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Anatomy
Undergraduate 1
11/01/2010

Additional Anatomy Flashcards

 


 

Cards

Term
Nervous System
Definition
[image]
Term
sympathetic nervous system (epinephrine) is fight or flight which is an antagonist to
Definition
the parasympathetic nervous system (acetylcholine). calms you down
Term
Microglia
Definition

– small, ovoid cells with spiny processes Phagocytes that monitor the health of neurons

 

phagocytes that live in brain and spinal cord. Job is to eat up bacteria that can cause damage

Term
Ependymal cells
Definition

– range in shape from squamous to columnar They line the central cavities of the brain and spinal column

 

- line the cavities of your spinal cord and brain. Brain has 4 cavaties full of cerebral spinal fluid.

 

  • have cilia and move the cerebral fluid around the brain and spinal cord.

Term
Satellite cells
Definition

surround neuron cell bodies with ganglia

 

-  hover around nerve cell bodies

Term
Processes
Definition

Armlike extensions from the soma Called tracts in the CNS and nerves in the PNS There are two types: axons and dendrites

 

outgoing info goes down the axon and out through the boutons

incoming messages comes in through the dendrites

axons and dendrites. Dendrites are shorter, diffusely branched, receptive (take in information to send in the body (the soma)) . the electrical signals on a dendrite are not action potentials;They are called graded potentials.

On the axons the electrical signals are always action potentials. Movement can be in two directions. Anterograde (toward the axon terminal) or retrograde (away from the axon terminal)

 

Term
Axons: Structure
Definition
Slender processes of uniform diameter arising from the hillock long ones are called nerve fibers usually one unbranched per neuron
Term
Axonal terminal
Definition
– branched terminus of an axon
Term
Axons: Function
Definition
Generate and transmit action potentials Secrete neurotransmitters from the axonal terminals
Term
Movement along axons occurs in two ways
Definition

Anterograde — toward axonal terminal

Retrograde — away from axonal terminal

Term
A Schwann cell:
Definition
Envelopes an axon in a trough Encloses the axon with its plasma membrane Has concentric layers of membrane that make up the myelin sheath
Term
Neurilemma
Definition
– remaining nucleus and cytoplasm of a Schwann cell
Term
Nodes of Ranvier (Neurofibral Nodes)
Definition
Gaps in the myelin sheath between adjacent Schwann cells They are the sites where axon collaterals can emerge
Term
Action potentials, or nerve impulses, are:
Definition
Electrical impulses carried along the length of axons Always the same regardless of stimulus The underlying functional feature of the nervous system
Term
Voltage (V)
Definition
– measure of potential energy generated by separated charge
Term
Potential difference
Definition

voltage measured between two points

 

the bigger the difference the bigger the potential.

Term
Current (I)
Definition

the flow of electrical charge between two points

 

how many electrons flowing along the axon

Term
Resistance (R)
Definition

hindrance to charge flow

 

what keeps the electrons from flowing.

Term
Insulator
Definition
– substance with high electrical resistance
Term
Conductor
Definition
substance with low electrical resistance
Term
whats saltary conduction
Definition

Occurs when current passes through a myelinated axon only at the nodes of Ranvier.

Term
electrochemical gradient
Definition
Ions flow along their _______ when they move from an area of high concentration to an area of low concentration Ions flow along their _______ when they move toward an area of opposite charge
Term
Graded Potentials
Definition
Voltage changes are decremental Current is quickly dissipated due to the leaky plasma membrane Only travel over short distances
Term
Nerve fibers are classified according to:
Definition
Diameter, Degree of myelination. and the Speed of conduction
Term
Synapses
Definition
A junction that mediates information transfer from one neuron: To another neuron To an effector cell
Term
Axodendritic
Definition
Types of Synapses  between the axon of one neuron and the dendrite of another
Term
Axoaxonic
Definition
Types of Synapses between (axon to axon)
Term
 Dendrodendritic
Definition
Types of Synapses between dendrite to dendrite)
Term
Dendrosomatic
Definition
Types of Synapses (dendrites to soma)
Term
Postsynaptic Potentials
Definition

- Neurotransmitter receptors mediate changes in membrane potential according to the amount of neurotransmitter released and the amount of time the neurotransmitter is bound to receptors.

