Module 10

nervous system

communication system made up of brain, spinal cord, and nerves

• brain tells body parts to move, organs to function, face to express emotion, etc.

the neural chain

• sensory info. enters body through receptor cells in eyes, nose, ears, etc.

• sensory (afferent) neurons carry info. to brain/spinal cord

• interneurons in brain process sensory info. and decide what to do

• motor (efferent) neurons send motor info. away from CNS to the muscles of the body

sensory (afferent) neurons

neurons that carry info. to brain/spinal cord

interneurons

neurons in the brain that process sensory info. and decide what to do

motor (efferent) neurons

neurons that send motor info. away from CNS to the muscles

spinal reflex

a reaction that occurs before info. makes it to the brain

• spinal cord sends message before the brain using motor neurons

central nervous system

consists of the brain (info. processing) and spinal cord (main pathway to and from brain)

• contains interneurons

peripheral nervous system

outer region surrounding the brain and spinal cord

• contains sensory and motor neurons

somatic nervous system

type of peripheral nervous system

• controls muscles, contains motor neurons that activate muscles

  (ex: carries command from CNS to leg muscles in order to walk)

autonomic nervous system

type of peripheral nervous system

• controls glands/muscles of internal organs

  (ex: breathing, blood pressure, digestion)

sympathetic nervous system

type of autonomic nervous system

• fight or flight response

• raises B.P. and breathing

• deals w/ perceived threats

parasympathetic nervous system

type of autonomic nervous system

• brings body back to normal, calms it down

endocrine system

communication system made up of a set of glands that produce hormones

hormones

chemical messengers that circulate through the blood

pituitary gland

master gland

• located at brain’s base

• controlled by hypothalamus

• controls other endocrine glands

• ex: oxytocin - promotes bonding/sparks labor in women

thyroid gland

releases hormones that regulate growth, metabolism, and appetite

• ex: thyroxine and triiodothyronine - metabolism, energy levels

pancreas

an internal organ that secretes hormones that regulate blood sugar levels

• ex: insulin - regulates level of sugar in blood

adrenal glands

primarily release hormones related to stress and anxiety

• also release androgens (sex hormones) that play a role in the development of male sexual characteristics

• ex: epinephrine and norepinephrine - fight or flight response

ovaries

the female reproductive organ, which produces ova and sex hormones

• ex: estrogen - ovulation

testes

 the pair of oval-shaped organs, about the size of a large grape

• ex: androgens - sperm production

oxytocin

acts as a chemical messenger

• sexual arousal

• mother–infant bonding

thyroxine and triiodothyronine

the two main hormones secreted into the bloodstream by the thyroid gland

• metabolism

insulin

a hormone that lowers the level of glucose (sugar) in the blood

epinephrine and norepinephrine

act as both neurotransmitters and hormones in the body

• fight or flight response

• increases in blood pressure, heart rate, and blood sugar levels

androgens

a substance capable of developing and maintaining masculine characteristics in reproductive tissues