Biomedical subjects

T H Quinn

Publications and source records attributed to T H Quinn.

4 recordsLinked to original sources

PubMed1999

Transversalis fascia: historical aspects and its place in contemporary inguinal herniorrhaphy.

Since the introduction of the term "fascia transversalis" by Sir Ashley Cooper in 1840, this thin layer of tissue has been discovered, denied, and redefined. The transversalis fascia was originally described as a bilaminar membrane. Although most subsequent descriptions do not reflect this analysis, some authors, especially in the surgical literature, believe that a posterior lamina of the transversalis fascia exists. Others believe that the posterior lamina of the transversalis fascia is, in fact, part of the preperitoneal fascia. The usefulness of the transversalis fascia and its derivatives or analogues; e.g., the crura of the deep inguinal ring, have also been extensively discussed. The aim of this paper is to provide a brief survey of the historical literature concerning the transversalis fascia and a discussion of some of the contemporary views on its morphology and significance in current laparoscopic hernia repair.

Anatomy↗

PubMed1995

Dissection of the anterior abdominal wall and the deep inguinal region from a laparoscopic perspective.

The usual dissection by medical students of the anterior abdominal wall and the inguinal region proceeds from superficial to deep; special emphasis is placed on the sheath of the rectus abdominis muscle and lateral muscular layers. We suggest an alternate approach to dissection of this region that has the following advantages: (1) sparing of delicate deep structures not often fully appreciated by students; (2) provision of an opportunity to visualize the region from a laparoscopic surgeon's vantage point; (3) considerably reduced time spent dissecting and identifying structures and relationships, especially peritoneal reflections important in laparoscopic procedures. Our dissection begins with bilateral subcostal incisions through the entire thickness of the anterior abdominal wall and peritoneum, which extend laterally and inferiorly to the level of the anterior superior iliac spines, thereby forming a large, inverted, U-shaped flap. This flap is reflected inferiorly, allowing abdominal viscera to be dissected, and ultimately removed en bloc. The flap is then drawn cranially and stretched somewhat to approximate its position when the abdomen is inflated with CO2 during laparoscopic procedures. Major landmarks, including the deep inguinal ring, are noted and the flap is again reflected inferiorly for dissection beginning with the peritoneum and transversalis fascia. This method of dissecting the anterior abdominal wall and inguinal region results in more facile and timely identification of both superficial and deep structures of the anterior abdominal wall and inguinal region, and provides a clinically relevant demonstration of anatomy from a laparoscopic perspective.

Abdominal Muscles↗

PubMed1993

Chiropteran tendon locking mechanism.

Rather than the usual mammalian scheme in which tendon and sheath surfaces provide as little friction as possible, the tendons and sheaths of many bats have a locking segment on the manual and pedal flexor tendon complex. This tendon locking mechanism (TLM) exists opposite the proximal phalanges of each toe and pollex of many bats. Its structure, similar to a ratchet mechanism, assists bats in hanging with little muscular effort. The third digit of the pelvic limb and the pollex of species representing 15 chiropteran families were studied to determine the presence or absence, morphology, and function of the TLM. Most of the species studied have a TLM consisting of a patch of tubercles on the ventral surface of the flexor tendon associated with the proximal phalanx of each pollex or toe. The sheath adjacent to this portion of the flexor tendon has a series of transverse folds or ridges, which, when engaged with the tubercles on the tendon, lock the tendon in place. The TLM is similar in megachiropterans and microchiropterans possessing it. The TLM is absent, however, in some of the microchiropterans studied, most notably in the phyllostomids. Since many birds have a TLM similar to that of bats, it is an excellent example of the convergent evolution of a feature brought about by similar functional pressures on birds and bats.

Animals↗

PubMed1977

Stereoscopic anatomy: evaluation of a new teaching system in human gross anatomy.

Traditionally, human gross anatomy teaching has revolved around anatomical dissection. Unfortunately, during the last decade a number of medical schools have experienced a decrease in the number of hours allotted to gross anatomy instruction compounded by a shortage of anatomical donors. This, in turn, has served to increase the difficulties of providing students with truly effective anatomical instruction. To help overcome this problem, a stereoscopic slide-based auto-instructional program has been developed as a substitute for dissection. Evaluation data suggest that this program, while having minor limitations in terms of anatomical orientation, does provide a viable alternative to dissection.

Anatomy↗