Neuro Midterm

1. What are the three main types of neurons?

   • Pseudounipolar, bipolar, and multipolar.

2. How do pseudounipolar neurons differ from bipolar neurons?

   • Pseudounipolar neurons have an axon that splits into two branches, while bipolar neurons have one axon and one dendrite.

3. What neurotransmitter is secreted by cholinergic neurons?

   • Acetylcholine.

4. Which neurotransmitter has excitatory or inhibitory effects depending on the receptor?

   • Norepinephrine.

5. What is the primary neurotransmitter of the sympathetic nervous system?

   • Norepinephrine.

6. What are the main functions of the sympathetic nervous system?

   • Fight-or-flight response, increasing heart rate, and regulating arterial pressure.

7. Which nerve is responsible for decreasing heart rate in the parasympathetic nervous system?

   • The Vagus Nerve.

8. What is the function of prevertebral ganglia?

   • Relaying signals to visceral organs.

9. What type of neuron innervates extrafusal muscle fibers?

   • Alpha (α) motor neurons.

10. What is the role of afferent neurons?

    • They convey sensory information to the CNS.

Muscle Physiology

11. What is the resting membrane potential (RMP) of skeletal muscle?

    • -90mV.

12. What is the resting membrane potential (RMP) of nerve cells?

    • -70mV.

13. Which muscle fiber type is slow-twitch and resistant to fatigue?

    • Type 1 fibers.

14. Which muscle fiber type primarily uses glycogen and glucose?

    • Type 2A fibers.

15. What ion links excitation to contraction in muscles?

    • Calcium ions.

16. In smooth muscle, what structure anchors thin filaments?

    • Dense bodies.

17. What triggers the power stroke in muscle contraction?

    • The release of ADP and Pi.

Cardiac and Smooth Muscle

18. What is autorhythmicity in cardiac muscle?

    • The ability to generate its own impulses.

19. What is the function of the SA node?

    • It acts as the heart’s pacemaker.

20. What is the myocardium responsible for?

    • Contracting to pump blood.

21. Which structures in cardiac muscle contain gap junctions and desmosomes?

    • Intercalated discs.

22. How does smooth muscle differ from skeletal muscle in contraction?

    • It contracts via second messengers and is involuntary.

23. Why is smooth muscle stronger per cross-sectional area than skeletal muscle?

    • Because of its dense actin-myosin interactions.

24. What is a treatment option for myasthenia gravis?

    • Immunosuppressants.

Neural Signaling and Action Potentials

25. What restores ion concentration gradients after an action potential?

    • The sodium-potassium pump.

26. What occurs during the absolute refractory period?

    • Sodium channels are inactivated.

27. What are graded potentials?

    • Local changes in membrane potential that can be summated.

28. What law do action potentials obey?

    • The all-or-none law.

29. How is electrical flow described in neural signaling?

    • As current.

Energy Systems

30. Which energy system does not use calories and is active for short durations?

    • The phosphagen system.

31. How many ATP molecules are produced in glycolysis?

    • 2 ATP.

32. What does the lactic acid system produce?

    • Hydrogen ions, but no ATP.

Endocrine and Physiological Functions

33. Which hormones affect smooth muscle?

    • Epinephrine, norepinephrine, and vasopressin.

34. What factor leads to vasodilation?

    • An increase in hydrogen ions.

35. What is the primary function of apocrine glands?

    • Secretion of thick, odoriferous substances.

Neuromuscular Junction and Synaptic Transmission

36. What are the main components of the motor end plate?

    • Axon terminal, synaptic cleft, and synaptic gutter.

37. What enzyme breaks down acetylcholine in the synaptic cleft?

    • Cholinesterase.

38. Where is an electrical signal converted into a chemical signal?

    • At the axon terminal.

Muscle Contraction Theories and Theorists

39. Who proposed the sliding filament theory?

    • A.F. Huxley and H.E. Huxley.

40. What is the main concept of the sliding filament theory?

    • Muscle contraction occurs as actin and myosin filaments slide past each other.

41. Which neurotransmitter is crucial for neuromuscular junction transmission?

    • Acetylcholine.

42. How do intercalated discs help cardiac muscle function?

    • They allow electrical signals to pass between cells rapidly.

43. What ion is necessary for neurotransmitter release at the synapse?

    • Calcium ions.

44. What part of a neuron transmits impulses away from the cell body?

    • The axon.

45. How does the parasympathetic nervous system affect digestion?

    • It enhances digestion by increasing gut motility.

46. Which type of muscle is striated and involuntary?

    • Cardiac muscle.

47. Why is the phosphagen system important for sprinting?

    • It provides immediate energy without requiring oxygen.

48. How do hormones like epinephrine affect blood vessels?

    • They can cause vasoconstriction or vasodilation, depending on the receptor type.

49. What distinguishes graded potentials from action potentials?

    • Graded potentials are local and summated, whereas action potentials are all-or-none.

50. What is the function of desmosomes in cardiac muscle?

    • They provide structural support by anchoring cells together.

