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Microanatomy > SM01 Mini2 > Flashcards

SM01 Mini2 Flashcards

1
Q

Mitochondria

A

long, ovoid membrane bound organelle found in the cytoplasm

has own DNA

responsible for converstion of food to usable ATP energy

avg. 1000/cell, erythrocytes= 0, more energy demand→ more mitochondria

& distribution vary according to cell type

under basal bodies in ciliated cells to provide ATP for dynein activity in ciliary beating

new ones are made via division, not linked to cell cycle & they do not all divide at the same time

sperm mitochondira are tagged with ubiquitin

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2
Q

Outer Mitochondrial Membrane

A

contains porin, large channel forming protein, that are ALWAYS open (only pore in the human body)

thus permeable to molecule 5000Da or less

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3
Q

Inner Mitochondrial Membrane

A

surrounds matrix, infoldings create cristae→ increased surface area

contains proteins that carry out oxidative rxns of electron transport chain & ATP synthase

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4
Q

Intermembrane Space

A

contains enzymes that use ATP passing out of matrix to phosphorylate other nucleotides

resembles cytosol

pH=7

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5
Q

Mitochondrial Matrix

A

inside inner membrane

highly concentrated mix of enzymes for oxidation of pyruvate & fatty acids & those for citric acid cycle

pH=7.5

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6
Q

Cristae

A

finger-like projections that cross the mitochondrion formed by the infoldings of the inner membrane

contain ATP transporters that pump new ATP from matrix to intermembrane space

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7
Q

mDNA

A

mitochondrial DNA

2-10 circular copies/mitochondrion

<1% of cellular DNA

only 13 out of 615 proteins of mitochondria are coded for on this DNA

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8
Q

oxidative phosphorylation

A
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9
Q

Lysosome

A

body where lysis occurs

membrane-bound organelle containing digestive enzymes, typically most active at acidic pH (4.8- proton pumps to acidify lumen)

only in cytoplasm, NOT nucleoplasm

degrades proteins, lipids, carbohydrates, DNA, RNA,

size, #/cell, & appearance vary greatly per need

ALWAYS smaller than nucleus in normal cell

material to be degraded is brought in by vesicles that fuse w/lysosome

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10
Q

M6P Signal

A

mannose 6 phosphate

signal on proteins to be packaged together to form a primary lysosome

phosphotransferase adds M6P to proteins with lysosomal amino acid sequence with N-linked sugar

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11
Q

primary lysosome

A

new lysosome that has just budded from the trans Golgi

contains newly synthesized enzymes

before it receives any material to be digested

“virgin lysosome”

sometimes exicytosed to degrade subtances in the ECF

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12
Q

secondary lysosome

A

primary lysosome after it has fused with vesicles containing material to be degraded

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13
Q

lysosomal storage diseases

A

>30

most linked to mutation in specifc acid hydrolase

leads to accumulation of partially degraded insoluble metabolite in lysosome

ex. I cell disease & Tay Sachs disease

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14
Q

Tay Sachs Disease

A

absence of hexosaminidase A→ cannot breakdown glycolipids (highly prevalent in neurons)→ neurons ballooned w/cytoplasmic vacuoles

destruction of neurons

symptoms: 6 months relentless motor & mental deterioration, and early childhood death (2-3 yrs)

more common in Ashkenazi jews

exception of one time lysosomes are bigger than nucleus

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15
Q

autophagy

A

catabolic process involving degradation of cell’s own components via lysosomal machinary

purpose: provide raw materials to sustain life, seen in starvation

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16
Q

endocytosis

A

uptake of material into cell by invagination of plasma membrane & internalization of membrane-bound vesicle

function: bring molecules from ECF inside cell &/or retrieve plasma membrane proteins

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17
Q

phagocytosis

A

endocytosis in which vesicle contains large food particle

ONLY macrophages & neutrofils

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18
Q

proteosome

A

degrades unneeded or damaged proteins by proteolysis that have been tagged with ubiquitin

found in cytoplasm & nucleoplasm

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19
Q

Peroxisome

A

small membrane-bound organelle that uses molecular oxygen to oxidze organic molecules

contains enzymes that produce organic molecules, produce hydrgen peroxide & degrade hydrogen peroxide

NOT found in every cell in body

important for liver & kidney function to detoxify bloodstream

rapid responce to change (proliferation when needed)

EM: dark due to stain rxn with catalase enzyme, but otherwise can’t be distinguished

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20
Q

fucntions of peroxisome

A
  • rid body of toxic substances: hydrogen peroxide, phenols, formic acid, formaldehyde, alcohol
    • 1/4-1/2 of ingested alcohol is broken down in perioxisomes

RH2 + O2 → R + H2O2

then catalase used H2O2 to oxidize other hydrocarbons: H2O2 + R’H2 → R’ + 2H2O

  • breakdown of long chain fatty acids (>22C) via beta-oxidation→ acetyl-CoA
    • NOT coupled with ATP production, but creates H2O2 instead
  • synthesis of bile acids in liver
  • synthesis of plasmalogens to make myelin→ thus contribution to neurologic symptoms
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21
Q

peroxisome formation

A
  • de novo: from ER & proteins are imported (-ser-lys-leu-COO-)
  • fission: an existing one divids into two
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22
Q

aerobic respiration

A

uses oxygen

oxidative phosphorylation takes place in mitochondria

approx. 30 ATP produced

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23
Q

anaerobic respiration

A

doesn’t use oxygen

takes place in cytoplasm by glycolysis

makes 4 ATP

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24
Q

Mitochondrial fission

A

one mitochondrion splits into two

don’t understand why yet

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25
Q

Mitochondrial fusion

A

two mitochondria fuse into one

don’t understand why yet

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26
Q

Functions of Mitochondria

A
  1. acetyl-CoA in oxidative phosphorylation in ATP production
  2. breakdown of fatty acid molecules to acetyl-CoA
    1. must be 22C or less
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27
Q

ATP synthase

A

makes ATP in mitochondrial matrix coupled with protons moving down their electrochemical gradient (intermembrane space to matrix of mitochondria)

found as transmembrane protein in inner membrane of mitochondria

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28
Q

mitochondrial targeting sequence

A

most mitochondrial proteins are still encoded by nuclear genome

always at amino terminus

binds to mitochondrial chaperones before binding to keep it exposed & target it to the mitochondria after ribosome relase

every fourth aa has a positive charge (this is the recognition site for the chaperones

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29
Q

mitochondrial disease

A
  1. defective gene in nuclear genome
  2. defective gene in mDNA (thus maternally inherited - 15% of total)
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30
Q

How Mitochondria Make ATP

A
  1. oxidation of fatty acids & pyruvate to acetyl-CoA, coupled w/reduction of NAD+ & FAD→ NADH & FADH2
  2. electrons from reduced coenzymes are transferred via 3 electron transport complexes to O2 & H+ are transported frommatrix to intermembrane space
    1. matrix becomes basic (low [proton]) & negatively charged (electric potential)
  3. ATP synthase makes ATP coupled with protons moving down their electrochemical gradient (intermembrane space to matrix of mitochondria)
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31
Q

proton-motive force

A

low proton concentration in matrix + negative charge of matrix relative to intermembrane space

