All ten regions from the explorer are collected here so the printed guide stands on its own.
Brain region
Frontal lobe
Front of the brain, behind the forehead
What it does
Planning, decision-making, personality and self-control, and starting voluntary movement. In most people the left frontal lobe also produces speech.
What people may notice
Changes here can show up as difficulty organising or starting tasks, changes in mood or personality that others notice first, weakness on one side of the body, or trouble getting words out while still knowing what one wants to say.
The frontal lobes are the largest part of the human brain and keep maturing into the mid-twenties.
Brain region
Parietal lobe
Top of the brain, toward the back
What it does
Making sense of touch, temperature and pain, and knowing where the body is in space. It helps combine what is seen and felt into a single picture of the world.
What people may notice
Effects can include numbness or odd sensations on one side, difficulty judging distances or finding things in view, or trouble with tasks that need a sense of space, such as dressing or reading a map.
Brain region
Temporal lobe
Side of the brain, around the ear
What it does
Hearing, forming and storing memories, recognising faces, and understanding the meaning of spoken language.
What people may notice
People may notice memory lapses, difficulty following what is said even when they can hear it, or, less often, brief unusual experiences such as a strange smell or a feeling of deja vu.
Brain region
Occipital lobe
Back of the brain
What it does
Vision: it receives signals from the eyes and turns them into the images we actually see, including colour, shape and movement.
What people may notice
Problems here affect seeing rather than the eyes themselves, for example a patch missing from the field of view, or difficulty recognising objects that are in plain sight.
Brain region
Cerebellum
Lower back of the brain
What it does
Balance, coordination and the smoothness and timing of movement. It fine-tunes actions rather than starting them.
What people may notice
Effects can include unsteadiness or a wide, careful walk, clumsy or shaky hand movements, or slurred speech, even when strength is normal.
Brain region
Brainstem
Where the brain meets the spinal cord
What it does
The body’s automatic controls: breathing, heart rate and blood pressure, swallowing, eye movements and staying awake. Almost every signal between the brain and body passes through it.
What people may notice
Because it is so densely packed, even small problems can affect several functions at once, such as double vision, swallowing or balance difficulty, or drowsiness.
Urgent care: Sudden double vision, slurred speech, difficulty swallowing, severe unsteadiness or a drop in alertness can be signs of a stroke or other emergency affecting the brainstem. Call your local emergency number right away. Do not wait to see if it passes.
Spine region
Cervical spine
The neck, vertebrae C1 to C7
What it does
Supports the head and protects the upper spinal cord. Nerves leaving the neck supply the shoulders, arms and hands.
What people may notice
Wear or a slipped disc here can cause neck pain, or pain, pins and needles or weakness travelling into an arm or hand.
Urgent care: Numbness or weakness in both arms or legs, unsteadiness when walking, or loss of bladder or bowel control after a neck injury needs emergency assessment. Call your local emergency number.
Spine region
Thoracic spine
The mid back, vertebrae T1 to T12
What it does
The longest, most stable part of the spine. Each level anchors a pair of ribs, and its nerves supply the chest and abdominal wall.
What people may notice
This region moves less and is a less common source of everyday back pain, so new, persistent mid-back pain is usually worth having checked rather than assumed to be muscular.
Spine region
Lumbar spine
The lower back, vertebrae L1 to L5
What it does
Carries most of the body’s weight and allows bending and twisting. Its nerves supply the hips, legs and feet.
What people may notice
This is the most common site of back pain and of sciatica, where a trapped nerve sends pain, numbness or weakness down a leg. Most episodes settle over weeks with movement and time.
Spine region
Sacrum and cauda equina
The base of the spine
What it does
Below the end of the spinal cord, a bundle of nerve roots called the cauda equina fans out to the bladder, bowel, and the backs of the legs.
What people may notice
These nerves control continence and sensation around the saddle area, which is why certain symptoms here are treated as emergencies.
Urgent care: Numbness around the groin, buttocks or inner thighs, new difficulty passing or controlling urine, or weakness in both legs is a possible cauda equina emergency. Go to an emergency department or call your local emergency number the same day. Early treatment protects long-term function.
