Question

Name the parts of the human forebrain indicating their respective function.

Answer 1

Hint: Human brain is the most complex organ. It acts as the chief organ of the central nervous system by controlling the functions of major organs of the body. Based on anatomy, it consists of 3 parts- the Forebrain, Midbrain, and Hindbrain.

Complete answer:
The human brain is one of the largest organs in our body. It is also called the command center or crown jewel of the body. It controls the sensory and motor organs of our body by supplying output signals to the muscles after processing the input signals from the sensory organs. It also regulates our speech, breathing, emotions, judgment, taste, touch, memory, attention, and various other voluntary and involuntary features. It weighs around 3 pounds and has four major lobes. It is made up of soft tissues and has a high amount of fat and water content.

Anatomically, the brain is divided into 3 major parts-
1)Forebrain- It is situated at the front of the brain and develops from the developmental prosencephalon.
2)Midbrain- It is situated in the middle portion of the brain and develops from the developmental mesencephalon.
3)Hindbrain- It is situated at the back or posterior end of the brain and develops from the developmental rhombencephalon.

The Forebrain of the human is the largest part of the brain and is further divided into two subdivisions- Telencephalon and Diencephalon. It consists of three major parts- Cerebrum, Hypothalamus, and Thalamus. The pituitary gland, olfactory lobe, and limbic system is also a part of the forebrain. Let us discuss each part of the forebrain.

Cerebrum- It constitutes 85 percent of the brain and is the uppermost part of the brain. It is also called telencephalon. It contains the cerebral cortex and can be divided into two hemispheres- the left hemisphere and the right hemisphere. A large sulcus or central fissure separates these two hemispheres. The hemisphere can be further divided into four functional lobes- Frontal, Parietal, Temporal, and Occipital. These hemispheres consist of white matter coated with grey matter. Its major functions are- controlling and planning the voluntary movements of the motor organs, processing and recognizing the visual, sensory, gustatory, and olfactory information. It also plays a major role in sensing, interpreting, and processing sounds and somatosensation, and proprioception. It also controls behavior, personality, emotions, judgment, organization, understanding of various languages, etc.

Hypothalamus- It lies at the base of the brain and is very small in structure. It is formed of various nerve fibers and neural connections. It modulates the endocrine gland by linking it with the nervous system through the pituitary gland. It has neurons that have a rich blood supply. Its major functions are- homeostasis of the body, thermoregulation, thirst, and hunger, emotional behavior, sex drive, blood pressure, and various other daily activities of the body. It also controls the release of hormones from the pituitary gland.
Thalamus- It is a subdivision of the diencephalon and is mostly made up of grey matter. It lies at the mid part of the forebrain and has extensive nerve connections from the cortex and the midbrain. It is a symmetrical paired structure that has blood supplies from various arteries. It plays a major role in maintaining the physiology of the body. Its major functions can be divided into four categories - Emotional, Sensory, Motor, and Vegetative. It affects the arousal, alertness, sexual sensation, language, and speech, reflex, and pain in the body.

Olfactory Lobes - Sensation of Smell
Pituitary Gland- Also called the Master gland. It secretes various hormones in the bloodstream that regulates and maintains the body environment of our body.
Limbic system- Behavioural and emotional responses.

Note: The midbrain consists of the parts -Tectum and Tegmentum and the hindbrain consists of the parts- Cerebellum, Pons, and Medulla oblongata. The midbrain plays a major role in the movement of the eye, the processing of auditory and visual responses. The hindbrain regulates the survival functions like respiratory rhythm, sleep, and wake cycle, etc.