Unit 2

Biological psychology

Biological psychology

branch of psychology concerned with the links between biology and behavior

Neuron/nerve cell

basic building block of the nervous system and it is the basic unit of communication

Dendrites

receive information from other cells

Soma/cell body

maintains the health of the neuron

Nucleus

maintenance of the neuron

Axon

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

Myelin sheath

covers the axon of some neurons and helps speed neural communication

Multiple sclerosis (MS)

The degeneration of the Myelin sheath resulting in a slowing down or interruption of communication to muscles and loss of muscle control

MS characteristics

loss of coordination, speech, visual disturbances, and muscular weakness

Nodes of Ranvier

gaps between the myelin sheath on axons

Glial

support cells that assist neurons by providing structural support, nutrition, removal of cell wastes, and manufacture Myelin, outnumber neurons 10:1

How do neurons communicate?

through an electrochemical process of communication

Why do neurons fire impulses?

when stimulated by pressure, heat, light, or chemical messages from adjacent neurons

First step of an action potential

When a neuron is waiting for stimulation the neuron is said to be polarized or in the resting potential state. The resting potential occurs because the cell membrane is selectively permeable. In this state, there are positive ions outside and negative ions inside the axon.

Step 2 of an action potential

When the neuron is stimulated the gates of the axon open causing the positive ions to pass through, this is the action potential. Action potential causes depolarization in each segment of the axon.

action potential

a brief electrical charge that travels down the neuron

Step 3 of an action potential

Once it has reached the end the neuron enters the refractory period. That electrical info is converted into chemical form called a neurotransmitter

refractory period

when the neuron pumps the positively charged ions back outside

Axon terminals

hold the neurotransmitters until they are released

neurotransmitter

has its own unique shape, has to find a dendrite that can fit its shape, the neurotransmitters and receptor sites fit together like pieces of a puzzle

all-or-none response

fires at 100% or 0%, if it is a stronger reaction it is because more neurons are firing or they fire more often

Acetylcholine

learning, memory, muscle contractions

Alzheimer’s disease (low levels) Memory loss, muscle loss, swallowing loss, talking loss

Dopamine

movement: Parkinson’s disease (low levels) shuffled gate, tremors

thought processes: Schizophrenia (excess) hallucinations, delusions, when they take meds to reduce, express symptoms of Parkinsons

pleasure, rewarding sensations: Drug Addiction (stimulants)

Serotonin

sleep, mood, arousal, hunger

Depression (low)

Norepinephrine

physical arousal, learning, memory

Depression (low)

GABA

inhibition of brain activity

Anxiety disorders

Endorphins

positive emotions, pain perception

Opiate addiction

Glutamate

Excitatory neurotransmitter, memory

Migraines, seizures (excess)

excitatory

pressing on an accelerator, if they are excitatory it continues communication, ex. Like people that have to gossip

inhibitory

like putting on the breaks, stopping the line of communication, ex. Like people you know you can trust

What needs to happen for an action potential to occur?

the combined signals must exceed the stimulus threshold

stimulus threshold

the minimum level of stimulation needed to activate the next neuron

Agonists

drug molecules that are similar enough to the neurotransmitter to mimic these effects

ex. opiate drugs: oxycodone, heroin, fentanyl

Antagonist

drug molecules that are similar enough to the neurotransmitter to occupy its receptor site and block its effect but not similar enough to stimulate the receptor

ex: poisons and venom

The blood-brain barrier

enables the brain to fence out unwanted chemicals circulating in the blood and some chemicals don't have the right shape to slither through this barrier

The tremors of Parkinson’s disease result from

the death of nerve cells that produce dopamine

What is given to patients with Parkinson’s dieseas

L-dopa a raw material that the brain can convert to dopamine can sneak through which helps patients gain better muscular control

Central Nervous System

made up of brain and spinal cord

Studying the brain

lesion, Electroencephalogram (EEG), Computed Tomography Scan (CT/CAT scan), Positron emission tomography scan (PET scan), Magnetic Resonance Imaging (MRI)

Lesion

destroying tissue in specific brain areas

Electroencephalogram (EEG)

Amplified recording of the waves of electrical activity that sweep across the brain surface, the waves are measured by electrodes placed on the scalp

Computed Tomography Scan (CT/CAT scan)

a series of X-ray photographs taken from different angles and combined by computer into a composite representation of a slice through the body

Positron emission tomography scan (PET scan)

visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task

Magnetic Resonance Imaging (MRI)

Uses magnetic fields and radio waves to produce computer-generated images that distinguish among different types of soft tissue allowing us to see structures within the brain

Peripheral Nervous System

everything else

Somatic/Skeletal NS

Contains all of the voluntary movements/functions

Autonomic NS

controls involuntary processes, internal organs

Sympathetic NS

arousal, fight or flight response

Parasympathetic NS

calming

Nerves

neural cables containing many axons. These bundled axons connect the CNS with our muscles, glands, and sense organs

three types of neurons

Sensory neurons, Interneurons, Motor neurons

Sensory neurons

the neurons that carry incoming information from the sense receptors to the CNS

Interneurons

CNS neurons that internally communicate and intervene between the sensory inputs and the motor outputs

