84 terms

Chapter 10: Organ Systems

nervous system
detects and interprets information from the surrounding environment, controls most body function
endocrine system
controls body functions through the use of chemical messengers called hormones
circulatory system
brings needed materials to the cells and carriers away waste materials
lymphatic system
recaptures and filters fluid from the tissues and returns it to the blood stream
respiratory system
takes oxygen into the body and releases carbon dioxide
digestive system
takes food into the body, breaks it down, and absorbs the nutrients from the food
urinary system
removes wastes from the blood
skeletal system
supports the body, protects it, and allows movement
muscular system
makes it possible for the body to move
protects the body and helps regulate body temperature
reproductive system
produces the cells necessary to produce offspring
nerve cells
neuron cell body
anything that sticks off something else
a neuron has several of these to receive messages
a neuron transmits an impulse down this
dendrite to cell body to axon
the direction in which an impulse travels through a neuron
when a neuron is resting, the inside of the neuron is negatively charged compared to outside the neuron
resting membrane potential
-70mV in most cells, a polarized cell maintains this when not transmitting
sodium-potassium pump
this uses a molecule of ATP to move three Na+ out of the cell and two K+ into the cell
leak channels
allow potassium to leak outside the cell to lower the charge inside the cell
voltage-gated channels
channels that open when the cell reaches a charge higher than its resting membrane potential, usually around -50mV
threshold potential
the voltage a cell must reach to fire an impulse
true or false: potassium voltage-gated channels open before sodium voltage-gated channels
action potential
from -70mV to -50mV to +35mV to -90mV to -70mV
the membrane potential moves in the positive direction
the membrane potential returns to its resting value
Schwann cells
special cells that wrap the axon to increase transmission speed
myelin sheath
this increases the speed at which an impulse can travel down the axon
nodes of ranvier
the gaps between Schwann cells
saltatory conduction
jumping conduction over the myelin sheath
refractory period
the amount of time in which a neuron is unable to fire another action potential which keeps the impulse from travelling in two directions
a neuron-to-neuron or neuron-to-organ junction
special chemicals which pass an impulse from one impulse to another
a neurotransmitter that, among its functions, triggers muscle contraction
synaptic cleft
the space between the axon of the first neuron and the dendrites of the second neuron
when a cell depolarizes toward the threshold
when a neuron moves away from threshold
the combining of inhibitory and stimulatory inputs
central nervous system
the brain and spinal cord make up the
peripheral nervous system
the nervous system excluding the brain and spinal cord
sensory neurons
involved in sending information to the CNS from the sensory organs of the body
motor neurons
involved in sending information from the CNS to the organs of the body
are completely within the brain and spinal cord, and often connect sensory and motor neurons
spinal cord
part of the nervous system involved in primitive, reflex actions
our conscious mind, where voluntary actions occur, such as movement, speech, and problem solving, where we have conscious awareness of sensations
part of the brain which coordinates muscle movement and balance
part of the brain in which involuntary acts originate, such as breathing and blood pressure regulation, and is a primitive area
this part of the body maintains homeostasis by monitoring hormone levels, electrolyte balance, temperature, etc.
somatic nervous system
the voluntary system of the PNS which controls skeletal muscles
autonomic nervous system
the involuntary system of the PNS which controls vital organs
sympathetic division
this part of the ANS helps prepare the body for stress by increasing heartbeat, blood pressure, etc. the neurotransmitter used is norepinephrine.
parasympathetic division
this part of the ANS is most active when you are at rest, and moves blood to the digestive organs, decreases heartbeat, and uses acetylcholine
chemicals made by glands, secreted into the blood, and has slow effects on targetted organs
peptide hormones
long distance messengers made of amino acids which must bind to receptors outside the cell, cause effects rapidly by turning enzymes in the cell on or off, and include insulin, prolactin, and glucagon
steroid hormones
long distance messengers made from cholesterol which can easily cross cell membranes and bind to receptors inside the cell, they are more slow, and cause their effects by binding to DNA and changing which genes are transcribed
pituitary gland
the master gland which is controlled by the hypothalamus and is divided into anterior and posterior
growth, thyroid stimulating, adrenocorticotropic, follicle stimulating, luteinizing, prolactin
six hormones that the anterior pituitary gland makes and secretes
growth hormone
targets all tissues and organs and causes them to grow, important in children, but stimulates cell-turnover rate in adults
thyroid stimulating hormone
causes the thyroid to secrete thyroid hormones
adrenocorticotropic hormone
stimulates the outer layer of the adrenal gland to secrete hormones
follicle stimulating hormone
targets the gonads: causes maturation of ova and release of ova and causes testes to make sperm
luteinizing hormone
targets the gonads, causing the ovaries to develop a corpus luteum and the testes to make testosterone
is released only after childbirth and stimulates the mammary glands to make breast milk
oxytocin, antidiuretic
two hormones secreted by the posterior pituitary gland
this hormone causes the uterus to contract during childbirth and causes the mammary glands to release milk
antidiuretic hormone
causes the kidneys to retain water, and is also known as vasopressin
thyroxine, calcitonin
two hormones secreted by the thyroid
this hormone affects body cell's by increasing their rate of metabolism, meaning they work harder and use more energy
activates special cells in bone that remove calcium from the blood and use it to build new bone. it reduces blood calcium levels.
parathyroid hormone
activates special cells in bone to dissolve the bone to release calcium into the blood
epinephrine, norepinephrine
two hormones secreted by the adrenal medulla that increase and prolong the effects of the sympathetic nervous system
glucocorticoids, mineralocorticoids, sex steroids
three types of steroids secreted by the adrenal cortex
steroid hormone that causes the liver to produce glucose from fats and to release the glucose into the blood, which is known as gluconeogenesis (cortisol)
this hormone-type is primarily aldosterone, which causes the kidney to retain sodium, which removes sodium from the urine and return it to the body
organ which secretes hormones and digestive enzymes
insulin, glucagon
two hormones secreted by the pancreas
this hormone is secreted when blood glucose levels are high, such as after a meal, by allowing cells to take glucose out of the body
this hormone is released when blood glucose is low, and causes the liver to break down glycogen and release free glucose into the blood
the male and female primary sex organs: testis and ovary
androgens, testosterone
male sex steroids produced by the testes, which develop male secondary sex characteristics during puberty and maintain them in adulthood
estrogens, progesterone, estradiol
three hormones produced by the ovaries, which are responsible for developing female secondary sex characteristics during puberty and maintaining them in adulthood
hormone which stimulates the growth of the uterine lining in the first half of the menstrual cycle
hormone which enhances and maintains the lining of the uterine during the second half of the menstrual cycle