Biology of Heredity, Environment, and Nervous Systems

Heredity (nature)

Genes from parents —> baby

Environment (nurture)

External factors/influences

Twin studies

investigating whether nature or nurture affects behavior

Family studies

look at the relative frequency of a trait within a family compared to the general population

Adoption studies

compare similarities between adopted children and their adoptive parents, relative to similarities with their biological parents

Central Nervous System (CNS)

brain and spinal cord, body's decision maker

Peripheral Nervous System (PNS)

the sensory and motor neurons that connect the CNS to the rest of the body

autonomic nervous system (ANS)

Automatic / involuntary movements

Somatic Nervous System (SNS)

Controls voluntary movements and sensory information.

Involuntary

Without intentional control

Voluntary

willing; unforced

parasympathetic nervous system (PNS)

calming body back down —> homeostasis

Sympathetic nervous system

fight or flight

Neuron

a nerve cell; the basic building block of the nervous system

glial cells (glia)

cells in the nervous system that support, nourish, and protect neurons

Reflex arc

sensory receptor, sensory neuron, motor neuron, and effector that are involved in a quick response to a stimulus

Sensory neurons

carry impulses from the sense organs to the spinal cord and brain

Motor neurons

neurons that carry signals from the spinal cord to the muscles to produce movement

Interneurons

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

all or nothing principle

Motor units either contract maximally or not at all.

Depolarization

loss or reduction of negative membrane potential

Threshold

Level of stimulation needed to trigger a neural impulse

Refractory period

a period of inactivity after a neuron has fired

Resting potential

electrical charge across the cell membrane of a resting neuron

Reuptake

a neurotransmitter's reabsorption by the sending neuron

Excitatory

Causes next cell to fire

Inhibitory

Keeps next cell from firing

Hormones

Chemicals produced by your glands that regulate the activities of different body cells

Adrenalin

A hormone released into the bloodstream in response to physical or mental stress

Leptin

hormone that signals the hypothalamus and brain stem to reduce appetite and increase the amount of energy used

Ghrelin

hunger hormone

Melatonin

sleep-inducing hormone

Oxytocin

Arousal

Endocrine system

the body's "slow" chemical communication system

pituitary gland

endocrine gland at the base of the brain

Agonist

A chemical that mimics the action of a neurotransmitter.

Antagonist

Molecule that blocks neurotransmitter's action

Reuptake inhibitors

stop reuptake, increasing neurotransmitters

Brain stem

Connects the brain and spinal cord

reticular activating system

Part of brain stem involved in arousal and attention, sleep and wakefulness, and control of reflexes.

Striatum

involved in reward-based learning, decision-making, emotion, and motor control

Basal ganglia

structures in the forebrain that help to control movement

Cerebellum

Balance and coordination

Cerebral cortex

outer region of the cerebrum, containing sheets of nerve cells; gray matter of the brain

Limbic system

neural system located below the cerebral hemispheres; associated with emotions and drives.

Thalamus

the brain's sensory control center

Hypothalamus

brain region controlling the pituitary gland

Hippocampus

A neural center located in the limbic system that helps process explicit memories for storage.

Amygdala

A limbic system structure involved in memory and emotion, particularly fear and aggression.

corpus callosum

A thick band of axons that connects the two cerebral hemispheres and acts as a communication link between them.

left hemisphere

controls language, math, and logic

right hemisphere

controls creative, intuitive, spacial

Frontal lobe

associated with reasoning, planning, parts of speech, movement, emotions, and problem solving

Parietal lobe

receives sensory input for touch and body position

Occipital lobe

visual processing

Temporal lobe

hearing

Visual cortex

receives written words as visual stimulation

Auditory cortex

the area of the temporal lobe responsible for processing sound information

Wernicke's area

language comprehension (temporal lobe)

Broca's area

Language comprehension (left frontal lobe)

somatosensory cortex

at the front of the parietal lobes that registers and processes body touch and movement sensations

motor cortex

controls voluntary movements

Aphasia

inability to speak

Plasticity

the brain's ability to change based on experience

EEG

An amplified recording of the waves of electrical activity that sweep across the brain's surface

fMRI

a form of magnetic resonance imaging of the brain that registers blood flow to functioning areas of the brain

Lesioning

removal or destruction of part of the brain

Circadian rhythm

the biological clock; regular bodily rhythms that occur on a 24-hour cycle