meyers psychology chapter 2

Structure of a neuron

Cell body, Dendrites, Axon, Terminal branches of axon, Myelin sheath and Neural impulse

Neural impulse

(action potential) electrical signal traveling down the axon

Cell body

the cell's life support center

Dendrites

receive messages from other cells

Axon

passes messages away from the cell body to other neurons, muscles, or glands

terminal branches of axon

form junctions with other cells

Myelin sheath

covers the axon of some neurons and helps speed neural impulses

Glial cells

support, nourish, and protect neurons and assist neural transmission

resting axon's fluid interior

mostly negatively charged ions

resting potential.

positive-outside/negative-inside state of axons membrane

axons surface

selectively permeable, meaning it is selective about what is allowed through its gates.

what happens neuron receives a signal from other neurons

some are telling it to fire and some are telling it not to fire.

what happens when the threshold is reached

the action potential starts moving. then The action potential travels down the axon from the cell body to the terminal branches. then The signal is transmitted to another cell.

The synapse

a junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. (also known as the synaptic junction of synaptic gap)

Neurotransmitters

chemicals used to send a signal across the synaptic gap.

Reuptake

After the neurotransmitters stimulate the receptors on the receiving neuron, the chemicals are taken back up into the sending neuron to be used again.

Serotonin

Affects mood, hunger, sleep, and arousal . Undersupply linked to depression; some antidepressant drugs raise serotonin levels

Dopamine

Influences movement, learning, attention, and emotion.

oversupply of dopamine

Oversupply linked to schizophrenia; undersupply linked to tremors and decreased mobility in Parkinson's disease and ADHD

The central nervous system (CNS)

the brain and spinal cord

The peripheral nervous system (PNS)

the rest of the nervous system. The PNS gathers and sends information to and from the rest of the body

Sensory neurons

carry messages in from the body's tissues and sensory receptors to the CNS for processing.

Motor neurons

carry instructions out from the CNS out to the body's tissues

Interneurons

(in the brain and spinal cord) process information between the sensory input and motor output

nerves

consist of neural "cables" containing many axons. Nerves are part of the PNS and connect muscles, glands, and sense organs to the CNS.

Parts of the nervous system

Central & Peripheral

parts of peripheral nervous system

Autonomic and somatic

Autonomic

controls self-regulated action of internal organs and glands. Sympathetic & parasympathetic

Sympathetic

arousing (fight-or-flight)

Parasympathetic

calming (rest and digest)

The sympathetic and parasympathetic nervous systems work together to keep us in a steady internal state called

homeostasis

Somatic

controls voluntary movements of skeletal muscles

neural networks

The brain's neurons cluster into these work groups

what do neurons do with other neurons

Neurons network with nearby neurons with which they can have short, fast connections. "Neurons that fire together, wire together."

spinal cord - what is it full of

full of interneurons that sometimes have a "mind of their own". Your spine's interneurons trigger your hand to pull away from a fire before you can say anything. This is an example of a reflex action.

endocrine system

glands secrete hormones which travel through the bloodstream and affect other tissues, including the brain. sends messages through the bloodstream

parts of endocrine system

Hypothalamus, Thyroid gland, Adrenal glands, Pituitary gland, Parathyroid, Pancreas, Ovary, Testis

Hypothalamus

brain region controlling the pituitary gland

Thyroid gland

affects metabolism among other things

Adrenal glands

inner part helps trigger the "fight-or-flight" response. Produce hormones such as epinephrine, norepinephrine, and cortisol. The sympathetic nervous system responds to stress by sending a message to adrenal glands to release these hormones listed above.

Effect: increased heart rate, blood pressure, and blood sugar. These provide energy for the fight of flight.

Pituitary gland

secretes many different hormones, some of which affect other glands. The pituitary gland is the "master gland" (regulates other glands). It is controlled by the hypothalamus. It also produces growth hormone (especially during sleep) and oxytocin, the "bonding" hormone

Parathyroid

helps regulate the level of calcium in the blood

Pancreas

regulates the level of sugar in blood

Ovary

secretes female sex hormones

Testis

secretes male sex hormones

The brainstem and cerebellum

coordinates the body

The brainstem includes the pons and medulla.

Medulla

controls the most basic functions such as heartbeat and breathing

Pons

helps coordinate automatic and unconscious movements

limbic (border) system

manages emotions, and connects thought to body

Consists of the hippocampus, amygdala, hypothalamus

Hippocampus

Processes conscious memories. Works with the amygdala to form emotionally charged memories. Animals or humans who lose their hippocampus to surgery or injury also lose their ability to form new memories of facts and events

Amygdala

Processes emotions, especially rage and fear

Hypothalamus

Lies below ("hypo") the thalamus. Regulates body temperature and ensures adequate food and water intake (homeostasis), and is involved in sex drive. Directs the endocrine system via messages to the pituitary gland

The cortex (the outer covering)

integrates information [the newest part of the brain in evolutionary terms because the brain started growing and would add on to the outside of the brain; the innermost part of the brain is the oldest part of the brain]

Thalamus ("inner chamber")

"Sensory switchboard"

Receives information from all senses except smell; sends to higher brain regions

Reticular ("netlike") formation

A neuron network extending from the spinal cord right up through the thalamus

Enables alertness (arousal)

If you damage this part of your brain you could slip into a coma and never wake up

Cerebellum ("little brain")

Helps coordinate voluntary movement

Has many other functions, including enabling nonverbal learning and memory

It also helps us judge time, modulate our emotions, and discriminate sounds and textures

If the cerebellum was injured, you would have difficulty walking, keeping your balance, or shaking hands.

Cerebral cortex lobes consist of:

Our grey "bark" structure that is wrinkled in order to create more surface area for 20+ billion neurons. 300 trillion synaptic connections. Frontal lobe, Parietal lobes, occipital lobes and temporal lobes

Frontal lobe

involved in speaking and muscle movements and in making plans and judgments. The frontal lobes are active in "executive functions" such as judgment, planning, and inhibition of impulses. Also active in the use of working memory and the processing of new memories.

parietal lobes

include the sensory cortex

Occipital lobes

include the visual areas; they receive visual information from the opposite visual field

temporal lobes

include the auditory processing areas

if the brain is damaged

It usually does not repair damaged neurons, but it can restore some functions. It can form new connections, reassign existing networks

Left hemisphere:

· Thoughts and logic

· Detail

· Language: words and definitions (literal)

· Calculation

· Pieces and details

Right hemisphere:

· Feelings and intuition

· Big picture

· Language: tone, inflection, context (inferences)

· Perception

· Wholes, including the self

neuroplasticity

the brain’s ability to change itself , including forming new neural connections, in response to conditions and experiences

association areas

regions of the cerebral cortex that integrate and interpret information from various sources, enabling higher cognitive functions such as memory, learning, and decision-making. 

hypnosis

sequential processing

parallel processing