BIO 322 Exam study guide Questions with
Complete Solutions
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
Complete Solutions
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
