Chapter 7 Flashcards
Together with the [ ], the nervous system is
responsible for regulating and maintaining homeostasis.
endocrine system
As a fetus in the womb, neurons develop at the rate of [ ] per minute.
250, 000
We have about 100 billion nerve cells in our brain by adulthood (over 600 miles worth) – yet we typically use around [ ] at any given time
4%
The longest cell is the [ ]. The largest cell in the human body is [ ].
nerve cell, female ovum
Messages transmit at speeds up of to [ ]
180 MPH
four primary function of nervous sytem
sensing the world
transmitting information
processing information
producing a response
The main difference between nerve and neuron
a nerve is a bundle of neurons along with their connective tissue sheaths, blood vessels, and lymphatics whereas a
neuron is a cell of the nervous system that conducts nerve impulses.
functional unit of the nervous system
neuron
line ventricles (brain) and central canal (spinal cord); assist in producing, circulating, and monitoring cerebrospinal fluid
ependymal cells
maintain blood-brain barrier; provide structural support; regulate ion, nutrient, and dissolved gas concentrations
astrocytes
myelinate cns axons; provide structural framework
oligodendrocytes
remove cell debris, wastes, and pathogens, by phagocytosis
microglia
myelination of peripheral axons
schwann cells
generates impulse in the neuron
axon hillock
allow diffusion of ions
node of ranvier
A progressive wave of electric and chemical activity along a
nerve fiber that stimulates or inhibits the action of a muscle, gland, or other nerve cell
nerve impulse
When a neuron is at rest, the plasma membrane is far more permeable to [ ] ions than to other ions present, such as [ ] and [ ].
potassium (K+) ions, sodium (Na+), chloride (Cl-)
threshold for action potential
-55mv
at resting neurons (resting membrane potential), it’s more [ ] inside the cell than the outside
negative
mV charge of resting membrane potential
-70mV
ions outside and inside the resting neuron
outside: positive sodium ion
inside: positive potassium ion with negatively charged proteins
sodium-potassium pump
for every two potassium ions it pumps into the cell, it pumps out three sodium ions
during depolarization…
sodium ions in (+40 mV)
during repolarization…
potassium ions out to rebalance charges
voltage drop of -75 mV
hyperpolarization
conduction of impulses
myelin sheath forms insulating layer, impulses jump from one intercellular non-myelinated region to another
describes the way an electrical impulse skips from node to node down the full length of an axon
saltatory conduction
detects stimuli
sensory neuron
relays sensory signals to brain then return message back to motor neurons
interneurons
pass message from brain to body for muscle response
motor neuron
a neural pathway that controls a reflex
reflex arc
- Smaller part of the brain towards the back
FUNCTIONS: - Coordinates all movement
- Helps maintain posture, muscle control, and balance
cerebellum
- Large front part of the brain
FUNCTIONS: - Voluntary activity
- Memory
- Language
- Receives and responds to sensory signals
- Controls motor functions
cerebrum
the most complex part of the human brain—the bit that separates us from our primate cousins, so to speak. This, the largest brain lobe, is responsible for executive function, with a hand in reasoning, decision-making, sensory integration, planning, and execution of movement.
frontal lobe
home of the somatosensory cortex, the area of the brain
responsible for processing sensation and touch information, as well as some aspects of spatial processing.
parietal lobe
the major processing center of sound (including language)
and some forms of memory.
temporal lobe
mainly responsible for processing and interpreting visual information. It’s the seat of the primary visual cortex.
occipital lobe
is the posterior stalk-like part of the brain that connects the
cerebrum with the spinal cord.
brain stem
components of brain stem
midbrain, pons, medulla oblongata
- respiratory rhythm of breathing
- fundamental to REM
pons
- motor movement: particularly movements of the eye
- auditory and visual processing
midbrain/mesencephalon
- passing messages between your spinal cord and brain.
- regulating your cardiovascular and respiratory systems.
medulla oblongata
