Flashcards in Week 8 Deck (81)
When do molecules need ATP to enter a cell?
They are not lipid soluble (cannot penetrate lipid bilayer)
Too large to pass through cell pore
Are on the wrong side of the concentration gradient
Name the electrolytes involved in active transport in cells
Specialized cells can transport which electrolytes?
Define symport system
All of the substances move in the same direction
Define antiport system
Some substances are moved in one direction, while others are moved in the opposite direction
Sodium Potassium Pump
To maintain proper levels of intracellular potassium and extracellular sodium, the cell must pump potassium in and sodium out.
Diffusion is ongoing, the active transport system must work continuously.
Stuff going in and out of cell. (nutrients in, waste out)
It's an active process, requiring ATP. A wall has to be broken to do it.
There is endo- and exocytosis.
Brings in particles
(e.g. white blood cells attacking bacteria)
Brings in liquids
Is very specific, occurring in cells that have specific proteins in their plasma membrane.
These proteins act as specialized receptor sites for ligands such as hormones, iron, and cholesterol, which are found in extracellular fluid.
(e.g. Insulin, once secreted from the pancreas, will only bind to those cells displaying specialized protein receptors for insulin)
Exporting substances from inside the cell to the outside
(e.g. an allergic reaction, thousands of granules containing histamine are released from mast cells)
What do you call exocytosis of waste products?
What do you call exocytosis of manufactured molecules?
Membrane potential or voltage
Potential electrical energy created by the separation of opposite charges (voltage created by the separation of opposite charges)
Resting membrane potential
Nerve impulses sitting in an imbalance
Not everyone is equal, there is a difference
A lot of potential to fire an impulse, when there is a difference (like a little battery, charged and ready to go)
Define neuron cell
Base unit of nervous system
Define central nervous system
Brain & spinal cord
Peripheral nervous system
Cordlike nerves that link the central nervous system with the rest of the body
Name the 3 functions of neurons
1. Sensory function (info going to the brain)
2. Integrated functions (nerves in between)
3. Motor function (response to a sensory function)
Which direction do impulses travel?
From dendrites to synaptic knobs
Nerve cells DO NOT
Support and protect the neurons structurally and functionally
Glial means glue
Look like tree branches (short, numerous, multibranched projections extending from cell body)
Receive stimuli (impulses) from other neurons & conduct this stimulation to the cell body
Looks like the palm of a hand
Looks like a tail or tree trunk
Conduct nerve impulses away from cell body toward another neuron or an effector cell (a cell that does something when stimulated, such as a muscle or gland cell)
Cells lined up end-to-end covering the axon
Cell membranes (fatty substance) of specialized glial cells in brain and spinal cord, they insulate the axon.
(this is what breaks down during MS)
Nodes of Ranvier
Small gaps between the Schwann cells in the myelin sheath..
Nodes of ranvier and myelin sheath work together to enhance the speed of conduction of nerve impulses along the axon (it's faster because it jumps (speeds up) from cell to cell)