central nervous system (CNS)
One of the two divisions of the nervous system. Includes the brain and the spinal cord.
peripheral nervous system (PNS)
One of the two divisions of the nervous system. The XXX is everything outside of the central nervous system. So all nervous system material that isn't in the brain and spinal cord . Has two sub-groups: afferent division and the efferent division
One of the two divisions of the Peripheral Nervous System. Takes messages IN to the central nervous system (primarily sensory input).
One of the two divisions of the Peripheral Nervous System. Takes messages OUT from the central nervous system to the peripheral nervous system. It's called the "motor division" since its info causes movement and is translated along motor units. Has two sub-divisions: somatic nervous system and the autonomic nervous system.
Somatic Nervous System
One of the two divisions of the efferent system. All of the nervous system under voluntary control. The system that stimulates the skeletal muscles (voluntary). Some involuntary responses are included (reflexes).
autonomic nervous system
One of the two divisions of the efferent system. All involuntary. Controls organs, smooth muscle, cardiac muscle, glands, adipose tissue. It has two subdivisions: sympathetic and parasympathetic.
function (neuron calculation - 3)
sensory (afferent) neurons
motor (efferent) neurons
interneuron (association) neuron
Sensory neuron (afferent system)
XXX system. Type of neuron?
Carry impulses IN from outside the CNS to the CNS. Made up of unipolar neurons. Action potential moves from the synaptic terminal (receptive endings), past the cell body to the central process and into the Central Nervous System.
motor neurons (efferent system)
XXX system. Type of neurons?
Take signals from the CNS to the organs that do the "work."
(aka association neurons )
Are IN the CNS. Pass info from one neuron to another. There are a lot of these in the CNS. "go between"
Multipolar (nerve cell type)
One axon and multiple dendrites i.e. multiple processes comes out of their cell body. An example would be motor neurons in the efferent system and interneurons inside the CNS
Bi - two processes coming out of the cell body: one dendrite, one axon. Sensory neurons - afferent system. These are only found in the eye, ear and nose.
Uni - one process coming out of the cell body. It becomes an axon. Sensory neurons - afferent system. They relay info to the CNS. Their cell bodies are OUTSIDE the CNS.
The main cells of the nervous system - they do the actual work of moving signals / messages. They don't divide (reproduce). They live a long time. They are constantly making proteins to repair themselves and are making neurotransmitters (i.e. "metabolically active")
4 kinds of glial cells (neuroglia) in CNS
ependymal cells, astrocytes, oligodendrocytes, microglia
1 of 4 types of neuroglia. They help make and circulate cerebrospinal fluid which is key for protecting the brain and spinal cord. They line the brain and the spinal cord.
1 of 4 types of neuroglia. Very diverse set of cells that scientists keep finding do more jobs. One of their jobs is keeping the blood-brain-barrier so substances in the blood do not get into the brain. Recycle neurotransmitters. Make scar tissue. Regulate concentrations of ions and gasses. Provide structural support.
1 of 4 types of neuroglia. "Myelinate CNS axons" (meaning they provide the myelin that protects the axons of CNS nerves. Also provide structure
1 of 4 types of neuroglia. Macrophages (phagocytic) cells of the CNS. They keep it clean ! They remove debris, waste products and harmful substances.
Neuron Cell Body
"Soma." Made up of the perikaryon (cytoplasm around the nucleus) and the nucleus. Along with the dendrites, it is the portion of the nerve cell that receives signals from other neurons. Usually the XXX is located in the CNS (brain or spinal cord) except for unipolar (sensory) neurons that have their cell bodies outside the CNS.
"Ligand gated" channels. The presence of a chemical at the channel gate causes it to open. Ex: Acetylcholine causing the ion channels to open at the motor end plate.
Voltage-gated channels (mV triggers? define.)
Open in response to a change in electrical voltage level.
Ex: Na+ gate: At the normal resting potential of -70mV it stays closed. At -60mV it opens. At +30mV it is closed again.
