Tag: nervous system of man

• Homeostasis is maintained by the action of various hormones and organs of the body
• Cerebrum is the centre of thought, intelligence etc
• Cerebellum Coordinates muscular activities
• The thalamus relays impulses

The cerebrum is that part of the brain that contains the two cerebral hemispheres and the subcortical structures and hippocampus, basal ganglia and olfactory bulbs. In most vertebrae, the neural tube of the embryo is subdivided to form the prosencephalon or forebrain, mesencephalon or midbrain, rhombencephalon or hindbrain and spinal cord. While the physical structure of the cat brain is very similar to that of humans and  have the largest percentage of its brain devoted to prosencephalon. Thus, the correct answer is option

1. The canal that passes through midbrain - canal aqueduct
   
2. The corpora quadrigemina are the four colliculi—two inferior, two superior—located on the tectum of the dorsal aspect of the midbrain.
   
3. The cerebral cortex of the human brain is highly convoluted, meaning it has many folds and creases. 
   
4. The medulla oblongata controls gastric secretion both by the parasympathetic branch of the nervous system and the endocrine system.
   

The forebrain is the part of the brain that includes cerebrum, thalamus and hypothalamus. It is involved in many functions, much of which are linked to the cerebrum. For example, intelligence or higher brain power is associated with the cerebrum. The outermost layer of the cerebrum is made up of four lobes frontal, temporal,parietal and occipital. The hearing, smelling and forming memories are functions of the temporal lobe. Vision is controlled by the occipital lobe. At the base of the forebrain-basal ganglia are found which control movement. Control and coordination are functions of nervous and endocrine systems because hypothalamus stimulates the master gland that regulates function of the other glands and brain and spinal cord (part of nervous system) directly regulates the function of other body parts.

The pia mater of the brain is the innermost of the three membranes, that cover it. It is the vascular membrane of the brain. It carries the minute branches of the two internal carotids and the two vertebral arteries. It also returns the blood to the heart. The dura mater is the most external membrane of the brain. It forms the internal periosteum of the skull. The dura mater is a dense, tough, inelastic fibrous membrane. The epidermis contains no blood vessels, and cells in the deepest layers are nourished by diffusion from blood capillaries extending to the upper layers of the dermis. So, the correct answer is option B.

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.