science quiz

medulla oblongata

responsible for maintaining an upright position and regulating most involuntary functions such as breathing and circulation

cerebellum

coordinates fine muscle movement and balance; extensive damage may cause inability to stand

pons

serves as the bridge to the midbrain and is responsible for sleep regulation

reticular formation

relays signals particularly from the eyes and ears to the cerebellum; controls general levels of alertness or lethargy

cerebrum (cerebral cortex)

seat of intelligence; responsible for thinking, learning, emotions, consciousness, and voluntary movements

thalamus

sorts and relays incoming and outgoing information to different parts of the brain; serves as the area of sensory integration

hypothalamus

monitors pleasurable activities such as eating and drinking; influences the endocrine system, particularly the pituitary gland, in secreting hormones in response to stress, emotions, and rewarding feelings

neuron

basic cellular unit of the nervous system that transmits impulses to and from various parts of the body

sensory neuron (afferent)

receives information and sends impulses to the spinal cord or brain

motor neuron (efferent)

conducts impulses from the brain or spinal cord to muscles or glands

interneuron

connects sensory and motor neurons within the brain and spinal cord

dendrite

extension of the cell body that increases surface area for reception of impulses

axon

extension of the neuron that transmits impulses away from the cell body

myelin sheath

insulating covering around the axon that speeds up transmission of impulses

synapse

gap between neurons across which neurotransmitters carry signals

neurotransmitters

chemical messengers that transmit signals across synapses

nerve fiber

composed of an axon and its myelin sheath

neurilemma

outer layer of nerve fibers that aids in repair and regeneration

fiber tract

bundle of nerve fibers within the central nervous system

nerve

bundle of nerve fibers outside the central nervous system, surrounded by epineurium and supplied with blood vessels

epineurium

fibrous sheath that surrounds and protects nerves

peripheral nervous system

connects the brain and spinal cord to the rest of the body; composed of 12 pairs of cranial nerves and 31 pairs of spinal nerves

somatic nervous system

division of the peripheral nervous system that controls skeletal muscles, skin, and voluntary movements

autonomic nervous system

division of the peripheral nervous system that controls involuntary activities such as heartbeat, digestion, breathing, and glandular functions

sympathetic mechanism

subdivision of the autonomic nervous system that dominates in times of stress; initiates fight-or-flight reactions by increasing heartbeat, breathing, and blood flow to muscles while decreasing digestion

parasympathetic mechanism

subdivision of the autonomic nervous system that restores the body to a normal state after stress; promotes digestion, elimination, and conservation of energy