What is the purpose of the nervous system?
to gather, process and organize information
Nervous systems consist of circuits of _____ and supporting cells.
In most cnidarians, interconnected nerve cells form a _____ ____,
which controls contraction and expansion of the gastrovascular cavity.
In more complex animals, the axons of multiple nerve cells are often
bundled together to form _____.
Fibrous structures that channel and organize information flow through
the nervous system
an evolutionary trend toward a clustering of sensory neurons and
interneurons at the anterior
Non-segmented worms have the simplest nervous system define as _____
central nervous system (CNS)
consists of a small brain and longitudinal nerve cords
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
the conversion of a physical or chemical stimulus into an electrical signal
touch, pressure, stretch, hearing, balance
internal chemical and osmolarity sensing, taste, smell
light, magnetic fields
heat and cold
chemicals and extreme pressure and temperatures that can damage tissues
Sensory information is ______ through the nervous system.
Action potential are all-or-none responses, so how do we detect the
differences in the intensity of stimuli?
the interpretation of sensory inputs
Invertebrates use ______ to detect gravity.
We use our ______ _____ (inner ears) to determine position and movement.
Calcium carbonate particles (otoliths) in the ______ and ____ detect position.
Different parts of the _____ detect vibrations at different frequencies.
______ is determined by the frequency and loudness by amplitude of
_______ (hair cells) in the cochlea detect the vibrations and
transmit the signal to the brain.
Bats use _____ to find prey even when it is too dark to see.
The lateral lines of fish have hair cells similar to those in our
________ _____ that allow them to sense vibrations in the water.
The _____ of planarians detect light, but do not form an image.
Bees see in color and can detect wavelengths into the _______ range.
______ muscles tug on the lens, changing its shape into focus the
image onto the retina.
In ______ the concave lens diverges light rays, so the object is
focused on the retina.
In _______ the convex lens diverges light rays, to the object is
focused on the retina.
old persons vision
In ______ the lens loses elasticity and stays flattened which leads
to the inability to focus on near objects.
The two types of photoreceptors in the retina.
cones and rods
allow us to see in color, but only function in bright light
function in low light, but can only detect light and dark (black/white)
The rods and cones in our eyes point to the back, so the axons of the
optic nerves must pass back through the _____.
The placement of the eyes determines field of vision and ______ ______.
Predators have eyes that face the ______.
Prey animals tend to have their eyes to the ______ of their heads.
Rattlesnakes have a pair of _____ _____ which are sensitive enough to
detect a warm mouse nearby.
the basic unit of a muscle
the functional unit of contraction, called a _______, is made up of
overlapping thick (myosin) and thin (actin) filaments.
Sliding of a filament requires ___.
During the muscle contraction, the __ _____ will decrease in length.
The stimulus to contract comes from the _______ ______.
The release of _____ from the axon terminus triggers an action
potential in the muscle cell.
______ is released into the cytosol and the muscle contracts.
Muscle cells can contract, but they cannot _____ on their own.
At death, fibers in the muscles are stuck in position due to the lack
savory and delicious sensation on the tongue
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.
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?