Week 5 - Functional Anatomy and Pathophysiology I: Lecture Notes
Week 5 - Functional Anatomy and Pathophysiology I: Lecture Notes PHCL 2600
Popular in Human Anatomy and Pathophysiology
verified elite notetaker
Popular in Biology
This 9 page Class Notes was uploaded by Audrey Hernandez on Sunday September 25, 2016. The Class Notes belongs to PHCL 2600 at University of Toledo taught by Dr. Frederick Williams in Fall 2016. Since its upload, it has received 10 views. For similar materials see Human Anatomy and Pathophysiology in Biology at University of Toledo.
Reviews for Week 5 - Functional Anatomy and Pathophysiology I: Lecture Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/25/16
Functional Anatomy and Pathophysiology I Dr. Frederick E. Williams Week 5 Lecture Notes Nervous system divisions ❖ Nervous system cell types ➢ Neurons ■ Parts of the neuron ● Soma ◆ The cell body ◆ Controls metabolism and protein synthesis ◆ Contains specialized organelles ➢ Nissl bodies ■ Are groups of ribosomes ◆ Has both microtubules and neurofilaments ➢ Microtubules for support and cell movement ➢ Neurofilaments to provide structure and support ● Dendrites ◆ Have receptors in postsynaptic membrane to receive signals from other neuron synapses ◆ A large expansion of the cytoplasm, sometimes containing organelles ● Axon ◆ Neural impulses travel down in one direction along this towards the synapse ◆ Insulated by the myelin sheath ◆ Substructures ➢ Axon hillock ■ Where the axon meets the soma ➢ Initial segment ■ First segment nearest to the axon hillock ■ Trigger zone ● The junction in which nerve impulses will arise ➢ Axon collaterals ■ Side branches the stretch out back to the soma or out to other cells ➢ Axon terminals ■ Form synapses with other neurons ■ Contain vesicle pockets that contain neurotransmitters Functional Anatomy and Pathophysiology I Dr. Frederick E. Williams Week 5 Lecture Notes ◆ Axonal transport styles ➢ Anterograde ■ Flows from soma to terminal ■ Has two speed flow rates ● Slow ◆ When it is moving microtubules or neurofilaments ● Fast ◆ When it is moving organelles with membranes ◆ Driven by kinesin ➢ Retrograde ■ Flows from terminal to soma ■ Flows fast ● Driven by dynein ● Transports vesicles or cellular materials to be reused and recycled ◆ Moves substances that can enter the neuron, whether it be food or poison ● Synapse ◆ Is the communication site with other cells ◆ Parts that make it up are… ➢ Presynaptic ■ Contains vesicles with neurotransmitters ➢ Synaptic cleft ■ Space between the pre and post synapses ■ Where neurotransmitters are shot through ➢ Postsynaptic ■ Contains receptors to receive neurotransmitters to carry on signal ➢ Neuroglia/glial cells ❖ Central nervous system (CNS) ➢ Consists of the brain and spinal cord ➢ Functions include… ■ Mechanical/voluntary movement ■ Involuntary movement Functional Anatomy and Pathophysiology I Dr. Frederick E. Williams Week 5 Lecture Notes ■ The processing of sensory input ❖ Peripheral nervous system (PNS) ➢ Consists of everything o utside of the CNS ■ Though the spine does connect the brain to the PNS ➢ Monitors environmental factors ➢ Divisions of the PNS ■ Automatic ● Sympathetic nervous system ◆ Linked to fightorflight ● Parasympathetic nervous system ◆ Linked to restanddigest ■ Enteric nervous system (ENS) ● Regulates organs in the gastrointestinal system ■ Somatic ● Related to the skeletal muscles ❖ Kinesin vs Dynein Kinesin Dynein Moves along microtubules More complex than the kinesin Head binds to ATP and microtubules Has multi subunit proteins in it Tail drags along cargo Also has accessory proteins Neuron classification ❖ Classification of neurons ➢ Generally classified by its structure and function ➢ There are multipolar, unipolar, and bipolar types ■ Multipolar ● Tend to be motor neurons with multiple dendrites ● Also brain and spinal neurons ■ Bipolar ● Has one axon and one main dendrite section ◆ Axon and dendrites are on opposite sides of the soma ■ Unipolar ● Commonly PNS sensory neurons ● Can be found around muscles, skin joints, or even internal organs Functional Anatomy and Pathophysiology I Dr. Frederick E. Williams ● Dendrites and axons are continuous and extend in opposite directions, soma located to the side of the axon ➢ Interneurons ■ Multipolar ■ Processes information from CNS to PNS ■ Are effectors ➢ Motor neurons ■ Multipolar ■ CNS ➢ Sensory neurons ■ Unipolar ❖ CNS neurons ➢ Are multipolar ➢ Two kinds ■ Purkinje ● Located in the cerebellum ● Used for motor functions ■ Pyramidal ● The soma is shaped like a pyramid ● Located in the cerebral cortex and hippocampus ◆ Are associated with memory and language ❖ Supporting cells ➢ Neuroglia (glia) ■ Capable of cell division ■ Support neurons by… ● Insulating neurons by forming a myelin sheath ◆ Glia cells can’t conduct electrical impulses ● Forming the blood brain barrier (BBB) ● Creates cerebrospinal fluid (CSF) ◆ Fluids that circulate in the brain and spinal areas ● Phagocytosis ■ The several types ● In the CNS ◆ Oligodendrocytes Functional Anatomy and Pathophysiology I Dr. Frederick E. Williams Week 5 Lecture Notes ● Leads to synthesis of a large amount of the plasma membrane ■ Doesn’t form a neurilemma ◆ Astrocytes ➢ Maintains the BBB ➢ Absorbs and recycles materials and neurotransmitters ■ Also maintains gas concentrations ➢ Helps to form scar tissue if there is damage ◆ Microglia ➢ Removes wastes and other unwanted material ◆ Ependymal ➢ Aids in production of CSF ● In the PNS ◆ Unmyelinated axons ➢ Axons are bundled together and loosely formed around, not wrapped up ◆ Satellite ➢ Regulates levels of O2 CO2, and nutrient levels ◆ Schwann ➢ Insulates neurons ■ Wraps round and round axon (like rolling a rug) ● Inner portion counts as the myelin sheath ● Outer portion is called the neurilemma ● 1:1 ration of cell to axon segment ➢ Aids in repairs in case of damage to cell ❖ Blood Brain Barrier (BBB) ➢ Prevents diffusion between endothelial cells ❖ Myelination ➢ The process for forming the myelin sheath aron neurons ■ Formed by schwann cells in the PNS ■ Formed by oligodendrocytes in the CNS ➢ The autoimmune destruction of myelin is known as multiple sclerosis ➢ Segments that are not myelinated are called nodes of ranvier ■ Increases speed of nerve impulses Functional Anatomy and Pathophysiology I Dr. Frederick E. Williams Week 5 Lecture Notes ● Impulses jump gap to gap Neural impulses ❖ Neurotransmission ➢ Nerve impulses produce action potentials ■ There is a change in membrane potential that triggers this ● Change in membrane potential is caused by the flow of ions ➢ Synaptic transmission is the release of neurotransmitters at the synapse ❖ Neural electrical signals ➢ Type types… ■ Graded potentials ● Short distance ● For local areas ■ Action potentials ● Long distance ● Within the body ➢ Production depends on…. ■ The type of ion channels that are open or closed in response to a stimulus ● Ion channels are located in the lipid bilayer of the membrane and help the flow of ions ● Two types... ◆ Nongated that are passive or leak channels ➢ Open and close randomly, do not respond to a stimulus ➢ Can be found in all cells ➢ Have a high permeability ◆ Gated ➢ Respond to a stimulus ➢ Types… ■ Ligand gated ● Respond to the presence or absence of chemical ● Condense in the dendrites, particularly in the synapse, of sensory neurons as well as interneurons ■ Voltage gated ➢ Functional Anatomy and Pathophysiology I Dr. Frederick E. Williams Week 5 Lecture Notes + ● At +30 mV the Na channels’ inactivation gates will close ➢ Repolarization ■ Part 4: + ● K channels begin to open and the ions leave the cell ◆ This contributes to the rebuilding of a negative charge inside ● Sodium ion gates begin to slowly open and close again ● There is a change in membrane potential to return to 70 mV from +30 mV ■ Hyperpolarization (part 6): ● The membrane potential drops to a lower value than the RMP ● As potassium channels close the membrane potential returns to RMP of 70 mV ❖ Propagation ➢ Action potential begins in the trigger zone towards the axon hillock ■ The action potential is regenerated again and again in segments adjacent to the hillock going towards the terminal ● Impulse flows only one way due to the refractory period of the channels, so it can’t flow backwards ➢ Types of action potential propagation ■ Continuous ● Deals with unmyelinated axons ● Is a continuous depolarization and repolarization with a flow of ions in adjacent segments of the membrane ● Works over a short distance ➢ Saltatory ■ Deals with myelinated axons ■ Each node of ranvier depolarizes and meets threshold requirement ● Impulses hope from node to node of the nodes of ranvier.
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'