Physiology Exam

Homeostasis- What is homeostasis?

The normal resting conditions of the body, maintaining variables within a set point.

Homeostasis- What is a set point?

The normal range homeostasis attempts to keep the body at.

Homeostasis- What is a feedback loop?

The body’s response after homeostasis is disrupted (negative or positive).

Homeostasis- What is negative feedback?

Response is opposite to stimulus; stabilizes variables (homeostatic).

Homeostasis- What is positive feedback?

Response is the same as stimulus; reinforces change (not homeostatic).

Homeostasis- What is feed-forward control?

Anticipates change (e.g., salivating when thinking of food).

Homeostasis- What happens if homeostasis compensation fails?

Illness or death.

Homeostasis- What are the steps in a feedback loop?

1. Variable

2. Stimulus

3. Receptor

4. Afferent pathway

5. Control/integration center (brain/spinal cord)

6. Efferent pathway

7. Effector

8. Response

9. Feedback

Proteins & Amino Acids- What are proteins made of?

Polypeptide chains (amino acids linked by peptide bonds).

Proteins & Amino Acids- What is a peptide bond?

The covalent bond linking amino acids into polypeptides.

Proteins & Amino Acids- What are monomeric proteins?

1 polypeptide chain

Proteins & Amino Acids- What are multimeric proteins?

Multiple polypeptide chains.

Proteins & Amino Acids- What are the types of R-groups?

1. Nonpolar (hydrocarbon, hydrophobic)
2. Polar uncharged (OH, SH, carboxamide, hydrogen bonding)
3. Polar charged (+ or – charge, ionic interactions, hydrophilic).

Proteins & Amino Acids- What are the four levels of protein structure?

1. Primary (sequence)

2. Secondary (α-helix/β-sheet)

3. Tertiary (3D fold of one chain)

4. Quaternary (multiple chains).

Membrane Transport- What is passive transport?

Movement down a gradient; no energy required.

Membrane Transport- What are examples of passive transport?

• Simple diffusion: Small, nonpolar molecules (O₂, CO₂).

• Osmosis: Water diffusion from low solute → high solute.

• Facilitated diffusion: With carrier or channel proteins.

Membrane Transport- What are carrier proteins?

1. Bind solute

2. Conformational change

3. Transport solute across membrane.

Membrane Transport- Types of carrier transport?

• Uniport (1 solute, e.g., GLUT).

• Symport (2 solutes same direction, e.g., SGLT).

• Antiport (2 solutes opposite directions).

Membrane Transport- What are channel proteins?

Hydrophilic pores; highly specific; gated (ligand, voltage, mechanosensitive).

Membrane Transport- What is active transport?

Requires ATP; moves substances against gradients.

Membrane Transport- Types of active transport?

• Primary (direct, ATPase pumps e.g., Na⁺/K⁺ pump).

• Secondary (indirect, coupled to ATPase-driven gradient).

Nervous System Basics- What are the two main nervous system cell types?

Neurons (excitable, APs) and Glia (supporting).

Nervous System Basics- What are neuron types?

Afferent (sensory), Interneurons (CNS only), Efferent (motor).

Nervous System Basics- What are examples of glial cells?

Astrocytes (blood-brain barrier), Microglia (immune defense), Oligodendrocytes (CNS myelin), Schwann cells (PNS myelin).

Nervous System Basics- What is resting membrane potential?

Voltage across membrane due to unequal ion distribution (about –70 mV).

Nervous System Basics- What maintains RMP?

Na⁺/K⁺ ATPase pump (3 Na⁺ out, 2 K⁺ in) + K⁺ leak channels.

Electrical Events- What are graded potentials?

Local, variable size, dissipate with distance; not all-or-none.

Electrical Events- What are action potentials?

All-or-none, same size, travel without loss, initiated at axon hillock.

Electrical Events- Steps of an action potential?

1. Depolarization (Na⁺ in).

2. Repolarization (K⁺ out).

3. Hyperpolarization (extra K⁺ out).

Electrical Events- What is the refractory period?

Absolute = no AP (Na⁺ inactivated). Relative = harder (hyperpolarized).

Electrical Events- What is saltatory conduction?

AP jumps node-to-node in myelinated axons (faster).

Synapses- What are the main synapse types?

Electrical (direct) and Chemical (neurotransmitter).

Synapses- Steps of chemical synapse transmission?

1. AP

2. Ca²⁺ influx

3. Vesicle release

4. NT diffuses

5. Receptor

6. EPSP/IPSP

Synapses- What are EPSPs?

Excitatory depolarization

Synapses- What are IPSPs?

Inhibitory hyperpolarization

Synapses- What are receptor types?

Ionotropic (ion channel, fast)

Metabotropic (G-protein, slow)

Synapses- Example of ionotropic receptor?

Nicotinic ACh receptor (nAChR, excitatory at NMJ).

Autonomic Nervous System- What are the ANS branches?

• Sympathetic (fight/flight, ↑ HR, ↓ digestion, NE/E at effectors).

• Parasympathetic (rest/digest, ↓ HR, ↑ digestion, ACh at effectors).

Autonomic Nervous System- What is the neurotransmitter pathway for parasympathetic?

1. Preganglionic ACh

2. nAChR

3. Postganglionic ACh

4. mAChR (effector).

Autonomic Nervous System- What is the neurotransmitter pathway for sympathetic?

1. Preganglionic ACh

2. nAChR

3. Postganglionic NE/E

4. adrenergic receptors (α/β).

Muscle Physiology- What are the three muscle types?

Skeletal (voluntary, striated), Cardiac (involuntary, striated), Smooth (involuntary, non-striated)

Muscle Physiology- What is a sarcomere?

Functional unit of muscle, Z-line to Z-line.

Muscle Physiology- What happens during the sliding filament model?

1. Myosin heads pull actin

2. sarcomere shortens

3. I-band & H-zone shrink, A-band constant.

Muscle Physiology- What are troponin’s subunits?

• TnI: binds actin.

• TnC: binds Ca²⁺.

• TnT: binds tropomyosin.

Muscle Physiology- What is rigor mortis?

Rigid muscles after death due to no ATP (myosin stuck to actin).

Muscle Physiology- Types of muscle contraction?

• Isometric (length constant).

• Isotonic → Concentric (shortens), Eccentric (lengthens).

Muscle Physiology- What regulates muscle force production?

Frequency of stimulation, sarcomere length, velocity, motor unit recruitment.

Muscle Physiology- Muscle fiber types?

• Type I (slow oxidative): small, fatigue-resistant, low force.

• Type IIa (fast oxidative glycolytic): medium.

• Type IIx (fast glycolytic): large, high force, fatigue quickly.