Embryology

Question 0

How long is the embryonic period?

Answer 0

2-8 weeks

Question 1

How long is the germinal period?

Answer 1

0-2 weeks

Question 2

How long is the fetal period?

Answer 2

8-40 weeks

Question 3

What is gastrulation?

Answer 3

When the embryo transforms from a bilaminar to trilaminar

Question 4

What is neurulation?

Answer 4

Process whereby the neural plates forms the neural tube

Question 5

When does closure of the cranial neuropore occur?

Answer 5

Day 25

Question 6

When does closure of the caudal neuropore occur?

Answer 6

Day 28

Question 7

What appears at the end of gastrulation?

Answer 7

Notochord (which forms to be the spinal cord)

Question 8

When does brain development begin?

Answer 8

Day 28

Question 9

What are the three main divisions of the brain?

Answer 9

Prosencephalon (forebrain), mesencephalon (midbrain), and rhombencephalon (hindbrain)

Question 10

What are the two divisions of the prosencephalon?

Answer 10

Telencephalon (cerebral hemispheres) and diencephalon (thalamus, hypothalamus, and epithalamus)

Question 11

What does the mesencephalon connect?

Answer 11

Forebrain to the hindbrain

Question 12

What are the three divisions of the rhombencephalon?

Answer 12

Pons, medulla, and cerebellum

Question 13

What is the spinal cord continuous with?

Answer 13

Rhombencephalon

Question 14

What are somites?

Answer 14

Form along the sides of the neural tube and give rise to the vertebrae, muscles of the back, and dermis of the skin

Question 15

What do somites develop into?

Answer 15

Myotomes, ventromedial sclerotomes, and dermatomes

Question 16

How many pairs of somites do we have?

Answer 16

42-44 pairs

Question 17

How long is the embryonic period?

Answer 17

Six weeks

Question 18

What are the three layers of the cells?

Answer 18

Ectoderm, mesoderm, and endoderm

Question 19

What does the endoderm form?

Answer 19

Digestive and respiratory systems

Question 20

What does the mesoderm form?

Answer 20

Muscles, skeleton, circulatory system, reproductive system, and dermis

Question 21

What does the ectoderm form?

Answer 21

CNS, PNS, eyes, ears, and outer skin

Question 22

What happens during embryo week 4?

Answer 22

Arm and leg buds appear and the heart pumps blood

Question 23

What occurs during embryo week 5?

Answer 23

Forebrain, midbrain, and hindbrain form

Question 24

What occurs during embryo week 6?

Answer 24

Digital rays are formed in hands

Question 25

What occurs during embryo week 7?

Answer 25

Eyelids begin to form and some motor behavior of neck

Question 26

What occurs during embryo week 8?

Answer 26

Eyes, ears, nose, mouth, and digits are formed, apoptosis, and muscle contraction appears

Question 27

What happens during week 9?

Answer 27

Sensory organs develop

Question 28

What happens during week 12?

Answer 28

Sex is recognized and brain configuration is nearly complete

Question 29

What happens during weeks 13-16?

Answer 29

Breathing and swallowing occurs

Question 30

What happens during week 16?

Answer 30

Motor activity begins, heart muscles developed, and sense organs are formed

Question 31

What happens during week 17?

Answer 31

Grasp reflex appears

Question 32

What happens during week 20?

Answer 32

Myelination of spinal cord begins

Question 33

What happens during week 24?

Answer 33

Lungs become viable organs and midgestation (full ROM)

Question 34

What happens during week 26?

Answer 34

Eyes open

Question 35

What happens during week 40?

Answer 35

Myelination of brain begins

Question 36

What are the two types of skeletal development?

Answer 36

Intramembranous and endochondral

Question 37

What is intramembranous ossification?

Answer 37

Replacement of connective tissue membranes with bony tissue - forms flat bones of skull and irregular shaped bones

Question 38

What is endochondral ossification?

Answer 38

Replacement of hyaline cartilage with bony tissue - most bones formed this way

Question 39

How does ossification occur?

Answer 39

From center of bone to the ends

Question 40

Are upper limb buds or lower limb buds more delayed with growth?

Answer 40

Lower limb buds by 1-2 days

Question 41

When do the limbs extend and rotate in opposite directions?

Answer 41

Week 7

Question 43

What happens if apoptosis does not occur?

Answer 43

Webbed fingers or toes

Question 44

When do the peripheral nerves extend from the limb plexus into the limb bud?

Answer 44

Week 5