Exam 2: Brain Development, Neurons, and Hormones

How many stages of human development are there?

8

What is the first stage of Human Development?

pre-natal period (in the womb)

What is the second stage of Human Development?

infancy (birth-2yrs)

What is the third stage of Human Development?

early childhood (3-5yrs)

What is the fourth stage of Human Development?

middle and late childhood (6-12yrs)

What is the fifth stage of Human Development?

adolescence (13-18yrs)

What is the sixth stage of Human Development?

early adulthood (19-29yrs)

What is the seventh stage of Human Development?

middle adulthood (30-60yrs)

What is the eighth stage of Human Development?

late adulthood (61+yrs)

How long does it take from conception to implantation (build a human)?

7-8 days

What is the basic building block of the brain and its systems?

neurons

What is the purpose/function of neurons?

transmits nerve impulses to and from brain

What happens to the brainstem development after 18 days of fertilization?

neural plate forms from embryonic tissues and becomes the neural tube at 21 days

Which stages of human development have the most rapid brain development?

conception to birth

During 9 months in utero, babies are without…

consciousness, knowledge, where they come from, emotions

From 1-5mths old after birth…

babies begin to gain consciousness and memory

What forms the strongest neural connections, twice that of an adult?

repeated stimuli

What is the earliest nervous system tissue?

neural tube, 21 days

What happens after 7 weeks of fertilization?

the brain structure starts to develop; neural tube thickens/enlarges into the forebrain, midbrain, and hindbrain

During the 6th week of pregnancy…

the first electrical brain activity begins to occur

DNA

blueprint contained on a 6’ long strip of genetic material

At birth the brain, heart, and lungs…

are well developed enough to allow the baby to survive outside of the mother’s womb

At birth the baby’s head/brain is…

relatively small to allow it to pass through birth canal; skull isn’t completely closed to allow the brain to grow

At birth, how many synapses are formed b/c of environmental stimuli?

31 trilllion

From age 3 to 11yrs old it is the easiest to…

learn a second language, drawing, playing an instrument

From age 3 to 11yrs old, the brain’s…

dense neural network is the most receptive

At around the age of 8…

critical thinking emerges

At the age of 3 to 11yrs, adolescents are less likely to

think before they act, pause to consider the consequences of their actions, change their dangerous/inappropriate behaviors

From age 11 and up…

pruning begins; neural pathways not used will be cut and fade away while remaining pathways will remain stronger and become more efficient

Which portion of the brain is dominant during the teenage years?

amygdala

Teenagers are more likely to

act on impulse, misread/misinterpret social cues/emotions, get into accidents, get involved in fights, engage in dangerous/risky behavior

In young adults their prefrontal cortex is…

the last to mature, memory is decreased/slowed, and critical memory brain-cell processes are lost

What is neurogenesis?

the process by which new neurons are formed in the brain

Our consciousness is mainly in the…

prefrontal cortex

Do we inherit cognitive function from our parents?

Yes

Genes+Expereinces (learning opportunities) = ….

Wisdom

What is a neuron?

specialized cell of the nervous system that processes info

What is the function of neurons?

responsible for receiving sensory input, sending motor commands, transforming+relaying electrical signals

What does EEGs stand for?

Electroencephalographs

What does as EEGs do?

follows current along pathways; shows state of consciousness in sleep, awake, anaesthetized states

What are the major drawbacks of EEGs?

cannot show the anatomy of brain or tell which specific regions of brain do what; do not anatomically map the brain; only electrical activity is protrayed

How many main parts are mentioned of the cell?

3

What are the 3 main parts of the cell?

cell membrane, nucleus, and cytoplasm

What is the function of the cell membrane?

provide a semi-permeable boundary that divides/regulates outer/inner substances of the cell

What is the function of the nucleus?

stores the DNA and genetic materials

What is the function of the cytoplasm?

fluid within the cell that serves as the body for the organelles to sit in; allows for bodily processes such as protein synthesis and glycolosis

Neurons of are capable of firing messages via…

chemical and electrical impulses

What are the dendrites on a neuron?

Top left purple ends of reef-like structure

What is the nucleus on a neuron?

a green circle glob at the center of the purple reef-like structure

What is the cell body/soma on a neuron?

the reef-like purple structure itself as a whole (left portion only)

What is the axon Hillock on a neuron?

the portion of the purple reef nearest to the yellow myelin structures; the whole communication bridging to the other purple reef end

What are the myelin sheaths on a neuron?

the yellow globs on the axon that helps speed up the message process

What are the nodes of Ranvier on a neuron?

the purple parts of the axon in between every yellow myelin sheath

What are the Schwaan cells on a neuron?

the pinkish-purple circles located within the myelin sheaths

What are the axon terminals on a neuron?

the very tips/ends of the purple reef structures

What are the synapses of a neuron?

the gap in between each one reef structure to another reef structure, the receptor that receives the info

electrical activity is known as…

action potential

At -70mV is…

resting potential

At -55mV is…

action potential

When a neuron is at rest it means that…

the inside is negative relative to the outside

What is depolarization?

membrane potential quickly changing from a negative to positive state in less than 1/1000 of a second, via movement of K+ and Na+ into cell

What does AP stand for?

Action potential

Ion channels in the axon are…

voltage gated

____ at one axon segment triggers the _____ of ion channels in the next segment

Depolarization and opening

The action potential spreads along the axon as…

a wave of depolarization

What are ions?

electrically charged chemicals

What are examples of ions?

sodium, potassium, calcium, and chloride

What is multiple sclerosis?

a disorder in which the body’s immune system attacks the myelin sheath of the nerve cells in the brain, optic nerve, and spinal cord

Multiple sclerosis is most common in…

ages 20-40, females

What are synapses?

connections between neurons

Neurons that fire together…

connect with repeated exposure

Experiences brings…

strong brain connections and learning

Neurotransmitters are produced in…

neurons

Neurotransmitters are released in…

synapses

Most of psychoactive meds work on NT concentrations…

increasing or decreasing levels, preventing re-uptakes, increased production

Neurotransmitters are also considered…

chemicals that fine-tune perceptions, feelings, and behaviors

Who is the Otto Loewi?

The founder of neurotransmitters

How did Otto Loewi come up with the experiment idea to test for a neurotransmitter?

a dream

What was the first ever discovered neurotransmitter?

acetylcholine