Tag: the structure of brain

Involuntary actions are those action that controlled by medulla oblongata which is a part of the autonomous nervous system where as voluntary actions are controlled by the cerebellum. The medulla oblongata directly controls heartbeat, blood pressure, breathing and digestion. It is located in the hindbrain, anterior to the cerebellum. It is a cone-shaped and contains the cardiac, respiratory, vomiting and vasomotor centers. Hence, the correct answer is option A.

The pneumotaxic center, also known as the pontine respiratory group (PRG), is a network of neurons in the rostral dorsal lateral pons. Its function is to inhibit inspiration, regulating inspiratory volume and rate.

Mid Brain of frog consists of two large optic lobes and crura cerebri. These optic lobes are centres for impulses coming to the eyes. They are hollow having cavities known as optocoel which communicates with the fourth ventricle behind a narrow cavity, iter. Hence, the correct answer is option C.

• The medulla oblongata is the part of the brainstem, that is situated between the pons and the spinal cord.
•  The medulla contains the cardiac, respiratory, vomiting and vasomotor centers and therefore deals with the autonomic (involuntary) functions of breathing, heart rate and blood pressure. 
• Thus compression of the medulla oblongata will lead to instant death.
• So, option A is correct here.

The hypothalamus and the brain stem controls the autonomic nervous system. They have control on the various functions like the respiration rate, heart rate, blood pressure, digestion, sweating, etc. The motor cortex area in the cerebrum is responsible for voluntary muscle activity. The cerebellum helps in coordinating the voluntary movements. Medulla oblongata is the brain stem which controls many involuntary activities like respiration, blood pressure, etc. The spinothalamic pathway is the tract followed by the sensation from skin to thalamus.

The midbrain is a small and contracted region of the brain. The anterior region of the midbrain is made up of two longitudinal bands of myelinated nerve fibres called the cerebral peduncles or crus cerebri or crura cerebri. The posterior part of the midbrain is made up of projected optic lobes called the colliculi.

The diencephalon is the small and posterior region of the forebrain. It is made up of the following parts:

The epiphysis or the pineal body is an endocrine gland that develops from the roof of the diencephalon. During the embryo development, it is connected with the brow spot in the embryo. The brow spot is the region between the two eyes. The cells are considered to be the modified neurological cells. It secretes a hormone called the melatonin that regulates the diurnal cycle of the body. Hence, the correct answer is 'Brow spot in embryo'