ANAT2341 Lab 11 - Embryo to Fetus
| Lab 11: Introduction | Heart | Heart Abnormalities | Individual Assessment Group Projects - Assessor Final review before next week submission. Signalling: 1 Wnt | 2 Notch | 3 FGF Receptor | 4 Hedgehog | 5 T-box | 6 TGF-Beta |
Introduction
- Week 8 Stage 22 and 23
- Selected Stage 22 cross-sections and animations
- Week 10 Fetus
Week 8 Stage 22
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stage 22, Week 8, 54 - 56 days, 23 - 28 mm
Mesoderm: heart prominence, ossification continues Head: nose, eye, external acoustic meatus Body:straightening of trunk, heart, liver, umbilicus: placental cord, midgut herniation, allantois, vitelline duct Limb: upper limbs longer and bent at elbow, foot plate with webbed digits, wrist, hand plate with separated digits Straightening of trunk, pigmented eye, eyelid, nose, external acoustic meatus, ear auricle, scalp vascular plexus, separated digits (fingers), thigh, ankle, umbilical cord |
Embryo Anatomy
Now examine selected regions of the Stage 22 embryo and their overall development in the 3D animations.
Head Region
Shoulder Region
Chest Region
Abdomen Region
Hip Region
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Week 8 Stage 23
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Week 8, 56 - 60 days, 27 - 31 mm
scalp vascular plexus, eylid, eye, nose, auricle of external ear, mouth, sholder, arm, elbow, wrist, toes separated, sole of foot, umbilical cord Mesoderm: ossification continues Head: eyelids, external ears, rounded head Body: straightening of trunk, intestines herniated at umbilicus Limbs: hands and feet turned inward |
Week 10 Fetus (40mm)
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This is an image of the actual size comparison shown in the introduction of the Embryonic stage 13, 23 and Fetal stage 10 week 40mm. This stage of development is after the embryonic period (up to week 8), but only 2 weeks into early fetal development. |
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The fetal period is a time of extensive growth in size and mass as well as differentiation of organ systems established in the embryonic period. In particular, the brain continues to grow and develop, the respiratory system differentiates, the urogenital system further differentiates between male/female, endocrine and gastrointestinal tract begins to function.
Compare this 10 week fetus with the earlier Carnegie stage embryos: size, head/body proportions, brain, head, skeletal development. Note that in the early fetus the midgut remains herniated and will only be taken into the peritoneal cavity on further body wall growth. |
There are 4 sections taken in the sagittal plane (moving from the right at Plane A towards the midline at Plane D). Click on the small images (or the text below) to open the linked large image pages.
Planes
Plane A
Plane B
Plane C
Plane D
Midgut Herniation
Related Images
Fetus (week 10) Planes A (most lateral), B (lateral), C (medial) and D (midline) from lateral towards the midline.
- Human Fetus - most lateral | lateral | medial | midline
- Head - most lateral | lateral | medial | midline
- Cerebellum - most lateral | lateral | medial | midline
- Urogenital Unlabelled - most lateral | lateral | medial | midline
- Urogenital Labelled - most lateral | lateral | medial | midline
- Large Images - midline
- Image Source: UNSW Embryology, no reproduction without permission.
Week 12
<html5media height="420" width="550">File:Ultrasound_Fetus_02.mp4</html5media>
- Links: Ultrasound
Size
- Crown Rump Length (CRL) 85 mm (week 10 CRL 40mm), femur length 15 mm, biparietal diameter 25 mm
- Biparietal diameter
- Head circumference
- Abdominal circumference
- Femur length
- Foot length (correlates with CRL)
- Placental parameters (covered in next practical)
Head
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| Fetal head lateral | Fetal head medial |
- Tongue Week 12 - first differentiated epithelial cells
| Lab 11: Introduction | Heart | Heart Abnormalities | Individual Assessment Group Projects - Assessor Final review before next week submission. Signalling: 1 Wnt | 2 Notch | 3 FGF Receptor | 4 Hedgehog | 5 T-box | 6 TGF-Beta |
