vocab

3. nervous system (PNS): consists of all nerves outside the brain and spinal cord
4. neurons: specialized nerve cells in the peripheral nervous system
5. any of the elongated contractile threads found in striated muscle cells.
9. a thin, two-layered serous membrane
11. branched, tree-like extensions of neurons that receive electrochemical signals from other neurons
12. the microscopic structural and functional unit of the kidney
13. microscopic air sacs at the end of this tree for gas exchange
14. The main artery of the body.
17. neuron: specialized nerve cells originating in the brain
18. the shortest and widest segment of the small intestine.
19. primary transmission cable of the nervous system

1. neurons:specialized nerve cells in the brain and spinal cord that transmit signals
2. the automatic relaxation of muscles in the digestive tract and other tubular organs.
6. airways branching into lungs
7. a tube that transfers urine out of the body
8. natural waste product of protein
10. a stiff flap at the base of the tongue.
15. artery: the essential blood vessels that supply oxygen-rich blood. directly to the heart muscle.
16. marrow: vascular tissue inside the bone.
20. junction: a specialized chemical synapse bridging motor neurons and skeletal muscle fibers