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Unit 10 Endocrine and Nervous System

Terms in this set (73)

What is the function of the nervous system?
collect information, process the information, respond
what is a neuron?
carry nerve impulses (electrical), building blocks of the nervous system
how does the neuron work?
dendrites receive message, message moves to axon, myelin sheath insulates message, message>axon terminal> releases neurotransmitters> synapse
what is a synapse?
gap between neurons
what are neurotransmitters?
chemicals that transmit information across the synpase
what are the types of neurons?
sensory, interneurons, motor
what is a sensory neuron?
in sensitive spots, carry impulses from stimulus to brain or spinal cord "alert"
what is an interneuron?
"middle men" brain, process info from sensory neurons and send commands to other interneurons or motor neurons
what is a motor neuron?
muscles, carry impulses from brain or spinal cord to muscle "responds"
what are the two parts to the nervous system?
central and peripheral
what is the central nervous system?
brain and spinal cord, process information, creates a response
what is the peripheral nervous system?
all around the body, sensory input, motor output, nerves and supporting cells, collects information (sensory division), delivers message from CNS to response organs
what is motor division of peripheral nervous system divided into?
somatic and autonomic system
what is the somatic system?
most voluntary (movement of skeletal muscle)
what is the autonomic system?
carries messages to internal organs, involuntary, "fight or flight" vs. "rest and digest"
what is reflex?
a quick, automatic response to a stimulus
what is reflex arc?
the pathway the message takes to allow a reflex
what peripheral system is reflex arc apart of?
somatic
what is a step by step reflex arc?
sensory receptors get a signal, signal goes to sensory neurons then to spinal cord, interneuron (in spinal cord) decides to act, motor neuron listesn to interneuron and acts by moving muscle
what is the central nervous system made of?
brain and spinal cord
what is the nervous system made of?
nerves/supporting cells
what is the myelin sheath?
fatty covering that protects the neuron
what is the dendrite?
branch-like extensions of the neuron that receive impulses and pass them to the cell body
what is the axon?
a single extension of the neuron, receives and transmits impulses away from the cell body
what is the brain protected by?
the skull, fluid, and 3 layers of membrane
what are the three major parts of the brain?
cerebrum, cerebellum, and the medulla oblongata
what is the cerebrum?
which functions in personality, consciousness, learning and memory, made up of several lobes and divided into 2 hemispheres each having different functions
what does the left side of the brain deal with?
verbal and analytical skills (reading, speech, math, writing, logic)
what does the right side of the brain deal with?
spatial and artistic skills (music and art)
what is the cerebellum?
coordinates the posture and balance of the body, plus helps muscles work together
what is the medulla oblongata?
brain stem that regulates the involuntary actions such as heartbeat, breathing, coughing, and sneezing
what is the function of the spinal cord?
integrate simple responses and transfer information to and from the brain
what is the function of the brain?
control center, processes and relays information, CPU of the body
a chemical capable of reacting with and changing the function of the body
drug
what are the effects of a good drug?
relieve pain, fever
what are the effects of a bad drug?
affect hunger, thirst, sleep, addictive, mood changing (depression, euphoria), seeing things (hallucinations), altar how your body responds to your own hormones
why do drug users take more and more of the drugs they use?
the brain reacts to excessive dopamine levels by reducing the number of receptors for the neurotransmitter. As a result, normal activities no longer produce the sensation of pleasure they once did. Addicts then begin to feel sad and depressed without their drug
what is the sympathetic nervous system?
it is more active when you are about to run a marathon. body will increase its blood pressure and send out more sugars to the body to create more energy
what is estrogen?
made in the ganads (ovaries), act on cell and tissue that develops the physical characteristics, sexual development, regulates menstrual cycle, bone growth
what is progesterone?
made in the uterus (ovaries), stimulates growth and development of uterine lining, maintains uterus in pregnancy, stimulates protein synthesis and cell growth
what is growth hormone?
made in the pituitary gland, helps body flow and develop
what is the epinephrine (adrenaline)?
made in the adrenal glands, increases heart rate and blood pressure and prepare the body for intense physical activity, need energy when adrenaline (fight to flight), stimulates air passage to open widely, stimulates release of glucose
what is the calcitonin?
made in the thyroid gland, reduces blood calcium levels makes iodine work properly
what is testosterone?
made in the testes, stimulates puberty, bone growth, sex drive in men, linked to aggression
what is thyroxin?
made in the thyroid gland, increases metabolic rate of cells throughout body
what is the function of the endocrine system?
"radio station" sends messages using chemicals, different parts of the body are tuned to different stations, can reach thousands of customers, helps maintain homeostasis
what is a hormone?
chemical messages (radio waves)
an organ that produces and releases a substance (secretions)
organs
what are the two types of glands?
exocrine and endocrine
what is the exocrine gland?
releases secretions into ducts (tubes) to the outside or into the digestive system (sweat glands)
what is the endocrine system?
releases secretions directly into the blood (ovaries)
what is the function of hormones?
deliver messages throughout the body, releases in 1 part of the body, travel in the blood, affect cells in other parts of the body (target organ)
cells with a receptor for a particular hormone (target for hormone)
target cells
what is the role of hormones in homeostasis?
hormones act in pairs like a tug of war
what is a feedback loop?
act to referee the tug of war, ex. sweating, dehydration>alerts your brain> brain produces adh> increase thirst decrease urine> body okay now> stop producing adh
insulin and glucagon control sugar
blood glucose
stimulates storage of sugar
insulin
stimulates release of sugar
glucagon
what is diabetes?
body fails to produce insulin (type 1), must receive injections of insulin
(type 2) fails to respond to insuline, must control with diet/exercise
what are the major endocrine glands?
pancreas, pituitary, gonads, thyroid, adrenal
what are the adrenal glands?
located on top of each of the kidney, glands secrete hormones, most familiar is adrenaline
what is the pancreas?
secretes insulin for beta cells, hormone helps lower blood sugar levels and increase storage of glucagon (secreted by alpha cells, stimulates conversion of glycogen to glucose)
what is the thyroid gland?
located at the base of the neck, produces thyroxin which controls metabolic rate
what is the pituitary gland?
"master" gland works in close operation with the hypothalamus, provides link between brain, nervous system, and endocrine
what is the anterior lobe?
produces 6 different hormones
what is the posterior lobe?
acts as a storage for 2 hormones produced by the hypothalamus
where can a hormone go wrong?
message doesnt get sent, feedback doesnt work, message inst heard
what is gigantism?
excessive growth hormone, excessive height, enlarged hands, feet, jaws
what is cretinism?
low levels of thyroxine> because low levels of iodine, skeletal and nervous systems dont develop properly
what is goiters?
enlargement of the thyroid gland, sign of hypothyroidism (not enough thyroxin produced, lack of energy, low body temp, weight gain)
what is hyperthyroidism?
too much thyroxine, symptoms: fast heart beat, tremors, anxiety, speedy digestive system>weight loss, diarrhea
what is hyperprolactinemia?
too much prolactin produced (prolactin-milk production), causes lack of period and spontaneous milk production
what is turners syndrome?
caused primarily by genetics, side effects is low estrogen (no secondary sex characteristics, short stature, no periods or puberty)
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