1. What is the function of the nervous system?

   • To process and transmit information throughout the body.

2. What type of neuron is found in the dorsal root ganglion?

   • Pseudounipolar neurons.

3. Which part of a neuron receives incoming signals?

   • The dendrites.

4. Which division of the autonomic nervous system is responsible for the fight-or-flight response?

   • The sympathetic division.

5. Which neurotransmitter is primarily released by postganglionic sympathetic neurons?

   • Norepinephrine.

6. What is the primary function of the parasympathetic nervous system?

   • Rest and digest functions.

7. Where are prevertebral ganglia located?

   • In front of the vertebral column.

8. What part of the nervous system controls voluntary muscle movement?

   • The somatic nervous system.

9. What are the two main divisions of the autonomic nervous system?

   • The sympathetic and parasympathetic nervous systems.

10. Which type of neuron carries information from the CNS to muscles?

    • Motor (efferent) neurons.

Muscle Physiology

11. What protein binds to calcium in muscle contraction?

    • Troponin.

12. What structure stores calcium in muscle cells?

    • The sarcoplasmic reticulum.

13. Which type of muscle fiber is most resistant to fatigue?

    • Type 1 (slow-twitch) fibers.

14. What is the primary function of Type 2A muscle fibers?

    • Fast oxidative glycolytic function using glycogen and glucose.

15. Which ion is necessary for muscle contraction to occur?

    • Calcium (Ca²⁺).

16. Which type of muscle contraction occurs when a muscle shortens under tension?

    • Concentric contraction.

17. Which type of contraction involves muscle lengthening under tension?

    • Eccentric contraction.

18. What is the neurotransmitter at the neuromuscular junction?

    • Acetylcholine (ACh).

19. What happens to actin and myosin during muscle contraction?

    • They slide past each other, shortening the sarcomere.

20. Which enzyme breaks down acetylcholine at the neuromuscular junction?

    • Acetylcholinesterase (cholinesterase).

Cardiac and Smooth Muscle

21. How is cardiac muscle similar to skeletal muscle?

    • Both are striated and contain sarcomeres.

22. How is cardiac muscle different from skeletal muscle?

    • It is involuntary and has intercalated discs.

23. What is the primary pacemaker of the heart?

    • The SA (sinoatrial) node.

24. How does smooth muscle contract differently from skeletal muscle?

    • It contracts more slowly and via second messengers.

25. What connects cardiac muscle cells for electrical communication?

    • Gap junctions.

26. What anchors smooth muscle filaments?

    • Dense bodies.

27. Which structure allows cardiac muscle to contract as a single unit?

    • Intercalated discs.

28. What is the function of desmosomes in cardiac muscle?

    • To provide structural integrity.

29. Which nervous system primarily controls smooth muscle?

    • The autonomic nervous system.

30. What is a unique characteristic of smooth muscle compared to skeletal muscle?

    • It can maintain contraction for long periods with little energy use.

Neural Signaling and Action Potentials

31. What is the role of the sodium-potassium pump?

    • To restore resting membrane potential by moving Na⁺ out and K⁺ in.

32. What is the threshold potential for initiating an action potential?

    • Approximately -55mV.

33. What happens during depolarization of a neuron?

    • Sodium (Na⁺) channels open, and Na⁺ enters the cell.

34. What happens during repolarization of a neuron?

    • Potassium (K⁺) channels open, and K⁺ leaves the cell.

35. What is the all-or-none principle?

    • An action potential either occurs completely or not at all.

36. What type of potential can summate: graded potential or action potential?

    • Graded potential.

37. What is saltatory conduction?

    • The jumping of action potentials between nodes of Ranvier in myelinated neurons.

38. What is the purpose of the absolute refractory period?

    • It prevents another action potential from occurring immediately.

39. How does myelination affect nerve conduction speed?

    • It increases conduction speed.

40. What is the difference between excitatory and inhibitory neurotransmitters?

    • Excitatory neurotransmitters depolarize the neuron; inhibitory neurotransmitters hyperpolarize it.

Energy Systems

41. Which energy system provides immediate ATP?

    • The phosphagen system.

42. Which process breaks down glucose to produce ATP anaerobically?

    • Glycolysis.

43. How many ATP molecules are produced per glucose molecule in aerobic metabolism?

    • 36-38 ATP.

44. What is the primary byproduct of anaerobic glycolysis?

    • Lactic acid.

45. Which energy system provides the most long-lasting ATP production?

    • The oxidative (aerobic) system.

46. What happens to lactic acid after intense exercise?

    • It is converted back into pyruvate or glucose in the liver.

47. Why is the phosphagen system important for high-intensity activities?

    • It provides ATP rapidly without using oxygen.

48. Which molecule is the primary fuel for long-duration, low-intensity exercise?

    • Fatty acids.

49. What is the main function of mitochondria in muscle cells?

    • ATP production via aerobic metabolism.

50. Which hormone plays a major role in glucose uptake into muscle cells?

    • Insulin.