What is the purpose of the nervous system?
to gather, process and organize information
Nervous systems consist of circuits of _____ and supporting cells.
neurons
In most cnidarians, interconnected nerve cells form a _____ ____,
which controls contraction and expansion of the gastrovascular cavity.
nerve net
In more complex animals, the axons of multiple nerve cells are often
bundled together to form _____.
nerves
Fibrous structures that channel and organize information flow through
the nervous system
nerves
an evolutionary trend toward a clustering of sensory neurons and
interneurons at the anterior
cephalization
Non-segmented worms have the simplest nervous system define as _____
______ ______.
central nervous system (CNS)
consists of a small brain and longitudinal nerve cords
CNS
The central nervous system consists of what two things?
brain and spinal cord
Consists of cranial nerves, ganglia outside CNS, and spinal nerves
Peripheral nervous system
the detection of the stimulus
reception
the conversion of a physical or chemical stimulus into an electrical signal
transduction
touch, pressure, stretch, hearing, balance
mechanorepectors
internal chemical and osmolarity sensing, taste, smell
chemoreceptors
light, magnetic fields
electromagnetic receptors
heat and cold
thermo-receptors
chemicals and extreme pressure and temperatures that can damage tissues
pain receptors
Sensory information is ______ through the nervous system.
transmitted
Action potential are all-or-none responses, so how do we detect the
differences in the intensity of stimuli?
perception
the interpretation of sensory inputs
perception
Invertebrates use ______ to detect gravity.
statocysts
We use our ______ _____ (inner ears) to determine position and movement.
semicircular canals
Calcium carbonate particles (otoliths) in the ______ and ____ detect position.
utricle, saccule
Different parts of the _____ detect vibrations at different frequencies.
cochlea
______ is determined by the frequency and loudness by amplitude of
sound waves.
pitch
_______ (hair cells) in the cochlea detect the vibrations and
transmit the signal to the brain.
mechanoreceptors
Bats use _____ to find prey even when it is too dark to see.
echolocation
The lateral lines of fish have hair cells similar to those in our
________ _____ that allow them to sense vibrations in the water.
semicircular canals
The _____ of planarians detect light, but do not form an image.
ocelli
Bees see in color and can detect wavelengths into the _______ range.
ultraviolet
______ muscles tug on the lens, changing its shape into focus the
image onto the retina.
ciliary
myopia
nearsightedness
In ______ the concave lens diverges light rays, so the object is
focused on the retina.
myopia
hyperopia
farsightedness
In _______ the convex lens diverges light rays, to the object is
focused on the retina.
hyperopia
presbyopia
old persons vision
In ______ the lens loses elasticity and stays flattened which leads
to the inability to focus on near objects.
presbyopia
The two types of photoreceptors in the retina.
cones and rods
allow us to see in color, but only function in bright light
cones
function in low light, but can only detect light and dark (black/white)
rods
The rods and cones in our eyes point to the back, so the axons of the
optic nerves must pass back through the _____.
retina
The placement of the eyes determines field of vision and ______ ______.
depth perception
Predators have eyes that face the ______.
front
Prey animals tend to have their eyes to the ______ of their heads.
sides
Rattlesnakes have a pair of _____ _____ which are sensitive enough to
detect a warm mouse nearby.
infrared receptors
the basic unit of a muscle
sarcomere
the functional unit of contraction, called a _______, is made up of
overlapping thick (myosin) and thin (actin) filaments.
sarcomere
thick filament
myosin
thin filament
actin
Sliding of a filament requires ___.
ATP
During the muscle contraction, the __ _____ will decrease in length.
I band
The stimulus to contract comes from the _______ ______.
neuromuscular junction
The release of _____ from the axon terminus triggers an action
potential in the muscle cell.
acetylcholine
______ is released into the cytosol and the muscle contracts.
calcium
Muscle cells can contract, but they cannot _____ on their own.
elongate
At death, fibers in the muscles are stuck in position due to the lack
of ATP.
rigor mortis
savory and delicious sensation on the tongue
umami
Injury to the hypothalamus would most likely disrupt _______.
regulation of body temperature
Emotion, motivation, olfaction, behavior, and memory, in humans, are
mediated by the _____ system.
limbic
In mammals, the eardrum transmits sound waves to three small bones,
which transmit the waves to fluid waves within the cochlea. Where are
the three small bones located?
middle ear