Term
 Catecholamines
Definition

  • dopamine, norepinephrine (NE), and epinephrine. Enzymes present in the cell determine length of biosynthetic pathway. Norepinephrine and dopamine are synthesized in axonal terminals. Epinephrine is released by the adrenal medulla.
Term
Neurotransmitters: Amino Acids
Definition
Include: GABA – Gamma ()-aminobutyric acid Glycine Aspartate Glutamate Found only in the CNS
Term
Neurotransmitters: Novel Messengers
Definition
ATP Is found in both the CNS and PNS Produces excitatory or inhibitory responses depending on receptor type Induces Ca2+ wave propagation in astrocytes Provokes pain sensation
Term
Neurotransmitters: Novel Messengers
Definition
Nitric oxide (NO) Activates the intracellular receptor guanylyl cyclase Is involved in learning and memory Carbon monoxide (CO) is a main regulator of cGMP in the brain
Term
Inhibitory neurotransmitters
Definition
 cause hyperpolarizations (e.g., GABA and glycine)
Term
 Direct
Definition
  • : neurotransmitters that open ion channels
    • Promote rapid responses
    • Examples: ACh and amino acids
Term
 Indirect
Definition
  • : neurotransmitters that act through second messengers
    • Promote long-lasting effects
    • Examples: biogenic amines, peptides, and dissolved gases

 

Term
how do axons grow?
Definition

Growth is guided by scaffold laid down by older neurons, orienting glial fibers, release of nerve growth factor by astrocytes, neurotropins released by other neurons, repulsion guiding molecules, and attractants released by target cells.

 

Term
Neuroglia (supporting cells)-
Definition
Provide a supportive scaffolding for neurons, Segregate and insulate neurons, Guide young neurons to the proper connections, Promote health and growth
Term
Action Potentials  
Definition

are a brief reversal of membrane potential with total amplitude of 100 mV.

are only generated by muscle cells and neurons. They do not decrease in strength over distance. They are the principal means of neural communication.

in the axon of a neuron is a nerve impulse.

Term
[image]
Definition
[image]
Term
Biogenic amines
Definition
part of amino acids
Term
Peptides-
Definition
  • - Substance P (mediator of pain signals), Beta endorphin, dynorphin, and enkephalins. Act as natural opiates; reduce pain perception. Bind to the same receptors as opiates and morphine. Gut-brain peptides – somatostatin, and cholecystokinin.
Term
Excitatory
Definition
 neurotransmitters cause depolarizations (e.g., glutamate)
Term
Neuronal Pools-
Definition
 Functional groups of neurons that integrate incoming information and forward the processed information to its appropriate destination.
Term
  •  
    • Sensory input
Definition
– monitoring stimuli
Term
Integration
Definition
  •  
    •  interpretation of sensory input. In the integration area the gray mater of the brain and spinal cord are where the cells are that make the decisions. And when they make a decision they send an input out to the muscles (the motor output)
Term

                            Motor output –

Definition
 response to stimulistem. Send message to arm muscles get hand outta fire.
Term

Neuron

 

[image]

Definition

: a body, axon and dendrites. Born w/ all the nerves you will ever have. Have a high metabolic rate (always doing something) so they have a bunch of mitchondrria. Function is to  send electrical signals, as well as signaling each other during development.

Term
36 Interneuron(association neurons)-
Definition

has unmyelinated axons. makes the decision. In comes the sense (ow hand on fire) out goes motor (pull hand outta fire) 1:51

Term
Where ever you see grey
Definition
theres bodies and unmyelinated axons.
Term

 

Yes cause in white matter, white matter has myelin

Definition

do motor fibers have myelin on their axons?

Term

Yes cause in the white matter. White matter has myelin

Definition
Do sensory fibers have myelin around their axons?
Term
? No because they are in the grey matter. Grey matter has no myelin
Definition
Do interneurons have myelin around their axons?
Term
.(insulators and conductors)
Definition

Have 2 things in  body

  • ___________– keep electricity from flowing where you don’t want it. That’s why axons are covered with myelin.

 __________ substance with low electrical resistance Ion channels

Term
Electrical Current and the Body
Definition
  • - Reflects the flow of ions rather than electrons. There is a potential on either side of membranes when:
  •                The number of ions is different across the membrane
    • The membrane provides a resistance to ion flow
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