Biological Bases of Behavior - Unit 2

Heredity

Passing on of traits from one generation to another

Nature vs nurture

Genes vs environment

What psychological perspectives lean on the nature side of the debate?

biological, cognitive, evolutionary

What psychological perspectives lean on the nurture side of the debate?

psychodynamic, behavioral, sociocultural

Epigenetics

How a person’s environment and behavior changes the way your genes work

Brain plasticity

Changes in the brain at a cellular level

Nervous system

Fast, short lasting messages

Endocrine system

Slow, target large areas of the body

Homeostasis

Ability to maintain internal stability

Pituitary gland

Base of the brain, connects nervous and endocrine systems, master gland

Growth hormones, oxytocin, vasopressin

Pineal Gland

Above brainstem in midbrain, regulates sleep cycles

Melatonin

Thyroid and parathyroid gland

In the throat, regulates metabolism

Thyroid and parathyroid hormones, calcitonin

Adrenal glands

Above kidneys, regulates blood pressure

Norepinephrine, epinephrine, aldosterone

Pancreas

By the stomach, regulates sugar levels

Insulin, glucagon

Gonads

Ovaries and testes, reproduction

Testosterone, estrogen, progesterone

Central nervous system (CNS)

Brain and spinal chord

Peripheral nervous system (PNS)

Nerves that branch off the CNS

sensory branch

Picks up info from outside stimuli

Motor branch

Impulses from the brain to neurons

Afferent

Approaching the brain

Afferent

Exiting the brain

Efferent

Exiting the brain

Somatic nervous system

Involuntary processes, smooth and cardiac muscle

Two divisions of autonomic nervous systems

Sympathetic and parasympathetic

Branches of PNS

Sensory and motor

Sympathetic

Arouses

Parasympathetic

Calms

Glial cell

Provides neurons with nutrients, most abundant cell in nervous system

Dendrites

Extension of cell body, receive chemical messages through receptors

Nucleus

Houses genetic material

Soma

Cell body that contains the most organelles

Nodes of Ranvier

Gaps where the axon is exposed, increases speed of action potential

Axon

Longest part of the neuron, connects soma to axon terminal

Myelin Sheath

Protects axon and increases speed of action potential

Axon terminal

neurotransmitter release into the synapse

Schwann cells

Produces myelin sheath

Action potential

Neuron fires an electrical impulse down the axon

Can a neuron fire a partial action potential?

All or nothing

Resting Neuron

More positive ions outside the neuron, will not fire

Depolarization

Positive ions move inside the cell and trigger an action potential

Repolarization

Neuron returns to resting potential

Refractory period

Time when neuron cannot fire, waiting for repolarization

Synapse

Space between the axon terminal of one neuron, and dendrites of another

Electrical synapse

Connected neurons, fast

Chemical synapse

Synaptic gap in between, slow

Neurotransmitter

Chemical messenger sent by a neuron

Presynaptic terminal

Releases neurotransmitter

Releases neurotransmitter

Postsynaptic terminal

Receives neurotransmitter

Reputake

Sending neuron reabsorbs the neurotransmitters

Excitatory neurotransmitter

Increases likelihood of neuron firing

Inhibitory neurotransmitter

Decrease likelihood of neuron firing

Hyperpolarization

Inside of neuron becomes extremely negative, moves further away from action potential

Acetylcholine

Excitatory, contracts muscles, learning, memory

Dopamine

Excitatory, contracts muscles, learning, memory

Dopamine

Happy hormone, satisfaction and motivation, addictive

Serotonin

Inhibitory, mood, sleep, hunger, arousal

Endorphins

Inhibitory, pain control, lower stress

Glutamate

Excitatory messages, long term memory, learning

GABA

Inhibitory, sleep and movement

Agonist

Increase effects of a neurotransmitter

Antagonist

Decrease or stop the effects of a neurotransmitter

How do agonists work?

Mimic neurotransmitter, block reuptake (neurotransmitter stays in the synapse)

How do antagonists work?

Block receptors on the postsynaptic terminal, block release at presynaptic terminal

Broca’s Area

Frontal lobe, controls speech muscles

Wernicke’s aArea

Temporal lobe, ability to comprehend and create speech

Medulla Oblongata

controls breathing, heart rate, blood pressure

Pons

Coordinates movement and sleep

Cerebellum

Smooth muscle movements, maintains equilibrium

Brain Stem

Contains midbrain, pons, and medulla (autonomic functions)

Spinal Cord

Connects brain to the rest of the body

Midbrain

Part of the brainstem, relays info from visual and auditory systems

Reticular Formation

Nerves and fibers through the brainstem, alertness and arousal

Reticular Activating System

Part of reticular formation, sleep-wake cycles

Cerebrum

Everything except the cerebellum and brainstem

Cerebral Cortex

Thin layer of gray matter over the brain

Corpus Callosum

Connects both hemispheres of the brain

Frontal Lobe

Higher level thinking and motor functions

Prefrontal Cortex

Frontal Lobe, planning, emotions, complex thought

Motor Cortex

Motor Homunculus

Parietal Lobe

Somatosensory Cortex

Occipital Lobe

Visual Corte

Temporal Lobe

Angular Gyrus

Auditory Cortex

Thalamus

Limbic System

Hippocampus

Amygdala

Hypothalamus

Nucleus Accumbens

Basal Ganglia

Brain lateralization

Left and right hemispheres are different

Left brain

Logic and language

Right brain

Spatial concepts, creativity

Phineas gage

Pole went through his head, he was fine

Corpus Callosum Cut

No loss of intelligence but the two hemispheres can no longer communicate