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32
Q

cardiolipin

A

double phospholipid (four fatty acid tails)

found mainly in mitochondrial inner membrane

catalyzed by mitochondria themselves

packs tighter than regular phospholipids, better to withstand stress

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33
Q

Ubiquination

A

attaching of ubiquitin to a protein to signal proteosome for degradation

signaled by exposure of string of hydrophobic aa that are normally buried

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34
Q

Special Properties of Lysosomes

A
  1. ATP driven proton pump for acidification
  2. glycoprotein coat on inner surface to protect it against hydrolysis by its own enzymes
  3. transport channels to transport products out of lysosome: amino acids, nucleotides, glucose, etc.
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35
Q

Opsinized

A

“seasoned”

addition of eat me ligand signals attached something to be phagocytosed

ex. antibody coating of bacterium, Fc is eat me signal

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36
Q

Autophagosomes

A

organelle wrapped in ER membrane

destined to fused with lysosome

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37
Q

Autolysosome

A

autosome that has fused with lysosome

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38
Q

residual body

A

remains of secondary lysosome

can be exocytosed or turn into lipofuscin granules (if pigmented)

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39
Q

M6P receptor

A

affinity for M6P at pH=6.5, but not low pH of lysosomes

drops cargo off in lysosomes & recycles

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40
Q

I cell disease

A

defective phosphotransferase→ cannot make M6P targeting signal→ all lysosomal hydrolases are secreted

waste buildup creates “I” (inclusion) cells

symptoms: 6 months failure to thrive & developmental delay, and early childhood death

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41
Q

PTS

A

peroxisomal targeting signal

ser-lys-leu at COOH terminus of protein

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42
Q

Zellweger’s Syndrome

A

defect importing proteins to peroxisomes

die soon after birth

homozygous recessive of PTS receptor mutation

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43
Q

sER Structure

A

continuous with rough ER

distal to nucleus

held in place by mictrotubules

more if cell needs to make a lot of lipid or hormones

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44
Q

sER Functions

A
  1. lipid biosynthesis
    1. all except for cardolipin (made in mitochondria)
  2. detoxification rxns
    1. more complex molecules than those in peroxisomes, ex. phenobarbital
      1. both do ingested alcohol
    2. cytochrome p450s (CYP)
  3. regulation of Ca2+
    1. especially in muscle contraction (sarcoplasmic reticulum)
    2. cellular signaling pathways
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45
Q

rER Structure

A

grows out of nuclear envelop

continuous with sER

contains bound ribosomes (they are signaled to attach, but are the same as free ribosomes) on outside of membrane

more of it if cell secretes a lot of protein

held in place by microtubules

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46
Q

rER Functions

A
  1. protein synthesis
    1. secreted proteins
    2. transmembrane proteins (except mitochondrial)
    3. lysosomal proteins
  2. protein modification
  3. sequestration of Ca2+
    1. released in signaling pathways
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47
Q

Flippases

A

moves phospholipids from extracellular leaflet to cytoplasmic leaflet

uses ATP

in Golgi

flips phosphatidylserine (negative charge attracts peripheral membrane proteins, ex. PKC) & phosphatidylethanolanine from lumenal (extracellular) to cytosolic face

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48
Q

Scramblases

A

does NOT use ATP

moves phospholipids form one leaflet of a membrane to the other in both directions

movement of two lipid in opposite direction

only found in sER

exist because all new lipids are added to cytosolic leaflet

non-specific to polar head group

makes sER membrane homogenous mixture

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49
Q

Lipid transport mechanisms

A
  1. lateral diffusion within a bilayer
  2. scramblase assisted translocation between leaflets
  3. lipid-transfer protein assisted movement thru cytosol
    1. non-specific, bump around from membrane to membrane
  4. incorporation in membrane-bound vesicles
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50
Q

Secretory Pathway

A
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51
Q

ER signal sequence

A

usually at amino terminus of protein

usually cleaved in rER lumen by signal peptidase

8 or more non0polar aa at the center

once translated, will be bound by SRP

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52
Q

SRP

A

signal recognition particle

binds to ER signal sequence→ stops mRNA translation→ binds to SRP receptor on rER→ ribosome binds ribosomal receptor on rER & translocator complex→ mRNA translation resumes→ protein pushed through translocon into rER lumen

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53
Q

Lipid biosynthesis in sER

A

newly synthesized lipids inserted into outer leaflet of sER bilayer

made on cytosolic side of sER

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54
Q

Floppases

A

moves phospholipids from cytoplasmic leaflet to extracellular leaflet

uses ATP

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55
Q

Chaperones

A

2 types: hsp70 (heat shock protein 70 in cytoplasm & BiP in ER lumen) & GroEL family

hsp family binds to hydrophobic domains in unfolded proteins

prevent aggregation of unfolded proteins & aid in proper folding

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56
Q

Protein membrane insertion

A
  • some use ER signal as transmembrane domain
    • translocon springs open to laterally release hydrophobic sequence into membrane
  • positively charged aa at either end are flipped so charge faces cytoplasm
    *
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57
Q

protein modifications in rER

A
  1. N-terminal singal peptide cleavage by signal pepidtase
  2. N-linked glycosylation (on asparagine)
    1. core= 2x N-acetylglucosamine & v branch of 3 mannose
    2. other mannose & glucose added
    3. only core survives trimming in Golgi for many
  3. formation of disulfide bonds via oxidatioin of cysteine sulfhydral groups
    1. stabilizes protein conformation
    2. cannot occur in cytoplasm due to reducting atmosphere of glutathione
    3. ex. light & heavy chains of antibodies & alpha & beta subunits of insulin receptor
    • transmembrane domain/+GPI anchor (lipid)
      1. ​covalent bond- still integral protein
  5. ​protein folding by chaperones
    1.
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58
Q

BIP

A

binding protein

homologous to HSP70

in rER

correct folding required to leave rER or will tag for degradation

binds to hydrophobic patches as they come through the translocon

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59
Q

N-glycanase

A

enzyme that removes N-linked glycosylation for protein ubiquination & degradation

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60
Q

Cystic Fibrosis

A

most common fatal genetic disease in US

death caused by repeated chest infection

mutation in cystic fibrosis transmembrane conductance regulator (CFTR) gene

chloirde ion transporter of epithelial cells misfolds→ transporter absent from plasma membrane

chloride imbalance causes cells to secrete less water, cells swell, secretions are very thick

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61
Q

secretory pathway

A

ER (rough or smooth)→Golgi→ secretory vesicle→ plasma membrane

regulatory signal required if bound for elsewhere (lysosome or regulated secretion)

