Parts of the Brain and What They Do

The human brain has three big parts. Each part sits in a specific place. The cerebrum is on top. It has two halves that control the body’s opposite side. The cerebellum lies under the back of the skull. It helps with balance and fine movement.

Key Takeaways

Brain Regions	Learn about parts of the brain and their roles.
Brain Protection	Find ways to keep parts of the brain healthy.
Warning Signs	Know when to seek medical care.
Daily Habits	Simple steps can boost brain health.

parts of the brain: major brain regions

The brainstem sits at the base. It links the brain to the spinal cord. It controls breathing, heart rate, and sleep-wake cycles. Between the cerebrum and brainstem is the diencephalon. It has the thalamus and hypothalamus. The thalamus sends sensory signals. The hypothalamus sets hunger, thirst, temperature, and hormone release. Each area has a clear job. If one area is injured, that function can change. Doctors test each area with exams and scans to find damage.

Cerebrum

The cerebrum is the big upper part of the brain. It spreads across the top and sides. It has two halves called hemispheres. Each side controls movement on the opposite side of the body. The cerebrum lets us think. It lets us solve problems. It stores memories. It also helps us talk and learn new skills. The outer layer is the cortex. It has many folds that make more space for cells.

The cortex runs the show for thought, senses, and voluntary actions. The inner part has white matter. White matter links different regions. It sends messages fast between areas. If this part is hurt, you may have trouble thinking or moving. A stroke or injury can harm the cerebrum. Damage can lead to loss of speech, weakness on one side, or memory loss. Doctors use scans to see this area. They also use tests that check your thinking, memory, and movement. These tests help find which lobe may be damaged.

The cerebrum is one of the parts of the brain that handles thinking and memory.

In some cases, doctors use a device called an EEG. It measures brain waves. It can show if parts of the cerebrum are overactive or underactive. That may help in epilepsy or sleep studies. Other tests use magnets or sound waves. They show the structure or blood flow of the cerebrum. This helps doctors plan surgery or therapy.

Frontal Lobe

The frontal lobe sits at the front of the cerebrum. It guides planning and decision making. It also controls voluntary movement. A strip called the primary motor cortex lies here. It tells muscles to move. The frontal lobe helps us speak. It helps us solve new problems. It also checks our behavior and mood. If this lobe is hurt, you may have trouble moving or planning. You may also have mood changes. This lobe can be affected by stroke, tumor, or injury. Early signs include weakness, speech trouble, or sudden mood shifts.

Parietal Lobe

The parietal lobe lies behind the frontal lobe. It processes touch and body position. A strip called the somatosensory cortex lives here. It senses pressure, pain, temperature, and position. The parietal lobe helps us know where our body is. It helps us find objects around us. If this lobe is hurt, you may have numbness or trouble with space. You may also have trouble with math or reading maps. Tests can check your sense of touch and spatial skills.

Temporal Lobe

The temporal lobe sits on the side of the brain. It handles hearing and language. A deep part called the hippocampus lies here. It makes new memories. The temporal lobe helps us remember names and faces. It also aids in speech understanding. If it is hurt, you may have memory issues or trouble with language. Conditions like epilepsy often start here. Tests may include hearing checks and memory exams.

Occipital Lobe

The occipital lobe lies at the back of the cerebrum. It processes vision. It turns light signals into images we can see. It lets us know color and shape. If it is hurt, you may have vision problems or see flashes of light. A scan can show damage after a head injury or stroke.

For more on basic brain layout, see the NINDS Brain Basics page.

subcortical parts of the brain

Under the cortex are key parts that run basic functions. These parts sit deep inside. They include the thalamus, hypothalamus, limbic system, and basal ganglia. These areas work together. They send, filter, and shape signals. They help set needs, emotions, and movement.

Thalamus

The thalamus sits near the center of the brain. It is like a relay station. It sends signals for touch, sight, sound, and movement to the right area of the cortex. It also helps with sleep and alertness. If the thalamus is hurt, you may feel numb or have trouble sleeping.

Hypothalamus

The hypothalamus lies just below the thalamus. It controls hunger, thirst, and body temperature. It also manages daily rhythms like sleep and wake. It tells the pituitary gland what hormones to release. If it is not working, you may have weight changes or heat regulation issues.

Limbic System

The limbic system includes the hippocampus and the amygdala. The hippocampus helps turn short-term memories into long-term memory. The amygdala handles fear and pleasure. This system links emotion with memory. If parts of the limbic system are hurt, you may have mood changes or trouble making new memories.

Basal Ganglia

The basal ganglia lie deep in the brain. They work with the cerebellum to plan and start movement. They also help us learn habits. Parkinson’s disease affects a part of the basal ganglia. This can cause slow movements and shaking.

For images and details, see the Johns Hopkins Medicine brain anatomy page.

