NEUR 101 Lecture 2 (A1, 1.1-1.2)

Genes

Encoded pairs of nucleotides (A,T,G,C) that form a double helix

DNA

the molecule that carries genetic information, consisting of sequences of nucleotides arranged in a double helix structure.

Enzyme

When DNA is “unzipped“ to be “read out“

Transcription

The process of copying the genetic sequence

mRNA

The single-strand copy, which is made for temporary use

• “Messenger RNA“

Translation

where a cell uses messenger RNA (mRNA) as a template to build a specific sequence of amino acids, creating a protein within structures called…ribosomes

Chromosomes

threadlike structures made of DNA and proteins that pack and store genetic information inside the nucleus of cells

Cell nucleus

a membrane-bound organelle that acts as the command center of eukaryotic cells

Genome

an organism’s complete set of genetic instructions, made up of all the DNA stored in its cells

Express

Genes can alter your environment by producing behaviors or traits that affect how people in your environment react to you.

can have an indirect effect

can increase probability that a behavior will develop under certain circumstances

Neurons can vary in…

size, shape, and function

Neurons

recieve, conduct, and transmit electrochemical signals

Information flows from…

Dendrites to terminals

Input-dendrites

recieve information from other cells

Integration-the cell body (soma)

integrates the information it receives C

Conduction-a single axon (or nerve fiber)

Conducts output information away from the cell body as an electrical impulse

Output-axon terminals

at the end of the axon communicate activity to other cells m

Motor neurons

large, have long axons, and stimulate muscles

Sensory neurons

have various shapes that best respond to specific environmental stimuli, such as light, odor, or touch

Interneurons

have tiny axons and analyze input from one set of neurons and communicate with others.

Multipolar neurons

one axon, many dendrites, most common

Bipolar neurons

one axon, one dendrite

Unipolar neurons

a single extension branches in two directions, forming an input zome and an output zone

presynaptic membrane

on the axon terminal of the presynaptic neuron

postysynaptic membrane

on the dendrite or cell body of the postsynaptic neuron

Synaptic cleft

the gap that separates the membranes

synaptic vesicles

small spheres in presynaptic axon terminals that contain a neurotransmitter, a specialized chemical. —> neurotransmitters are released in response to electrical activity in the axon

Neurotransmitter receptors

in the postsynaptic membrane are specialized proteins that react to neurotransmitter molecules.

neural plasticity

refers to the continual remodeling of neuronal connections

axon hillock

a cone-shaped area of the cell body that gives rise to the axon. the hillock converts input into electrical signals that travel down the axon and innervate target cells

Axon collateral

a branch of an axon that also ends in terminals

Axonal transport

the bidirectional movement of materials within an axon (different from neuronal communication)

• it’s for moving materials, and it goes both ways (anterograde and retrograde)

Glial cells

assist neuronal activity by providing raw materials, chemical signals, and structure and also participate in information processing - mediate many aspects of neuronal communication

Oligodendrocytes (wrap around myelin)

form the myelin sheaths in the brain and spinal cord

Schwann cells (wrap around myelin)

provide myelin to neurons outside the brain and spinal Nod

Nodes of Ranvier

gaps between sections of myelin where the axon is exposed A

Astrocytes

star-shaped cells with many processes that stretch around and between neurons and sometimes blood vessels; secrete chemicals; help form the outer membrane around the brain M

Microglial cells / Microglia

tiny, mobile cells that remove debris from injured or dead cells

Central Nervous System (CNS)

consists of the brain and spinal cord. P

Peripheral Nervous System

includes all other parts of the nervous system outside the brain and spinal cord

Motor nerves

transmit information from the spinal cord and brain to muscles and glands S

Sensory nerves

convey information from the body to the CNS

Somatic nervous system

nerves that interconnect the brain and the major muscles and sensory systems of the body

Autonomic nervous system

nerves that connect to the viscera (internal organs)

The somatic nervous systems interacts with the external environment:

conveys sensory info. to the CNS

controls voluntary muscle movement

cranial nerves

innervate the head, neck, and visceral organs directly from the brain

spinal nerves

connect to the spinal cord

spinal cord injury…

loss of function depends on the location of the injury.

Quadriplegic: cervical

Paraplegic: thoracic/lumbar

Sympathetic nervous system

chains of linked ganglia bordering the spinal cord

“fight or flight“

Parasympathetic nervous system

unlinked ganglia, act more independently

“rest and digest“

sagital

brain from side

horizontal/axial

brain from aboveco

coronal/frontal

brain from the front

afferent = arriving

carries information into a region of interest

sensory

efferent = exiting

carries information away from a region of interest

motor

dorsal

toward the back

ventral

toward the stomach an

anterior

toward the front end

posterior

toward the rear end

superior

above another part

inferior

below another part

lateral

toward the side, away from midline

medial

toward the midline,away from side

proximal

located close to the point of origin or attachment di

distal

located more distant from the point of origin or attachment

Ipsilateral

on the same side of the body

Contralateral

on the opposite side of the body