cerebrum -largest part of brain 23 of brain 45 of

Question

CEREBRUM -

1. Largest part of brain. 2/3 of brain. 4/5 of brain's weight.
2. Cerebrum is devided into 2 cerebral hemispheres by longitudinal cerebral fissure.
3. Gyri and sulci are present on surface to bring neuron closer.
4. Surface area is increased. It occupies 2200 cm2, nearly 3 times to inner surface of cranium.
5. Both hemispheres are connected by a largest commissure i.e. corpus callosum.
6. Its function is to tell one side of the brain what the other side is doing.
7. Anterior and posterior ends curved downward forming genu & splanium.
8. Splanium is attached to fornix.
9. Between callosum splanium & fornix 5th ventricle or pseudo ventricle is present.
10. Outer part of wall is cortex and inner part is medulla.
11. Dorsal wall of cerebrum is thick known as neopellium.
12. Lumen is lat. ventricules or Ist (right) or 2nd (left) ventricle open in to diocoel by foramen of monaro.
13. A central fissure divide each hemisphere into frontal lobe and parietal lobe.
14. A perietooccipital fissure demarcates the parietal lobe from occipital lobe.
15. A lateral or sylvian fissure demarcates the frontal & parietal lobe from temporal lobe.
16. So total 4 lobes present -   Ant. - Frontal lobe, Middle - Parietal lobe, Post. - Occipital lobe, Lat. - Temporal lobe.
17. Temporal lobes are concerned with sound & smell.
18. Parietal lobe is concerned with pain, touch, temp. & taste.
19. Frontal lobes controls volumtary actions and some involuntary actions.
20. Visual and auditory areas in the occipital lobes are centre of sight and hearing.
21. Speech and smell areas lie in frontal lobe, speech area is broca's area.

FUNCTIONS -

1.      Intelligency, memory, thinking, reasoning, learning, decission taking.

2.      Seeing, speaking, laughing & weeping.

3.      To control voluntary acitons.