CH. 3 DEFINITIONS [UNIT 2]

Neuron

made up of 3 major parts cell in the nervous system, its job is to receive + transmit info

Cell body (soma)

contains the nucleus of the cell, keeps cell alive

Dendrite

collects info from other cells, sends info → soma

Axon

Transmits info away from the cell body → other neurons or to the muscles/glands

Myelin sheath

layer of fatty tissue surrounding the axon of a neuron that acts as an insulator, allowing faster transmission of the electrical signal

Nodes of Ranvier

gaps in between myelin sheath; action potential jumps node

Terminal Button

Axons branch out towards the end and have tips @ each branch

Electrochemical process

how the NS operates; electrical charge moves through the neuron, chemicals are used to transmit info between neurons

Neurotransmitters

Chemical that relays signals across synapses between neurons

Synapse

the small gap between neurons across which nerve impulses are transmitted

Resting potential (

70mV)

Threshold (

55mV)

Action Potential

Change in electrical charge that occurs in a neuron when a nerve impulse is transmitted

Refractory Period

Prevents the neuron from repeated firing, axon cannot fire again since the neuron hasn’t returned to its resting potential

Excitatory

make the cell more likely to fire

Inhibitory

they make the cell less likely to fire

Reuptake

process where neurotransmitters in the synapse are reabsorbed into the transmitting terminal buttons, ready to be released again after the neuron fires

Agonist

drug that has chemical properties similar to a specific neurotransmitter, allowing it to mimic the neurotransmitter’s effects

Antagonist

drug that reduces/stops the normal effects of a neurotransmitter

Homeostasis

Stable, balanced, and optimal function of the body’s physiological systems

Hypothalamus

regulates our basic biological needs, sending signals

Cerebral cortex

Large + highly developed outer layer of the brain

Brain stem

Oldest + innermost region of the brain. Controls the most basic functions of life (breathing, attention, motor skills)

Medulla

area of the brain stem that controls heart rate + breathing

Pons

Controls movements of the body (chewing), carries sensory info to other areas of the brain

Reticular Formation

Long network of neurons that runs through the medulla + pons. Controls walking, eating, sex activity, and sleeping

Cerebellum

Consists of 2 wrinkled ovals behind the brain stem, functions to coordinate voluntary movement, and contributes to emotional responses

Substantia Nigra

Layer of neurons within the midbrain that coordinates movement

Cerebrum

Planning, thought, language, along with the integration of sensory info

Cortex

Wrinkled layer of the cerebrum

Thalamus

Egg

Limbic System

Brain area located between the brain stem + 2 cerebral hemispheres

Amygdala

2 almond

Sympathetic Nervous System

facial responses to perceive + express emotions, processing of smells, and the release of neurotransmitters related to stress + aggression

Hypothalamus

Consists of two horns that curve back from the amygdala; regulates hunger, thirst, and sex (feelings of pleasure)

Hippocampus

stores info in long

Cerebral cortex

outer, bark

Glial cells

cells that surround + link to the neurons, protects them + provides them with nutrients, absorbing unused neurotransmitters

Frontal Lobe

Located behind the forehead, responsible for thinking, planning, memory, and judgment

Parital Lobe

Located middle → back of the skull, responsible for processing info for touch

Occipital Lobe

Located @ the back of the skull, processes visual info

Temporal Lobe

Located in front of the occipital lobe + between the ears, responsible for hearing + language

Motor cortex

Part of the cortex that controls + executes body movements via sending signals → cerebellum + spinal cord

Somatosensory cortex

Receives info from the skin’s sensory receptors + movements of different body parts

Visual cortex

Processes visual info

Auditory cortex

Responsible for hearing + language

Association areas

Remainder of the cortex; sensory + motor info is combined + associated with our stored knowledge

Contralateral control

Brain is wired so that the left hemisphere receives sensations from + controls the right side of the body

Neuroplasticity

refers to the brain’s ability to change structure + function in response to damage

Neurogenesis

formation of new neurons, originating deep in the brain → migrates to other areas to form new connections

Brain lateralization

idea that left + right hemispheres of the brain are used to perform different functions

Corpus Callosum

when the region that connects both halves of the brain/communication between hemispheres is severed

