exam 1, week 2 Flashcards
fertilization occurs in
ampulla
general timeline
Day 1- zygote
Day 2- 2 blastomeres
Day 3- about 8 cells, end of synchronous division
Day 4- Morula
Day 5-6- blastocyte,
then hatching of zona pellucida-> late blastocyte, where every it is, it will attach
Day 6-8- implantation
Day 10: embryonic cells fill in the layer between trophoblast and yolk sak/amniotic cavity
Day12: chorionic cavity develops within extraembryonic mesoderm
Day 13: yolk sak divides into primary and seonddary umbilical vesicle
Day 14- chorionic cavity isolate embryo, connecting stalk formed
review pictures
blastomeres
First 2 cells after first cleavage
Morula
ball of 16 cells, made after 4 consecutive sets of division, still in zona pellucida (day 3-4)
blastocyst
cells in morula shrink leaving spaces due to getting rid of excess storage in the cytoplasm. Cell migrate to the edge allowing morula to shrink (day 4-5)
Trophoblast layer
outer edge of cells, become placenta
Embryooblast
inner cell becomes embryo
Blastocyst cavity
open space
further development
o Early hypoblast forms, otherwise undifferentiated embryoblast
o Blastocystic cavity-> exocelomic cavity
o Embryoblast-> epiblast
o Hypoblast-> exocelomic membrane
o Amniotic cavity is formed (later becomes yolk sak)
o Cytotrophoblast (cellular layer), synctyiotriphoblast (contacts maternal blood stream for nutrients and immunoresponse)
o Bilaminar disc embryo- epiblast and hypoblast
Day 10- embryonic cells fill in the layer between trophoblast and yolk sak/amniotic cavity, extra-embryonic mesoderm forms
o Chorionic cavity develops by cavitation within extraembryonic mesoderm (chroionic membrane (somatropleuric layer) and exocoelomic (splanchnopleuric or Heuser’s) Membrane)
o Yolk sak divides to primary umbilical vesicle and secondondary umbilical
o Chorionic cavity isolates embryo, connecting stalk formed
Parthenogenesis
development of zygote without fertilization, oocytes will divide
Cloning-
for stem cell research, for reproductive and therapeutic purposes
CNS
brain and spinal cord
white matter
myelinated axon tracts, relays info
on the outside of spinal cord and inside of brain
gray matter
cell bodies, dendrites, unmyelinated, neurolgia, blood
inside of spinal, inside brain
myelin made in CNS
oligodendrocytes
myeline made in PNS
schwann cells
PNS
peripheral nerves, cranial nerves (12 pairs), spinal nerves (31 pairs)
Collection of PNS cell bodies is a ganglion
peripheral nerves
bundles of axons and supporting neuroglia
dorsal rami
supply veretabral joints, deep back muscles, skin of back
ventral rami
supply the rest of the muscles, many plexuses
SNS
somatic, voluntary
2 branches general motor (efferent) general sensory (afferent)
motor pathway
2-3 neurons
upper motor neuron
interneuron (sometimes)
lower motor neuron
sensory pathway
cell bodies are in dorsal root ganglion
3 neurons
1st order- to spinal cord or brain
2nd order to thalamus
3rd order to cerebral cortex
ANS
2 branches 1. visceral motor efferent (sympathetic/parasympathetic) goes to smooth muscle 2. visceral sensory (afferent), cell bodies in doral root
how many nerves at each level
cervical 8 nerves, 7 vertebrate over until C8
T12
L5
S5
coccylgeal
ANS
motor
sympathetic vs parsympatetic
2 neuron systems
preganglonic
postganglionic
sympathetic neuron
short, long
synapse in ganglion root
parasympathetic
long, short
synapse in wall of target
Sympathetic nerves
Lateral nerves only exist at T1-L2, only place with sympathetic cell bodies
Sympathetic nerves must travel up or down sympathetic chain
Rami communicans
White- on to ventral rami (only on T1-L2)
Gray- off to ventral rami (along entire spinal cord) superior to white
sympathetic to head
Sympathetic to head: up the chain, synapse in closest cervical ganglia
To throax- chain off gray rami communicans to closet ganglia to organ
To abdomen- 3 neurons greater, lesser, and least thoracic splanchnic nerves to preaortic ganglia (in front of aorta), also lumbar splanchnics
To pelvis- sacral splanchnics
3 options for sympathetic pathways
- Synapse at same level and exit into ventral rami
