TEAS® Science Study Guide
Nervous System
The nervous system senses the environment, processes information, and directs the body’s response.
Two main divisions
- Central nervous system (CNS) — Brain and spinal cord. Processes and interprets.
- Peripheral nervous system (PNS) — All nerves outside the CNS. Carries messages in and out.
The PNS splits again
- Somatic — Voluntary; controls skeletal muscle.
- Autonomic — Involuntary; controls organs, heart rate, digestion.
- Sympathetic — "Fight or flight." Raises heart rate, dilates pupils, slows digestion.
- Parasympathetic — "Rest and digest." Lowers heart rate, stimulates digestion.
Brain regions
- Cerebrum — Thinking, memory, voluntary movement, senses.
- Cerebellum — Balance, coordination, fine motor control.
- Brainstem — Automatic survival functions: breathing, heart rate, blood pressure.
The neuron
- Dendrites receive signals → cell body → axon carries the signal away → synapse, the gap where neurotransmitters cross to the next cell.
- Myelin sheath insulates the axon and speeds signal transmission.
Terms to know
- Neuron — Nerve cell; the basic unit of the nervous system.
- Synapse — Junction between two neurons.
- Neurotransmitter — Chemical messenger that crosses the synapse.
- Reflex arc — A rapid, involuntary response routed through the spinal cord — it doesn’t wait for the brain.
What the TEAS asks most
- What makes up the CNS? Brain and spinal cord.
- Which division handles fight-or-flight? Sympathetic.
- Which brain part controls balance and coordination? Cerebellum.
- Which part of a neuron carries signals away from the cell body? Axon.