1.) 1.1 Interaction of Heredity and Environment & 1.2 Overview of the Nervous System (#1-7)

1.) #1-7

Epigenetics

• the study of the relative effects of our genes and how experience can influence genetic expression

• changes in gene expression that do not involve alterations to the underlying DNA sequence

Example: a mother using drugs prenatal, and neglecting child postnasal can influence the child’s genetic expression as he or she grows up.

plasticity

humans’ enormous capacity to learn and adapt

nature vs nurture debate

the biggest and most persistent debate in psychology debating if human traits are present at birth (nature) or if they are developed through experience (nurture).

evolutionary perspective

the perspective that considers many different behaviors and traits like memory, perception, and language as the result of natural selection.

natural selection

The principle that the inherited traits that better enable an organism to survive and reproduce in a particular environment will, in competition with other trait variations, most likely be passed on to succeeding generations.

• explains how human behaviors, emotions, and traits evolve to provide adaptive advantages.

evolutionary psychology

the study of how natural selection influences behavior.

(Focuses on how humans are alike because of their shared biology and history)

behavior genetics

the study of the relative power and limits of genetic and environmental influences on behavior. (How humans differ because of their differing genes and environments.)

• the study of the environmental factors that affect how our genes are expressed

mutations

random errors in gene relocation that leads to change

heredity

• the genetic transfer of characteristics from parents to offspring

• how genes influence your behavior

• nature

survival of the fittest

• adapted traits, including psychological traits, that can and are more likely to be passed on to help with survival and reproduction of successful generations (natural selection).

• Evolutionary psychology uses this to explain why certain traits and behaviors evolved to help humans survive by natural selection

adaptation

the process by which a species becomes fitted to its environment through natural selection

eugenics

• selectively breeding humans to promote certain characteristics

• theorists used evolutionary principles in racist ways such as selectively breeding humans to promote certain characteristics (ex: white facial features)

twin studies

• research designs used in psychology to measure the influence of genetic factors on human behavior by comparing identical (monozygotic) twins with fraternal (dizygotic) twins.

• researching twins can find the nature of how their behaviors, traits, and personalities are alike or different because of their same/identical genes, and how their behaviors are nurtured through their environmental influences or epigenetics.

• genetics: identical twins will have a higher percentage of also developing a disease

• environment: identical twins raised in different environments show differences in behavior

adoption studies

a research method that compares adopted children to their biological and adoptive parents to determine the effects of genes and environment on behavior and mental processes.

family studies

looks at traits across biological relatives to see how succeeding traits are passed down through generations (natural selection) and which is more common with closer genetic relatedness. They can support nurture if the family members share a common environment.

genome

• humans’ common set of genes

• no more than 5% of genetic differences among humans arise from population group differences

hereditability

the proportion of observed differences on a trait among individuals of a population that are due to genetic differences.

chromosomes

threadlike structures made of DNA molecules that contain the genes

DNA (deoxyribonucleic acid)

a complex molecule containing the genetic information that makes up the chromosomes

gene

• smallest unit of heredity

• small segments of the giant DNA molecules

molecular genetics

the subfield of biology that studies the molecular structure and function of genes

environment

• every nongenetic influence surrounding a person

• can trigger genetic expression

• how outside situations (outside of genes) influence your behavior

• nurture

breakdown the nervous system

nervous system

the body’s fast, electrochemical communication network (neurotransmitters), consisting of all nerve cells and is divided into several smaller systems based on function

Central Nervous System (CNS)

• In the brain and spinal cord

• The body’s decision maker

• Nerves link the CNS with the body’s sensory receptors, muscles, and glands

• acts as the body’s main hub for managing esverything it does, from your thoughts and feelings to your movement

Peripheral nervous system

• responsible for gathering information and for transmitting CNS decisions to other body parts

• the network of nerves outside the brain and spinal cord (CNS) that acts as a communication highway.

• Connects the CNS decisions and the rest of the body (sensory info to the brain and motor commands to the body)

• two main divisions: autonomic and somatic nervous system

autonomic nervous system

• controls involuntary functions like: heartbeat, digestion, breathing, etc.

• controls our glands and internal organ muscles, in means of its sympathetic and parasympathetic divisions

  • both work together to regulate homeostasis

how does the sympathetic system act on the body?

• fight or flight

• Pupils dilate (enlarge) and inhibits/restricts tear production

• heart rate increases

• restriction digestion

• bladder relaxes

• release of adrenaline + noradrenaline

how does the parasympathetic system act on the body?

• the aftermath of a stressful evet

• pupils constrict (stress) and stimulates tear production

• heart rate decreases

• stimulates digestion

• bladder contracts

• stimulates elimination in sexual arousal

spinal cord

a two way information highway connecting the peripheral nervous system and the brain.

Ascends neural fibers send up sensory neurons/info and descending fibers send back motor neurons to the body.

reflexes

our automatic response to stimuli, which illustrate the spinal cord’s work

motor (EFFERENT) neurons

motor neurons that carry OUTgoing information from the brain and spinal cord to the muscles and glands

sensory (AFFERENT) neurons

afferent nerves of sensory neurons that carry INcoming information from the body’s tissues and sensory receptors to the brain and spinal cord

interneurons

neurons within the brain and spinal cord that serve as mediators between sensory and motor neurons; carry info around the brain for processing

reflex arc

a simple spinal reflex pathway is composed of a single sensory neuron and a single motor neuron; communicates through a spinal cord interneuron

somatic nervous system

enables voluntary movement and control of our skeletal muscles

parasympathetic nervous system

• part of the autonomic nervous system

• “rest and digest” after fight and flight

• conserves energy by automatically slowing the body down AFTER a stressful event

sympathetic nervous system

• controls “fight or flight” response during a stressful event

• automatically accelerates heart rate, blood pressure, breathing, dilates pupils, slows down digestion.