Motor neurons

the neurons that carry outgoing information from the CNS to the muscles and glands

Reflexes

simple automatic inborn responses to sensory stimuli ex. Knee Jerk response and blinking

Neural networks

interconnected neural cells that with experience can learn and as feedback strengthens or inhibits connections can produce certain results, enabling us to be able to do the variety of tasks we learn and progress through life, they grow as rapidly as stimulation allows

Hemisphere

half of the brain, each side seems to demonstrate specific differences

Right-brain thinkers

more creative thinkers that gather information by feelings and intuition

Characteristics of right brain thinkers

visual, good with people, often daydream, often lose track of time, fun, witty, spontaneous, hard to follow verbal instructions, extroverted and are energized by others

Left-brain thinkers

critical thinkers who collect information using logic and sense

Characteristics of left brain thinkers

have a daily task list, good at math and science, rational, logical, organized, follow directions, don't let feelings get in the way, introverted, and energized by themselves

Corpus callosum

large bundle of neural fibers connecting the hemispheres and carrying messages between them

Split brain patients

condition in which the two hemispheres are isolated by cutting the connecting fibers mainly those of the corpus callosum

Divided into four lobes

frontal lobes, parietal lobes, temporal lobes, Occipital lobes

Cerebral cortex

convoluted area of interconnected neural cells that covers the cerebral hemispheres, it is the body's ultimate control and information processing center

Frontal lobe

lies just behind the forehead, involved in speaking and muscle movements and in making plans, and judgement

• tends to affect personality when injured

• “is this affecting me in some way, is it causing an emotional feeling”

Motor Cortex/strip

located at the rear of the frontal lobes, controls voluntary movements

Parietal lobes

at the top rear of the frontal lobe, deals with senses

Sensory cortex/strip

front of the parietal lobe, registers and processes body sensations

Occipital lobes

lying at the back of the head, including visual areas, detect what eyes are seeing and process what eyes are seeing.

Temporal lobes

lying roughly above the ears, including auditory areas

association areas

areas of the cerebral cortex that are not involved in primary motor or sensory functions but are involved in higher-level mental functions such as learning, remembering, thinking, and speaking and enable us to make judgments and plan.

Language

the result of the intricate coordination of many brain areas, mostly controlled by left hemisphere

Broca’s area

controlled by left frontal lobe and directs the muscle movements in speech

Wernicke’s area

in the left temporal lobe, involved in language comprehension

Aphasia

impairment of language usually caused by left hemisphere damage either to Broca’s area (impairing speaking) or to Wernicke’s area (impairing understanding)

Angular gyrus

involved in reading aloud, receives information from the visual area and re-codes it into the auditory form, from which Wernicke’s area derives its meaning, damage to this area leaves the person able to speak and understand but unable to read

Plasticity

the brain can repair itself and learn new functions, the younger a person is the greater the plasticity

Reticular formation

involved in waking us up/putting us to sleep/arousal

Pons

fine tune motor coordination

Cerebellum

involved in balance and coordination and movement

Corpus Callosum

bridges right and left hemispheres

Medulla

heartbeat and breathing

Cerebral Cortex

higher level learning

Thalamus

the relay station between senses and parts of the brain involved in processing sensation

Limbic System

amygdala, hypothalamus, hippocampus

amygdala

fear and rage center

Hypothalamus

included in hunger, regulating body temperature, thirst, emotions, reproduction

hippocampus

included in learning and memory

Endocrine System

glands that transmit information throughout the body via chemical messengers called hormones that are secreted into the bloodstream

• slower chemical communication system whose effects are longer lasting

• the nervous system and endocrine system are interlinked by the hypothalamus

hypothalamus

a brain structure that controls the pituitary gland which controls the rest of the endocrine system

pituitary gland

located in the brain, regulates the activities of several other glands, it produces the growth hormone, it also produces prolactin and oxytocin

prolactin

involved in production of milk in women (males have it but not sure of role)

oxytocin

helps begin and continue labor stimulates the secretion of breast milk and is released by both males and females during orgasm

pineal gland

located in brain, produces melatonin, which helps regulate the sleep-wake cycle, does so in the changes in the environment and light, so when it gets dark it will release melatonin, when the sun rises the production is decreased

thyroid glands

located in the neck, control the body’s metabolism rate

metabolism rate

the way the body burns energy during exercise and at rest

adrenal glands

located above the kidneys, they produce epinephrine (adrenaline) and norepinephrine (nor or non-adrenaline), which causes physical arousal in response to danger, fear, anger, stress, and other strong emotions, involved in the fight or flight response, raises blood pressure, increases blood sugar, which provides us with a surge of energy

pancreas

located behind stomach, regulates blood sugar and insulin levels and it’s involved in hunger

The sex hormones

estrogen, progesterone, testosterone