topic 3 psych test

Neuron

A nerve cell- the basic building block of our nervous system, that sends and receives messages with electrochemical signals.

Cell body

"soma"-cell's life support center

Dendrites

Receive messages from other cells

Axon

Sends messages from cell body to other neurons, tissues, etc

Myelin Sheath

Fatty tissue covering axon; helps speed up neural impulses

Glial cells

Cells in the nervous system that support, nourish, and protect neurons. They provide nutrients, guide connections, insulate with myelin, clean up ions & neurotransmitters. Communicate with neurons- participate in informations transmission & memory

Action potential/Neural impulse

A brief electrical charge sent down the axon of a neuron when stimulated by our senses or by other neurons-travels from 2 to 200mph

Threshold

- Neurons receive both inhabitability signals (saying not to fire) and excitatory signals (telling the neuron to fire)

- If excitatory signals outweigh the inhibitory signals by a certain minimum threshold, the neuron will fire

Refractory period***

a period of inactivity after a neuron has fired

All-or-none response

A neuron either fires or it doesn't. Stronger stimuli might cause more neurons to fire, or cause neurons to fire more often, but a neuron can't fire more or less strongly

Synapse***

The gap between neurons

Neurotransmitters

Chemical messengers that travel the gap between neurons and bind to receptor sites on a receiving neuron, influencing whether that neuron will fire

Reuptake

excess neurotransmitters drift away, are broken down by enzymes, or are reabsorbed in a process called reuptake

Endorphins

Euphoria

Function: Influence the experience of pain & pleasure, released in brain during exercise, excitement, pain, etc Produces a feeling of well-bring or euphoria

Malfunction: Too much and body doesn't respond appropriately to pain; too little and experience too much pain, oversupply with opiates suppresses body's natural production

Agonist

"mimic"

- increase neurotransmitters action

- increase production/release on neurotransmitters

- block reuptake

- mimic neurotransmitters and bind to receptors

Antagonist

Block

- Decrease neurotransmitters action by blocking their production or release

- some similar enough to fit into and block receptor sites but not similar enough to activate them

Central Nervous System (CNS)

- Consists of brain and spinal cord

- body's control center

- Spinal cord: Highway connecting brain with peripheral nervous system

- Brain: Made up of billions of neurons organized in work groups called neural networks

Peripheral Nervous System (PNS)

- Includes the sensory nerves that connect the CNS to the rest of the body

- Purposes:

- gathers info from internal/ external stimuli

- Transmits CNS decisions to other body parts

Nerves

- electrical cables formed from bundles of axons

ex: Optic nerve bundles 1 million axons

sensory (afferent) neurons

arrive: receptors->CNS

- Neurons that carry incoming info from sensory receptors to the brain and spinal cord

Motor (effrent) Neurons

Exit: CNS->Effector

- Neurons within the brain and spinal cord that communicates internally and process to the muscles and glands

Interneurons

- neurons within the brain and spinal cord that communicate internally and process info between the sensory inputs and motor outputs

Reflex

Signal is sent from a sensory organ to the spinal cord, which processes the information instead of passing it on to the brain

Endocrine system

The body's slow chemical communication system- a set of glands that secrete hormones into the bloodstream to send messages to other areas of the body

Hormones

Chemical messenger that is manufactured by the endocrine glands, then travels elsewhere in the body and affects other tissues

Adrenal glands***

a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.

Pituitary gland***

secretes many different hormones, some of which affect other glands

Lesion***

tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue

EEG(electroencephalogram)

Electrodes placed on the scalp measure waves of electrical activity across the brain's surface

used for studying sleep stages, seizure activity, response to stimuli, etc

MEG(magnetoencephalography)

A head coil records magnetic fields from the brain's natural electrical activity

used for understanding how tasks influence brain activity

CT or CAT scan(computed tomography)

Series of x-ray photos taken from different angles and combined into a composite representation of the brain

Used for seeing ones, soft tissues, blood vessels, etc and quickly reveal brain damage(often used in ER's)

PET(positron emission tomography)

tracks where a radioactive form of glucose goes while the brain is performing a task

used for studying most active brain areas during a task

MRI(magnetic resonance imaging)

People lie in a chamber that uses magnetic fields and radio waves to produce computer-generated images of soft tissue

used for studying brain anatomy and usually more detailed than a CT

fMRI(Functional MRI)

measures blood flow to brain regions by comparing successive MRI scans

used for allowing you to understand both structure and function of brain

Brainstem

- most primitive part of the brain

- begins where spinal cord swells as it enters the skull

- responsible for automatic survival functions(breathing and heart beating)

Medulla

- located at the top of the spinal cord/base of brain stem

- controls life-sustaining functions-if damaged likely to result in death

- regulates heart rhythm, blood flow, etc

Thalamus

- all sensory info except smell passes through the thalamus

- it is considered the sensory "relay station" of the brain, passing info onto the cerebral cortex

Reticular formation

- nerve network through brainstem

- filters incoming info and relays important info

- helps people focus on useful sensory input while filtering out unnecessary stimuli

- controls arousal

Cerebellum

"little brain"

- non-verbal + skull memory

- process sensory info

- coordinates motor function, integrating motion and positional info from inner ear and muscles, help maintain balance

Limbic system

The neural system between the brainstem and cerebral hemispheres. Contains the amygdala, hypothalamus, and hippocampus. Associated with emotion and drives hunger, thirst, sex

Amygdala

- primarily involved in processing emotion and survival responses

- influences aggression and fear

Hypothalamus

- maintain homeostatic state

- regulates body temp, thirst, hunger, sleeping, sexual activity

- link between brain and endocrine system

- triggers the pituitary gland to release hormones controlling other glands

- linked to emotion and reward

Hippocampus

(memory)

-seahorse shaped structure

- helps process explicit memories of facts & events & prepare them for storage

- decrease in size & function with age or with brain injury

Cerebral cortex

The thin surface layer of neurons covering the cerebral hemisphere is the cerebral cortex; it is considered the brain's ultimate control and processing center. The tissue is folded in on itself, allowing more surface area of cortex to fit into the skull

the cerebral cortex is divided into four sections called lobes

Frontal lobes

area of the cortex located in the front and top of the brain

involved in speaking and muscle movement

involved in higher order mental functions, such as: making plans and judgment

Motor cortex

area located in the back of the frontal lobe

controls voluntary movement

can determine where along the motor cortex different body parts are controlled, but area is not proportional to size-depends on degree of control you have over that body part

Parietal lobes

area of the cortex located at the top and back of the brain

contains centers for processing sensory signals such as touch, pressure temp, pain

somatosensory cortex

area at the front of the parietal loves that registers and processes body touch and positions

more area devoted to parts of the body that are more space is devoted to them

temporal lobes

area of the cortex located above ear(sides)

responsible for sense of hearing and for meaningful speech