The brain and behaviour

Get to know about the structure and functions of the brain, the various parts of the brain, their roles, parts and working in detail.

1. THE BRAIN AND BEHAVIOUR Structure and functions of the brain Group 3 AN INTRODUCTION

2. Brain- The human computer The brain is one of the largest and most complex organs in the human body. From running to sleeping, all our day-to-day activities is carried by the use of brain. It is believed that the human brain has evolved over millions of years from the brains of lower animals, and this evolutionary process still continues. We can examine the levels of structures in the brain, from its earliest to the most recent form in the process of evolution. The brain is organised into structures and regions that perform specific functions. They are :- Hindbrain – it consists of Medulla Oblongata, Pons and Cerebellum. Midbrain – it is relatively small in size and it connects the hindbrain with the forebrain. Forebrain - It is considered to be the most important part of the brain because it performs all cognitive , emotional, and motor activities. Major parts are hypothalamus, thalamus, limbic system, and cerebrum.

3. Parts of the brain and their functions Click here to watch a video :- https://www.youtube.com/watch?v=-nH4MRvO-10&t=1s

4. Do you know? An adult brain weighs about 1.36 kg and contains around 100 billion neurons that communicate in trillions of connections called synapses. The limbic system, brain stem and cerebellum are the oldest structures, while Cerebral Cortex is the latest development in the course of evolution of the brain. The brain is surrounded by a layer of tissue called the meninges. The skull (cranium) helps protect the brain from injury.   About 75 percent of the brain is made up of water. This means that  dehydration , even in small amounts, can have a negative effect on the brain functions. The human brain is the largest brain of all vertebrates relative to body size. The brain makes up about 2 percent of a human's body weight. The human brain will grow three times its size in the first year of life. It continues to grow until you’re about 18 years old.

5. HINDBRAIN Hindbrain i.e. one of the major divisions of brain after the midbrain and forebrain is also called rhombencephalon, region of developing vertebrate brain. It is composed of the medulla oblongata, the pons, and the cerebellum. Hindbrain coordinates functions that are primary to survival, including respiratory rhythm, motor activity, sleep, and wakefulness

6. Parts of Hindbrain: HINDBRAIN MEDULLA OBLONGATA PONS CEREBELLUM

7. MEDULLA OBLONGATA : It is the lowest part of the brain conjoined with spinal cord. It contains neural centres which helps in activities like breathing, heart rate, and blood pressure. Medulla is the vital centre of the brain and also helps in some autonomic activities. PONS: It is connected with medulla on one side and midbrain on the other. The neutral centre of pons receives auditory signals transferred by our ears. Pons are involved in sleep mechanism, especially dreaming. It has nuclei which affects respiratory movement and facial expressions also. CEREBELLUM: It is the highly developed part of the hindbrain that can be recognised by wrinkled surface. It maintains and controls posture and equilibrium of the body. Cerebellum mainly function in coordination of muscular movements. The motor commands that are originated in forebrain, cerebellum coordinates them to relay to the muscles, and also stores the memory of movement to ease walk or dance .

8. Mid brain Mesencephalon

9. Introduction Most superior of the regions of brainstem ( medulla ) Relatively small in size It connects hind brain with fore brain Special reflexes and visuals and auditory sensation are found here Important part : reticulate activating system ( ras ),responsible for our arousal It makes us alert and active by regulating sensory inputs Associated with vision ,hearing ,motor functions https://youtu.be/NsWukc8G6wE

10. CEREBRUM

11. Cerebrum 1 It is located in the upper portion of brain and it is the area that processes thoughts,judgement, memory , problem solving and language 2 Cerebral Cortex- Its is the superficial layer of the cerebrum. Its thickness varies from 1.5mm to 4mm, conatins neurons, neural nets and bundles of axon 3 The most prominent fissure,the longitutional fissure, sperates the cerebrum into right and left halves called “ Cerebral Hemisphere” each hempisphere has 4 lobes 4 The cerebrum is subdivided into the left and right both hemisphere are connected by bridge of nerves fibres that relay information between 2 hemispheres called “Corpus Collosum”

12. 5 left hemisphere controls right side of the body 6 Right hemisphere controls the left side of the body

13. LOBES OF CEREBRUM

14. LOBES OF CEREBRUM Frontal Lob e a)M ost anterior portion of cerebrum b) It is involved in reasoning ,planning,some parts of speech , movement ,emotions ,problem solving c) it is also called MOTOR CORTEX 2 Parietal lobe- a)The most superior portion of cerebrum b)It recieves sensory input from the skin ( touch ,pressure , temperature and pain) d ) it is also called SENSORY CORTEX 3 Occipital Lobe a)The most posterior portion of the cerebrum b) recieves input from the eyes and controls vision c) It is also called VISUAL CORTEX

15. 4 Temporal Lobe a) The left and right lateral portion of the cerebrum
b) controls hearing and smelling
c) it is also called AUDITARY CORTEX Functions Of Cerebrum 1) Motor functions like control of voluntary movements 2) sensory functions like perception of pain,temperature,touch,hearing,taste and smell 3) control of intelligence , speech , memory and learning

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