Year 2 Anatomy: Neural Crest, Eye and Ear

<p>Neuroectoderm (A)</p> Signup and view all the answers

<p>It disappears as the walls of the optic cup oppose each other (D)</p> Signup and view all the answers

<p>Elevating and fusing of the neural folds (A)</p> Signup and view all the answers

<p>Hirschsprung's disease (A)</p> Signup and view all the answers

<p>Melanocytes (C)</p> Signup and view all the answers

<p>Cataract formation (C)</p> Signup and view all the answers

<p>They migrate and differentiate into ganglia. (C)</p> Signup and view all the answers

<p>Rett syndrome (D)</p> Signup and view all the answers

<p>Enhanced ability to migrate and differentiate (B)</p> Signup and view all the answers

<p>Neural crest cells (A)</p> Signup and view all the answers

<p>Central artery and vein of the retina (C)</p> Signup and view all the answers

<p>7th week (A)</p> Signup and view all the answers

<p>Pars iridica retinae (C)</p> Signup and view all the answers

<p>Choroid (B)</p> Signup and view all the answers

<p>It forms the optic nerve and chiasm (D)</p> Signup and view all the answers

<p>Optic cup (B)</p> Signup and view all the answers

<p>It loses contact with the surface ectoderm (A)</p> Signup and view all the answers

<p>Outer layer of mesenchyme (A)</p> Signup and view all the answers

<p>It becomes fully myelinated by 3 months after birth. (C)</p> Signup and view all the answers

<p>Oligodendrocytes (D)</p> Signup and view all the answers

<p>Coloboma iridis (D)</p> Signup and view all the answers

<p>Tympanic membrane (B)</p> Signup and view all the answers

<p>1st pharyngeal arch (A)</p> Signup and view all the answers

<p>Neural crest (B)</p> Signup and view all the answers

<p>Saccule (A)</p> Signup and view all the answers

<p>It cannot regenerate. (B)</p> Signup and view all the answers

<p>Two germ layers (A)</p> Signup and view all the answers

<p>Auricular hillocks (A)</p> Signup and view all the answers

<p>Tympanic membrane rupture (A)</p> Signup and view all the answers

<p>Contribution to skeletal components of the face (C)</p> Signup and view all the answers

<p>First pharyngeal cleft (B)</p> Signup and view all the answers

<p>Mesenchymal tissue covered by ectoderm and endoderm (B)</p> Signup and view all the answers

<p>Incus (A)</p> Signup and view all the answers

<p>Microtia involves an underdeveloped external ear. (C)</p> Signup and view all the answers

<p>Fibrous and vascular coats of the eye (D)</p> Signup and view all the answers

<p>Surface ectoderm (B)</p> Signup and view all the answers

<p>They form the double-walled optic cup. (B)</p> Signup and view all the answers

<p>It completely disappears as the optic cup develops. (B)</p> Signup and view all the answers

<p>Neuroectoderm (C)</p> Signup and view all the answers

<p>Defective parasympathetic plexus (B)</p> Signup and view all the answers

<p>Liver parenchyma (C)</p> Signup and view all the answers

<p>Cataract formation (B)</p> Signup and view all the answers

<p>Inner ear (D)</p> Signup and view all the answers

<p>Hirschsprung's disease (B)</p> Signup and view all the answers

<p>Parasympathetic ganglia of the gastrointestinal tract (A)</p> Signup and view all the answers

<p>Coloboma (C)</p> Signup and view all the answers

<p>Inner layer of mesenchyme (D)</p> Signup and view all the answers

<p>Pars ciliaris retinae (D)</p> Signup and view all the answers

<p>7th week (D)</p> Signup and view all the answers

<p>Ciliary muscles and sphincter pupillae (C)</p> Signup and view all the answers

<p>Sclera (D)</p> Signup and view all the answers

<p>Optic stalk (D)</p> Signup and view all the answers

<p>Outer wall of the optic cup (B)</p> Signup and view all the answers

<p>Vacuolisation (B)</p> Signup and view all the answers

<p>The optic nerve does not regenerate after transection. (B)</p> Signup and view all the answers

<p>Bony labyrinth (D)</p> Signup and view all the answers

<p>It includes the tympanic membrane and auricle. (B)</p> Signup and view all the answers

<p>Oligodendrocytes (A)</p> Signup and view all the answers

<p>Congenital Aphakia (D)</p> Signup and view all the answers

<p>From first pharyngeal membrane components. (C)</p> Signup and view all the answers

<p>It is an element of the otic vesicle's ventral region. (D)</p> Signup and view all the answers

<p>They develop into the malleus, incus, and stapes. (D)</p> Signup and view all the answers

<p>Two germ layers (A)</p> Signup and view all the answers

<p>Anotia (C)</p> Signup and view all the answers

<p>First cleft (C)</p> Signup and view all the answers

<p>Neural crest cells (C)</p> Signup and view all the answers

<p>Skeletal muscles of the face (D)</p> Signup and view all the answers

<p>Microtia (A)</p> Signup and view all the answers

<p>Core of mesenchymal tissue (C)</p> Signup and view all the answers

<p>It forms the tympanic membrane. (D)</p> Signup and view all the answers

Specialized cells found at the border of the developing neural tube

Neural crest cells leave the neuroectoderm and travel to different parts of the developing embryo to make different tissues

Failure of neural crest cells to migrate properly to the bowel wall

A congenital disorder resulting in a lack of certain nerve cells (aganglionic segment) in the bowel, commonly the rectum and sigmoid colon

Neural crest cells differentiate into connective tissues and bones of the face and skull

Contribute to ganglia of the sympathetic and parasympathetic nervous systems

Eye development abnormalities that affect the structure and function

Problems during ear development are possible factors to the condition

The eye develops from neuroectoderm, surface ectoderm, mesoderm, and neural crest cells.

