Lesson 23: Fetal Skeleton Flashcards
Fetal limb buds can be seen as early as week ____.
Eight (8)
Long bones fully develop during the _______th to _______ week
7th to 12th
Bones in the hands and feet develop between weeks _____th to _____th
11th to 13th
Fetal long bones can be accurately measured from this many weeks onward
Twelve (12)
What femur do we measure? Why?
Anterior lying
Artificial bowing of posterior (short)
How many mm do the femurs grow per week from week 14-27? How many mm per week in the third trimester?
3 mm
1 mm
What factors can femur length depend on?
Maternal height
Weight
Ethnicity
True or False: The femur lies laterally
False
True or false: The radius is bigger than the ulna and lies medially
False: smaller and medial
This digit has two phalanges
Thumb
Each toe has ____ phalanges
Two (2)
The abnormal development of cartilaginous and osseous tissues is known as skeletal _______.
Dysplasia
True or False: Skeletal Dysplasia is common
False: rare
Short, bowed, thin or uneven long bones can be a sign of skeletal ________.
Dysplasia
Name the four classifications of skeletal dysplasia
1) Rhizomelia
2) Mesomelia
3) Acromelia
4) Micromelia
Rhizomelia is the _______ portion of the extremity shortened.
Proximal (think R is for Root)
Mesomelia is the ______ portion of the extremity shortened
Middle
Acromelia is the ________ portion of the extremity shortened
Distal
What is micromelia?
Shortening of the entire extremity
( Category of Skeletal Dysplasia)
Cloverleaf deformity, also known as craniosynostosis, is a sign of this type of _______ dysplasia
Thanatophoric
Lethal skeletal dysplasias are usually accompanied by __________ hypoplasia
Pulmonary
What is the most common form of lethal skeletal dysplasia?
Thanatophoric Dysplasia
Thanatophoric Dysplasia is more common in this sex
Male (2x)
Type 1 Thanatophoric dysplasia presents with extreme __________, ___________ long bones, normal trunk length, frontal _______, and ______ vertebral bodies.
Rhizomelia
Bowed
Bossing
Widened
Type 2 Thanatophoric Dysplasia presents with ________ long bones, _______ vertebral bodies, and this sign.
Straighter
Taller
Kleeblattschadel (Clover Leaf)
What is the most common NON lethal type of dwarfism?
Achondroplasia
“Trident” hand configuration is most commonly seen in ___________
Achondroplasia
True or False: Achondrogenesis is a rare and lethal form of skeletal dysplasia
True
Achondrogenesis is lethal due to _________
Pulmonary hypoplasia
What type of achondrogenesis presents with severe micromelia and a large head
Type 1 (Parenti-Fraccaro)
What type of Achondrogenesis presenets with prominent forehead and microagnathia
Type 2 ( Langer-Saldino)
What type of collagen does Osteogenesis Imperfecta affect?
Type 1: found in skin, ligaments, tendons and bone
Long bone rib fratures, blue sclera, and hearing impairment are found in patients who have ___________ ___________
Osteogenesis Imperfecta
What is the most severe type of Osteogenesis Imperfecta? What sign presents?
Type 2
Transparent Bone Sign
What kind of Dysplasia presents with a Bell-Shaped chest?
Camptomelic
Low or absent tissue non-specific alkaline phosphatase activity presents in this inherited disease
Congenital Hypophophotasia
When is Congenital Hypophosphotasia Type 1 detected? Type 2?
Prenatally (lethal)
Later in life
What type of Osteogenesis Imperfecta is the mildest?
Type 4
“Mitten hand”, also known as bilateral syndactyly is seen in this condition, particularly in this syndrome
Dysostosis: Apert Syndrome
A persistently clenched hand with an overlapping in fingers is strongly associated with trisomy ___.
18
Preaxial polydactly affects the ______side, while postaxial polydactyly affects the _______ side
Radial
Ulnar
Which long bone is most commonly affected by aplasia or hypoplasia?
Radius
Hemimelia is the absence of one or more extremities below the _____ or the ______.
Elbows
Knees
Acheira is absence of one or both _____
hands
Phocomelia is the absence of the ______ portion of an extremity, with the hand or foot attached to the trunk.
Proximal
Meromelia is absence of part of a ____
Limb
VACTERL stands for:
Vertebral, Anorectal, Cardiac, Tracheoesophageal, Renal, Limb abnormalities
How many of the abomalies of VACTERL must be present to confirm a condition?
3
What is commonly associated in affected fetuses of VACTERL?
Polyhydraminos
True or False: Club foot is often seen with cases of polyhydraminos
False: Oligohydraminos- restricts movement
The fusion of both lower extremities into a single lower extremity, with renal agenesis and severe oligohydraminos is called:
Sirenomelia or Mermaid Syndrome
Constriction rings, edema of digits, and multiple anamolies is associated with ____ _____ _____
Amniotic Band Sequence