- Travel in chain, synapse at another level, exit into ventral rami,
- Travel through chain without synapsing, exit on splanchnic to preaortic ganglia, synapse and go to organ (splanchnic nerve)
Parasympathetic (cranial sacral)
Only derive from cranial serves 3,7,9,10 and from sacral spinal cord S2-4
Ex vagus nerve
Pelvic splanchnic nerves- carry parasympathetic fibers
Dermatomes
spinal level of sensation, area of skin where all cutaneous fibers track back to the same spinal level
Can’t be dissected
Cutaneous nerves
sensory nerves, carry axon, can be multiple spinal levels and contribute to multiple dermatomes
derm vs cutaneous nerve
Derm, cutaneous- have different patterns
Derm- trace back to 1 level, fuzzy borders
Cutaneous- trace back to a nerve, ex entrapments
myotome
muscles that spinal nerves innervate
Isomers
same chemical formula, different congiburation
epimer
molecules that differ in arrange at a single carbon
example
galatose and glucose at C4
glucose and mannose at C2
enantiomers
mirror images
example D-glucose and L-glucose
cyclization
linear to cyclic, a new asymmetric carbon is made
ex: D-glucose to alpha D glucopyranose (6 C ring)
D-fructose to alpha D fructofuranose (5 C ring)
cylicization creates
alpha vs beta
anomers
alpha OH below
beta OH above
interconvert by mutaroation, determines bonding
lactose
galactose beta 1-4 glucose
sucrose
glucose alpha 1-2 fructose
maltose
glucose alpha 1-4 glucose
isomaltose
glucose alpha 1-6 glucose
glycogen
D glucose polymer
alpha 1,4 linear change
alpha 1,6 branch points
starch
D glucose polymer
amylose: unbranched alpha 1,4 glucose bonds
amylopectin: alpha 1,4 and alpha 1,6 glucose bonds
cellulose
D glucose polymer
beta 1,4 bonds
non digestible fibers
what is the significance of isomers
Isomers dictate the type of bonding and physical processing
Enzymes create or digest bonds that are specific for a type of bond
define specificity affinity capacity hormonal regulation
in terms of transporters
Specificity- what does it transport
Affinity- high affinity- active at low fasting and high fed, low affinity active at high fed
Capacity- low capacity- easily saturated
Hormonal regulation- ex insulin dependent transporters
Basal glucose uptake
constant supply of glucose
Glut 1 and 3
high affinity, low capacity, red blood cells and brain, constant glu supply, uptake is independent of concentration
Glut 2
low affinity, high capacity, liver and pancreas, equilibrium of intracellular glu with blood glu concentrations
Glut 4
GLUT 4- insulin dependent uptake after meal, high affinity, important for lowering blood glu levels, insulin increases the number of receptor on cell surface, in muscle or adipose tissue
sources of glucose for glycolysis
Sources from glycogenolysis in exercising muscle
Dietary intake of carbs
Glycogenolysis and gluconeogenesis in liver
glucokinase vs hexokinase
Glucose to glucose-6-phosphate by hexokinase or glucokinase, uses 1 ATP, irreversible
Glucokinase- in liver and pancreas, high Km (low affinity), high Vmax, more active in fed state, inducible by insulin
Hexokinase- everywhere else, low Km (high affinity for glucose), low Vmax, more active in fasting state, allosterically inhibited by glucose-6P
know all of glycolysis
AHHHHHH
aerobic glycolysis
glucose -> 2 pyruvate, 2 ATP and 2 NADH (NADH to ECT, pyruvate to AcCoA to TCA)
anaerobic glycolysis
glucose-> 2 lactate, 2 ATP NO NADH, lactate cannot be converted to AcCoA, cannot enter TCA cycle
pyruvate kinase regulators
allosteric and hormonal
Pyruvate kinase allosteric regulators:
Inhibited by ATP
Activated by fructose 1,6-BP
Pyruvate kinase hormonal regulators:
ONLY occurs in LIVER
Glucagon inactivates pyruvate kinase via phosphorylation (directs PEP to gluconeogenesis)
PFK-1 inhibtors
allosteric
hormonal
how it relates to PFK 2
PFK-1:
Inhibited by ATP and citrate
Activated by AMP and fructose 2,6 BP
PFK 1 vs 2 pathway (2 goes to fructose 2,6 BP)
Hormonal regulation:
Insulin activates PFK-2
Glucagon activates f-2,6-Bpase
Looks at pics
Describe how pyruvate kinase deficiency results in hemolytic anemia.
