Embryology

Question 1

Pre-Embryonic Stage

Answer 1

0-14 days
-Inner cell mass of cells becomes embryonic disc
-endoderm and ectoderm

Question 2

Embryonic Stage

Answer 2

15dy- 8wks
-3 layers

Question 3

Ectoderm

Answer 3

-NS
-epidermis

Question 4

Mesoderm

Answer 4

-CS
-Excretory sys
-dermis
-muscles
-skeleton

Question 4

Endoderm

Answer 4

-Respiratory sys
-organs

Question 5

Fetal Stage

Answer 5

8wks - Birth
-myelination starts

Question 6

Neural Tube Development

Answer 6

18-26 days
-Neural groove done at 21d
-closes at cervical 1st
-Superior neuropore closes at 27d

Inner layer
-grey matter
-dorsal horn: sensory
-ventral horn: motor

Outer layer
-white matter

Question 7

Somites

Answer 7

-appear in occiput first, the caudally

Anteromedial: vertebrae and skull
Posteromedial: muscles of myotome
Later: dermis/dermatome

Question 8

Conus Medullaris

Answer 8

-end of SC

Question 9

Cauda Equina

Answer 9

-individual nerves extending at end of SC
-starts at L1-L2

Question 10

Filum Terminale

Answer 10

-connection of meninges at end of SC

Question 11

SC Growth

Answer 11

-stops at 4-5
-vertebral column stops at 16-18y

Question 12

Grey and White Matter

Answer 12

SC:
Grey: outside, unmyelinated
White: inside, myelinated

Brain:
Grey: inside, unmeylinated, cell bodies
White: outside, myelinated

Question 13

Brain Development

Answer 13

Hindbrain: brainstem (w/o midbrain), 4th ventricle

Midbrain: cerebral aquaduct

Forebrain
Posterior: Diencephalon
Anterior: telencephalon (cortex, white matter, lateral ventricles

Question 14

Abnormal Neck and reflexes

Answer 14

-Asymmetric tonic reflex
-Symmetric tonic reflex
-Tonic labyrinth reflex

Question 15

Neural Tube Defects

Answer 15

-Anencephaly: head does not develop
-Chiari Malformation: foramen magnum contains part of brainstem
-Spina Bifida
-Tethered cord syndrome: filum terminale is stretched

Question 16

Geriatric Cognition

Answer 16

-decreases everywhere
-long term memory and procedural are stable
-retention of new info stable but needs more cues
-visual recognition of objects are stable
-decrease in vocabulary

Question 17

Atypical Cognition Aging

Answer 17

-mood changes
-visual-spacial changes
-memory changes
-difficulty communicating

Question 18

Mild cognitive impairment

Answer 18

-do not interfere with ADLS (unlike dementia and Alzheimer’s)
-90% develop alzheimer’s
-gradual, opposite of learning

Question 19

Causes of Aging Changes

Answer 19

-25% of motor neurons die
-myelin fragmented
-less dendrite density, less neurotransmitters, less synapses
-shrinkage