Weeks 1&2 Terms

Front 1

Cell

Back 1

Smallest unit of life; at minimum, consists of plasma membrane, cytoplasm, and DNA.

Front 2

Plasma Membrane

Back 2

A cell's outermost membrane.

Front 3

Cytoplasm

Back 3

Semifluid substance enclosed by a cell's plasma membrane.

Front 4

Interstitial Fluid

Back 4

Of a multicelled organism, body fluid in between cells.

Front 5

Tissue

Back 5

In multicelled organisms, specialized cells organized in a pattern that allows them to perform a collective function.

Front 6

Organ

Back 6

In multicelled organisms, a grouping of tissues engaged in a collective task.

Front 7

Organ System

Back 7

In multicelld organisms, set of organs engaged in a collective task.

Front 8

Homeostasis

Back 8

Set of processes by which an organism keeps its internal conditions within tolerable ranges.

Front 9

Stimulus/Response

Back 9

A form of energy that is detected by a sensory receptor./Reaction to a stimulus.

Front 10

Negative Feedback

Back 10

A change causes a response that reverses the change; important mechanism of homeostasis.

Front 11

Positive Feedback

Back 11

A response intensifies the conditions that caused its occurance.

Front 12

Metabolism

Back 12

All the enzyme-mediated chemical reactions by which cells acquire and use energy as they build and break down organic molecules.

Front 13

Excretion

Back 13

(in living organisms and cells) The process of eliminating or expelling waste matter.

Front 14

Neuron

Back 14

One of the cells that make up communication lines of a nervous system; transmits electrical signals along its plasma.

Front 15

Neuoglial Cell

Back 15

Cell that supports and assists neurons.

Front 16

Nerve

Back 16

Neuron fibers bundled inside a sheath of connective tissue.

Front 17

Nerve Cord

Back 17

Bundle of nerve fibers that runs the length of the body in many invertebrates.

Front 18

Myelin Sheath

Back 18

Lipid-rich wrappings around axons of some neurons; speeds propagation of action potentials.

Front 19

Central Nervous System

Back 19

Brain and spinal cord.

Front 20

Peripheral Nervous System

Back 20

Nerves that extend through the body and carry signals to and from the central nervous system.

Front 21

Somatic Nervous System

Back 21

Set of nerves that control skeletal muscle and relay signals from joints and skin.

Front 22

Autonomic Nervous System

Back 22

Set of nerves that relay signals to and from internal organs and to glands.

Front 23

Sympathetic Neurons

Back 23

Neurons of the autonomic system that prepare the body for danger or excitement.

Front 24

Parasympathetic Neurons

Back 24

Neurons of the autonomic system that encourage "housekeeping" tasks in the body.

Front 25

Sensory Neuron

Back 25

Neuron that responds to a specific internal or external stimulus and signals another neuron.

Front 26

Interneuron

Back 26

Neuron that receives signals from and send signals to other neurons.

Front 27

Motor Neuron

Back 27

Neuron that receives signals from another neuron and sends signals to a muscle or gland.

Front 28

Axon

Back 28

Of a neuron, a cytoplasmic extension that transmits electrical signals along its length and releases chemical signals at its endings.

Front 29

Axon Terminals

Back 29

Distal terminations of the branches of an axon.

Front 30

Dendrites

Back 30

Of a motor neuron or interneuron, a cytoplasmic extension that receives chemical signals sent by other neurons and converts them to electrical signals.

Front 31

Membrane Potential

Back 31

Voltage difference across a plasma membrane.

Front 32

Transport Proteins

Back 32

Protein that passively or actively assists specific ions or molecules across a cell membrane.

Front 33

Channel Proteins

Back 33

Trans-membrane proteins found in the phospholipid bilayer membranes in our bodies.

Front 34

Ions

Back 34

Atoms that carry a charge because they have an unequal number of protons and electrons.

Front 35

Action Potential

Back 35

Brief reversal of the voltage difference across the plasma membrane of a neuron or muscle cell.

Front 36

Threshold Potential

Back 36

Neuron membrane potential at which gated sodium channels open, causing an action potential to occur.

Front 37

Synapse

Back 37

Region where a neuron's axon terminals transmit chemical signals to another cell.

Front 38

Neurotransmitter

Back 38

Chemical signal released by axon terminals of a neuron.

Front 39

Neuromodulator

Back 39

Any signaling molecule that reduces or magnifies the influence of a neurotransmitter on target cells.

Front 40

Reflex

Back 40

Automatic response that occurs without conscious thought or learning.

Front 41

Stimulus

Back 41

A form of energy that is detected by a sensory receptor.

Front 42

Sensory Receptors

Back 42

Cell or cell component that detects a specific type of stimulus.

Front 43

Sensation

Back 43

Detection of a stimulus.

Front 44

Sensory Perception

Back 44

The meaning a brain derives from a sensation.

Front 45

Sensory Adaptation

Back 45

Slowing or cessation of a sensory receptor response to an ongoing stimulus.

Front 46

Endocrine System

Back 46

Hormone-producing glands and secretory cells of a vertebrate body.

Front 47

Hormone

Back 47

Intercellular signaling molecule secreted by an endocrine gland or cell; travels in teh blood to target.

Front 48

Signaling Molecule

Back 48

A chemical involved in transmitting information between cells.

Front 49

Cell Receptors

Back 49

A protein molecule, embedded in either the plasma membrane or the cytoplasm of a cell, to which one or more specific kinds of signaling molecules may attach.

Front 50

Physiology

Back 50

The branch of biology that deals with the normal functions of living organisms and their parts