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62
Q

SNAREs

A

(Soluble NSF Attachment protein Receptor)

v-snares on vesicles; t-snares on target membranes

used for targeting & drive membrane fusion reaction

35 different SNARES, each associated with particular membrane enclosed organelle

snap membranes together so strongly it drives water out→ stalk formation→ hemifusion cytosolic leaflet fused but not lumenal leaflet)→ fusion

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63
Q

Rabs

A

small GTP binding proteins

found on vesicle membranes (different types for direction)

contribute to specificity of docking

binds to tetherin protein on target membrane→ brings SNARES in closer proximity

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64
Q

NSF

A

(N-ethylmaleimide-sensitiven factor)

solubel protein responsible for breaking apart v- & t-SNAREs for recycling with help of SNAPs, uses ATP

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65
Q

SNAPs

A

acessory proteins that aide NSF in recycling of v- &t-SNAREs

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66
Q

Botox

A

uses various forms of botulinum toxin to paralyze muscle activity

cleaves SNAREs for exocytosis of regulated secretory vesicles at neuromuscular junction→ no neurotransmitter release→ no muscle contraction

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67
Q

Golgi

A

membraneous complex of vesicles, vacuoles, & flattened sacs in the cytoplasm

involved in portien modification, intracellular secretion & transport

located on one side of nucleus on top of centrosome (mictrotubule organizing center)

cis (closest to ER), medial (mulitple sacs), trans (faces plasma membrane-exit)

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68
Q

modifications in Golgi

A
  • trimming of N-linked carbohydrates
  • addition of sialic acid to glycoproteins & glyolipids
    • aka NANA
    • turned black w/ Golgi stain
    • onlly carbohydrate group w/ - charge
    • give extracellular leaflet of plasma membrane negative charge
  • addition of O-linked sugars to serine & threonines
  • glycosylation of some lipids, ex. ceramide
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69
Q

glycocalyx

A

cell coat created by thick rim of carbohydrates fanning out from plasma membrane

functions: protection, cellular recognition, slows rate of degradation of secreted & membrane proteins

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70
Q

regulated secretion

A

signal mediated secretion

directed to lysosome or secretory vesicles

ex. insulin, neurotransmitters (acetylcholine, glutamine)

rise of intracellular Ca2+ often triggers release

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71
Q

constitutive secretion

A

secretion without signal mediation

operates continuously

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72
Q

M6P signal mechanism

A
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73
Q

phagocytosis mechanism

A

types of molecules: 0.1-10micrometers in size

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74
Q

pintocytosis mechanism

A

“cell drinking”

each budding vesicle traps a drop of extracellular fluid as it pinches off

types of molecules: indiscriminate

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75
Q

receptor-mediated endocytosis

A

100-500nm

mediated by clathrin coat proteins

receptors for specific proteins cluster in clathrin pits, can have many different receptors in same pit

viruses like to exploit (ex. flu)

types of molecules: insulin, EGF (epidermal growth factor), transferrin, LDL (low density lipoprotein), & polymeric IgA

possible fates: recycling, transcytosis, degradation

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76
Q

LDL endocytosis pathway

A

receptor recycles, ligand degrades

receptor needed for multiple round of endocytosis

ligand is degraded for the cell to use the cholesterol

LDL= low-density lipoprotein, carries cholesterol made in liver through the blood to the body (75% from liver/25% from food)

10-15 min process

proton pump of endosome acidifies vesicle after pinching off→ 6.5 receptor unbinds LDL & pinches off vesicle→ 4.5 merge with lysosome for LDL degradation

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77
Q

transferrin endocytosis pathway

A

ligand & receptor recycle

transferrin blinds to Fe in bloodstream

apotransferrin= no bound Fe

diferric-transferrin= bound to Fe (2Fe3+)

7.2 transferrin receptor has low affinity for apotransferrin, but high for diferric-transferrin→ 6.5 of early endosome Fe release from transferrin & leaves endosome→ transferrin & transferrin receptor are recycled

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78
Q

EGF endocytosis pathway

A

ligand & receptor are degradated by lysosome→ mechanism for down-regulation of signaling pathway

EGFR only cluster in clathrin pits when they are bound to ligand

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79
Q

IgA secretion

A

ligand & receptor are translocated acorss cell & released on the other side

IgA antibodies coming from bloodstream→ bind to receptor on one side of a polarized cell→ travel with receptor in vesicle to other side of cell→ released to ECF on opposite side

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80
Q

caveolae

A

“little caves”

small invaginations of plasma membrane, specialized lipid rafts

many cell types, but neurons have none

abundant in endothelial blood vessel cells (most transcytosing vessels in this cell type)

caveolin: protein that causes invagination

proteins found in them: GPI-linked & proteins w/longer than average transmembrane domains (signaling pathways)

functions: signal transduction & caveolar endocytosis

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81
Q

secretory vesicles

A

regulated ones are often transported intracellularly by dyenin & kinesin on MT to plasma membrane→ actin & myosin take over→ vesicles enmeshed in actin waiting for trigger to release (often rise of intracellular Ca2+)

usually darker on EM due to aggregation of contents

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82
Q

Coat proteins

A

clathrin, COPI, COPII, (caveolin possible 4th)

vesiculation requires coat proteins

water soluble

assemble on membrane face & induce curvature→ serve to cluster membrane cargo proteins→more added to shape membrane into sphere→vesicle pinches off & coat falls off

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83
Q

Clathrin

A

protein coat portein for receptor-mediated endocytosis of plasma membrane

triskelion= unassembled state

lattice= assembled on membrane

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84
Q

COPI

A

protein coat portein for receptor-mediated endocytosis of Golgi

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85
Q

COPII

A

protein coat portein for receptor-mediated endocytosis of ER

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86
Q

mitosis

A

eukaryotic cell division

stages: prophase, metaphase, anaphase, telophase

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87
Q

prophase

A

second stage of mitosis

chromatin condenses to chromosomes, nuclear envelop breaks down, & initiation of mitotic spindle but centrosomes

4X chromosomes, 2n DNA

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88
Q

metaphase

A

third stage of mitosis

chromosomes line up on equatorial plate, spindles bind to kinetichores, centrosomes are at opposite poles

4X chromosomes, 2n DNA

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89
Q

anaphase

A

fourth stage of mitosis

sister chromatids are pulled apart to opposite poles & initiation of cleavage furrow

4X chromosomes, 2n DNA

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90
Q

telophase

A

fifth (last) stage of mitosis

chromosomes unravel to chromatin, nuclear envelop forms, & cytokinesis forming two daughter cells both exactly like the parent cell

