IB Biology C3.1 Definitions
This page contains our IB Biology definitions for C3.1. By learning each one of these definitions, you will fully cover the content for IB Biology 'Body systems'.
Cerebellum
The part of the brain that coordinates balance and fine-tunes motor skills
Cerebrum
The largest part of the brain, divided into two hemispheres and four lobes (temporal, frontal, occipital, and parietal), responsible for higher brain functions such as speech, planning, and memory
circadian rhythm
The daily rhythm of light from day and night
excretion
The process of removing waste products from the body
Gyri
Deep folds on the surface of the cerebrum that increase its surface area
homeostasis
An organism's ability to maintain it's internal environment
muscle contraction
The sliding of actin and myosin filaments over each other to pull the ends of each sarcomere together and shorten the entire muscle fiber
Myelin
A fatty insulating sheath around neurons in the peripheral nervous system (PNS) synthesized by Schwann cells, and in the central nervous system (CNS) by oligodendrocytes
Neuroglia
Supporting cells in the nervous system that provide structural and functional support to neurons
neuron
A nervous system cell that carries electrical impulses from the brain to the body or vice versa
peristalsis
A wave of muscle contraction that passes along the entire digestive tract
Proprioception
The sense of the relative position of body parts and strength of effort employed in movement, detected by receptors in muscles and joints
skeletal muscle
Muscle attached to bone
Sulci
Deep grooves in the cerebrum that divide the hemispheres into lobes
ventilation
The consistent removal and replacement of air in the lungs via inhalation and exhalation of air
ventilation rate
The number of inhalations or exhalations per minute
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