Answer
In the parasympathetic division of the autonomic nervous system, the terminal ganglia, also known as intramural ganglia, are typically found close to or within the target organs themselves. This location is in contrast to the sympathetic division, where ganglia are typically situated in a chain along the vertebral column. The proximity of parasympathetic terminal ganglia to target organs allows for more precise and localized control of parasympathetic responses.
Here's a general idea of where terminal ganglia of the parasympathetic division are found:
1. **Cranial Nerves**:
- In the head and neck, many terminal ganglia are associated with cranial nerves. For example, in the head, the ciliary ganglion (associated with Cranial Nerve III) is located near the eye and controls pupil constriction and lens accommodation.
- Terminal ganglia associated with Cranial Nerve VII (facial nerve) are found near the salivary glands to regulate salivation.
2. **Thoracic and Abdominal Organs**:
- As the parasympathetic fibers travel toward the thoracic and abdominal organs, terminal ganglia are often located within or very close to these target organs.
- For example, terminal ganglia for the heart are located in the heart itself, and terminal ganglia for the digestive organs (e.g., stomach, liver, pancreas) are situated within or near these organs.
3. **Pelvic Organs**:
- In the pelvic region, terminal ganglia control parasympathetic innervation of the bladder, rectum, and reproductive organs.
- These terminal ganglia are located in close proximity to these pelvic structures.
The proximity of terminal ganglia to target organs allows for highly specific and localized parasympathetic control. When a preganglionic parasympathetic fiber reaches its target organ, it synapses with postganglionic neurons within or near the organ. This arrangement enables precise regulation of functions such as digestion, urination, and reproductive processes, as well as the maintenance of homeostasis in various organ systems.
Work Step by Step
In the parasympathetic division of the autonomic nervous system, the terminal ganglia, also known as intramural ganglia, are typically found close to or within the target organs themselves. This location is in contrast to the sympathetic division, where ganglia are typically situated in a chain along the vertebral column. The proximity of parasympathetic terminal ganglia to target organs allows for more precise and localized control of parasympathetic responses.
Here's a general idea of where terminal ganglia of the parasympathetic division are found:
1. **Cranial Nerves**:
- In the head and neck, many terminal ganglia are associated with cranial nerves. For example, in the head, the ciliary ganglion (associated with Cranial Nerve III) is located near the eye and controls pupil constriction and lens accommodation.
- Terminal ganglia associated with Cranial Nerve VII (facial nerve) are found near the salivary glands to regulate salivation.
2. **Thoracic and Abdominal Organs**:
- As the parasympathetic fibers travel toward the thoracic and abdominal organs, terminal ganglia are often located within or very close to these target organs.
- For example, terminal ganglia for the heart are located in the heart itself, and terminal ganglia for the digestive organs (e.g., stomach, liver, pancreas) are situated within or near these organs.
3. **Pelvic Organs**:
- In the pelvic region, terminal ganglia control parasympathetic innervation of the bladder, rectum, and reproductive organs.
- These terminal ganglia are located in close proximity to these pelvic structures.
The proximity of terminal ganglia to target organs allows for highly specific and localized parasympathetic control. When a preganglionic parasympathetic fiber reaches its target organ, it synapses with postganglionic neurons within or near the organ. This arrangement enables precise regulation of functions such as digestion, urination, and reproductive processes, as well as the maintenance of homeostasis in various organ systems.