2X chromosomes, n DNA

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91
Q

actin function in mitosis

A

formation of contractile ring during cytokensis

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92
Q

microtubule function in mitosis

A

form spindle fibers that bind to kinetochore of chromosomes to pull the sister chromatids apart

minus-end directed motor protein is part of kinetochore protein complex

some motor anchor MT to plasma membrane & pull

other motors push overlapping MT to push the poles apart

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93
Q

intermediate filaments function in mitosis

A

break down nuclear envelope in prophase triggered by phosrylation of nuclear lamins

create two new nuclear envelopes during telophase

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94
Q

cohesins

A

proteins that cross-link two adjacent sister chromatids, multiple along the length of chromosome

critical for chromosome segregation

degraded at start of anaphase

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95
Q

condensins

A

proteins that mediate intramolecular cross-linking to coil DNA during chromosome condensation

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96
Q

Taxol

A

anti-microtubule drug used for cancer treatment

arrest mitotic cells because spindle fibers cannot form so that they perform apoptosis

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97
Q

G0

A

quiescent phase

inactive

neurons stay in this phase permenantly

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98
Q

G1

A

phase most variable in length, dependent on tissue type (bone= 25h)

the differentiated the longer it will stay in this phase

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99
Q

S phase

A

synthesis phase

DNA is replicated, 2n DNA, 4X chromosomes (but they are not condensed yet)

in bone= 8hrs

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100
Q

G2

A

growth and preparartion for mitosis

in bone G2 + mitosis= 2.5-3hrs

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101
Q

Preprophase

A

first stage of mitosis

intranuclear condensation of chromatin & centriole duplication to two centrosomes

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102
Q

organelles during mitosis

A

ER: vesiculates (breaks down) when the nuclear envelope does, reforms during telophase

Golgi: vesiculates (breaks down) when the nuclear envelope does, reforms during telophase

mitochondria, lysosome, & perxoisomes: nothing, but stay out of spindle region (unexplained as of yet)

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103
Q

necrosis

A

premature, accidental death

cells swell & break open, releasing their contents

effects on organism: can damage surrounding tissue & possibly damaging inflammtory response

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104
Q

apoptosis

A

programmed cell death

appearance: round up, appear bigger but are NOT actually bigger

intracellular changes: fragmentation of DNA, shrinkage of cytoplasm, membrane changes→ pieecs bleb off & are phagocytosed by macrophages

effects on organism: no lysis/no inflammation→ no damage to surrounding cells, imperceptible to organism

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105
Q

causes of necrosis

A

mechanical trauma, eposure to toxic agent, burning, freezing, intense UV radiation, anything that quickly depletes ATP of cell (ie hypoxia→ ischemic stroke & heart attack)

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106
Q

mitochondrial role in apoptosis

A

pro-apoptotic BCL-2 family member forms channel in outer mitochondrial membrane releasing cytochrome c (part of the apoptosome) & apoptosis inducing factor

anti-apoptotic BCL-2 family member can bind to these to inhibit channel formation

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107
Q

caspases

A

protein family of proteases that play a role in necrosis, apoptosis & inflammation

cysteine proteases that cleave just C-terminal to asp residues

synthesized as inactive pro-enzymes

cells die in few hours-a day after receiving negative signal or withdrawal of positive signal

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108
Q

BCL2

A

family of proteins that regulate when apoptosis occurs, some pro & some anti

they can regulate each other by forming heterodimers

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109
Q

caspase cascade

A

pro-apoptotic signal→ activation o f initiator caspases→ cleaves & activates effector caspases→ break down of cellular targets

1 molecule of activated caspase can amplify & kill the cell

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110
Q

cell survival requirements

A

produce ATP

be able to maintain barrier to external environment

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111
Q

Effects of increased [Ca2+]cytoplasmic

A

major cause of cellular injury

denatures protein

poisons mitochondria

inhibits cellular enzymes

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112
Q

inflammation

A

protective attempt by organism to remove the injurious stimuli & initiate healing process

characterized by redness, pain, heat, & swelling

caused by: increased blood flow & leakiness of capillaries→ bringing white blood cells to affected tissue

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113
Q

hypoxia

A

oxygen deficiency that causes cell injury & death by reducing oxidative respiration in mitochondria

ex. ischemic stroke & heart attack
causes: ischemia (reduced blood flow), inadequate oxygenation of blood due to cardiorespiratory failure, decrease oxygen carrying capacity (anemia, CO poisoning, severe blood loss)

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114
Q

calpains

A

calcium-activated neutral proteases

activated in brain by high calcium (which can occur during hypoxia b/c neuron can’t make enough ATP to maintain strong ion gradient)

cause a lot of damage in brain trauma

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115
Q

functions of apoptosis during development

A
  1. deleting unwanted structures (tadpole tail)
  2. sculpting specific tissues by ablating fields of cells (developing digits)
  3. controlling cell # (50% of neurons eliminated during maturation)
  4. eliminating cells during development that are abnormal, nonfunctional, or potentially dangerous (T & B lymphocytes that recognize self)
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116
Q

functions of apoptosis during adulthood

A
  1. maintaining homeostatis- cell #
  2. eliminating damaged, mutated, or infected cells
  3. withdrawal of growth factors
  4. viral infection (hopefully before virus can infect surrounding cells)
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117
Q

cell loss disorders

A

AIDS, Alzheimer’s, Parkinson’s, aplastic anemia, myocardial infarction

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118
Q

cell accumulation disorders

A

CANCER, lupus erythematosus, glomerulonephritis, viral infections

119
Q

triggers for apoptosis

A

cellular stress (growth factor depletion, free radicals)

viral infection

ionizing radiation/DNA damage

120
Q

intrinsic apoptosis pathway

A

signal to commit suicide coms from within

growth factor depletion, limited DNA damage, buildup of misfolded proteins in ER

usually uses mitochondrial release of cytochrome c

121
Q

extrinsic apoptosis pathway

A

signal to commit suicide comes from outside cell

virally infected cell is recognized by death receptor on NK cell→ triggers caspase cascade

122
Q

Phagocytosis of apoptotic cells

A
  1. scramblase in plasma membrane becomes active
  2. plasma membrane phospholipids are randomized
    1. 50% phosphatidylserine faces extracellularly
    2. PS acts as “eat me” signal on bleb
  3. macrophages have PS receptor & phagocytose remnants of cell
123
Q

dynamin

A

protein that cuts the stalk to a clathrin-coated vesicle to release it from the plasma membrane

uses GTP

124
Q

adaptin

A

proteins tha tbind both clathrin & cytoplasmic tails of certain receptors

125
Q

transcytosis

A

mechanism for trancellular transport

requires polarized epithelia

used in cells/tissue that move a lot of fluid ie. capillaries & kidney tubules

clathrin-coated & caveolae can transcytose

126
Q

meiosis

A

cellular division that reduces the number of parent chromosomes in half to produce gametes

127
Q

nondisjunction

A

failure of homologous chromosomes or sister chromatids to separate during cellular division

