Question | Answer |
what does homeostasis depend on | the ability of different systems in your body to communicate with one another |
what two systems help you maintain homeostasis | nervous and endocrine |
what is the nervous system | a physically connected network of cells, tissues, and organs that controls thoughts, movements, and simpler life processes |
what is the endocrine system | a collection of physically disconnected organs that helps to control growth, development, and responses to your environment |
what is a stimulus | something that causes a response |
what kind of changes can trigger a stimulus | chemical, cellular, or behavioral |
which system's chemical signals are carried by the bloodstream throughout the body | endocrine system |
what does your nervous system send its signals through | a network of specialized tissues |
what are the 3 main parts of the neuron | cell body, dendrites, axon |
cell body | contains nucleus and organelles |
dendrites | branchlike extensions of cytoplasm and cell membrane, receives messages |
axon | long extension that carries electrical messages away from cell ]body |
what are the 3 types of neurons | sensory, inter, and motor |
sensory neuron | detects stimuli
transmits signals to brain and spinal cord |
inter neuron | brain and spinal cord
receives signals from sensory neurons
relays signals within the brain and spinal cord
process info and pass signals to motor neurons |
motor neuron | pass messages from NS to other tissues in the body |
why does a neuron maintain a charged difference across its membrane | so it is ready to transmit impulses when stimulated |
what is the main reason for the resting potential | 1. there are more channels for K+ then Na+
+ charges leave cell faster then they enters unequal diffusion
2. the sodium-potassium pump transports Na+ and K+ against their gradients |
what are the 5 senses | sight, hearing, smell, taste, touch |
what are the 5 receptors | photorec (sense light), mechanorec (responds to pressure, movement, and tension), thermorec (monitors receptors), chemorec (detects chemicals dissolved in fluid), pain rec (responds to extreme heat, cold, and pressure, and to chemicals) |
which sense do humans rely on more then any other sense | sight - eye has 70% of all sensory rec in the body |
what and where are photorec | rods and cones on the retina |
what is an iris | the colored part of the eye and it controls the size of the pupil |
what is the cochlea | a structure of fluid-filled canals
moves in response to vibrations |
hearing | sound waves/air/vibrations- pinna- auditory canal- eardrum=tympanic membrane- drum vibrates- vibrations amplified by three bones in middle ear, cochlea (fluid moves)- and causes cilia hair cells to bend- impulse- auditory nerve- brain- sound |
what are the three bones of the middle ear | malleus, incus, stapes |
smell | airborne chemicals enter nose- which dissolve in mucus- detected by olfactory cells- generates impulse- olfactory nerves takes impulse to the brain |
what are taste buds | chemoreceptors that detect tastes, found in bumps on the tongue called papillae |
what does smell and taste have in common | they both have chemorec where the chemicals must be dissolved in fluid before it generates an impulse |
what kind of receptors are on the skin | mechanorec- two types are receptors that detect gentle which is located in the upper layer of the skin, and receptors that detect heavy pressure which is located in the deeper layers |
what information is gathered by the frontal lobe | personality, reasoning, and judgement, voluntary movement, and speech |
what information is gathered by the parietal lobe | sensory cortex gathers information about touh |
what information is gathered by the temporal lobe | speech interpretation, hearing, and memory |
what information is gathered by the occipital lobe | visual information |
what are meninges | three layers of connective tissue that protect the brain |
3 structures of the brain | cerebellum, cerebrum, brain stem |
what is gray matter | collection of neurons cell bodies |
what is white matter | collection of axons (myelin sheath) |
corpus callosum | nerves that connect the two hemispheres |
thalamus | sorts info from sensory organs and passes signals between the spinal cord and other parts of the brain |
hypothalmus | gathers info about body temperature, hunger, and thirst. sends signals to maintain homeostasis |
3 parts of the brain stem | midbrain- controls reflexes such as people size, pons- regulates breathing, and medulla oblongata- controls life sustaining functions such as the heart, vommiting, swallowing, and coughing |
spinal cord | ropelike bundle of neurons connecting the brain to the nerves |
how do stimulants cause more action potentials | increase neurotransmitter in synapse
decrease removal of neurotransmitter in synapse |
how do depressants cause fewer action potentials | produce neurotransmitter that prevent impulses
slow release of neurotransmitter that generates impulses |
whats the difference between steroid and nonsteroid hormones | steroid diffuses into the cell membrane and nonsteroid does not (binds on cell membrane)
steroid causes DNA to make proteins, nonsteroid makes enzymes |
what are the two major functions of the hypothalamus | as part of CNS, it receives info from sensory organs
as part of Endocrine System, it produces releasing hormones |