Lesson 23: Fetal Skeleton

Question 1

Fetal limb buds can be seen as early as week ____.

Answer 1

Eight (8)

Question 2

Long bones fully develop during the _______th to _______ week

Answer 2

7th to 12th

Question 3

Bones in the hands and feet develop between weeks _____th to _____th

Answer 3

11th to 13th

Question 4

Fetal long bones can be accurately measured from this many weeks onward

Answer 4

Twelve (12)

Question 5

What femur do we measure? Why?

Answer 5

Anterior lying
Artificial bowing of posterior (short)

Question 6

How many mm do the femurs grow per week from week 14-27? How many mm per week in the third trimester?

Answer 6

3 mm
1 mm

Question 7

What factors can femur length depend on?

Answer 7

Maternal height
Weight
Ethnicity

Question 8

True or False: The femur lies laterally

Answer 8

False

Question 9

True or false: The radius is bigger than the ulna and lies medially

Answer 9

False: smaller and medial

Question 10

This digit has two phalanges

Answer 10

Thumb

Question 11

Each toe has ____ phalanges

Answer 11

Two (2)

Question 12

The abnormal development of cartilaginous and osseous tissues is known as skeletal _______.

Answer 12

Dysplasia

Question 13

True or False: Skeletal Dysplasia is common

Answer 13

False: rare

Question 14

Short, bowed, thin or uneven long bones can be a sign of skeletal ________.

Answer 14

Dysplasia

Question 15

Name the four classifications of skeletal dysplasia

Answer 15

1) Rhizomelia
2) Mesomelia
3) Acromelia
4) Micromelia

Question 16

Rhizomelia is the _______ portion of the extremity shortened.

Answer 16

Proximal (think R is for Root)

Question 17

Mesomelia is the ______ portion of the extremity shortened

Answer 17

Middle

Question 18

Acromelia is the ________ portion of the extremity shortened

Answer 18

Distal

Question 19

What is micromelia?

Answer 19

Shortening of the entire extremity
( Category of Skeletal Dysplasia)

Question 20

Cloverleaf deformity, also known as craniosynostosis, is a sign of this type of _______ dysplasia

Answer 20

Thanatophoric

Question 21

Lethal skeletal dysplasias are usually accompanied by __________ hypoplasia

Answer 21

Pulmonary

Question 22

What is the most common form of lethal skeletal dysplasia?

Answer 22

Thanatophoric Dysplasia

Question 23

Thanatophoric Dysplasia is more common in this sex

Answer 23

Male (2x)

Question 24

Type 1 Thanatophoric dysplasia presents with extreme __________, ___________ long bones, normal trunk length, frontal _______, and ______ vertebral bodies.

Answer 24

Rhizomelia
Bowed
Bossing
Widened

Question 25

Type 2 Thanatophoric Dysplasia presents with ________ long bones, _______ vertebral bodies, and this sign.

Answer 25

Straighter Taller Kleeblattschadel (Clover Leaf)

Question 26

What is the most common NON lethal type of dwarfism?

Answer 26

Achondroplasia

Question 27

"Trident" hand configuration is most commonly seen in ___________

Answer 27

Achondroplasia

Question 28

True or False: Achondrogenesis is a rare and lethal form of skeletal dysplasia

Answer 28

True

Question 29

Achondrogenesis is lethal due to _________

Answer 29

Pulmonary hypoplasia

Question 30

What type of achondrogenesis presents with severe micromelia and a large head

Answer 30

Type 1 (Parenti-Fraccaro)

Question 31

What type of Achondrogenesis presenets with prominent forehead and microagnathia

Answer 31

Type 2 ( Langer-Saldino)

Question 32

What type of collagen does Osteogenesis Imperfecta affect?

Answer 32

Type 1: found in skin, ligaments, tendons and bone

Question 33

Long bone rib fratures, blue sclera, and hearing impairment are found in patients who have ___________ ___________

Answer 33

Osteogenesis Imperfecta

Question 34

What is the most severe type of Osteogenesis Imperfecta? What sign presents?

Answer 34

Type 2 Transparent Bone Sign

Question 35

What kind of Dysplasia presents with a Bell-Shaped chest?

Answer 35

Camptomelic

Question 36

Low or absent tissue non-specific alkaline phosphatase activity presents in this inherited disease

Answer 36

Congenital Hypophophotasia

Question 37

When is Congenital Hypophosphotasia Type 1 detected? Type 2?

Answer 37

Prenatally (lethal) Later in life

Question 38

What type of Osteogenesis Imperfecta is the mildest?

Answer 38

Type 4

Question 39

"Mitten hand", also known as bilateral syndactyly is seen in this condition, particularly in this syndrome

Answer 39

Dysostosis: Apert Syndrome

Question 40

A persistently clenched hand with an overlapping in fingers is strongly associated with trisomy ___.

Answer 40

18

Question 41

Preaxial polydactly affects the ______side, while postaxial polydactyly affects the _______ side

Answer 41

Radial Ulnar

Question 42

Which long bone is most commonly affected by aplasia or hypoplasia?

Answer 42

Radius

Question 43

Hemimelia is the absence of one or more extremities below the _____ or the ______.

Answer 43

Elbows Knees

Question 44

Acheira is absence of one or both _____

Answer 44

hands

Question 45

Phocomelia is the absence of the ______ portion of an extremity, with the hand or foot attached to the trunk.

Answer 45

Proximal

Question 46

Meromelia is absence of part of a ____

Answer 46

Limb

Question 47

VACTERL stands for:

Answer 47

Vertebral, Anorectal, Cardiac, Tracheoesophageal, Renal, Limb abnormalities

Question 48

How many of the abomalies of VACTERL must be present to confirm a condition?

Answer 48

3

Question 49

What is commonly associated in affected fetuses of VACTERL?

Answer 49

Polyhydraminos

Question 50

True or False: Club foot is often seen with cases of polyhydraminos

Answer 50

False: Oligohydraminos- restricts movement

Question 51

The fusion of both lower extremities into a single lower extremity, with renal agenesis and severe oligohydraminos is called:

Answer 51

Sirenomelia or Mermaid Syndrome

Question 52

Constriction rings, edema of digits, and multiple anamolies is associated with ____ _____ _____

Answer 52

Amniotic Band Sequence