Physio / Bio Psych 2

Front 1

 From Greek root word meaning “tree”

 Branching fibers with a surface in information from other neurons

 The greater the surface area, the more information it receives

Back 1

dendrites

Front 2

short outgrowth of dendrites

– go to areas the shaft cannot reach

Back 2

 Dendritic Spines

Front 3

 Contains the nucleus, mitochondria, ribosomes, and other structures found in other cells

 Also responsible for the metabolic work of the neuron

Back 3

soma

Front 4

 Thin fiber of a neuron responsible for transmitting nerve impulses away

- more than meter in length (ex: spinal cord to feet)

 Longest – giraffes, whales, elephants

 Dendrites = tree (size), one axon

 Axon = more than 25 meters (size), many dendrites

 Invertebrates have no axons

Back 4

axon

Front 5

 Bulbs, bouton, button

 End points of an axon responsible for releasing chemicals to communicate w other neurons

 Junction for other neurons

Back 5

Presynaptic Terminals

Front 6

 Many chemicals cannot cross blood to the brain why we need BBB:

 A highly selective and protective barrier that separates the blood circulating our body from brain and spinal cord

 Eliminates virus along with the infected cell (effective when virus affected skin cells/blood cells) – because brain cannot change damaged neurons except for few exceptions

- ex: rabies and syphilis

Back 6

blood brain barrier

Front 7

occurs when the inside of the neuron becomes negative, ex: -100,mv

Back 7

hyperpolarization

Front 8

occurs when the inside of the cell becomes more positive, ex: +20mv

Back 8

depolarization

Front 9

 Burst of depolarization followed by hyperpolarization that proceeds like a wave along the axon, starting at the point where the axon meets the soma and proceeding to the terminal buttons

Back 9

action potential

Front 10

 Neurons at rest (-70mv)

 When no stimulus

 It is possible artificially charge a neuron through electrical charges

 Each human has a threshold of excitation

 Threshold

Back 10

resting potential

Front 11

minimum requirements that the nerve impulse needs to meet to trigger action potential

Back 11

threshold

Front 12

 The difference in charge between the inside and outside of the axonal membrane is generated by the force of diffusion, electrostatic pressure, and the activity of sodium- potassium pumps

 explains how axonal membrane generates potential difference between outside and inside

Back 12

The Membrane Potential

Front 13

describes the process by which molecules distribute themselves evenly throughout the medium they are dissolved in

Back 13

*Force of diffusion

Front 14

describes the phenomenon in which like charge repel and opposite charges are attracted to each other

– positively charged ions inside the cell are attracted to negatively charged ions outside (changes occur)

Back 14

 Electrostatic pressure

Front 15

helps maintain the resting membrane potential by pumping three – sodium ions and two potassium ions into the cell with each molecule of ATP

Back 15

 Sodium – potassium pump

Front 16

 Bringing information into a structure

 Sensory, admit

Back 16

Afferent Axon (Sensory, admit)

Front 17

key player in studying axon

– have giant axons compared to found in other organism - .5mm in diameter (100x larger than largest mammal)

Back 17

 Squid

Front 18

 Carrying information away from a structure

- motor, exit

Back 18

Efferent Axon (motor, exit)

Front 19

 Whose dendrites and axons are completely contained within a structure

Example: Thalamus – many neurons has its dendrites and axons within the thalamus

Back 19

Interneurons / Intrinsic Neurons

Front 20

 Outnumber neurons (10 to 1)

 Support cells that assist neurons by:

• Providing structural support

• Removing cell wastes (phagocytosis)

• Manufacturing myelin (myelin sheath)

 Very important, provides nutrition, acts as scaffolding (skeletal support)

Back 20

glial cells

Front 21

the tip of an axon releases chemicals that cause the neighboring astrocyte to release chemicals of its own

Back 21

 Tripartite Synapse

Front 22

microfilm

Back 22

microglia

Front 23

 Oligodendrocytes – brain

 Schwann Cells – periphery of the body

 Both help in building the myelin sheath in different sizes

Back 23

Oligodendrocytes and Schwann Cells

Front 24

 During cephalocaudal development

 Guide the migration of neurons and their axons and dendrites during embryonic development

 affected during development = infant’s brain affected

Back 24

Radial Glia

Front 25

 brief electrical impulse that travels along the membrane of a neuron (nerve cell) / muscle cell

 key mechanism by which information is transmitted within the nervous system

 essential for proper functioning of NS (no action potential, no reaction to stimulus)

 acts as a spark that ignites something that will create a chain reaction.

Back 25

The Action Potential

Front 26

 Neuron is not transmitting any signals

 Have negative charge inside due to uneven distribution of ions / charge

Back 26

1. Resting Membrane Potential

Front 27

 Brain, and Spinal Cord

 Encased in a bone – skull, vertebral column

Back 27

• Central NS:

Front 28

 Cranial nerves, spinal nerves, peripheral ganglia

 Connects brain and spinal cord to the rest of the body

 Somatic NS -> controls voluntary muscles (movements)

 Autonomic NS -> involuntary muscles (heartbeat, digestion)

Back 28

• Peripheral NS:

Front 29

controls voluntary muscles (movements)

Back 29

somatic NS

Front 30

involuntary muscles (heartbeat, digestion)

Back 30

autonomic NS

Front 31

• Directions in the NS are normally described relative to the neuraxis

Back 31

Anatomical Directions:

Front 32

is an imaginary line drawn through the length of the CNS, from the lower end of the spinal cord up to the front of the brain.

Back 32

Neuraxis