128
Q

monosomy

A

when one chromosome is missing

caused by nondisjunction

gamete has 22 chromosomes instead of 23

129
Q

trisomy

A

when there is an extra chromosome

caused by nondisjunction

gamete has 24 chromosomes instead of 23

130
Q

oogenesis

A

primary ooctye (diploid, 4n DNA)→ meiosis I→ secondary oocyte (haploid, 2n DNA) + 1 polar body→ meiosis II→ mature oocyte (haploid, 1n DNA) + 1 polar body

secondary oocytes suspended until fetilization

131
Q

capatication

A

period of conditioning of sperm cells that occurs in the uterine tubes & lasts 7 hours

glycoproteins & seminal coat of sperm cell are removed by mucosal surface of the tube

after capacitation, sperm can pass freely through corona radiata (outer most covering of oocyte)

132
Q

acrosomal reaction

A

occurs after binding to the zona pallucida

induced by zona proteins ZP3

release of acrosomal enzymes (acrosin, esterases, neuraminidase) to break through the zona pellucida

133
Q

germ cell

A

gamete

sperm or oocyte

134
Q

gametogenesis

A

formation of gametes

involves meiosis & morphological changes

135
Q

prophase I

A

5 steps: leptotene, zygotene, pachytene, diplotene, & diakinesis

4n DNA

136
Q

leptotene

A

condensation of chromatin

sister chromatids become connected by Rec8p cohesion complex (specific for meiosis)

pairing of homologous chromosomes initiated

4n DNA

137
Q

zygotene

A

binding of homologous chromosomes to form tetrad

4n DNA

138
Q

pachytene

A

crossing-over of different chromatids

creates genetic variation

4n DNA

139
Q

diplotene

A

disjunction of homologous chromosomes begins

chiasmata (opening between chromosomes) forms

all oocytes rest at this stage

4n DNA

140
Q

diakinesis

A

condensation concludes

nucleolus disappears & nuclear membrane disintegrates

4n DNA

141
Q

metaphase I

A

homologous chromosomes line up on equatorial plate

4n DNA

142
Q

anaphase I

A

homologous chromosomes are pulled to opposite poles

4n DNA

143
Q

meiosis II

A

separation of sister chromatids

2n DNA→ 1n DNA

144
Q

spermatogenesis

A

type A spermatogonia (stem cells)→ type B spermatogonia→ mitosis→ primary spermatocyte (diploid, 4n DNA)→ undergo meiosis I→ secondary spermatocyte (haploid, 2n DNA)→ undergo meiosis II→ spermatids (haploid, 1n DNA)→ spermiogenesis→ spermatozoon

145
Q

acrosome

A

forms from the Golgi→ acrosomal granule→ acrosomal vesicle→ acrosomal cap→ acrosome

forms over anterior portion of nucleus in sperm cells

contains enzymes for acrosome reaction

146
Q

fertilization

A

200-600 million sperm deposited on external os of cervix

300-500 sperm reach ampullary region

occurs in ampullary region of Fallopian tube (larger outer 1/3- toward ovary)

viability: oocyte (24hrs) & sperm (48hrs)

takes 24hrs

147
Q

endometrium

A

lining of uterus

divided into two layers: functional & basal

basal contains: spiral artery & base of uterine glands

functional contains: opening of uterine glands, sinusoidal capillaries, & venous lacunae

ALL of functional layer lost during menstration

148
Q

myometrium

A

middle layer of uterus

contains uterine & arcuate arteries

149
Q

perimetrium

A

peritoneal covering the outer wall of the uterus

150
Q

stages of fertilization

A
  1. capacitated sperm pass thru corona radiata
  2. bind to zona pellucida→ release of ZP3→ release of acrosomal enzymes→ pass thru zona pellucida
  3. sperm head attaches to oocyte plasma mebrane & they fuse
  4. fast block- 1 minute depolarization of plasma membrane
  5. slow block- cortical reaction→ Ca2+ release triggers cortical granules move to plasma membrane
  6. zonal rxn- cortical granules released & alter plasma membrane receptors of oocytes & nature of zona pellucida→ prevents polyspermy
151
Q

female pronucleus

A

nucleus of ovum at fertilization

152
Q

male pronucleus

A

nucleus of sperm during fertilization after degradation of flagella & flagellar mitochondria

153
Q

corona radiata

A

originates from cumulus oophorus cells from the follicle

becomes outermost layer around the oocyte & zona pellucida

sperm cells have to have undergone capacitiation to pass freely through this layer

154
Q

zona pellucida

A

originates from cumulus oophorus cells from the follicle

becomes layer around the oocyte & under teh corona radiata

sperm undergo the acrosome reaction to degrade and pass through this layer

155
Q

corpus albicans

A

mass of fibrotic scar tissue formed form the shrinking corpus luteum when an oocyte goes unfertilized

corpus luteum will reach its peak at D9 & start to shrink

156
Q

corpus luteum

A

formed from the remaining granulosa cells of the follicle & theca interna

influenced by leutinizing hormone

develops yellowish pigment & differentiates into lutein cells

secrets estrogen & progesterone that prepares urterine mucosa for implantation

157
Q

corpus luteum of pregnancy

A

increased growth of corpus luteum after fertilization

grows to 1/3 to 1/2 of ovary size by 3rd month

continues to secrete progesterone through fourth month until the trophoblastic component of the placenta replaces it as the key progesterone secreter

will cause an abortion if removed before the fourth month

158
Q

blastomeres

A

early mitotic divisions in which the cells become smaller and smaller

until 8 cell stage or 3rd mitotic division

159
Q

compaction

A

3rd mitotic division or 8-cell

cells form tight junctions between cells

160
Q

morula

A

day 3

16-cell

formation of inner and outer cell masses

inner cell mass→ embryo proper

outer cell mass→ trophoblast→ placenta

161
Q

blastocele

A

when morula enters uterine cavity, fluid enters zona pellucida→ when confluent forms single cavity

formation of blastocele marks the evolution of the morula to the blastocyst

162
Q

blastocyst

A

inner mass= embryoblast

outer mass= trophoblast

cavity in between= blastocele

163
Q

embryoblast

A

inner cell mass of blastocyst

164
Q

trophoblast

A

outer cell mass of the blastocyst

cells near embryoblast pole begin the process of implantation on D6

epithelial wall of blastocyst

165
Q

Day 6

A

zona pellucida has disappeared

L-selectins of trophoblast & carbohydrate receptors on uterine epithelium bind and start implantation

further attachment driven by trophoblast integrins & laminin & fibronectin of the extracellular matrix

166
Q

cytotrophoblast

A

inner layer of trophoblast

mononucleated cells

mitotic dividing cells that feed the syncytotrophoblast

167
Q

syncytotrophoblast

A

outer layer of the trophoblast

multinucleated with no clear cellular boundaries

responsible for human chorionic gonadotropin hormone production & secretion used for pregnancy detection by end of 2nd week

