bio 322 exam 2 study guide UPDATED ACTUAL Questions and
CORRECT Answers
Animal physiology depends on integration — the coordination of many cells and tissues into a functional whole
, The nervous and endocrine systems are the two primary control systems
Integration Example Squid jet propulsion: Rapid signaling through giant axons enables immediate
escape.
Coordination: Sensory input → CNS integration → motor output
The two systems are complementary: -Nervous system can control endocrine output (e.g., adrenal medulla
→adrenaline)
-Hormones modulate neural function (e.g., sex steroids affect behavior and brain)
nervous system ex: reflex when you touch a hot stove
endocrine system example: pancreas releases insulin after eating
Neuronal Structure -Dendrites: Receive input.
-Soma: Integrates signals.
-Axon: Transmits action potentials.
-Axon terminals: Release neurotransmitters.
Neural pathways: -CNS tracts = bundles of axons within the brain/spinal cord.
-PNS nerves = axon bundles outside the CNS.
Glial Cells Glia-to-neuron ratio increases in complex animals, supporting higher processing
capacity
Membrane Potentials *Electrical signaling arises from ion gradients and selective membrane
permeability.
*Resting potential: typically -60 to -90 mV (inside negative)
Key ions: -High K⁺ inside, low Na⁺ and Cl⁻ inside.
-Gradients maintained by Na⁺/K⁺ ATPase pump (3 Na⁺ out, 2 K⁺ in)
Nernst Equation -Describes equilibrium potential for one ion (Eₓ).
-Example: EK ≈ -90 mV, ENa ≈ +60 mV.
Goldman Equation -Extends Nernst by combining multiple ions, weighted by permeability (P).
-Resting potential ≈ weighted average of EK, ENa, and ECl
Electrical Models *Resistance (R): Ion channels.
*Capacitance (C): Membrane stores charge.
*Time constant (τ = RC): Rate of voltage change.
*Length constant (λ): Distance over which voltage decays
CORRECT Answers
Animal physiology depends on integration — the coordination of many cells and tissues into a functional whole
, The nervous and endocrine systems are the two primary control systems
Integration Example Squid jet propulsion: Rapid signaling through giant axons enables immediate
escape.
Coordination: Sensory input → CNS integration → motor output
The two systems are complementary: -Nervous system can control endocrine output (e.g., adrenal medulla
→adrenaline)
-Hormones modulate neural function (e.g., sex steroids affect behavior and brain)
nervous system ex: reflex when you touch a hot stove
endocrine system example: pancreas releases insulin after eating
Neuronal Structure -Dendrites: Receive input.
-Soma: Integrates signals.
-Axon: Transmits action potentials.
-Axon terminals: Release neurotransmitters.
Neural pathways: -CNS tracts = bundles of axons within the brain/spinal cord.
-PNS nerves = axon bundles outside the CNS.
Glial Cells Glia-to-neuron ratio increases in complex animals, supporting higher processing
capacity
Membrane Potentials *Electrical signaling arises from ion gradients and selective membrane
permeability.
*Resting potential: typically -60 to -90 mV (inside negative)
Key ions: -High K⁺ inside, low Na⁺ and Cl⁻ inside.
-Gradients maintained by Na⁺/K⁺ ATPase pump (3 Na⁺ out, 2 K⁺ in)
Nernst Equation -Describes equilibrium potential for one ion (Eₓ).
-Example: EK ≈ -90 mV, ENa ≈ +60 mV.
Goldman Equation -Extends Nernst by combining multiple ions, weighted by permeability (P).
-Resting potential ≈ weighted average of EK, ENa, and ECl
Electrical Models *Resistance (R): Ion channels.
*Capacitance (C): Membrane stores charge.
*Time constant (τ = RC): Rate of voltage change.
*Length constant (λ): Distance over which voltage decays
