neurons

• Sense - get info
• Analyze - sort and process info received (linked to experience)
• Effect - tell body what to do in response

• Central Nervous System - CNS
• Neural tracts and no CT sheaths
• Peripheral Nervous System - PNS
• Nerves and have CT sheaths

• Spinal cord
• Sort info
• Relay info
• Basic reflex processing
• Brain
• Sort
• Relay info
• Reflex processing
• Memory
• Language
• Homeostasis

all neural tissue outside the CNS. It delivers sensory information to the CNS and carries motor commands to peripheral tissue and systems.

• Cranial Nerves are nerves connected to the brain.
• Spinal Nervesare nerves connected to the spinal cord

• Afferent Neuron Division
• Efferent Neuron Division
• Interneuron Divison

• (Sensory)
• a division of PNS that brings sensory information to CNS from receptors in peripheral tissues and organs

• (Motor)
• a division of PNS that carries motor commands away from CNS to muscles, glands and adipose tissue

• Somatic Nervous System (SNS)
• Autonomic Nervous System (ANS)

Control skeletal muscles, both voluntary and involuntary

Reflex

also called the visceral motor system, it provides automatic regulation organs and organ systems at the subconscious level

they are asociation neurons and are most numerous neurons in body. Nost associated with the CNS but some are autonomic ganglia. They are responsible for distribution of sensory information and the coordination of motor activity.

• Sympathetic - speeds up heart rate
• Parasympathetic Division - slows down heart rate

cell body of neuron

• Houses nucleus and perikaryon
• receives and processes info

Receive info from other neurons

its the "tail" of the neuron that is capable of spreading and electrical impulse known as an action potential

the "neck" area of the neuron where the axon attaches to the soma

collective brances that extend from the main axon

very end of axon or telodendria aka. synaptic terminals

lipids

insulate and speed the AP along the axon

oligodendrocytes

Schwann cells

the gaps in myelin on the axon. They are there for ion channels to continue electrical currents.

ion channels

myelinated fibers. AP jumps from node of Ranvier to node of Ranvier. Because it jumps, it is much faster than non-mylinated. uses less E cuz contacts less surface area

non-myelinated fibers. covers/depolarizes entire length of axon. requires more ion channels therefore uses more E. MUCH slower than saltatory propagation

• Unipolar
• Bipolar
• Multipolar

one process attached to cell body that splits into receiving and sending. found in sensory areas like skin for touch and temp

2 distinct processes off the soma, one for sending and one for receiving. found in sensory areas (eyes, mouth, nose) for senses.

The "common neuron". multiple dendrites and a single axon. All motor and intermeurons and some sensory neurons.

• Ependymal cells
• Astrocytes
• Oligodendrocytes
• Microglia

• Satellite cells
• Schwann Cells

located in space around central canal of central canal of spinal cord and in spaces of brain. Helps make cerebral spinal fluid and acts as filter and blood-brain barrier

largest and most numerous in CNS, they maintin a stable environment for neurons, fill in damaged areas of CNS and forms scar tissue after injury

Produce myelin in the CNS and physically support and organize CNS

sm glial cell that fxns as phagocytes (clean up crew)

poduce myelin for neurons and assist in healing process in PNS

cells that support nuerons

found in ganglia, they produce myelin for neurons in PNS as well as assist in healing

myelinated neuro tissue in CNS such as axons, Tracts and Nerves.

non myelinated neuro tissue in CNS including somas, dendrites, some axons and are found at sites of connection processing - areas will lots of cell bodies like on the surface of the brain and in the ctr of the spinal cord

• Extra cellular fluid (ECF) - high levels of Na+, Cl- and Ca2+ ions
• Intra cellular fluid (ICF) - high levels of K+ and negatively charged proteins (Pr-)
• Important because it creates potential energy because of the differences in charges

High level of Potassium ions within a cell at rest keep a neg charge while a high level of sodium outside the cell make it a + charge thus creating a polarized neuron. It is these 2 ions that control the set up, maintaining and restoring resting membrane potential

passive channels that are always open but are ion specific. They are located on the plasma membrane

They maintain the resting Resting membrane potential

• chemically gated channels
• mechanically gated channels
• voltage gated channels

NT and hormones. ACh common key

Any shift from resting potential toward a more positive potential

Na+ or Ca+2

stimulus with depolarization large enough to open voltage-gated channels which initiates an action potential

Na+ channels close and K+ channels open

• making the inside of the cell more negative than RMP
• Move + ions like K+ out of cell or - ions like Cl- into cell

lg diameter and myelinated. FAST (140m/sec). Usually deal with balance and protective reflexes

sm in diameter and myelinated. Not as fast as A but still (18m/sec). found for heart rate, breathing, muscles and facial

smallest and non-myelinated. Slowest (1m/sec). internal organ control

the pre and post synaptic membranes are locked together at gap junctions thus resulting in AP quickly and efficiently propagating from one cell to the next. Rare except in heart, some areas of brain and in the eye.

reliability

pre and post synaptic neurons do not touch. Space in between is called synaptic cleft

the time it takes signal to cross cleft and NT to bind to post synaptic cell

Electrical potential generated in the post-synaptic cell in response to NT. Graded potentials and can be Excitatory Post-synaptic potential (EPSP) or Inhibitory Post-synaptic Potential (IPSP)

The size of the stimulus determines the local depolarization or hyperpolarization