Lobes, Nerves and Deeper Structures of the Brain Oh My

In a previous article, we talked a bit about the basic anatomy of the human brain. We didn’t delve too deeply into it. The brain, as you may have guessed, is a complicated organ with many parts to it. As we mentioned before, the brain has two hemispheres, which are part of the cerebellum. Within these hemispheres reside four sections, known as lobes. The lobes of the brain are:

• The frontal lobe,
• The parietal lobe,
• The temporal lobe,
• And the occipital lobe.

Each lobe is responsible for different functions.

The Frontal Lobe is the largest lobe in the brain. It resides in the front of the head. It is involved in personality characteristics, decision-making and movement. Recognition of the sense of smell is usually found in the frontal lobe, which also contains Broca’s area, which is associated with the ability of speech.

The Parietal Lobe can be found in the middle of the brain. This area assists us in identifying objects and understanding spatial relationships. Spatial relationships related to where one’s body is located in comparison to objects surrounding them. The Parietal Lobe is also responsible for interpreting both pain and touch. Within the parietal lobe is Wernicke’s area which helps us understand spoken language.

The Occipital Lobe, which is housed in the back of the brain. It is involved with sight.

The Temporal Lobe is on the sides of the brain. This area, which is rather important, is involved in short-term memory, speech, musical rhythm and a small degree of smell recognition.

Deeper structures within the brain include the:

• Pituitary Gland,
• Hypothalamus,
• Amygdala,
• Hippocampus,
• Pineal Gland,
• And Ventricles & Spinal Fluid.

Pituitary Gland

Also referred to as the master gland, the pituitary is small (pea-sized) but mighty. It is located deep in the brain behind the ridge of the nose. This powerhouse governs the functions of all the other glands in the body, regulating the flood of hormones from the thyroid, adrenals, ovaries and testicles. The pituitary receives signals from the hypothalamus.

Hypothalamus

Located above the pituitary gland, it sends chemical messages which control its function. The hypothalamus regulates body temperature, regulates circadian rhythms (sleep patterns), controls hunger and thirst. It also plays a role in certain aspects of memory and emotion.

Amygdala

This small, almond-shaped structure is located under each hemisphere of the brain. Included in the limbic system, the amygdala regulates emotion and memory. It is also associated with the brain’s reward system, stress and the ‘fight or flight’ response when one perceives a threat.

Hippocampus

This is a curved, seahorse-shaped organ located under each temporal lobe. The hippocampus is part of a larger structure known as the hippocampal formation. It supports learning, memory, navigation and the perception of space (distance between ourselves and between objects, not space as in the Universe). The hippocampus receives its information from the cerebral cortex. Studies suggest that it plays a significant role in Alzheimer’s Disease.

Pineal Gland

Located deep in the brain, the pineal gland is attached by a stalk to the top of the third ventricle. It responds to light and dark. This gland also secretes melatonin which regulates circadian rhythms and regulates the sleep-wake cycle.

Ventricles and Cerebrospinal Fluid

Deep within the brain are four open areas that have multiple passageways between them. These open into the central spinal canal and the area beneath the arachnoid layer of the meninges. The ventricles manufacture cerebrospinal fluid (CSF). CSF is a watery fluid that circulates in and around the spinal cord and ventricles. It also exists between the meninges. Cerebrospinal Fluid surrounds and cushions both the spinal cord and the brain. It also washes out impurities and delivers nutrients.

What’s the deal with arteries?

Blood and oxygen are supplied to the brain by the vertebral and carotid arteries. The external carotid arteries extend up the sides of your neck. You can feel your pulse when you touch this area with your fingertips. The internal carotids branch into the skull and circulate blood to the front of the brain. The vertebral arteries follow the spinal column directly into the skull. There, they join together and form the basilar artery, which supplies blood to different portions of the brain. The circle of Willis is a loop of blood vessels located near the bottom of the brain connecting major arteries, circulating blood flow from the back of the brain to the front. It also helps arterial systems communicate with one another.

Cranial Nerves

Inside the cranium, aka the dome of the skull, reside 12 nerves. Unsurprisingly, these are referred to as the cranial nerves. They are in order:

1. Olfactory Nerve (allows for sense of smell).
2. Optic Nerve (governs eyesight).
3. Oculomotor Nerve (controls pupil response and eye movements).
4. Trochlear Nerve (controls eye muscles).
5. Trigeminal Nerve (conveys sensation from the scalp, teeth, jaws, sinuses, parts of the mouth and face to the brain. It also allows for functionality of chewing muscles, among other things).
6. Abducens Nerve (innervates some eye muscles).
7. Facial Nerve (supports facial movements, taste, glandular functions and more).
8. Vestibulocochlear Nerve (facilitates both balance and hearing).
9. Glossopharyngeal Nerve (controls taste as well as ear and throat movements, etc.).
10. Vagus Nerve (allows sensation around the ear and digestive system. As part of the Parasympathetic Nervous System, it controls motor activity in the heart, throat and digestive system.)
11. Accessory Nerve (innervates specific muscles in neck, shoulder and head).
12. Hypoglossal Nerve (supplies and controls motor activity of the tongue).

Where are the nerves located?

The first two originate in the cerebellum. The remaining ten emerge from the brainstem, which you may remember from our previous article, has three parts – the midbrain, pons and medulla.

I hope you enjoyed this two-part foray into the brain. As you can imagine, I find brain anatomy fascinating. However, as a mental health coach, I am much more interested in brain functionality specifically when it comes to regulating and generating emotions. If you’d like to book a complimentary 60-minute session with me, I’d love to chat with you. Reach out to me at dcgoodson@gmail.com for more information.