Neuroimaging

A method for scientists to look at our brains in action

Lesions

Damages to the brain as a result from strokes, falls, automobile accidents, gunshots, tumours

Feature Detectors

Techniques that find specific neurons in the visual cortex that detect movement, lines, edges, and faces

Electroencephalography (EEG)

Records the electrical activity produced by the brains neurons via the use of electrodes placed around the research participant’s head

Computerized Tomography Scan (CT)

Structural imaging, x

Magnetic Resonance Imaging (MRI)

Provides detailed images of the brain’s structures from all angles + from any perspective

Functional Magnetic Resonance Imaging (fMRI)

Most common method of brain structure, uses magnetic field to create brain activity in each brain area

Transcranial Magnetic Stimulation (TMS)

magnetic pulses applied to the brain of a living person to temporarily + safely deactivate a small brain region

Nerves

Bundles of interconnected neurons that fire in sync to carry messages

Central Nervous System (CNS)

Major controller of the body’s functions; tasked with interpreting sensory info + responding to it with its own directives

Sensory (afferent) neuron

Carries info from sensory receptors

Motor (efferent) neuron

Transmit info to muscles + glands

Interneuron

Most common neuron, located in CNS, responsible for communicating among neurons

Reflex

Involuntary + nearly instantaneous movement in response to stimulus

Peripheral Nervous System (PNS)

Links CNS to the body’s sense receptors, muscles, and glands

Somatic Nervous System (SNS)

External aspects (skeletal muscles, skin, and sense organs)

Autonomic Nervous System (ANS)

Internal activities (heart rate, breathing, digestion, salivation, perspiration, urination, arousal)

Sympathetic

Prepares body for behaviour in response to stress, activating organs + glands in endocrine system

Parasympathetic

Calms body by slowing heart + breathing, allowing the body to recover from activities that the sympathetic system causes

Homeostasis

Natural balance in the body’s system

Endocrine System

Elicit chemicals that provide another way of influencing our feelings + behaviours

Gland (in endocrine system)

Group of cells that function to secrete hormones

Hormones

Chemical that moves throughout the body to help regulate emotions + behaviour

Hypothalamus

Brain region controlling pituitary gland

Pituitary Gland (Master Gland)

Pea

Thyroid Gland

Affect metabolism among other things

Parathyroid/Thyroid

Help regulate calcium level in the blood, determines how quickly the body uses energy + hormones

Adrenal Glands

Triggers fight or flight response

Pancreas

Regulates sugar level in blood, secretes hormones to keep body supplied with fuel to produce/store energy

Ovary

Secretes female sex hormones

Testis

Secretes male sex hormones

Pineal Gland

Located in the middle of the brain, secretes melatonin

Adrenal Glands

Produce hormones regulating salt + water balance in body, responsible for metabolism, the immune system, and sexual development

Sexual Selection Theory

How evolution has shaped us to provide a mating advantage > survival advantage

Gene Selection Theory

Modern explanation behind evolutionary biology, occurs via the desire for gene replication

Sexual Strategies Theory

How humans evolved a list of different mating strategies + the way in which women + men differ

Error Management Theory

Evolution of biases in the way we think about everything, make decisions, and evaluate uncertain situations

Evolution

Certain traits + behaviours develop over time because they are advantageous to our survival

Natural Selection

Reproductive success

Adaptations

Traits + behaviours evolved to increase our reproductive success

Intrasexual Competition

Occurs when members of one sex compete against each other, winner gets to mate with a member of the opposite sex

Intersexual Selection

Preferential mate choice, members of one sex are attracted to certain qualities in mates (health, intelligence), those desired qualities get passed on in greater #s because they mate often

Mutual Mate Choice

Both women + men have a say in choosing mates, value qualities that are beneficial to long

Psychological Adaptations

Mechanisms of the mind that evolved to solve specific problems of survival/reproduction

Physiological Adaptations

Adaptations that occur in the body as a consequence of one’s environment

Interactionist Framework

Taking into account multiple factors when determining an outcome

Cost Asymmetries

One option has low costs, but great reward; other has a low reward but high cost

Visual Descent Illusion

People who overestimate the distance when looking down from a height compared to looking up