Embryology

The development of the ________ occurs during the first 8 weeks after fertilization.

Embryo

From week 8 to birth, the developing organism is referred to as a ________.

Fetus

A fertilized egg becomes a ________ during the early stages of development.

Zygote

The zygote undergoes division to produce a cluster of 8-16 cells called the ________.

Morula

The ________ is a solid mass of undifferentiated cells that can become any tissue of the embryo or placenta.

Morula

Upon entering the uterus, the morula undergoes further development to become a ________ around day 5.

Blastocyst

The ________ is the outer cell layer of the blastocyst.

Trophoblast

The inner cell mass of the blastocyst is also referred to as the ________.

Embryoblast

The trophoblast differentiates into two layers: ________ and syncytiotrophoblast.

Cytotrophoblast

The hormone ________ is secreted by the syncytiotrophoblast and helps maintain the corpus luteum.

hCG

The corpus luteum produces ________, which supports the uterine lining.

Progesterone

The inner cell mass forms two layers: epiblast and ________ (hypoblast).

Endoderm

The ________ forms dorsal to the epiblast during embryonic development.

Amniotic Cavity

The prochordal plate marks the ________ end of the embryo.

Cranial

A blighted ovum occurs when the trophoblast is maintained but the inner cell mass fails to ________.

Develop

During gastrulation, the primitive streak forms at the ________ end of the epiblast.

Caudal

The cells that migrate through the primitive streak give rise to the ________ layer of the embryo.

Mesoderm

Cells from the primitive knot migrate cranially to form the ________.

Notochord

The ectoderm differentiates into ________ as directed by the notochord.

Neuroectoderm

The thickness of the ectoderm above the notochord forms the ________ plate.

Neural

The closure of the neural tube begins around day ________ at the cranial neuropore.

26

Failure of neural tube closure can lead to ________ defects such as spina bifida or anencephaly.

Neural

Somites are formed from the ________ mesoderm during development.

Paraxial

The dorsal aspect of each somite is called the ________, which forms dermal tissue.

Dermatome

Motor fibers that innervate muscles originate from the ________ aspect of the spinal cord.

Ventral

The second arch in branchial arch development is innervated by cranial nerve ________ (VII).

Facial

The first branchial arch is associated with cranial nerve ________ (V), which has a maxillary and mandibular division.

Trigeminal

Muscles of mastication arise from the ________ branchial arch.

First

Oculomotor muscles are innervated by cranial nerve ________ (III) from the pre-otic somites.

Oculomotor

The ________ arch gives rise to the stylopharyngeus muscle innervated by cranial nerve IX.

Third

Taste sensation for the body of the tongue is primarily provided by the ________ nerve (V3).

Lingual

The ________ arch is responsible for innervating the pharyngeal constrictors and taste buds of the pharynx.

Fourth

The sixth arch is responsible for motor innervation to muscles like the trapezius and sternocleidomastoid via the ________ nerve.

Spinal Accessory

Paralysis of the spinal nerve can lead to ________, characterized by loss of motor function.

Flaccid paralysis

Sensory fibers that provide sensation from the ear canal travel through the ________ nerve.

Dorsal Root Ganglion

Development of facial structures involves the movement of the frontal nasal process towards the ________ nasal process.

Lateral

Muscles of facial expression are derived from the ________ branchial arch.

Second

Failure of cranial closure during development can result in ________, which is often incompatible with life.

Anencephaly

Dorsal and ventral roots of the spinal nerve connect with the ________ and myotome respectively.

Dermatome

In the context of neural development, the primary function of the notochord is to induce the ectoderm to differentiate into ________ cells.

Neuroectoderm

Occipital somites exclusively contribute to structures innervated by the ________ from the brain stem.

Cranial nerves

The ________ helps protect the cervical spinal nerve during the formation of the brachial arches.

Pretrematic nerve

Each arch is associated with a specific ________ arch and cranial nerves responsible for innervation.

Aortic

The second branchial arch gives rise to muscles of facial expression, and its sensory component is responsible for ________ innervation from the skin.

GSA

Branches of the facial nerve include the chorda tympani, which is responsible for ________ sensation from the anterior tongue.

Taste

Somite innervation maintains a pattern that persists even after ________.

Birth

Muscles of the palate receive their innervation primarily from the ________ nerve.

Vagus

The ________ cord connects to the brainstem and is involved in neck movements during development.

Cervical spinal

Spastic paralysis occurs due to damage to ________ nerves affecting muscle control.

Cortical