168
Q

hypoblast

A

cuboidal cells from the embryoblast that form need the blastocele

169
Q

epiblast

A

high columnar cells from the embryoblast that form near the amniotic cavity

170
Q

amniotic cavity

A

forms as a small cavity in the epiblast & enlarges

171
Q

amnioblasts

A

epiblast cells adjacent to cytotrophoblast

172
Q

Day 8

A

formation of cytotrophoblast & syncytotrophobalst from trophobalst

formation of hypoblast & epiblast from embryoblast

173
Q

week of 2’s

A

2nd week

trophobalst forms cytotrophoblast & syncytotrophoblast

embryoblast forms hypoblast & epiblast

extraembryonic layer forms somatic & splanchnic layers

amniontic & definitve yolk sac are formed

174
Q

Day 9

A

fibrin coagulum forms over uterine epithelim defect at site of embeding embryo

lacunar stage at embryonic pole

formation of primitive yolk sac

175
Q

lacunar stage

A

vacuoles appear in syncytium & fuse to form lacunae

occurs at embryonic pole

176
Q

primitive yolk sace

A

aka exocoelomic cavity

@ aembryonic pole, formation of exocoelomic (Heuser) membrane around inner surface of cytotrophoblast + hypoblast

177
Q

sinusoids

A

syncytotrophobalst erodes endothelial lining of maternal capillaries→ congest & dilate

178
Q

Day 11 & 12

A

formation of sinusoids & establishment of uteroplacental circulation

chorionic cavity formation

decidua reaction at implantation site

179
Q

extraembryonic mesoderm

A

derived from yolk sac cells

forms loose connective tissue layer in between cytotrophoblast & exocoelomic cavity

later cells that migrate most caudally from the primitive streak also contribute to this layer

180
Q

chorionic cavity

A

aka extraembryonic cavity

formed by convergence of cavities in the extraembryonic membrane

surrounds amniotic & primitive yolk sacs

181
Q

extraembryonic somatic mesoderm

A

extraembryonic mesoderm lining the cytotrophoblast & amnion

182
Q

extraembryonic splanchnic mesoderm

A

extraembryonic mesoderm that covers the primitve yolk sac

183
Q

Day 13

A

possible bleeding with increased blood flow to lacunar spaces

primary villi formation

definitive yolk sac formation

trophobalstic lacunae present at abembryonic pole

184
Q

primary villi

A

cellular columns made of cytotrophoblast cells that porliferate & penetrate into the syncytotrophoblast

185
Q

definitive yolk sac

A

aka secondary yolk sac

derived from hypoblast cells that migrate along the lining of the exoembryonic mesoderm

smaller than the primitive yolk sac & the exocoelomic cavity

186
Q

chorionic plate

A

extraembryonic mesoderm lining the inside of the cytotrophoblast after chorionic cavity formation

187
Q

connecting stalk

A

extraembryonic mesoderm that transverses the chorionic cavity

later becomes the umbilical cord

188
Q

gastrulation

A

formation of germ layers (endoderm, mesoderm, & ectoderm) during the thrid week

189
Q

primitive streak

A

forms on the epiblast during D15 or 16

signals start of gastrulation

narrow groove with slight bulging on either side

190
Q

primitive node

A

slightly elevated area surrounding the primitive pit at the cephalic end of the primitive streak

191
Q

primitive pit

A

depression at cephalic end of the primitive streak surrounded by the primitive node

192
Q

FGF8

A

fibroblast growth factor 8

synthesized & secreted by primitive streak & node cells

controls cell migration & specification

193
Q

invagination

A

inward movement of cells from the epiblast that detach and slip beneath it

194
Q

endoderm

A

invaginated cells from the epiblast that displace the hypoblast

195
Q

mesoderm

A

migrated cells from the epiblast that form a layer between the endoderm & ectoderm (previously epiblast)

196
Q

ectoderm

A

remaining cells of the epiblast on the dorsal surface

197
Q

oropharyngeal membrane

A

small region of tightly adherent ectoderm & endoderm cells at the cranial end of the trilaminar germ disc

future opening of the oropharyngeal cavity

ruptures in W4, creating communication of foregut with amniotic fluid

198
Q

prechordal plate

A

thickened region of endoderm in contact with the ectoderm at the cranial end of the primitive streak

anterior to the notochord

stimulates formation of forebrain

199
Q

prenotochordal cells

A

invaginate at the primitive node & move cranially up the midline until the reach the prechordal plate

intercalculate with the hypobalst for a short time

200
Q

notochordal plate

A

two cell layer at midline of embryo

201
Q

definitive notochord

A

formed from notochordal plate as cells migrate to form endoderm & replace hypoblast, notochordal plate proliferates, detaches & forms a tube

solid cord of cells, cranial forms first

underlies neural tube & is signaling center for axial skeleton

considered a type of/part of mesoderm

secrets noggin, chordin, & follistatin to induce neuralization of ectoderm

202
Q

cloacal membrane

A

similar to oropharyngeal membrane in that it is formed of endoderm & ectoderm w/no interveneing mesoderm

forms at caudal end of disc

forms around D15 or 16

ruptures in W7, creating communication of hindgut with amniotic fluid→ forms anus

203
Q

allantois

A

aka allantoenteric diverticulum

when cloacal membrane forms

posterior wall of yolk sac forms diverticulum that extends into the connecting stalk

involved in early blood formation & connection to urinary bladder

204
Q

AVE

A

anterior visceral endoderm

cranial end of trilaminar disc

secretes lefty1 & cerberus→ inhibit nodal→ established cranial end of embryo

205
Q

Day 17

A

formed trilaminar embryo with definitive notochord

206
Q

laterality

A

L-R sidedness

accumulation of serotonin (5-HT) on left side→ expression of MAD→ restricts NODAL expression to left side of primitive streak

if expressed ectopically (on right side), results in laterality defects

207
Q

Nodal

A

activated by FGF8

member of TGF-beta family

inhibited by cerberus & lefty1 in cranial embryo

then restricted to left side caudally by MAD

208
Q

sonic hedgehog

A

expressed more toward the notochord

may serve as midline barrier

ciliary movements are the primitive node sweep high concentrations of shh toward left side

consequence of mutation: holoprosencephaly (forebrain fails to develop into two hemispheres) & synopthalmia (fusion of the eyes)

209
Q

LEFTY-1

A

expressed more toward the lateral plate mesoderm

may serve as midline barrier

210
Q

SNAIL

A

transcription factor restricted to right side of lateral plate mesoderm

others are unknown

211
Q

paraxial mesoderm

A

cells that migrate from the lateral edges of the primitive node and the cranial edges of the primitive streak

later become divide into the somitomeres & somites

212
Q

intermediate mesoderm

A

cells that migrate through the midstreak region

later become urogenital system (kidneys & gonads)

connects paraxial mesoderm & lateral plate mesoderm

213
Q

lateral plate mesoderm

A

cells migrating more caudally

become body wall

214
Q

3rd week

A

gastrulation

differentiation of cephalic germ cell layers by midweek

notochord formation

secondary villus formation→definitive placental villus

embryo connected to cytotrophoblast shell by connecting stalk

215
Q

4th week

A

invagination of cells through the primitive streak concludes & primitive streak shrinks & disappears

caudal cells start to differentiate

intraembryonic circulatory system & heart beat

216
Q

secondary villus

A

extraembryonic mesoderm invades into primary villus growing toward the decidua

early in thrid week

217
Q

definitive placental villus

A

aka tertiary villus

end of 3rd week

mesodermal cells differentiate into blood cells & blood vessels forming

make connection with blood vessels in mesoderm of chorionic plate & connecting stalks

