Communication

• Arousal States• Neurons• Neurotransmitters• Experience and Plasticity

True or False?

T/F The human brain is larger than that of any other animal.

T/F A single cell can stretch all the way from your spine to your toe.

T/F Messages travel in the brain by means of electricity.

T/F A brain cell can send out hundreds of messages each second, and manage to catch some rest in between.

T/F Fear can give you indigestion.

T/F If a surgeon were to stimulate a certain part of your brain electrically, you might swear that someone hade stroked your leg.

Nervous System

Our nervous system consists of two main bodies:• Central Nervous System• Peripheral Nervous System

“The more flexible we can form associations the more humanlike we are. This is what makes us special.”

(Remark considering left frontal lobe specialization)

Nervous System

Central Nervous System: (CNS)• Brain• Spinal cord: Collection of neurons and

supportive tissue running from the base of the brain down the center of the back, protected by a column of bones.– Spinal reflexes are automatic

Peripheral Nervous System: (PNS)• All portions of the nervous system outside the brain and spinal

cord.• Sensory Nerves (Afferent Impulses)• Motor Nerves (Efferent Impulses)• Contains:

– Somatic Nervous System– Autonomic Nervous System

Somatic and Autonomic Nervous Systems

Somatic Nervous System: (connects) Sensory receptors Skeletal muscles• AKA: Skeletal Nervous System

Autonomic Nervous System: Regulates the internal organs and glands.• Contains:

– Sympathetic Nervous System– Parasympathetic Nervous Systems

Arousal States

Sympathetic Nervous System (SNS):

Physical Changes ElementsIncrease in norepinephrin All elements necessary for survivalPupil dilation Fight-or-Flight instinct Increased heart-rate Activated during anxiety and stressSweatingDecrease in digestionVein dilation in peripheryPilo erection

Parasympathetic Nervous System (PNS):

Physical Changes ElementsIncreased digestion Conserves energyOpposite of SNS Tired/Relaxed

Nervous System

Nervous System

Spinal Cord Reflex- Not regulated by the brain.

Neurons

Neurons:

• Specialized nerve cell that receives, processes, and transmits information to other cells in the body.

Neurons

Three Types of Neurons:

• Sensory (afferent) neurons: Carry messages

from sense organs to the spinal cord or brain.

• Interneurons (association neurons): Carry

messages from one neuron to another.

• Motor (efferent) neurons: Carry messages

from the spinal cord or brain to the muscles

and glands.

NeuronsStructure:• Soma: cell body, processing center

– Nucleus: contains DNA

• Neurites: structures that extend from the soma– Dendrites: receives information and sends to soma– Axon: transports messages from the soma

• Dentrite Divisions:– Spine: receives NT message

• Also known as a receptor site

• Axon Divisions:– Hillock: initiates action potential– Myelin Sheath: fatty covering on axon– Node of Ranvier: unmyelinated space– Axon Terminal: sends message to terminal buttons– Terminal Button: site where vesicles are released

• Terminal Button Divisions:– Synaptic Vesicles: carries NT to synapse– Neurotransmitter: chemical messenger– Synapse: Space between buttons and spines

• Also known as synaptic gap or synaptic cleft.

Neurons

Neurons

• In what ways are neurons like other cells?

• Which features are unique to neurons?

Neurons

Presynaptic Neruon: Sends the message.

Postsynaptic Neuron: Receives the message.

Neurons

Neurons

Glia Cells: (Support Cells)

• CNS

– Astrocytes

• Phagocytosis

• Blood Brain Barrier

– Oligodendrocytes

• Myelination

• Increase speed and insulate

– Ependymal

• Line walls of the ventricles

• Create cerebrospinal fluid

– Endothelial

• Help with BBB

– Radial

• Aide in neuronal migration

• PNS

• Schwann

Neurotransmitters

Chemical messengers in the brain.

Catecholamines: Norepinephrine, Epinephrine, Dopamine

Indoleamines: Serotonin

Neurotransmitters

Neurotransmitters

Locations of production sites for major NT’s:• Dopamine- Substantia Nigra• Norepinephrine- Locus Coeruleus• Serotonin- Raphe Nuclei

Experience and Plasticity

Endorphins and Hormones

Endorphins: Pain reduction, pleasure, contentedness, memory. Endogenous opiate peptides.

Hormones: Affects the functioning of organs. Released directly into the blood stream. Promote growth, increase digestion, and regulate metabolism. Secreted by organs called glands. Produced primarily in endocrine glands.

Melatonin: Secreted by the pineal gland, helps regulate daily biological rhythms and promotes sleep (seasonal depression).

Adrenal Hormones: Produced by adrenal glands, emotion and stress.

Sex Hormones: Secreted in gonads (testes and ovaries), produce androgens (testosterone) and estrogens (progesterone).

Genetics

• Traits: Characteristics on which organisms differ.

• Heredity: Transmission of traits from one generation to the next.

• Genes: Elements that control the transmission of traits; they are found on the chromosomes.

• Chromosomes: Pairs of threadlike bodies within the cell nucleus that contain the genes.

• Deoxyribonucleic acid (DNA): The main ingredient of chromosomes and genes that forms the code for all genetic information.

Genetics

• Dominant: Member of a gene pair that controls the appearance of a certain trait.

• Recessive: Member of a gene pair that can

control the appearance of a certain trait only if it is paired with another recessive gene.