**Question:** All take part in anastomosis in little's area except: (Repeat)

A. Lumbar sympathetic ganglia
B. Postganglionic neurons
C. Corticospinal tract
D. Postganglionic sympathetic fibers

**Core Concept:** Anastomosis is the process by which neurons from different pathways or systems can connect with each other, allowing for functional integration and coordination of various physiological functions. Little's area refers to the region of the spinal cord where anastomosis occurs between sympathetic and parasympathetic pathways.

**Why the Correct Answer is Right:** The correct answer, Corticospinal tract, does not take part in anastomosis in Little's area due to its distinct role in controlling voluntary movements and sensory processing in the brain. The corticospinal tract originates from the cerebral cortex and projects to the motor neurons in the ventral horn of the spinal cord, which in turn control skeletal muscles.

**Why Each Wrong Option is Incorrect:**

A. Lumbar sympathetic ganglia: These are part of the autonomic nervous system and are involved in the regulation of various physiological functions, such as blood flow and organ function. They do not participate in anastomosis, as they are part of the sympathetic division, while anastomosis involves integration between different systems.

B. Postganglionic neurons: These are the final output neurons of the autonomic nervous system, responsible for transmitting signals to target organs and glands. Postganglionic neurons are involved in the regulation of organ function and are part of the sympathetic or parasympathetic pathways, not anastomosis.

D. Postganglionic sympathetic fibers: Similar to option B, postganglionic sympathetic fibers are involved in the regulation of organ function and not anastomosis. They transmit signals from the sympathetic ganglia to target organs.

**Clinical Pearl:** Understanding the specific roles and functions of various neural pathways is essential for appreciating the complexity of physiological processes and their integration. Anastomosis is a critical concept in neuroscience and neurology, contributing to the coordination of various physiological functions in the body.