisson's capsule: meso
kupffer: meso
156
all glands have what kind of tissue?
epithelial tissue -- it is avascular
| why surrounded by CT w/ NV bundles
157
Kupffer cells
macrophages in liver
| monocyte derived
158
What lobe of liver is closest to gallbladder?
| closest to IVC?
closest to gall bladder: quadrate
| closest to IVC: caudate
159
Lobes of liver?
| How many sections based on venous blood flow?
R, L, caudate, quadrate
| 8 sections
160
Porta hepatis
hepatic portal v
hepatic a proper
hepatic duct
161
Glisson's capsule
fibrous CT layer of liver
162
Falciform lig has what lig that is embryo remnant?
ligamentum teres (From umb v)
163
Type of blood in hepatic portal v vs hepatic a?
| Type of blood in central v
v: deoxy but nutrient rich (From GI wall)
a: oxy blood
Central v: deoxy and nutrient depleted
164
Describe structure of hepatocytes in liver
| Describe structure of lobules
Hepatocytes: vertical stacks
Lobules: hexagon with micro portal triad at each corner
165
M1 vs M2 macrophages
M1: inflammation (IL-1 and TNF alpha)
M2: repair (IL-10 and TGF beta)
166
Where is alcohol absorbed in GI tract?
stomach wall b/c very lipid soluble
| then moves to hepatic portal v --> liver
167
What histo layer is absent in gallbladder?
muscularis mucosa
168
What structure of the gallbladder is linked with inc likelihood of developing gall stones?
many RA crypts (from mucosa, penetrate lamina propria)
169
Accessory pancreatic duct dumps into what opening?
| Main pancreatic duct?
accessory: minor duodenal papilla
main: major duodenal papilla
170
Mechanisms that prevent autodigestion of pancreas
dig enz packaged in VESICLES
dig enz inactivated by low pH in vesicles
dig enz stored as PROENZYMES
INHIBITORY MOLEC (trypsin inhibitor keeps dig enz inactive in pancreas)