218
Q

outer cytotrophoblast shell

A

cytotrophoblast cells penetrate through the synsytotrophoblast & create a thin layer around the trophoblast

function: firm attachment of chorionic sac to maternal endometrium

219
Q

cardiogenic area

A

mesodermal cells in front of the oropharyngeal membrane

later gives rise to the heart

220
Q

urachus

A

what the allantois becomes as the bladder enlarges

represented as median umbilical ligament in adults

221
Q

PCD

A

primary cilia dyskinesia

technically cilia move, but are insufficient or out of synch

50% of cases show transposition of organs in thorax & abdomen due to improper ciliary movement during the 3rd week (shh & FGF8)

222
Q

Kartagener Syndrome

A

missing dynein arms for ciliary movement

associated triad: sinusitis, bronchiectasis, & complete situs inversus

223
Q

sirenomelia

A

caudal dysgenesis

loss of mesoderm in lumbosacral region→ fusion of limb buds

associated with maternal diabetes

224
Q

sacrococcygeal teratoma

A

tumor from the remnants of the primitive streak

has pluripotent cells & various tissue types

225
Q

neural plate

A

thickening of ectoderm caused by the presence of the notochord & prechordal mesoderm

induced by FGF & repression of BMP4

226
Q

neuroectoderm

A

cells of the neural plate

227
Q

BMP4

A

bone morphogenetic protein 4

responsible for ventralizing ectoderm & mesoderm

member of TGF-beta family

high levels induce ectoderm to form epidermis

induces mesoderm to form lateral plate & intermediate mesoderm

inhibited by noggin, chordin, & follistatin cause neural plate induction

low levels induce neural crest formation

228
Q

caudal neural plate

A

forms hindbrain & spnial cord

dependent on FGF & WNT3a

229
Q

neurulation

A

process in which the neural plate becomes the neural tube

occurs mid-week 3 thru week 4

*lengthening of neural plate with lateral to medial movement of cells in plane of ectoderm & mesoderm

230
Q

neural folds

A

elevated lateral edges of neural plate as it lengthens

231
Q

neural groove

A

depression between the neural folds

232
Q

neural tube

A

fusion begins at fifth somite & extends cranially & caudally

233
Q

anterior neuropore

A

aka cranial neuropore

cranial opening of the neural tube that communicates with the amniotic cavity

closed around day 25

234
Q

posterior neuropore

A

aka caudal neuropore

caudal opening of the neural tube that communicates with the amniotic cavity

closes around D28

235
Q

neural crest cells

A

cells from the lateral border or crest of the neurectoderm that undergo epithelial-to-mesenchymal transition

leave neuroectoderm by active migration to mesoderm

236
Q

crest cells from trunk

A

leave neuroectoderm after closure

  1. dorsal pathway: thru dermis→ enter ectoderm through holes in basal lamina→ form melanocytes of skin & hair follicles
  2. ventral pathway: thru anterior 1/2 of each somite→sensory ganglia, sympathetic & enteric neurons, & cells of adrenal medulla
237
Q

crest cells from cranium

A

leave neuroectoderm before closure

cells contribute to craniofacial skeleton, cranial ganglia, glial cells, & melanocytes

238
Q

otic placode

A

ectodermal thickening formed aroudn the time of neural tube closure

will invaginate to become otic vesicles which develop into structures for hearing & balance

239
Q

lens placodes

A

ectodermal thickening formed aroudn the time of neural tube closure

will invaginate to become the lenses of the eyes during the 5th week

influences overlying ectoderm to form the cornea

240
Q

splanchnic mesoderm

A

layer of mesoderm covering the yolk sac

from lateral plate mesoderm

241
Q

somatic mesoderm

A

layer of mesoderm covering the amnionic sac

from lateral plate mesoderm

242
Q

mesenchyme

A

loosely organized embryonic connective tissue from any origin

243
Q

intraembryonic cavity

A

formed by the somatic & splanchnic mesoderm layers

continuous with the extraembryonic cavity on each side of the embryo

W8 gives rise to peritoneal, pleural, & pericardial cavities (secreting membranes)

244
Q

somitomeres

A

segements of arranged paraxial mesoderm

formation begins cranially and moves caudally

head region: form with segmentation of neural plate into neuromeres & contribute to mesenchyme of the head

occipital region caudally: organize into somites

245
Q

somites

A

somitomeres occipital region caudally

organized segments of paraxial mesoderm that form rings on either side of the neural tube

3 pairs/day starting at D20 until end of W5 (42-44 pairs)

1st cervical and last 5-7 coccygeal disappear

form axial skeleton

246
Q

segmentation clock

A

NOTCH goes up in pre-somites cells→ decreases as somites form

boundaries regulated by: retinoic acid (RA) (higher cranially, lower caudally), FGF8 & WNT3a (both higher caudally & lower cranially)

247
Q

FGF2/FGFR

A

mesoderm cells→ express VEGF-R2

248
Q

VEGF/VEGF-R2

A

VEGF/Flk1

mesoderm cells→ hemangioblasts

249
Q

VEGF/VEGF-R1

A

VEGF/Flt1

endothelial coalescences into blood vessels

250
Q

VEGF

A

vascular endothelial growth factor

directs angiogenesis & vasculogenesis

secreted by mesoderm

251
Q

sclerotome

A

ventral & medial walls of somite that undergo epitelial→ mesenchymal shift @ W4

will become vertebrae & ribs (tendon, cartilage & bone of that somite)

ventromedial portion of somite induced by NOGGIN & shh from notochord & floor plate of neural tube

PAX1 expression tehn initiates bone & cartilage formation pathway

252
Q

dermatome

A

forms dermis of the back

cells between dorsomedial & ventrolateral upper edges of somite

retains innervation from its segment

253
Q

myotome

A

retains innervation from its segment

254
Q

dorsomedial & ventrolateral upper edge somites

A

precursors to muscle cells

some become mesenchymal again & migrate under dermatome to create dermomyotome

dorsomedial: produces MYF5 (muscle specific) as induced by WNT from dorsal medial tube

255
Q

dermomyotome

A

creates dermis for skin of back, back muscles, intercostal muscles, & some limb muscles

expresses PAX3 as regulated by WNT from dorsal neural tube

neurotrophin 3 (NT-3) secreted from dorsal region of neural tube directs midportion of dorsal epithelium of somite to become dermis

