Human Anatomy and Embryology Quiz

The presence of an extra copy of chromosome 21, resulting in characteristic physical features and intellectual disabilities.

The failure of the cranial neuropore to close during embryonic development, leading to the absence of a cranial vault.

Motor neurons located in the anterior horn of the spinal cord, responsible for sending nerve impulses to skeletal muscles.

The tibialis posterior tendon, which runs through a groove on the inferior aspect of the sustentaculum tali, would be damaged by a fracture of the sustentaculum tali.

The dorsal/posterior roots of a typical spinal nerve carry only sensory nerve fibers.

Sympathetic nerve fibers that bypass the sympathetic/paravertebral ganglia without synapsing are called splanchnic nerves.

The sympathetic nervous system has short preganglionic axons and long postganglionic axons.

The peroneus longus muscle, a plantar flexor and everter of the foot, pulls the fibula upwards, counteracting the downward pull exerted by the other eight muscles.

A type of twin pregnancy where the two embryos share a placenta and chorionic cavity but have separate amniotic sacs.

A group of three injuries that often occur together in the knee: a torn anterior cruciate ligament (ACL), a torn medial collateral ligament (MCL), and a torn medial meniscus.

A ligament that attaches at the acetabular rim anteriorly and the intertrochanteric line of the femur. It helps prevent hyperabduction of the thigh.

A nerve that innervates the skin on the dorsum of the foot. Damage to this nerve can result in loss of sensation in that area.

A muscle located in the leg that extends the big toe. It is innervated by the deep fibular nerve.

The process of splitting during early embryonic development that results in the formation of identical twins. It occurs after the formation of the bilaminar germ disc.

The process of splitting during early embryonic development that results in the formation of identical twins. It occurs before the formation of the bilaminar germ disc, at the two-cell stage.

A direct connection between an artery and a vein, bypassing the capillary bed.

A series of interconnected blood vessels that provide alternative pathways for blood flow if one vessel is blocked.

The normal anatomical position is standing upright with the head facing forward, upper limbs at the sides, and palms facing forward.

The erector spinae muscle group, which supports the spine and allows for back extension, develops from the epaxial cells of the myotome, located on the dorsal side of the somites.

The process by which the blastocyst escapes the zona pellucida, facilitated by trophoblastic enzymes that digest the zona pellucida. This allows the blastocyst to attach to the uterine lining.

The inner cell mass of the implanted blastocyst differentiates into two layers: the epiblast, which forms the embryo, and the hypoblast, which contributes to the yolk sac.

A positive pregnancy test is typically due to the presence of human chorionic gonadotropin (hCG), a hormone produced by the developing embryo.

Primordial germ cells, destined to form eggs or sperm, migrate from the yolk sac to the gonadal ridge, the future site of the gonads, early in embryonic development.

The superficial peroneal nerve runs along the lateral leg, medial to the fibularis brevis tendon and lateral to the fibularis tertius tendon.

The great saphenous vein runs along the medial side of the leg, passing medial to the calcaneal tendon.

The obturator nerve supplies the adductor muscles of the thigh, including gracilis, adductor longus, adductor brevis, and adductor magnus. A complete block of the obturator nerve would paralyze all of these muscles.

The medial circumflex femoral artery is a branch of the profunda femoris, which in turn is a branch of the femoral artery. It is a major source of blood supply to the medial compartment of the thigh.

The gastrocnemius muscle is located in the calf. It is a powerful plantar flexor of the foot and its actions are mainly controlled by the tibial nerve.

Lateral rotation of the thigh is primarily performed by the external rotator muscles of the hip, which include the gluteus maximus, piriformis, obturator internus, and obturator externus.

The deep femoral artery supplies the muscles of the thigh, including the adductors. Therefore, if the external iliac artery is blocked, blood can reach the thigh via the deep femoral artery.

The plantar muscles of the foot include the flexor digitorum brevis, flexor hallucis brevis, abductor hallucis, and abductor digiti minimi. These muscles help with plantar flexion of the toes and support the arch of the foot.

The deep fibular nerve (also known as the peroneal nerve) is responsible for dorsiflexion of the foot.

The deep fibular nerve innervates the muscles responsible for dorsiflexion (lifting the foot) and eversion (turning the foot outward). Injury to this nerve can cause difficulty in dorsiflexion, leading to problems with walking, such as 'foot drop'.

The superficial fibular nerve is responsible for eversion (pointing the foot outward) of the ankle. You could consider its role in allowing you to push off with your foot when walking.

The tibial nerve controls plantar flexion (pointing the toes downwards) and inversion (pointing the foot inward).

The common fibular nerve provides sensory innervation to the lateral and anterior compartments of the leg. Injury to this nerve might affect sensation in those areas.

The superior gluteal nerve innervates the gluteus medius and gluteus minimus muscles, primarily responsible for hip abduction. If this nerve is injured, the affected leg will drop during walking, leading to a positive Trendelenburg sign.

The medial plantar nerve innervates the muscles involved in flexing and abducting the big toe. Damage to this nerve could lead to an inability to flex or abduct the big toe. Additionally, it provides sensory innervation to the plantar aspect of the three and a half medial toes, explaining the numbness on the plantar side of the toes.

The lateral plantar nerve primarily innervates the muscles responsible for flexing the 4th and 5th toes, as well as abducting the little toe and flexing the little finger. It could also be involved in the overall flexion of the foot.

The formation of the three germ layers (ectoderm, mesoderm, and endoderm) in the developing embryo, giving rise to all organs and tissues.

A fertilized egg cell that has undergone several cell divisions, forming an inner cell mass and an outer layer of cells.

A genetic condition caused by a mutation in the FMR1 gene, characterized by mental retardation, large ears, prominent jaw, and pale blue irises.

A birth defect caused by the failure of the caudal neuropore to close during neurulation, leading to abnormalities in the spinal cord and lower limbs.

A birth defect characterized by a small forebrain, merged ventricles, and eyes that are close together, caused by a failure of the forebrain to separate properly during development.

A type of tumor that arises from retained primitive streak remnants, often found in the sacrococcygeal region, containing tissues derived from all three germ layers.

A rare genetic disorder caused by a deletion of the paternal chromosome 15q11-13 region, characterized by obesity, short stature, hypogonadism, and mild to moderate intellectual disability.

A genetic condition caused by having an extra X chromosome in females, leading to mild developmental delays and other symptoms.