PSYC 372 GMU Exam 1

Division of nervous system

Central Nervous System (CNS) and Peripheral Nervous System (PNS)

Division of central nervous system (CNS)

brain and spinal cord

Division of the Peripheral Nervous System (PNS)

Somatic and Autonomic

Division of Autonomic Nervous System

sympathetic and parasympathetic

Santiago Ramon y Cajal

Hispanic doctor awarded the Nobel Prize in 1906 for his work on the structure of the nervous system

Neurons are composed of

dendrites, cell body, axon

Types of Neurons

motor, sensory, interneurons

motor neurons

neurons that carry signals from the spinal cord to the muscles to produce movement

sensory neurons

neurons that receive information from the external world and convey this information to the brain via the spinal cord

afferent neurons

neurons that take information from the senses to the brain

efferent neurons

neurons that take information from the brain to the rest of the body

Sensory neurons are to _______________

as Motor neurons are to ______________

afferent; efferent

What are the types of glia

astrocytes, microglia, oligodendrocytes, schwann cells, radial glia

Radial Glia

Think: baby sitter

(guide) the migration of neurons and the growth of their axons and dendrites during (embryonic development)

Microglia

Think: platelets/white blood of the brain.

Act as phagocytes, eating damaged cells and bacteria, act as the brains immune system.

Schwan cells

Form myelin sheath in PNS

Oligodendrocytes

Form myelin sheath in CNS

Astrocytes

Think: supplier/ dealer

-Regulates chemical composition of extracellular fluid:Surrounds synapses, takes up or releases ions released by axons

-Remove waste when neurons die

-Control blood flow to brain areas, dilate blood vessels

action potential

a neural impulse; a brief electrical charge that travels down an axon.

6 ion movement process of action potential propagation

1. Na+ channels open, Na+ enters cell

2. K+ channels open, K+ leaves cell

3. Na+ channels become refactory no more no less (peak is hit)

4. Voltage gated channels open. K+ continues to leave cell, causing membrane potential to return to resting

5. K+ channels close, Na+ channels reopen.

6. Extra K+ diffuses away causing hyperpolerization

absolute refractory period

The minimum length of time after an action potential during which another action potential cannot begin.

relative refractory period

the period of time following an action potential, when it is possible, but difficult, for the neuron to fire a second action potential, due to the fact that the membrane is further from threshold potential (hyperpolarized)

Saltatory conduction

action potentials jump from node to node

How do neurons communicate?

By transmitting chemicals at junctions (synapse)

Who is Sherrington?

Studied reflexes: Dog in harness and pinched its feet.

- The Reflex arc

Reflex arc

A relatively direct connection between a sensory neuron and a motor neuron that allows an extremely rapid response to a stimulus, often without conscious brain involvement.

Three important points about Reflexes made by Sherrington

(1) Reflexes are slower than conduction along an axon

(2) Several weak stimuli present at slightly different times or slightly different locations produce a stronger reflex than a single stimulus

(3) As one set of muscles becomes excited, another set relaxes

How does length and number of neuron effect communication speed?

E1: (a)-------------< (b) shorter time

E2: (c)----<(d)-----< (e) longer time

temporal summation

Summation by a postsynaptic cell of input from a single source over time.

spatial summation

The sum of multiple synapses firing at different locations at one time to create a net effect.

excitatory postsynaptic potential (EPSP)

a slight depolarization of a postsynaptic cell, bringing the membrane potential of that cell closer to the threshold for an action potential

inhibitory postsynaptic potential (IPSP)

temporary hyperpolarization of a membrane

presynaptic neuron

neuron that sends the signal

postsynaptic neuron

neuron that receives the signal

IPSP are both EPSP

Graded Potentials

Otto Loewi's experiment

- Frog heart experiment

- Realized that he was collecting and transferring chemicals, not loose electricity

types of neurotransmitters (NT)

Amino Acids

A modified amino acid

Monoamines

Neuropeptides

Purines

Gases

NT: Amino acid

Glutamate, GABA, glycine

Asparate

NT: A modified amino acid

Acetylcholine

NT: monoamines

indoleamines: serotonin

Catecholamines: Dopamine, norepinephrine, epinephrine

NT: Neuropeptides

Endorphines, substance P,

neuropeptide Y

NT: Purines

ATP, adenosine

Gases

NO (nitric oxide)

ionotropic effects

synaptic effects that depend on the rapid opening of some kind of gate in the membrane

Quick

metabotropic effects

effect at a synapse that produces a relatively slow but long-lasting effect through metabolic reactions

Long lasting and slow

Pain and smell is to __________

as vision and hearing is to _________.