Low pyruvate kinase leads to decreased ATP production
This impairs stability of RBCs-> change in cell shape -> echinocytes (Burr cells)-> cell lysis -> nonspherocytic hemolytic anemia
malate-apspartate shuttles vs glyceral 3-phosphate
NAD/NADH
vs
FAD/FADH2
recycling
GLUT 5
transports fructose from blood into cells
3 types of artifacts
- reverberation artifact (A lines)
- Mirror-image
- Acoustic shadowing artifact
anechoic
dark (no gray),
ex blood vessel
hypoechoic
dark gray
hyperechoic
bright white
linear probe
high frequency (5-12) good for arteries, veins, thyroid, lymph, skin, nerves)
Phased Array (ECHO) probe
rectangular, low frequency
good for heart, lungs, thorax
curvilinear
low frequency
good for gallbladder, liver, kidney, spleen, bladder, abdomen, uterus/ovaries
intracavitary
low or high frequency
good for uterus/ovaries, pharynx, oral, rectal
2 axis
long axis- longitudinal, sagittal plane
short- transverse axis
RNA polymerase in Euks vs Ecoli
E coli- has 1 type of RNA
s unit binds directly to promotor
Euks
pol 1- rRNA
pol 2- mRNA
pol 3- tRNA
brought to RNA via transcription factors
2 RNA inhibitors
Rifampin- bacteria
alpha- amanitin- euk
Rifampin
antibiotic
bacterial RNA polymerase inhibitor, binds b subunit and blocks the path of nascent RNA. Mutations in b subunit prevent rifampin binding
alpha amanitin
poisonous mushroom
a-amanitin binds to the largest subunit of eucaryotic RNA polymerase
The presence of nucleus in eucaryotic cells uncouples
translation from transcription
mRNA editing
Euk mRNAs are modified by addition of a 7-methyl guanosine cap at the 5’-end and a polyA tail at the 3’-end. Following their modifications, these mRNAs are subjected to splicing.
mRNA splicing
Splicing involves spliceosomes (ribonucleoproteins), conserved 5’-splice (donor), branch and 3’-splice (acceptor) sites that facilitate transesterification
alternative splicing example
calcitonin and CGRP synthesis
tRNA processing
tRNAs are processed by ribozyme RNAse P, endonuclease and ligase
rRNA processing
on the other hand, are processed by chemical modifications and cleavage of a large precursor RNA
RNA editing examples
Same pre-mRNA leads to two apolipoprotein B100 and B48. Apolipoprotein B48 arises due to editing of CAA to UAA, a stop codon
transcription factors
bind to promoter for basal transcription
Pit 1 and Prop 1
Pit 1- regulates growth hormone
Prop 1- regulates Pit 1
Both are transcription factors. When mutated it leads to GH deficiency
Huntington protein
Brain dervived neurotrophic factor (BDNT)
Normal huntingon gene- REST is bound, can make NRSE-> BDNT occurs
Mutant huntington- REST is loose -> represses NRSE-> no BDNF- death or neurols
