nervous system

• a network of neurons inside the GI tract • can work without the brain or spinal cord • communicates with sympathetic and parasympathetic systems

• submucosal plexus • myenteric plexus

• found in submucosa • controls secretions, absorption and blood flow • regulates submucosal muscle

• found between circular and longitudinal muscle layers • controls GI motility • increases tone, rate, and strength of contractions

• central nervous system • peripheral nervous sytem

• nerves outside the CNS • sends info to and from the CNS

• brain + spinal cord • integrates and controls information

• Sensory (afferent) - brings signals to CNS • Motor (efferent) - carries signals from CNS

• Somatic nervous system - voluntary - controls skeletal muscles • Autonomic nervous system - involuntary - controls smooth and cardiac muscle, and glands

• sympathetic division - fight or flight • parasympathetic division - rest and digest

• mechanoreceptors - pressure and touch • chemoreceptors - chemicals like smell and taste • photoreceptors - light • thermoreceptors - temperature • nocireceptors - pain

sense the outside world (external environment)

tell your brain where your body is and how its moving

monitor the internal environment inside the body

• their main job is to carry signals from the CNS to muscle and glands • somatic motor is voluntary • autonomic motor is involuntary

• detecting change in the body and environment • processing and interpreting the information • sending signals to make the body respond • responses include: breathing, memory, digestion, movement, temp

• it communicates with the rest of the body through the PNS • afferent division brings info to the CNS • efferent division sends instructions away from the CNS

• connects nervous system to endocrine system • decides what hormones need to be released to fix the problem detected by the nervous system

• signals go to the hypothalamus • hypothalamus controls pituitary • pituitary controls other glands • this maintains homeostasis

• phasic receptors • tonic receptors

• respond quickly then stop noticing the stimulus • clothes on skin • helps you focus on new or changing sensations

• fire continuously as long as the stimulus is present • give constant information the body needs all the time • pain receptors, propioreceptors

• Hindbrain • Midbrain • Forebrain

• medulla, pons and cerebellum • controls basic survival functions