Shallow grooves on each side of the forebrain are the initial indicators of eye formation in a 22-day embryo.

Initially shallow grooves, the development leads to outpocketings called optic vesicles, as the neural tube closes.

The optic vesicles then invaginate further and forms a double-walled structure, like a cup; the optic cup

The lens vesicle is a structure which is formed when the optic vesicle comes into contact with the surface ectoderm that induces changes and forms a crucial part in eye development.

A fissure that allows passage of hyaloid vessels during development.

Temporary vessels that become central retinal vessels.

Surface ectoderm cells involved in lens development.

Invaginated lens placode.

Highly vascularized pigmented layer behind the retina, part of the eye.

Outer protective layer of the eye wall.

Space in front of the iris and behind cornea, part of the eye's structure.

Nerve formed by axons from ganglion cells of retina, part of the eye.

The optic nerve (CN II) is not fully myelinated until 3 months after birth. Myelination is done by Oligodendrocytes.

The optic nerve (CN II) cannot regenerate after being severed or damaged.

A birth defect where the iris doesn't fully form due to an incomplete closure of the choroid fissure.

A condition where the iris is completely absent at birth.

The ear develops from a thickened ectodermal placode at the rhombencephalon and from the first and second pharyngeal arches.

The ear has three main sections: the outer ear (auricle, external auditory meatus, eardrum), the middle ear (malleus, incus, stapes and the auditory tube), and the inner ear (cochlear duct, semicircular canals).

The membranous labyrinth includes the cochlear duct, utricle, saccule, and semicircular canals inside the bony labyrinth.

The eardrum (tympanic membrane) develops from the first pharyngeal membrane, combining ectoderm of the first pharyngeal cleft and endoderm of the first pharyngeal pouch.

The eardrum, or tympanic membrane, is a three-layered structure formed from two germ layers: ectoderm and endoderm. The outer layer originates from ectoderm, while the inner layer comes from endoderm.

The outer ear, or auricle, develops from six mesenchymal proliferations (auricular hillocks) surrounding the first pharyngeal cleft.

Congenital deafness can occur in the inner ear (due to factors like rubella), middle ear (due to problems with the first and second pharyngeal arches), or external ear (due to agenesis).

These are birth defects of the external ear, including accessory tragus (extra cartilage), microtia (small ear), anotia (absence of ear), and preauricular pits or sinuses (depressions or openings near the ear).

Each pharyngeal arch consists of a core of mesenchymal tissue covered by surface ectoderm (outer layer) and endoderm (inner layer) epithelium. Neural crest cells migrate into the arches, contributing to facial skeletal components, while mesoderm cells form face and neck muscles.

The first pharyngeal arch has a dorsal portion (maxillary process) and a ventral portion (mandibular process) containing Meckel's cartilage, which contributes to the development of the lower jaw.

Pharyngeal pouches are outpouchings of the primitive pharynx that contribute to the development of important structures like the parathyroid glands, thymus, and tonsils.

The first pharyngeal cleft, the only one to contribute to the development of the external auditory meatus, is involved in the formation of the ear canal. This cleft also contributes to the formation of the tympanic membrane.

A special group of cells found at the border of the developing neural tube, which migrate to various locations and differentiate into diverse structures.

A birth defect where neural crest cells fail to migrate to the bowel wall, resulting in a lack of nerve cells necessary for proper digestion and elimination.

The eye develops from several sources: neuroectoderm, surface ectoderm, mesoderm, and neural crest cells. These cells interact to form the different parts of the eye.

A birth defect that occurs when the choroid fissure, a gap involved in eye development, fails to close completely.

The ear develops from specialized ectoderm (placode) and contributes from pharyngeal arches, specifically the first and second, which contribute to its different parts.

Hearing loss present at birth due to problems during ear development, including issues with the inner, middle, or external parts.

Curved structures in the developing embryo that give rise to important facial structures, muscles, and nerves. Each arch involves a core of mesenchymal tissue, covered by ectoderm and endoderm.

The eye develops from four embryonic sources: neuroectoderm (retina, posterior iris, optic nerve), surface ectoderm (lens, cornea epithelium), mesoderm (vascular and fibrous layers), and neural crest cells (choroid, sclera, corneal endothelium).

The first sign of eye development is seen in a 22-day embryo as two shallow grooves on either side of the forebrain.

The lens vesicle, formed from the surface ectoderm, interacts with the optic vesicles and induces changes leading to the formation of the double-walled optic cup. This cup is a crucial structure for the eye's development.

The optic cup is a double-walled structure formed by the invagination of the optic vesicles. It eventually becomes the retina and the pigmented epithelial layer of the eye.

The inner wall of the optic cup develops into the neural retina (light-sensitive layer), while the outer wall forms the pigmented epithelium, which supports the retina.

Temporary blood vessels that supply the developing lens and retina.

The main blood vessels that supply the retina after the hyaloid vessels disappear.

Pharyngeal pouches are outpouchings of the primitive pharynx that contribute to the development of important structures like the parathyroid glands, thymus, and tonsils.

The first pharyngeal cleft, the only one to contribute to the development of the external auditory meatus, is involved in the formation of the ear canal. This cleft also contributes to the formation of the tympanic membrane.