Cerebellum

The cerebellum lies under the back of the cerebrum. It is smaller but very dense. It has many folds like the cerebrum. It tunes movement and balance. It makes sure movements are smooth and timed well. It also helps us learn new physical skills. When you learn to ride a bike, the cerebellum forms new connections. It also helps keep posture and eye focus when you move.

The cerebellum is one of the parts of the brain that controls coordination and balance.

If the cerebellum is hurt, you may walk with a wide stance. You may also have shaky hands. You may not be able to touch your nose with a finger if asked. Therapy can help you regain skills. It uses exercises that train balance and coordination. This can be part of stroke or injury rehab.

Brainstem

The brainstem lies under the cerebrum and in front of the cerebellum. It has three parts: midbrain, pons, and medulla. The midbrain helps with vision and hearing. The pons links messages between the brain and the cerebellum. It also helps with breathing. The medulla controls heart rate, breathing rate, and blood pressure.

The brainstem is one of the parts of the brain that control vital functions like breathing and heart rate.

If the brainstem is damaged, you may have trouble breathing or regulating heartbeat. You may also feel very weak or stay in a coma. Doctors monitor brainstem function in critical care. They check breathing patterns and reflexes. They may use a ventilator to help with breathing. This area is very sensitive and must be protected.

protecting parts of the brain

The brain sits in a hard skull. The skull is strong bone. It stops objects from hitting the brain. Inside are three layers of soft tissue called the meninges. The first is the dura mater. It is thick and close to the skull. The second is the arachnoid. It is a lace-like layer. The third is the pia mater. It sits close to the brain surface.

A clear liquid called cerebrospinal fluid flows around the brain. It acts like a shock absorber. It also carries away waste. Blood vessels bring oxygen and glucose to the brain. A circle of arteries called the Circle of Willis helps share blood flow. A filter called the blood brain barrier lets nutrients in but blocks harmful items.

Injury or disease can harm these protective layers. A bleed in the brain can press on tissue and cause damage. An infection called meningitis can inflame the layers. A tumor can press on the meninges or blood vessels. Doctors may use surgery to fix some of these issues. A scan like MRI or CT shows the problem.

Learn more about protection and structure at the MedlinePlus – Brain.

Health and Prevention

Good habits can keep the brain strong. A healthy heart brings good blood flow. A good diet gives brain cells fuel. The brain needs glucose and oxygen. It also needs vitamins and minerals like magnesium and potassium. See foods high in magnesium and foods high in potassium. These foods help brain cells work well.

High blood pressure can hurt blood vessels in the brain. You can use an app to track your pressure. Learn how in how to check blood pressure in Samsung Health app. Keep your pressure in a safe range. Talk with your doctor if it is high.

Exercise boosts blood flow and supports new brain connections. Aim for thirty minutes each day. You can walk, swim, or ride a bike. Exercise also helps control weight and blood sugar.

Sleep lets the brain clear waste. It also helps form memories. Aim for seven to nine hours of good sleep. Keep a routine time to sleep and wake. Avoid screens before bed.

Mental activities help the brain stay sharp. Read a book. Do a puzzle. Learn a new skill. Social time also helps. Talk with friends or family.

Find more tips at the NIH Brain Health overview.

Healthy habits protect parts of the brain and support function.

Warning Signs and When to Seek Care

Some brain issues need fast care. Call emergency services if you see:

Sudden weakness or numbness on one side of the body
Sudden trouble speaking or slurred speech
Sudden vision loss or double vision
Severe new headache with no known cause
Sudden dizziness with loss of balance or face droop
Sudden confusion, seizure, or loss of consciousness

These signs may show a stroke or serious brain injury. Fast care can save brain cells and lives.

If you have milder but lasting problems, see a doctor soon. These include:

Chronic headaches
Memory loss that gets worse
Personality or mood changes
Persistent numbness or tingling
New trouble with walking or coordination

These may need tests or scans. A doctor will ask questions and do simple exams. They may order an MRI or CT scan to look at the brain. They may check blood tests to find infections or other issues.

Treatment and Recovery

Serious brain events need quick action. For stroke, doctors may give clot-busting medicine. They may remove a clot with a small tube. For bleeding in the brain, they may do surgery to stop bleeding. In brain injury, they may need to reduce pressure inside the skull.

After the acute event, you need rehab. Physical therapy helps with movement. Occupational therapy helps with daily tasks like dressing and eating. Speech therapy helps with talking and swallowing. A team plans these steps. They track your progress and set goals. Rehab can take weeks or months. It helps your brain make new connections. This is called plasticity.

For long term conditions like Alzheimer’s or Parkinson’s, treatments focus on symptoms. Medicines may help with memory or movement. A doctor will review side effects and adjust doses. You may also use support groups and counseling.

For mild brain injuries like a concussion, rest is key. Do not return to heavy activity until a doctor says it is safe. Follow step by step guides from a health professional. This helps avoid more harm.

See detailed diagrams at Cleveland Clinic Brain Anatomy.