It performs higher functions like interpreting touch, vision and hearing, as well as speech, reasoning, emotions, learning, and fine control of movement. Cerebellum: is located under the cerebrum. Its function is to coordinate muscle movements, maintain posture, and balance. Brainstem: acts as a relay center connecting the cerebrum and cerebellum to the spinal cord.
It performs many automatic functions such as breathing, heart rate, body temperature, wake and sleep cycles, digestion, sneezing, coughing, vomiting, and swallowing. The cerebrum is divided into two halves: the right and left hemispheres Fig. Each hemisphere controls the opposite side of the body.
If a stroke occurs on the right side of the brain, your left arm or leg may be weak or paralyzed. Not all functions of the hemispheres are shared. In general, the left hemisphere controls speech, comprehension, arithmetic, and writing. The right hemisphere controls creativity, spatial ability, artistic, and musical skills. The cerebral hemispheres have distinct fissures, which divide the brain into lobes.
Each hemisphere has 4 lobes: frontal, temporal, parietal, and occipital Fig. Each lobe may be divided, once again, into areas that serve very specific functions. There are very complex relationships between the lobes of the brain and between the right and left hemispheres. In general, the left hemisphere of the brain is responsible for language and speech and is called the "dominant" hemisphere.
The right hemisphere plays a large part in interpreting visual information and spatial processing. In about one third of people who are left-handed, speech function may be located on the right side of the brain.
Left-handed people may need special testing to determine if their speech center is on the left or right side prior to any surgery in that area. Aphasia is a disturbance of language affecting speech production, comprehension, reading or writing, due to brain injury — most commonly from stroke or trauma. The type of aphasia depends on the brain area damaged. If this area is damaged, one may have difficulty moving the tongue or facial muscles to produce the sounds of speech.
The person can still read and understand spoken language but has difficulty in speaking and writing i. Wernicke's area: lies in the left temporal lobe Fig 3. Damage to this area causes Wernicke's aphasia. The individual may speak in long sentences that have no meaning, add unnecessary words, and even create new words. They can make speech sounds, however they have difficulty understanding speech and are therefore unaware of their mistakes.
The surface of the cerebrum is called the cortex. It has a folded appearance with hills and valleys. The nerve cell bodies color the cortex grey-brown giving it its name — gray matter Fig. Beneath the cortex are long nerve fibers axons that connect brain areas to each other — called white matter.
Each fold is called a gyrus, and each groove between folds is called a sulcus. There are names for the folds and grooves that help define specific brain regions. Pathways called white matter tracts connect areas of the cortex to each other. Messages can travel from one gyrus to another, from one lobe to another, from one side of the brain to the other, and to structures deep in the brain Fig. Hypothalamus: is located in the floor of the third ventricle and is the master control of the autonomic system.
It plays a role in controlling behaviors such as hunger, thirst, sleep, and sexual response. It also regulates body temperature, blood pressure, emotions, and secretion of hormones. Pituitary gland: lies in a small pocket of bone at the skull base called the sella turcica. The pituitary gland is connected to the hypothalamus of the brain by the pituitary stalk. It secretes hormones that control sexual development, promote bone and muscle growth, and respond to stress.
Pineal gland : is located behind the third ventricle. It has some role in sexual development. Thalamus : serves as a relay station for almost all information that comes and goes to the cortex. It plays a role in pain sensation, attention, alertness and memory. Basal ganglia: includes the caudate, putamen and globus pallidus. The outermost layer, the dura mater , is thick and tough. It includes two layers: The periosteal layer of the dura mater lines the inner dome of the skull cranium and the meningeal layer is below that.
Spaces between the layers allow for the passage of veins and arteries that supply blood flow to the brain. The arachnoid mater is a thin, weblike layer of connective tissue that does not contain nerves or blood vessels.
Below the arachnoid mater is the cerebrospinal fluid, or CSF. This fluid cushions the entire central nervous system brain and spinal cord and continually circulates around these structures to remove impurities. The pia mater is a thin membrane that hugs the surface of the brain and follows its contours. The pia mater is rich with veins and arteries. Lobes of the Brain and What They Control Each brain hemisphere parts of the cerebrum has four sections, called lobes: frontal, parietal, temporal and occipital.
