Tag: the structure of brain

Forebrain consists of two regions; namely cerebrum and diencephalon. A deep cleft divides the cerebrum longitudinally into two halves, which are termed as the left and right cerebral hemispheres. Each cerebral hemisphere is divided into four lobes, viz., frontal lobe, parietal lobe, occipital lobe and temporal lobe. The frontal lobe is associated with intelligence, memory, judgment, problem-solving ability and controls voluntary activities. The parietal lobe is associated with the sense of touch, temperature, pressure, and pain. The temporal lobe is associated with the sense of taste, hearing, and smell. The occipital lobe is associated with sight.

Piameter is the innermost membrane of the brain and arachnoid is the middle membrane. The space between arachnoid and piameter is caleed sub-arachnoid space. This space is filled with cerebrospinal fluid.

Broca's area is a region in the frontal lobe of the dominant hemisphere, usually the left, that is specifically responsible for the motor production of speech.

Pneumotaxic centre is present in the dorsal part of the pons varolii of the brain. Its function is primarily to limit inspiration.

Cerebrum is the main site of intelligence and consciousness in the body of the organism. The hypothalamus is the area of brain that is important in controlling the balance of bodily functions. It controls the release of hormones from the pituitary gland. The midbrain is responsible for controlling the vision and hearing features of the organism. Medulla oblongata is responsible for controlling the rate of the heart beat.

• 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.