Cerebrum

Nervous system-Cerebrum

1. Human Anatomy and Physiology-II Nervous system ( Brain-Cerebrum ) Mr N.JEGAN Associate Professor K.M.COLLEGE OF PHARMACY. MADURAI .

2. Brain-Introduction Brain is situated in the skull It lie in the cranial cavity The adult human brain weighs an average of 1.4 kg , or about 2 percent of the total body weight The brain is the largest mass of nervous tissue in the body. It made up of about 100 billion neurons  .

3. Brain-Layers Brain and spinal cord are surrounded by three layers of meninges 1.outer dura mater, 2.Middle arachnoid mater 3.Inner pia mater The space between arachnoid mater and pia mater is known as subarachnoid space. This space is filled with a fluid called cerebrospinal fluid(CSF).

4. Parts of Brain

5. Cerebrum

6. Cerebrum (forebrain) This is largest part of the brain It is egg shaped organ. It occupies the anterior & middle cranial faossa and It is located in the upper portion of the brain  

7. Layers of the Cerebrum Gray matter- Outer layer Composed mostly of neuron cell bodies It is also called Cerebral cortex White matter Fiber tracts inside the gray matter Eg : corpus callosum connects hemispheres

8. cerebral hemispheres It is divided by a deep cleft, the longitudinal cerebral fissure, into right and left cerebral hemispheres, each containing one of the lateral ventricles. Deep within the brain the hemispheres are connected by a mass of white matter (nerve fibres ) called the corpus callosum .

9. Lobes of the Cerebrum Each hemisphere of the cerebrum is divided into lobes which take the names of the bones of the cranium under which they lie: 1.Frontal lobe 2. Parietal lobe 3. Temporal lobe 4. Occipital lobe

10. Sulcus The boundaries of the lobes are marked by deep sulci (fissures). These are the 1.Central sulcus - Between frontal and parietal lobe 2. lateral sulcus - Between parietal and occipital lobe 3.Parieto-occipital sulcus - Between frontal and temporal lobe

11. Cerebral lobe -Functions Frontal lobe:- Center of reasoning, Planning, Emotion, Speech,Problem solving. Parietal lobe:- Receive sensory input from Skin (touch, pain, perception etc. Occipital lobe:- Receive input from eye. Temporal lobe:- Hearing, Memory, Speech

12. Functional Areas of the Cerebrum The main areas of the cerebrum associated with 1. Motor areas of the cerebrum Skeletal muscle activity 2. Sensory area Sensory perception 3. Association area It control the complex activity in our body.

13. Motor areas of the cerebrum Area Lobe Location Function Primary motor area Parietal anterior to central sulcus Contraction of skeletal muscles Broca's area F rontal above the lateral sulcus Muscle necessary for speech

14. Sensory area of the cerebrum Area Lobe Location Function The Somatosensory area Parietal behind the central sulcus . sensations of pain, temperature, pressure and touch The auditory area Temporal below the lateral sulcus Hearing The olfactory area Temporal deep within the temporal lobe Smell The taste area Frontal lie just above the lateral sulcus Taste The visual area occipital lobe behind the parieto -occipital sulcus Vision

15. Association areas of the cerebrum Area Lobe Location Function Premotor area F rontal A nterior to the motor area Learned pattern of movements . For eg . Tying a shoe lace or writing The frontal area F rontal A nteriorly from the premotor area Behaviour , character and emotional Wernick ' s area Temporal Near parieto -occipital sulcus Intelligence, Language and spoken word perceived

16. Functions of the cerebrum 1.Mental activities involved in memory, intelligence, sense of responsibility, thinking, reasoning, moral sense and learning . 2. Sensory perception, including the perception of pain, temperature, touch, sight, hearing, taste and smell 3. Initiation and control of skeletal (voluntary ) muscle contraction.

17. Thank you