Derivatives of Mesoderm and Endoderm & Body Folding

Flashcards covering the derivatives of the mesoderm and endoderm, body folding, and teratology.

Cells close to the midline form a thickened plate known as ___ (future somites)

Future somites

Intermediate mesoderm contributes to the formation of the___.

Urinary and genital (gonads and ducts) systems i.e kidneys (but not the urinary bladder), gonads and their ducts

The major structures moved ventrally and caudally by head folding are___.

Septum transversum: future diaphragm (central part), cardiogenetic region and the future pericardial cavity, oropharyngeal membrane

Results of formation of the head fold includes reposition of the organs such as___.

Brain, oropharyngeal membrane, heart and septum transversum (will become the central part of the diaphragm)

The terminal part of the hindgut dilates to form___.

The cloaca, the precursor of the urinary bladder and rectum

Lateral folding results in the___.

Formation of ventral body wall and part of the endoderm is incorporated into the embryo as the midgut

The mesoderm that surrounds the gut is the Splanchnic mesoderm which forms the___.

Smooth muscles of the wall of the GIT

Dorsally, the foregut will form___.

Digestive portion which will form pharynx, esophagus and stomach

Ventrally, the foregut will form___.

Respiratory portion that forms trachea and lungs

List some major derivatives of the mesoderm germ layer:___.

All skeletal and cardiac muscle tissue and most smooth muscle tissue, cartilage, bone, and other connective tissues, blood, red bone marrow, and lymphatic tissue, blood vessels and lymphatic vessels, dermis of skin, fibrous tunic and vascular tunic of eye, mesothelium of thoracic, abdominal, and pelvic cavities, kidneys and ureters, adrenal cortex, gonads and genital ducts (except germ cells), dura mater

Major derivatives of the ___germ layer include epidermis, hair, nails, glands of skin, nucleus pulposus of intervertebral discs, dermis of dorsal body region, trunk and limb musculature, connective tissues of limbs (bones, joints, and ligaments), wall of digestive and respiratory tracts (except epithelial lining).

Epidermis, hair, nails, glands of skin, nucleus pulposus of intervertebral discs, dermis of dorsal body region, trunk and limb musculature, connective tissues of limbs (bones, joints, and ligaments), wall of digestive and respiratory tracts (except epithelial lining)

___is a branch of embryology that studies the causes, mechanisms and the patterns of abnormal development.

A branch of embryology that studies the causes, mechanisms and the patterns of abnormal development

A teratogen is___.

Any agent that may cause birth defects

Most vulnerable period for induction of birth defects is___.

Embryonic period (3- 8 weeks)