BIOLOGY MID-TERM REVIEW

biology

Nervous System

The system that sends messages quickly between the brain and other body parts, enabling movement, feeling, thinking, and responses to stimuli.

Central Nervous System (CNS)

Composed of the brain and spinal cord; controls thoughts, decisions, and message transmission between the brain and body.

Peripheral Nervous System (PNS)

Composed of nerves outside the brain and spinal cord; connects the body to the CNS and aids in movement and sensation.

Endocrine System

A group of glands that release hormones into the blood, controlling long-term body processes like growth and metabolism.

Stimulus

An event that causes a reaction in the body, such as touching something hot or hearing a loud noise.

Neuron

A specialized cell in the nervous system that transmits electrical and chemical signals, serving as the basic building block of the nervous system.

Parts of a Neuron

Includes the cell body (processes information), dendrites (receive signals), and axon (carries signals away).

Types of Neurons

Sensory neurons (carry information to CNS), motor neurons (send signals to muscles/glands), and interneurons (connect sensory and motor neurons).

Resting Potential

The state of a neuron when no signal is being transmitted, characterized by a higher concentration of Na+ outside and K+ inside the cell.

Sodium Ions (Na+)

Ions that are more concentrated outside the neuron during resting potential.

Potassium Ions (K+)

Ions that are more concentrated inside the neuron during resting potential.

Sodium/Potassium Channel

A protein that actively moves sodium out and potassium into the neuron, maintaining resting potential.

Action Potential

A brief electrical charge that travels along the axon when a neuron is stimulated, reversing resting potential.

Signal Transmission

Occurs at a synapse where neurotransmitters are released to transmit signals between neurons.

Sensory Receptors

Specialized cells that detect stimuli; include photoreceptors, mechanoreceptors, thermoreceptors, chemoreceptors, and pain receptors.

Pathway of Light

The route light takes through the eye:Cornea → Iris → Pupil → Lens → Retina → Optic nerve → Brain.

Cerebrum

The part of the brain responsible for intelligence, learning, judgment, and sensory processing.

Cerebellum

The part of the brain that controls balance and coordination.

Brain Stem

Controls vital functions such as heart rate, breathing, and digestion.

Somatic Nervous System

Regulates voluntary movements of the body.

Autonomic Nervous System

Controls involuntary functions, including the sympathetic (fight or flight) and parasympathetic (rest and digest) systems.

fMRI

A technique that uses magnetic fields and radio waves to study brain activity.

CT Scan

A technique that uses X-rays to diagnose brain injuries and tumors.

MRI

A technique that provides detailed images of soft tissues and neurological disorders using magnetic fields.

Stimulant

A substance that increases neurotransmitter activity, enhancing alertness and energy.

Inhibitor

A substance that decreases neurotransmitter activity, helping regulate mood and relieve depression.

Hormone

A chemical messenger released by glands that travels through the bloodstream to target organs.

Receptor

A protein that binds to a specific hormone, initiating a response in the target cell.

Target Cell

A cell that has receptors for a particular hormone and responds to its signals.

bio

bio

bio

bio

bio

bio

bio

bio