EMBRYOLOGY

Question 1

ROSTRAL

Answer 1

head end

Question 2

CAUDAL

Answer 2

tail end

Question 3

NEURULATION

Answer 3

• folding process
• flat disc folds at edges
• forms a hollow cylinder
• 3 germ layers: ectoderm, mesoderm + endoderm
• neural plate to neural tube

Question 4

NOTOCHORD

Answer 4

• induce neural plate formation
• induce ectoblast cells above it to transform into neuroectoblast cells
• beneath ectoderm, neural groove
• becomes vertebral column

Question 5

NEURAL PLATE

Answer 5

includes neural crest cells + neural tube

Question 6

NEURAL TUBE

Answer 6

• precursor to central nervous system (from ectoderm)
• aka will form brain, spinal cord + retina
• cylinder of ectodermal cells

Question 7

NEURAL CREST CELLS

Answer 7

• when neural tube closes + separates from surface they migrate away
• form structures peripheral to CNS + sensory nerves

Question 8

NEURAL TUBE ORIGIN

Answer 8

• ectodermal origin
• neural ectoderm
• surface ectoderm

Question 9

NEURAL ECTODERM

Answer 9

produces all neurons, glial cells + epithelia of brain, spinal cord, retina e.t.c.

Question 10

SURFACE ECTODERM

Answer 10

• exterior
• forms exterior layers of skin
• e.g. corneal epithelium, conjunctiva, eyelid skin, lens + lacrimal drainage system

Question 11

WHEN DOES NEURAL TUBE CLOSE?

Answer 11

complete closure at end of week 4

Question 12

SOMITES

Answer 12

differentiate into dermis, skeletal muscle, cartilage, tendons + vertebrae

Question 13

NUMBER OF SOMITES PRESENT BY END OF WEEK 5?

Answer 13

42-44 pairs of SOMITES

Question 14

TWO WALLS OF OPTIC CUP GIVE RISE TO WHICH ADULT STRUCTURE?

Answer 14

RETINA

Question 15

PARAXIAL MESODERM DEVELOPS INTO WHICH MUSCLES OF EYE?

Answer 15

OCULAR MUSCLES

Question 16

ANOPTHALAMIA

Answer 16

absence of eye as a result of exposure of the mother to toxic chemicals during pregnancy

Question 17

WHAT IS OPTIC STALK RESPONSIBLE FOR?

Answer 17

connecting optic cup to forebrain, becomes optic nerve

Question 18

WHAT IS ABNORMALITY THAT IS THE FAILURE OF THE CHOROIDAL FISSURE TO CLOSE?

Answer 18

COLOBOMA

Question 19

SURFACE ECTODERM GIVES RISE TO WHICH STRUCTURES?

Answer 19

lens, lacrimal gland, corneal + conjunctival epithelium

Question 20

SCLERA + CHOROID DEVELOP FROM?

Answer 20

MESODERM

Question 21

SMOOTH MUSCLES OF IRIS DEVELOP FROM?

Answer 21

ectoderm at margin of optic cup

Question 22

LENS PLACODES CREATED FROM WHAT WHEN OPTIC VESICLES MAKES CONTACT WITH IT?

Answer 22

ECTODERM

Question 23

RETINA + OPTIC NERVE DEVELOP FROM?

Answer 23

NEUROECTODERM

Question 24

OPTIC VESICLES DEVELOPS FROM?

Answer 24

DIENCHEPHALON

Question 25

CONGENITAL CATARACT

Answer 25

cloudiness of lens

Question 26

REMAINING UNSPECIFIED STRUCTURES OF EYES ARE FORMED FROM THE?

Answer 26

MESODERM

Question 27

MICRO-OPTHALAMIA

Answer 27

too small eyes, caused by toxoplasmosis

Question 28

SMOOTH MUSCLES OF IRIS DEVELOPS FROM THE?

Answer 28

ECTODERM

Question 29

OCULAR MUSCLES DEVELOPED FROM THE?

Answer 29

PARAXIAL MESODERM

Question 30

TWO WALLS OF OPTIC CUP GIVE RISE TO?

Answer 30

PIGMENTED LAYER + SENSORY LAYER

Question 31

WHAT STRUCTURE MAKES CONTACT WITH OVERLYING ECTODERM + INDUCES IT TO THICKEN TO FORM LENS PLACODE?

Answer 31

OPTIC VESICLES

Question 32

OPTIC VESICLE INVAGINATES TO FORM A DOUBLE WALLED?

Answer 32

OPTIC CUP