Open in response to pressure.
Ex: receptors in the ear that open in response to the pressure in the fluid of the inner ear.
Ex: touch receptors that open in response to mechanical pressure from touch.
The potential of the membrane becomes LESS negative. When XXX happens, the normal resting potential of -70mV becomes -60mV and much higher until it actually becomes positive. It must reach a threshold potential to start the domino effect of action potential.
The potential of the membrane becomes MORE negative (more than -70mV). This acts as an inhibitor. Since the threshold stays the same at approx. -60mV, any XXX forces a stronger signal to start the actual potential.
The axons of some neurons branch to form XXX that can be divided into a number of smaller branches called telodendria. Along these the bifurcated impulse travels simultaneously to signal more than one other cell.
dural septa (1. falx cerebri 12-to-6-for-cerebrum. 2. falx cerebelli 12-to-6-on-cerebellum. 3. tentorium cerebelli tent-over-cerebellum)
emotions, autonomic control, homeostasis, sleep, endocrine system regulation
(part of brain controlling)
seems to be specialized in reading, writing,
speaking, logic, math, etc. Performs: analytical tasks, language-based skills (speaking, writing, reading, etc.) and logical decision making. People that are XXX
brain dominant have a tendency to be more scientific.
seems to be more specialized in interpreting sensory information, determining spatial relationships, interpreting emotional responses, etc. Performs analysis of sensory
information and comprehending three-dimensional relationships. XXX brain dominant people are more artistic.
Primitive emotions are spontaneous (requiring no conscious thought). It is this characteristic that differentiates them from the higher emotional states (i.e., jealousy, humor, etc.) produced in the XXX . XXX is convoluted to increase its gray matter capacity. This surface is marked by fissures (deep valleys), sulci (shallow grooves), and gyri (ridges) which delineate it into various regions.
The XXX lies approximately in the center of the brain. More specifically, the XXX is inferior to the thalamus. Because of its central location, the XXX connects the lower brain stem to brain's upper regions. Therefore, it contains motor tracts that
go to the cerebellum and sensory tracts that go to the thalamus. These tracts facilitate the XXX's function which is RELAYING information to the proper brain region.
This structure is thought to act like a biological clock by melatonin (controls wake and sleep patterns).
Separates the parietal lobe from the frontal lobe. The
frontal lobe is anterior to it (in front of it), while the parietal lobe is posterior (behind it).
longitudinal (cerebral) fissure
divides the cerebrum into two regions called cerebral hemispheres. These regions are connected by a bridgelike
structure called the corpus callosum.
Resting Membrane Potential DEPENDS ON
K+ leakage channels and Na+ leakage channels ("membrane ion permeability").
is the plasma membrane more permeable to K+ or Na+ ?
K+ predominates inside the cells.
Na+ predominates outside the cell
[explain plasma membrane permeability]
XX predominates inside the cell.
XX predominates outside the cell.
Leakeage channels (passive transport) let K+ diffuse OUT of the cell. Membrane less permeable to Na+ but some do diffuse into the cell.
hyperpolarization vs. depolarization
If XXX crosses the threshold potential (and voltage-gated channels are nearby) it becomes the self-propogating action potential.
where on the neuron does the action potential occur?
conducting region: axon and telodendria.
(axon hillock is where the XXX starts!)
where on the neuron does the graded potential happen?