Metabotropic effect; Ionotropic

Drugs that bind to receptors

- Many hallucinogenic drugs

- Nicotine

- Antipsychotic drugs

- Opiates

Nicotine stimulates the ________ receptors. Resulting in a ___________ feeling

acetylcholine; rewarding

Antipsychotic drugs block --------- receptors.

Side effects: decreased pleasure and motivation

Dopamine

Opiates bind to _______________ receptors , thus reliving ___________.

endorphin; pain

Dorsal (posterior)

toward the back or spine

Ventral (anterior)

Toward the belly or front

Superior

toward the head, Above

Inferior

away from the head, towards to feet, down/ below

Lateral

Away from the midline of the body

Medial

Toward the midline of the body

Proximal

Closer to the point of attachment

Distal

away from the point of attachment

Ipsilateral

on the same side of the body

Contralateral

on the opposite side of the body

Coronal plane

divides body into front and back

saggital plane

divides the body into a right and left side

Horizontal plane (transverse plane)

divides body into top and bottom

gyrus (gyri)

rounded elevation on the surface of the brain

Lamina

Row or layer of cell bodies separated from other cell bodies by layer of axons and dendrites

Suclus

A fold or groove that separates one gyrus from another

Fissure

a long, deep sulcus

Spinal cord consist of what two types of matter

Grey and white Matter

White matter

Whitish nervous tissue of the CNS consisting of neurons and their myelin sheaths.

Grey Matter

- The portions of the central nervous system that are abundant in cell bodies of neurons rather than axons. - Unmyelinated.

autonomic nervous system

Sends and receives messages to regulate the automatic behaviors of the body (heart rate, blood pressure, respiration, digestion, etc.)

Sympathetic Nervous System

- A network of nerves that prepares the organs for rigorous activity

- (fight or flight)

Parasympathetic Nervous System

Facilitates vegetative and nonemergency responses

- Rest and Relaxation

Neurotransmitters in the ANS:

parasympathetic mostly uses ___________ as Sympathetic mostly uses ______________

Acetylochine; norepinephrine

Major division of the brain

Fore-brain; mid-brain; Hind-brain

Major structures in the forebrain

thalamus, hypothalamus, cerebral cortex, hippocampus, basal ganglia

Major structures in the Midbrain

tectum, tegmentum, superior colliculus, inferior colliculus, substantia nigra

Major structures in the Hindbrain

medulla, pons, cerebellum

- they combine to make up brain stem

medulla oblongata

hint: gotta go long

Responsible for vital life-sustaining functions such as heartbeat, breathing, blood pressure, digestion, and vomiting

Cranial Nerves

Allow the medulla to control sensations from the head, muscle movements in the head, and many parasympathetic outputs

Cranial Nerve I: Olfactory

smell

Cranial Nerve III: Oculomotor

eyelid movement, pupil constriction and accommodation

Cranial Nerve II: Optic

vision

Cranial Nerve IV: Trochlear

eye movement

Cranial Nerve V: Trigeminal

Skin sensations from most of the face; control of jaw muscles for chewing and swallowing

Cranial Nerve VI: Abducens

eye movement

Cranial Nerve VII: Facial

facial expression; taste - anterior 2/3 of tongue; eyelid and lip closure

Cranial nerve VIII: Vestibulocochlear

hearing and equilibrium

Cranial Nerve IX: Glossopharyngeal

gagging; swallowing - sensory; taste

Cranial Nerve X: Vagus

Sensation from neck and thorax; control of throat, esophagus, and larynx parasympathetic nerves to stomach, intestines and other organs

Cranial Nerve XI: Accessory

Control of neck and shoulder movement

Cranial Nerve XII: Hypoglossal

movement of tongue

Mnemonic for cranial nerves

(rated R)

Oh Oh Oh To Touch And Feel Virgin Girl Vagina Ah Heaven

Pons (bridge)

the part of the brainstem that links the medulla oblongata and the thalamus.

Cerebellum (Bella Balance)

Balance and coordination

Tectum

roof of the midbrain

superior colliculus is to ___________

as inferior colliculus is to __________

vision; hearing or eye movement ; auditory information processing

Tegmentum

contains nuclei for cranial nerves and part of the reticular formation

substantia nigra

gives rise to the dopamine-containing pathway facilitating readiness for movement

limbic system

Associated with motivation emotions, such as eating, drinking, sexual activity, anxiety, and aggression