By T. Norris. State University of New York College at Buffalo (Buffalo State College).
The body between the column of the fornix (located somewhat rostrome- of the caudate is located in the lateral wall of the body of the lat- dially) and the anterior nucleus of the thalamus (located some- eral ventricle order extra super avana 260 mg online. The anterior nucleus is located internal to and does not border on any ventricular space buy discount extra super avana 260mg on-line. The head of the caudate is fornix are located in the medial wall of the ventricle, and the pul- found in the lateral wall of the anterior horn of the lateral ven- vinar borders on the superior cistern. Answer E: The posterior limb of the internal capsule is located minalis extends from the anterior commissure inferiority to the between the lenticular nucleus, which is lateral, and the thalamus, upper edge of the optic chiasm. This large ﬁber bundle contains thalamocortical in the caudal and medial wall of the third ventricle. The anterior limb of the internal capsule is lo- cated between the head of the caudate and the lenticular nucleus, 11. Answer D: The mammillary body forms an obvious elevation and the retrolenticular limb is found caudal to the lenticular nu- on the inferior aspect of the hemisphere rostral to the interpe- cleus. The anterior commissure is in the rostroventral portion of duncular fossa/cistern; this small bulge is clearly evident in MRI. The former is rostral to the in- fundibulum (and the mammillary body) and the latter is caudal to 5. Answer A: The column of the fornix, commonly called the post- the interpeduncular fossa. The lamina terminalis forms the rostral commissural fornix, lies caudal to, and against, the anterior com- end of the third ventricle and the anterior commissure is adjacent missure as it arches around the interventricular foramen and the an- to the column of the fornix. The precommissural fornix is a diffuse bundle of ﬁbers rostral to the anterior commissure, and the 12. Answer B: The medial and lateral geniculate nuclei are located mammillothalamic tract is located between the mammillary body inferior to the pulvinar, and form elevations on the surface of the and the anterior nucleus of the thalamus. The lamina terminalis and dorsal thalamus; the medial geniculate is adjacent to the lateral the optic chiasm are inferior to the anterior commissure. The subthalamic nucleus is located inter- nally, the mammillary nuclei (medial and lateral) are on the infe- 6.
A networkof membranous chan- cle myofibrils are due to the arrangement of these myofilaments extra super avana 260mg overnight delivery. At high magnification generic 260 mg extra super avana mastercard, thin dark lines can be seen in the of transverse tubules (T tubules) runs perpendicular to the sar- middle of the I bands. The arrangement coplasmic reticulum and opens to the outside through the sar- of thick and thin filaments between a pair of Z lines forms a re- colemma. Also embedded in the muscle fiber are many threadlike peating structural pattern that serves as the basic subunit of structures called myofibrils (fig. These subunits, from Z line to proximately one micrometer (1µm) in diameter and extend in Z line, are known as sarcomeres (fig. A longitudinal section parallel from one end of the muscle fiber to the other. They are of a myofibril thus presents a side view of successive sarcomeres so densely packed that other organelles—such as mitochondria (fig. Each extend from the edge of one stack of thick myosin filaments to myofibril is composed of even smaller protein filaments, or myo- the edge of the next stack of thick filaments. Thin filaments are about 6 nm in diameter and are appearance because they contain only thin filaments. Thick filaments are about 16 nm in filaments, however, do not end at the edges of the I bands. Because thick and thin filaments overlap at the edges of each A band, the edges of the A band are darker in appear- actin: L. Muscular System © The McGraw−Hill Anatomy, Sixth Edition Companies, 2001 242 Unit 4 Support and Movement Sarcolemma Myofibrils Triad of the reticulum: Terminal cisternae A band Transverse tubule I band Sarcoplasmic reticulum Z line Mitochondria Nucleus Waldrop FIGURE 9. The central H zones thus contain only thick filaments on a single row of dark thick myofilaments in this transverse sec- that are not overlapped by thin filaments. There are numerous sarcomeres within each When a muscle is stimulated to contract, it decreases in myofibril that are out of the plane of the section (and out of the length as a result of the shortening of its individual fibers.