SYSTEMS OF THE BODY
A specialized cell that receives, processes, and transmits information using electrical and chemical signals.
nueron
The tough connective tissue that covers the outside of a bone (except at joint surfaces).
Periosteum
Fibrous connective tissue that attaches muscle to bone.
tendon
The brain and spinal cord.
central nervous system
“Powerhouse” organelle that makes ATP.
mitochondrion
The tiny junction where one neuron communicates with another neuron or a muscle/gland cell.
synapse
The place where two bones meet, allowing movement or stability.
(Joint / articulation)
The basic functional unit of a skeletal muscle fiber
sarcomere
A neuron that carries impulses from receptors to the central nervous system
sensory (afferent) neuron
Selective barrier controlling what enters/exits the cell.
cell (plasma) membrane
A fatty insulating covering around many axons that speeds up nerve signal transmission.
Myelin sheath
The type of bone cell that breaks down bone tissue during remodeling.
Osteoclast
Explains how actin and myosin slide to shorten a muscle.
sliding filament
Part of a neuron that carries signals away from the cell body
axon
One layer of flat cells; good for diffusion (alveoli/capillaries).
squamous epithelium
The division of the nervous system that controls involuntary body functions like heart rate, digestion, and pupil size.
Autonomic nervous system
The type of bone cell that builds new bone tissue during remodeling.
osteoblast
The synapse where a motor neuron communicates with a muscle fiber.
neuromuscular junction
Three protective membranes around the brain and spinal cord.
meninges
Cell division making two genetically identical body cells.
mitosis
The “jumping” of an action potential from one node to the next along a myelinated axon, making conduction faster.
Saltatory conduction
The process where bone is broken down and rebuilt to maintain strength and regulate minerals like calcium.
bone remodeling
Contraction where tension rises but muscle length stays the same.
isometric contraction
Brain region for balance, coordination, and posture.
cerebellum
Water moving across a membrane toward higher solute concentration.
osmosis