Presentation on forebrain

By: Madan K. Paneru

Presentation on:

FORE BRAIN

Fore Brain:Information Aafter hind brain and midbrain travels to Fore Brain.Consists of two areas;One covers: Thalamus, Hypothalamus and Limbic System,Other Covers: Cerebral Cortex. Cerebral cortex is divided into two symmetrical halves called “Cerebral Hemisphere. Right hemisphere regulates left hemisphere functions and left hemisphere handles right hemisphere.Each hemisphere has four lobes:The frontal, temporal, occipital & parietal lobes.These lobes are folded into ridges and sub-cortical part by two major landmarks; Central fissure & lateral fissure.

Frontal lobe is behind the forehead.Parietal lobe is at the top of the head and to the rear.Occipital lobe is at the bottom or back of the head.Temporal lobe is above the ears.

Three important functions centralcortex:

Sensory Function Motor Function Associative Function

* Somatosensory area lies at the front of the parietal lobes.* Parallel to motor area.* Responsible to receive the information coming from skin senses and body movements.

(i) Parietal lobe- Centers on somatosensory function.

* Work on upside down fashion. Eg: sensation for toes are located on the top and the lips on the bottom of the brain.

* When specific part of right hemisphere is stimulated, the left part of the body experiences that stimulation i.e. works in an opposite manner.

* The more body parts used the greater area of the sensory cortex is developed. E.g. lips have a larger brain area than toes.

Important characteristics of somatosensory area:

* Lies at very back of cortex.

* Responsible for light and colors.

* Visual informations are processed and conveyed to association area of brain.

* Helps to recognize words, faces etc.

* Damage can cause cortical blindness even without any defect in the eyes.

(ii) Occipital lobe- visual centers

* Responsible for audition and language to some extent.

* Has two basic centers:

-Primary center & - Secondary center

* The primary area is said to generate sound while secondary area gives elaboration and meanings to them.

* wernick’s area discovered by Karl Wernicke in 1870, controls the understanding of spoken language.

* Damage in it results people only speaking meaningless words and inability to comprehend other words.

(iii) Temporal lobe- auditory centers

* It is near the face.

# Body sense area controls all the body movements. It has four characteristics;• The responses are mediated from upside down fashion.• Movement on right side of the body came through

stimulation of the motor area of left hemisphere and vice versa.

• The more parts of the body are used the more creates the space in the cortex.

• The functions of motor cortex can be mapped and localized.

(iv) Frontal lobe-centers for motor functions

# Broca’s speech area was discovered by Paul Broca in 1965.

* Plays specific role in our ability to speak languages.

* Situated in left frontal lobe.

* Located in right hemisphere of the left handed people and left hemisphere of the right handed people.

Contd.

Any

Ques

tions Any

Questions

Any

QuestionsAny

Questions

Thank You!!!