Embryology & Histopathology Flashcards
20445 – S. The spinal cord possesses two fusiform enlargements BECAUSE R. at the limb plexuses there is a greatly increased mass of motor cells in the spinal cord
S is true, R is true and a valid explanation of S
Last PAGE: 536
23804 – The endoderm of the first pharyngeal pouch gives rise to the
1: superior parathyroid gland
2: epithelium of the external acoustic meatus
3: thymus
4: epithelium of the auditory (Eustachian) tube
Answers: FFFT
Last PAGE: 41
21298 – Derivatives of the first branchial arch (Meckel’s) cartilage include the
1: body of the mandible
2: spheno-mandibular ligament
3: stapes
4: incus
FTFT
Last PAGE: 39, 40, 460.
stapes - 2nd branchial arch
819 – The first pharyngeal pouch gives rise to
1: the auditory (pharyngo-tympanic) tube
2: part of the tympanic membrane
3: the middle ear
4: the mastoid antrum
Answer: TTTT
ANATOMY Page 78 of 215
Last 10th ed, Ch 1
15350 – In the branchial arches
1: the second arch artery remains as the stapedial artery
2: the fourth on the right is the pulmonary artery
3: the fifth arch artery disappears completely
4: the fifth arch may persist as the ligamentum arteriosum
TFTF
Refer to Last, 10th Ed, Ch 1, page 25-26.
2 - Fourth on the right subclavian artery, on the left arch of aorta
4 - 6th arch ligamentum arteriosum
23809 – Derivatives of the first branchial arch include the
1: mucous membrane of the anterior two-thirds of the tongue
2: maxillary artery
3: temporalis muscle
4: intrinsic muscles of the tongue
TTTF
Last PAGE: 40
22884 – The second branchial arch gives rise to the
1: stylo-mandibular ligament
2: stylo-hyoid muscle
3: stapedial artery
4: anterior belly of the digastric muscle
Answers: FTTF
Last PAGE: 41
1st brachial arch - stylo-mandibular lig, anterior belly of digastric muscle
2nd brachial arch - posterior belly, stylohyoid m/lig, stapes, styloid, hyoid bone, stapedius m stapedial a, platysma
21303 – The third branchial arch gives rise to the
1: greater cornu of the hyoid bone
2: stylo-pharyngeus muscle
3: glossopharyngeal nerve
4: platysma muscle
Answers: TTTF
Last PAGE: 41
4- 2nd brachial arch
20949 – S. The thymus usually has a single lobe BECAUSE R. the thymus is derived from the central diverticulum of the third pharyngeal pouch
S is false and R is true
Last 10th ed. Page: 189
Thymus has 2 lobes
24149 – Derivatives of the sixth branchial arch artery include
1: the ductus arteriosus
2: the arch of the aorta
3: the right pulmonary artery
4: the right subclavian artery
Answers: TFTF
Last PAGE: 42, 43
2 - arch of aorta is 4th (on left)
3 - 6th derives to pulmonary trunk / arteries
4- subclavian artery is 4th (on right only)
22889 – Derivatives of the third pharyngeal arch include the
1: crico-thyroid muscle
2: superior laryngeal nerve
3: carotid sinus
4: thyroid gland
FFFF
Last (6). Updated Dec 03
1,2,4: 4th brachial arch
3: separate from arches
7706 – S: The right recurrent laryngeal nerve ‘loops’ under the subclavian artery because R: on the right side the fifth and the dorsal part of the sixth branchial arch arteries degenerate.
S is true, R is true and a valid explanation of S
Last 10th ed, Ch 1
13529 – Derivatives of the left sixth pharyngeal arch include the
1: ductus arteriosus
2: left recurrent laryngeal nerve
3: left pulmonary artery
4: left superior laryngeal nerve
TTTF
The dorsal part of the sixth arch artery persists on the left side as the ductus arteriosus (A true), while the ventral part which is connected to the pulmonary trunk becomes the pulmonary artery (C true). The recurrent laryngeal nerve is the nerve of the sixth arch (B true), while the superior laryngeal nerve is the nerve of the fourth arch (D false).
20205 – S. Pain sensation in the heart is subserved by the sympathetic
system BECAUSE R. the heart is a modified blood vessel
S is true, R is true and a valid explanation of S
Last 10th ed. PAGE: 187
21593 – The septum transversum
1: has a cranial part which forms the pericardial membranes and part of the diaphragm
2: is invaded by cervical myotomes
3: picks up its innervation, the phrenic nerve - as it migrates past the 4th cervical segment
4: forms the ventral mesogastrium around the developing liver
TTFT
Last 10th ed. PAGE: 24; 181
21308 – The ductus arteriosus
1: contracts at birth on account of its sensitivity to reduced oxygen tension
2: is part of the fifth branchial arch arterial system
3: remains patent in the tetralogy of Fallot
4: has thick walls of smooth muscle
FFFT
1: At birth the ductus arteriosus is occluded by contraction of its muscular walls. The ductus is caused to contract into closure by the stimulus, acting locally, of a RAISED oxygen tension.
2 - 6th
13367, 20235 – S: The ductus arteriosus closes at birth by muscular contraction because R: oxygen tension in the blood perfusing the ductus arteriosus rises when the pulmonary circulation opens up
S is true, R is true and a valid explanation of S
Last’s Page 46.
At birth the ductus arteriosus is occluded by contraction of its muscular walls (S true). The ductus is caused to contract into closure by the stimulus, acting locally, of a raised oxygen tension (R true and is a valid explanation).
8500 – The ventral mesogastrium
1: has a free border containing the left umbilical vein
2: has a free border containing the common bile duct
3: forms the gastrosplenic ligament
4: forms the lesser omentum
Answers: TTFT
Last 10th ed, Ch 5
3 - dorsal mesogastrium forms the gastrosplenic ligament
7789 – The diaphragm is derived from
1: the transverse septum
2: the pleuroperitoneal membrane
3: body wall tissue
4: 3rd, 4th and 5th cervical myotomes
Answers: TTTT
Last 10th ed, Ch 4.
14591 – In its development, the diaphragm receives contributions from
1: the transverse septum
2: fourth cervical myotomes
3: pleuro-peritoneal membranes
4: transversus layer of body wall musculature
TTTT
Last’s 9th Ed., p251.