256
Q

lateral edge somite cells

A

migrate to parietal layer of lateral plate mesoderm to form muscles of anterior body wall & most of the limb muscles

inhibition of BMP4 & FGF & activation of WNTs from epidermis→ expression of MYOD (muscle specific)→ formation of primaxial & abaxial muscel precursors

257
Q

parietal layer

A

from lateral plate mesoderm

forms dermis of skin of the body wall & limbs, bone & connective tissue of the limbs, & sterum

scerlotome & muscle precursors that migrate here form costal cartilages, body wall muscles, & limb muscles

258
Q

visceral layer

A

from lateral plate mesoderm

w/embryonic endoderm, forms lining of gut tube

forms thin serous membranes around each organ

259
Q

mesothelial membrane

A

thin membranes from mesoderm cells of the parietal layer surrounding intraembryonic cavity

line peritoneal, pleural, & pericardial cavities & secrete fluid

260
Q

angiogenesis

A

when new blood vessels form from other blood vessels

induced by VEGF/VEGFR signaling

261
Q

vasculogenesis

A

formation of new blood vessels from blood islands

first blood island formation in W3 in mesoderm surrounding the yolk sac

blood islands arise from hemangoblasts that were once mesoderm cells

262
Q

neural inducers

A
  • noggin, chordin, follistatin
    • secreted by notochord to induce neuralization of ectoderm
    • cause development of forebrain & midbrain
  • WNT3a & FGF
    • caudal nerve plate induction to become hindbrain & spinal cord
263
Q

optic vesicle

A

evaginates form diencephalon→ grows toward lens placode

becomes optic cup: inner layer forms sensory retina & outer layer forms pigmented layer of eye

264
Q

ectoderm derivatives

A
  1. CNS
  2. PNS
  3. sensory eplithelium EEN
  4. epidermis of skin (hair, nail, mammary glands)
  5. anterior portion of pituitary gland
  6. tooth enamel
  7. neural crest cell derivatives
265
Q

D21

A

fusion of heart tubes into a sinle tube

heart beat at D21 or D22

single atrium & ventricle

266
Q

mesoderm derivatives

A
  1. connective tissue, cartilage, & bone (except head & neck)
  2. striated, smooth, & cardiac muscles
  3. blood, blood & lymph vessels, & heart
  4. kidney cortex
  5. gonads & ducts
  6. adrenal gland cortex
  7. spleen
  8. serous membranes lining body cavities
267
Q

vitelline duct

A

temporary communication of midgut (endoderm) with the yolk sac

268
Q

septum transversum

A

mass of cranial mesenchyme that gies rise to part od the diaphragm

269
Q

gastroschisis

A

birth defect in teh abdominal wall

intestines will be on the outside of the body

270
Q

Endoderm derivatives

A
  1. epitelial lining of GI tract
  2. epithelial lining of respiratory tract
  3. parenchyma of tonsils, thyroid, parathyroids, thymus, liver, & pancreas
  4. epithelial lining of urinary bladder & most urethra
  5. epithelial lining of tympanic cavity & auditory tube
271
Q

chondrotin sulfate

A

high levels inhibit migration of neural crest cells to the posterior somite

272
Q

neural crest cell derivatives

A
  1. Connective tissue of face & skull
  2. cranial nerve ganglia
  3. C cells of thyroid
  4. conotruncal septum of heart
  5. odontonblast (make dentin of teeth)
  6. dermis of face & neck
  7. dorsal root ganglia
  8. adrenal medulla
  9. schwann cells
  10. glial cells (enteric)
  11. melanocytes
  12. forebrain
273
Q

placenta

A

fetomateranal organ that facilitates nutrient & gas exchange between maternal & fetal compartments

torn from uterine wall & expelled as afterbirth, 30min after child birth

274
Q

chorion frondosum

A

villous (bushy) chorion of placenta formed by the fetus

villi of decidua basalis

increase in # & size

275
Q

decidua basalis

A

maternal placental part

functional layer of teh endometrium

W8

276
Q

decidua capsularis

A

superficial part of decidua that overlies conceptus

277
Q

decidua parientalis

A

decidua basalis of abembryonic side

278
Q

chorion laeve

A

smooth chorion

villi of decidua capsularis become compressed & degenerate after W8

279
Q

amniochorionic membrane

A

fusion of amnion & smooth chorion

due to faster speed of amniotic sac growth compared to chorionic sac

adheres to decidua parietalis

membrane that ruptures during birth

280
Q

placenta septa

A

aka decidua septa

form during M4 & 5, wedge shape area that form when decidua basalis erodes to enlarge intervillous space

divide placenta into compartments called cotyledons

281
Q

fetal circulation

A

umbilical arteries= 2, O2 poor blood

umbilical vein= 1, O2 rich blood

282
Q

placental membrane barrier

A

forms by W16, 4 layers: syncytiotrophoblast, cytotrophoblast, connective tissue (mesenchyme) of villous core, & endothelium of fetal capillaries

after W20, only syncytiotrophoblast & endothelium of fetal capillaries

IgG, T4, T3, & unconjugated steroids can cross

many drugs & viruses & treponema pallidum & toxoplasma gondii

283
Q

maternal IgG

A

can move through placental membrane barrier

confers fetal immunity to diptheria, smallpox, & measles

adult levels of IgG are not reached until 3

284
Q

erythroblastosis fetalis

A

aka hemolytic dz of newborn

if fetus is Rh+ & mother is Rh-, mother will create Rh antibodies that will pass to fetus & case hemolysis (rupture of red blood cells)

treated with anti-Rh immunoglobulin

285
Q

hCG

A

human chorionic gonadotropin

maintains corpus luteum

used to determine pregnancy starting at W2

peaks at W8

286
Q

hCS

A

human somatomammotropin

allows fetus priority on maternal blood glucose

promotes breast development for milk production

287
Q

estriol

A

maximum at end of pregnancy

stimulates uterine growth & development of mammary glands

288
Q

treponema pallidum

A

causes syphilis

can cross from mother to fetus

289
Q

toxoplasma gondii

A

protazoan that can cross from mother to fetus

causes damage to brain & eyes

290
Q

primitive umbilical cord

A

W5

connecting stalk (allontois & umbilical vessels), yolk sac, & canal connecting intra & extraembryonic cavities

formed as the amniotic cavity rapidly grows enveloping the connecting stalk & yolk sac stalk

291
Q

function of amnionic fluid

A

absorbs shock

allows for fetal movement

prevents adherence of embryo to amnion

maintains body temperature of fetus

barrier to infections

*replaced every 3 hrs, fetus swallow 400mL/day 5M and later

292
Q

hydramnios

A

aka polyhydramnios

excessive amounts of amniotic fluid

caused by maternal diabetes or congenital abnormalities that prevent fetal swallowing (anencephaly or esophageal atresia)

293
Q

oligohyramnios

A

insufficient amount of amniotic fluid

fetus can’t excrete urine (obstructive uropathy or fetal renal agenesis)

294
Q
A

Microanatomy (9 decks)

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