The cell bodies. The receptive region of the neuron (dendrite and cell body). You don't have voltage-gated channels on the cell bodies or dendrites so you CAN'T get an action potential there, so you get XXX here.
jump from node to node i.e. myelinated
FAST .. myelin sheath slows decay of membrane potential
(there is no "nonsaltatory")
unmyelinated. Propagation relatively SLOW due to time for ion flow and channel opening
excitatory (type of neurotransmitter)
(what type of neurotransmitter causes depolarization?)
ventral (anterior) horn (function)
(which part of spinal cord?)
somatic (somatic = voluntary) MOTOR neurons and some interneurons
dorsal (posterior) root (function)
sensory (sensory = afferent = receptor) neurons
(Found in what part of the spinal cord?)
dorsal (posterior) horn (function)
(PART OF SPINAL CORD)
somatic (somatic = voluntary) SENSORY interneurons
and visceral (visceral = autonomic = involuntary) SENSORY interneurons
spinal nerves (function)
dorsal root + ventral root = merge together to form a XXX before exiting spinal column
white matter (spinal cord function)
myelinated axons (what part of the spinal cord do these make up?)
gray matter (spinal cord function)
neuronal cell bodies (what part of the spinal cord are neuronal cell bodies?)
dural (venous) sinus
formed by the separation of periosteal and meningeal layers. Drain blood and CSF from the brain. Arachnoid villi protrude into them.
the axons cross to the ___ side at the decussation of the pyramids
cross to the contralateral side
What is the cauda equina?
It is below L1 or L2 (where the spinal cord ends) to the sacrum (S2) are spinal nerve roots enclosed in dura and arachnoid mater. The spinal nerves are free floating in fluid. "horse tail"
What is the conus medullaris? and where is it located?
The "medullary cone" (also known as XXX) is the terminal end of the spinal cord. It occurs near lumbar vertebral levels 1 (L1) and 2 (L2).
Explain the functions of the denticulate ligaments.
These paired ligaments run along the length of the spinal cord. They extend from the pia mater through the arachnoid mater to the dura mater. They PREVENT LATERAL movement. At the foremen magnum and the coccygeal ligament, they prevent LONGITUDINAL movement.
Explain the functions of the filum terminale.
It is a slender strand of fibrous tissue which extends from the inferior tip of the conus medullaris. It continues along the length of the vertebral canal as far as the second sacral vertebra. It provides LONGITUDINAL support to the spinal cord as a component of the coccygeal ligament.
Why is the lumbar puncture done where it is?
Less likely to damage the spinal nerves because they are floating there below the end of the spinal cord at L1 or L2
3 types of fibers in the brain
association fibers (connect regions of the same hemisphere)
commissural fibers (connect regions of the two hemispheres)
projection fibers (connect the lobe to the spinal cord)
cerebral cortex (location)
This is the gray area of the brain. It covers the cerebrum and cerebellum. "The cerebellum and the cerebrum have external gray matter layer called the XXX."
1 of 4 major regions of the brain (xxx, cerebellum, diencephalon, brain stem). the major part of the brain. divided into right and left hemispheres.
corpus callosum (function)
Wide, flat bundle of neural fibers beneath the cortex at the longitudinal fissure. It connects the left and right cerebral hemispheres and facilitates interhemispheric communication. It is the largest white matter structure in the brain.
basal nuclei (location)
masses of gray matter that lie deep to the floor of the lateral ventricle. Embedded in the white matter of the cerebrum.
basal nuclei (function)
(what part of brain does ...) background patterns of movement involved in voluntary motor activities. Ex: control muscles that determine the background position fo the trunk or limbs or direct rhythymic cycles of activities such as walking or running.
pituitary gland (location)
about the size of a pea and weighing 0.5 grams (0.018 oz) in humans. It is not a part of the brain. It is a protrusion off the bottom of the hypothalamus at the base of the brain, and rests in a small, bony cavity (sella turcica) covered by a dural fold
pituitary gland (function)
synthesizes and secretes important endocrine hormones (HGH, oxytocin, etc.)
A small outgrowth of the ventral wall of the embryo brain from which the pars nervosa (the posterior lobe) of the pituitary gland develops is also called the XXX. (Another name for this structure is the pituitary stalk.) Connection between the hypothalamus and the posterior pituitary.
optic chiasm (function)
part of the brain where the optic nerves cross (partially). At bottom of the brain immediately below the hypothalamus
brain stem (function)
most basic, automatic survival behaviors
(what part of brain controls these?)