Nervous System

Front 1

Function

Back 1

- Allows organisms to detect stimuli in external and internal environment and respond accordingly

- Coordinates rapid and complex activities

Front 2

Four parts to the Nervous System

Back 2

Sensory Neurons, Motor Neurons, Receptors, Interneurons

Front 3

Sensory Neurons: Function

Back 3

Carry signals from periphery (outer part) to inner Central Nervous System

Front 4

Motor Neurons: Function

Back 4

AKA Motoneurons. They carry signals from CNS to muscles, skin, and glands of the body

Front 5

Receptors: Function

Back 5

Sense the environment (light, chemicals, sense, touch) and encode this information into electrochemical messages, which are then transmitted by sensory neurons

Front 6

Interneurons: Function

Back 6

Connects neurons in brain and spinal cord

Front 7

Describe monosynaptic (single connection) neural pathway Ex: Knee Jerk Reflex

Back 7

Signal Reception> Conductor (Sensory Neuron)> Interneurons (in brain)> Effector System (Motoneurons)

1. Hammer taps knee

2. Receptor sends signal to spinal cord through sensory neuron

3. Sensory neuron passes message to motor neuron for leg muscle to move

4. Nerve impulses travel down motor neuron and stimulate leg muscle to contract

Front 8

Two main Nervous Systems and its derivatives

Back 8

Central Nervous System (CNS): Brain and Spinal Cord

Peripheral Nervous System (PNS): Motor Nerves and Sensory Nerves

CNS derives from Neural Ectoderm, becomes Neural Tube

PNS derives from Neural Crest cells

Front 9

INPUT and OUTPUT: PNS to CNS

Back 9

PNS sends signals to CNS to interpret before sending signals back to more parts of the body

INPUT (afferent): Sensory Nerves send signals to Spinal Cord

OUTPUT (efferent): Brain sends signals to Motor Nerves telling them what part of the body to move

Front 10

Subclassification: Sensory Nerves (2)

Back 10

Somatic Sensory Nerves: detects muscles, tendons, and skin that allow for external stimuli

Visceral SN: detects internal stimuli from organs and glands

Front 11

Subclassification: Motor Nerves (2)

Back 11

Somatic (voluntary)

Visceral (involuntary, autonomic)

Front 12

Subclassification: Visceral (involuntary) Motor Nerves: Function, Location

Back 12

Parasympathetic

- located in head and tail region

- calm and relaxes body

Sympathetic

- focused throughout mid-portion of the spine

- action and stress

Front 13

Parasympathetic and Sympathetic Characteristics

Back 13

Parasympathetic

- stimulates digestion, salivation

- constricts pupils

- slows down heart

Sympathetic

- inhibits digestion, salivation

- dilates pupils

- accelerates heart

Front 14

Collection of Nerve Fibers in CNS vs PNS

Back 14

CNS: tract

PNS: nerve

Front 15

Brain has two major types of cells

Back 15

Neurons and Glia Cells

Front 16

Glia Cells: Function

Back 16

Myelinating cells that speeds up synapse, and provides insulation and support between neurons. Glia cells do not conduct electrical impulses

Front 17

Glia Cells: CNS + PNS Classification and function

Back 17

CNS

1. Oligodendryocytes: forms myeline, that acts as an insulator of axon segments

2. Astrocytes: nutrient cell. Connects neurons to capillaries in brain. Forms tighter epithelial cell adhesion

3. Microglial: cleans up cellular debri. They are the phagocytes of CNS tissue. Responsible for eating bacteria

PNS

1. Schwann cells: forms myeline, acts as an insulator of axon segments

Front 18

Neuron Function

Collection of Neural Cell bodies in CNS vs PNS

Back 18

Neurons are electric activated cells that process and deliver information. Neurons are major components in the brain that can help control movement; therefore, motor systems are more complex in complex animals.

CNS: nuclei

PNS: ganglia

Front 19

Basic: How does a Neuron receive information?

Back 19

- Dendrites/Cell Bodies receive information

- Axons of a nerve cell is responsible for transmitting information over a long distance

- Neural Pathways are made up of neurons

Front 20

Nerve Anatomy Break it DOWN

Back 20

Within a nerve are Nerve Bundles

Nerve Bundle Outer Shell: Perineurium

NB: Inner: Endonerium

In each nerve bundle are myelinated Axons

The tissue that surrounds the nerve bundles and blood vessels is the Epineurium

Front 21

Synapses: Function, Two Types

Back 21

Gaps between neuron junctions

1. Electrical Synapses: best adapted for regular, rhythmic activities like breathing

2. Chemical Synapses

Front 22

Neuron Signaling: Electrical Synapses - Steps and Benefits

Back 22

1. Pre and Postsynaptic Neurons are connected by paired channels

2. Ions flow through the gaps in the ion channel

- Don't need neurotransmitter to initiate reaction

- Bidirectional Flow is possible

- Adapted for speedy electrical ion flow

Front 23

Neuron Signaling: Chemical Synapses - Steps

Back 23

1. Synaptic Cleft separates Pre and Postsynaptic Neurons

2. Neurotransmitters secreted from presynaptic terminal, which diffuses across the synaptic clef

3. These neurotransmitters bind to channels and other molecules in the membrane

Postsynaptic membrane then determines if it is an excitatory or inhibatory response

Front 24

Chemical Synapses: Benefits, Excitatory, Inhibatory Response, Checks and Balances

Back 24

Excitatory (stimulates the brain) or Inhibatory (calms the brain) response

This sort of delegation is good because it provides a Checks and Balances scheme in the Nervous System