Exam 1 Structures/Germ Layer Fates Flashcards
What structures are identifiable in week 4?
- neural tube
- pharyngeal arches
- forebrain
- caudal eminence
- upper limbs buds
- otic pits
- lens placode
- lower limb buds
- rudiments of CV system
What structures are identifiable in week 5?
- minor changes in body form
- increased cranial growth
- cervical sinus
- some increased growth and development of existing structures, particularly limb buds
What structures are identifiable in week 6?
- upper limb buds show regional differentiation; large hand plates; digital rays
- auricular hillock
- external acoustic meatus
- heart prominence prominent
What structures are identifiable in week 7?
- limbs continue to develop
- communication between primordial gut and yolk sac decreases
- intestines enter the extraembryonic coelom in the proximal part of the umbilical cord
What structures are identifiable in week 8?
- digits of hands are separated, but webbed
- scalp vascular plexus becomes prominent
- head still disproportionately large
- neck region established
- eyelids more obvious and close by end of 8th week due to epithelial fusion
- auricles of the ear begin to take shape
- some sex differentiation but inaccurate identification
Epidermis arises from
surface ectoderm
Hair arises from
surface ectoderm
Nails arise from
surface ectoderm
Cutaneous glands arise from
surface ectoderm
Mammary glands arise from
surface ectoderm
Anterior pituitary gland arises from
surface ectoderm
Parenchyma of salivary gland arises from
surface ectoderm
Enamel of teeth arise from
surface ectoderm
Lens arises from
surface ectoderm
Inner ear arises from
surface ectoderm
Mesoderm divides into:
- paraxial mesoderm
- lateral plate mesoderm
- intermediate mesoderm
Epithelial component of trachea arises from:
endoderm
Bronchi and lungs arise from
endoderm
Epithelium of GI tract arise from
endoderm
Urinary bladder and urachus arise from
endoderm
Epithelial component of pharynx arises from
endoderm
Thyroid arises from
endoderm
Tympanic cavity arises from
endoderm
Pharyngotympanic tube arises from
endoderm
Tonsils and parathyroids arise from
endoderm
Cranial and sensory ganglia and nerves arise from:
neural crest
Adrenal medulla arise from:
neural crest
Ectomesenchyme bones and skull arise from
neural crest
Dentin arises from
neural crest
Periodontal ligament arises from
neural crest
Alveolar bone arises from
neural crest
Posterior pituitary arises from
neuroectoderm
Pineal body arises from
neuroectoderm
Retina arises from
neuroectoderm
CNS arises from
neuroectoderm
Urogenital system arises from
Intermediate mesoderm
Muscles of trunk and skeleton, except skull, arise from
paraxial mesoderm
Dermis of skin arises from
paraxial mesoderm
Connective tissue (mesenchyme) arises from
paraxial and lateral plate mesoderm
Muscles of viscera arise from
Lateral plate mesoderm
Serous membranes of pleura arise from
Lateral plate mesoderm
Pericardium and peritoneum come from
Lateral plate mesoderm
Blood and lymph cells arise from
Lateral plate mesoderm
CV and lymphatic systems arise from
Lateral plate mesoderm
Spleen arises from
Lateral plate mesoderm
Adrenal cortex arises from
Lateral plate mesoderm