Edexcel International A Level (IAL) Biology - The Brain: Structures, Techniques, and Diseases

Vocabulary-style flashcards covering the anatomy of the brain, clinical scanning techniques, and neurological diseases (Parkinson's and Depression) based on Edexcel IAL Biology notes.

Central Nervous System (CNS)

The classification of the nervous system that consists of the brain and the spinal cord.

Cerebrum

The largest part of the brain, making up about $80\%$ of its total mass, responsible for conscious activities including vision, hearing, speech, thinking, and memory.

Cerebral hemispheres

The two halves into which the cerebrum is divided; the right hemisphere controls the left side of the body and the left hemisphere controls the right side.

Corpus callosum

A band of nerve fibres that joins the two cerebral hemispheres together.

Cerebral cortex

The thin, highly folded outer layer of the cerebrum also known as 'grey matter', which consists of the cell bodies of neurones.

White matter

The layer beneath the cerebral cortex that consists of the myelinated axons of neurones.

Hypothalamus

A region that monitors blood flow to regulate homeostatic mechanisms such as body temperature, osmoregulation (releasing $ADH$), appetite, and endocrine functions via the pituitary gland.

Pituitary gland

A gland located below the hypothalamus divided into the anterior pituitary (produces and releases hormones) and the posterior pituitary (stores and releases hormones like $ADH$ and oxytocin).

Cerebellum

The brain region responsible for coordinating movement and balance by processing information from the eyes, ears, and muscles.

Medulla oblongata

The part of the brain containing co-ordination centres for unconscious functions, including the cardiac centre (heart rate) and the respiratory centre (breathing rate).

Computerised Tomography (CT)

A scanning technique that uses x-ray radiation to produce cross-section images of physical brain structures and locate tissue damage or bleeding.

Magnetic Resonance Imaging (MRI)

A high-resolution imaging technique using magnetic fields and radio waves to identify abnormal or damaged soft tissues and tumours without x-ray risks.

Functional MRI (fMRI)

A variation of MRI that studies brain function in real time by measuring the ratio of oxygenated to deoxygenated haemoglobin to identify active regions.

Positron Emission Tomography (PET)

A technique using radioactive tracers (such as radioactively labelled glucose) to detect areas of high metabolic activity, blood flow, or neurotransmitter activity.

Parkinson's disease

A brain disorder affecting movement coordination caused by the loss of neurones that produce the neurotransmitter dopamine.

Dopamine

A neurotransmitter involved in muscle control; insufficient levels lead to symptoms such as tremors, slow movement, and stiff muscles.

Dopamine agonists

Drugs that treat Parkinson's by binding to and activating dopamine receptors on the postsynaptic membrane to mimic the effect of dopamine.

L-dopa

A dopamine precursor chemical that can be converted into dopamine within the neurones of the brain.

Monoamine oxidase B (MAOB) inhibitors

Enzymes that inhibit the activity of enzymes which break down neurotransmitters (like dopamine) in the synaptic cleft.

Depression

A condition linked to low levels of the neurotransmitter serotonin, which transmits nerve impulses through brain areas that control mood.

SSRIs (Selective Serotonin Reuptake Inhibitors)

A class of antidepressant that increases serotonin levels by preventing its uptake at the synapses.

TCAs (Tricyclic Antidepressants)

Antidepressants that increase the levels of both serotonin and noradrenaline in the brain.