Produced in ER, inserted by Golgi (via exocytosis). Change membrane’s H2O permeability.
Carrier mediated transport description? Active vs. passive?
Both – bind to substance on one side, change shape to release substance on other side, have a maximum rate of transport (can become saturated), highly specific.
Passive (facilitated diffusion) effected by diffusion variables.
Active (pumps) act against concentration gradient
Active transport examples, details?
Ca2+ pumps – Ca2+ binds to carrier protein in cytosol, carrier protein is phosphorylated by ATP -> ADP + Pi, carrier protein changes shape moving Ca2+ out of cell (where concentration is greater).
Na+/K+ ATPase – pumps 3 Na+ out of cell and 2 K+ into cell simultaneously to generate gradients for electrical impulses in nerves and muscles AND drive co-transport of other substances across the membrane (glucose)
Tracts vs. nuclei vs. nerves vs. ganglia
Tracts (axons, CNS).
Nuclei (cell bodies, CNS).
Nerves (axons, PNS).
Ganglia (cell bodies, PNS)
Axon hillock vs. axon terminal
Axon hillock – where action potential originates, base of axon near cell body.
Axon terminal – where neurotransmitters are released (presynaptic terminal).
Types of neurons (functional)? Cell body/axon location? (_polar)? Afferent/Efferent? Function?
Sensory – afferent, cell body in PNS, axon in CNS, relays stimuli from tissue to CNS, dendrites/sensory receptors, unipolar.
Motor – efferent, cell body in CNS, axon in PNS, carries signals from CNS to effector (muscle/gland), multipolar. Somatic motor – skeletal muscles. Autonomic motor – smooth and cardiac muscle, glands. Autonomic divided into sympathetic (fight or flight) and parasympathetic (rest and digest).
Association – interneurons, cell body and axon in CNS, receive from/send to other neurons, analyze/modulate/modify/integrate signals, responsible for cognition/memory, 99% of neurons, multipolar
Types of neurons (structural)? Location? Shape?
Multipolar – many dendrites with a single axon, most common (motor/association).
Pseudounipolar – single short process that branches like a T (sensory).
Bipolar – two processes, one dendrite one axon, rare (sensory in eyes, ears, nose)