Frontal lobe. The largest lobe of the brain, located in the front of the head, the frontal lobe is involved in personality characteristics, decision-making and movement. Recognition of smell usually involves parts of the frontal lobe.
Parietal lobe. The parietal lobe is also involved in interpreting pain and touch in the body. Occipital lobe. The occipital lobe is the back part of the brain that is involved with vision. Temporal lobe. The sides of the brain, temporal lobes are involved in short-term memory, speech, musical rhythm and some degree of smell recognition.
Hypothalamus The hypothalamus is located above the pituitary gland and sends it chemical messages that control its function. Amygdala Small, almond-shaped structures, an amygdala is located under each half hemisphere of the brain. Hippocampus A curved seahorse-shaped organ on the underside of each temporal lobe, the hippocampus is part of a larger structure called the hippocampal formation.
Pineal Gland The pineal gland is located deep in the brain and attached by a stalk to the top of the third ventricle. Ventricles and Cerebrospinal Fluid Deep in the brain are four open areas with passageways between them. Blood Supply to the Brain Two sets of blood vessels supply blood and oxygen to the brain: the vertebral arteries and the carotid arteries. Cranial Nerves Inside the cranium the dome of the skull , there are 12 nerves, called cranial nerves: Cranial nerve 1: The first is the olfactory nerve, which allows for your sense of smell.
Cranial nerve 2: The optic nerve governs eyesight. Cranial nerve 3: The oculomotor nerve controls pupil response and other motions of the eye, and branches out from the area in the brainstem where the midbrain meets the pons. Cranial nerve 4: The trochlear nerve controls muscles in the eye. It emerges from the back of the midbrain part of the brainstem.
Cranial nerve 5: The trigeminal nerve is the largest and most complex of the cranial nerves, with both sensory and motor function. It originates from the pons and conveys sensation from the scalp, teeth, jaw, sinuses, parts of the mouth and face to the brain, allows the function of chewing muscles, and much more. Cranial nerve 6: The abducens nerve innervates some of the muscles in the eye.
Cranial nerve 7: The facial nerve supports face movement, taste, glandular and other functions. Cranial nerve 8: The vestibulocochlear nerve facilitates balance and hearing. Cranial nerve 9: The glossopharyngeal nerve allows taste, ear and throat movement, and has many more functions. Cranial nerve The vagus nerve allows sensation around the ear and the digestive system and controls motor activity in the heart, throat and digestive system.
Think back to the first time you rode a bike. Your brain had to think about pedaling, staying balanced, steering with the handlebars, watching the road, and maybe even hitting the brakes — all at once. Hard work, right? But eventually, as you got more practice, the neurons sent messages back and forth until a pathway was created in your brain.
Now you can ride your bike without thinking about it because the neurons have successfully created a "bike riding" pathway. With all the other things it does, is it any surprise that the brain runs your emotions? Maybe you had fun on your birthday and you were really happy.
Or your friend is sick and you feel sad. Or your little brother messed up your room, so you're really angry! Where do those feelings come from? Your brain, of course. Your brain has a little bunch of cells on each side called the amygdala say: uh-MIG-duh-luh. The word amygdala is Latin for almond, and that's what this area looks like. Scientists believe that the amygdala is responsible for emotion. It's normal to feel all different kinds of emotions, good and bad.
Sometimes you might feel a little sad, and other times you might feel scared, or silly, or glad. Reviewed by: Larissa Hirsch, MD.
Larger text size Large text size Regular text size. The Cerebellum's Balancing Act Next up is the cerebellum. Pituitary Gland Controls Growth The pituitary gland is very small — only about the size of a pea! Hypothalamus Controls Temperature The hypothalamus is like your brain's inner thermostat that little box on the wall that controls the heat in your house.
You Have Some Nerve! Emotion Location With all the other things it does, is it any surprise that the brain runs your emotions? Be Good to Your Brain So what can you do for your brain? Eat healthy foods. They contain vitamins and minerals that are important for the nervous system. Get a lot of playtime exercise.
Wear a helmet when you ride your bike or play other sports that require head protection. Don't drink alcohol, take drugs, or use tobacco.
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