Overview of the principal parts of the brain

Dorn Spinal Therapy

Spine Healing Therapy

Get Instant Access

Part of brain

Location

Function

Makes up front and top part of brain

Intelligence Emotions

Thalamus

Lies either side of forebrain

Relays sensory impulses to the cerebral cortex

Hypothalamus

Small structure lies beneath the thalamus

Governs many important homeostatic functions (hunger, thirst, temperature regulation, anger, aggression, hormones, sexual behaviour, sleep patterns and consciousness)

Pineal gland

Pea-sized mass of nervous tissue attached by a stalk in the central part of the brain

Attached to the upper portion of the thalamus

Secretes melatonin Regulation of circadian rhythms

Cerebellum

Cauliflower-shaped structure located at the posterior of the cranium, below the cerebrum

Coordination of skeletal muscles, posture and balance

Brain stem

Enlarged continuation of the spinal cord

Connects the brain with the spinal cord

Contains control centres for heart, lungs and intestines

Cerebrum

This is the largest portion of the brain and makes up the front and top part of the brain. It is divided into two large cerebral hemispheres. Each cerebral hemisphere is divided into four lobes - frontal, temporal, parietal and occipital, named according to the skull bones that lie over them.

A mass of nerve fibres known as the corpus callosum bridges the hemispheres, allowing communication between corresponding centres in each hemisphere. The surface of the cerebrum is made up of convolutions called gyri and creases called sulci.

The outer layer of the cerebrum is called the cerebral cortex and is the region where the main functions of the cerebrum are carried out. The cortex is concerned with all forms of conscious activity such as vision, touch, hearing, taste and smell, as well as control of voluntary movements, reasoning, emotion and memory. The cortex of each cerebral hemisphere has a number of functional areas:

Sensory areas

Receive impulses from sensory organs all over the body. There are separate sensory areas for vision, hearing, touch, taste and smell

Motor areas

These have motor connections through motor nerve fibres with voluntary muscles all over the body

Association areas

In these areas association takes place between information from the sensory areas and remembered information from past experiences

Conscious thought then takes place and decisions are made which often result in conscious motor activity controlled by motor areas

Speech area

Speech area

Intellect, learning, and personality

Language area

General interpretation

Spinal cord

Fig 8.5 Functional areas of the brain

Language area

General interpretation area area

Motor area

Sensory area

Taste area

Vision area

Hearing area

Balance area

KEY FACT

The brain requires a continuous supply of glucose and oxygen as it is unable to store glycogen, unlike the liver and muscles.

Thalamus

Lying deep in the cerebral hemispheres in each side of the forebrain are one of two egg-shaped masses of grey matter called the thalami. The thalami are relay and interpretation stations for the sensory messages (except olfaction) that enter the brain before they are transmitted to the cortex.

Hypothalamus

This small structure lies beneath the thalamus and governs many important homeostatic functions. It regulates the autonomic nervous and endocrine systems by governing the pituitary gland. It controls hunger, thirst, temperature regulation, anger, aggression, hormones, sexual behaviour, sleep patterns and consciousness.

area area

Student activity

Now complete Activity 8.1 in the resources for this book on Dynamic Learning Online.

Pineal gland

This is a pea-sized mass of nerve tissue attached by a stalk in the central part of the brain. It is located deep between the cerebral hemispheres where it is attached to the upper portion of the thalamus. The pineal gland secretes a hormone called melatonin which is synthesised from serotonin. The pineal gland is involved in the regulation of circadian rhythms. These are patterns of repeated activity that are associated with the environmental cycles of day and night such as sleep/wake rhythms. The pineal gland is also thought to influence mood.

Cerebellum

The cerebellum is a cauliflower-shaped structure located at the posterior of the cranium, below the cerebrum. It is the brain's second largest region. Like the cerebrum, it has two hemispheres and has an outer cortex of grey matter and an inner core of white matter. The cerebellum is concerned with muscle tone, the coordination of skeletal muscles and balance.

Brain stem

The brain stem contains three main structures:

• Mid-brain — this contains the main nerve pathways connecting the cerebrum and the lower nervous system. It also contains certain visual and auditory reflexes that coordinate head and eye movements with things seen and heard.

• Pons — this is below the mid-brain and relays messages from the cerebral cortex to the spinal cord and helps regulate breathing.

• Medulla oblongata — this is often considered the most vital part of the brain.

It is an enlarged continuation of the spinal cord and connects the brain with the spinal cord. Control centres within the medulla oblongata include those for the heart, lungs and intestines. The medulla also controls gastric secretions and reflexes such as sweating, sneezing, swallowing and vomiting.

Was this article helpful?

0 0
Healthy Sleep

Healthy Sleep

A Guide to Natural Sleep Remedies. Many of us experience the occasional night of sleeplessness without any consequences. It is when the occasional night here and there becomes a pattern of several nights in arow that you are faced with a sleeping problem. Repeated loss of sleep affects all areas of your life The physical, the mental, and theemotional. Sleep deprivation can affect your overall daily performance and may even havean effecton your personality.

Get My Free Ebook


Responses

  • SIMONE
    What are the principal parts of the brain?
    11 months ago

Post a comment