Biology 2121 – Chapter 9 Objectives

I. Overview of MuscleTissue

A. Types

1. Know the characteristics of each muscle tissue type

a. Skeletal

b. Smooth

c. Cardiac

B. FunctionalCharacteristics

1. Describe each functional characteristic

a. excitability and irritability

b. contractility

c. extensibility

d. elasticity

C. Functions

a. Movement

b. Posture

c. Joint stabilization

d. How muscles generate heat

II. SkeletalMuscle

A. GrossAnatomy

1. Nerve and BloodSupply

a. Know that skeletal muscles are controlled by the somatic motor division of CNS

b. Know the function of motor neurons

c. Know how blood reaches the muscle tissue

d. Know that gas exchange and nutrient delivery takes place at the capillary level

e. Know the levels of structure and organization on page 282 (table 9.1)

  • Whole muscle, fascicles
  • Parts of a fascicle
  • Parts of the myofibril
  • Sarcomere and proteins within (structural, regulatory and functional)
  • Actin and myosin
  • sarcolemma

B. ConnectiveTissueSheaths and Attachments

1. Distinguish between the three connective sheaths (endomysium, perimysium and epimysium)

2. The structure and function of tendons

3. Aponeurosis

4. Indirect vs direct attachment

C. MicroscopicAnatomy

1. Function and characteristics of the sarcolemma

2. Characteristics of the Sarcoplasma

3. Distinguish between the following in the sarcomere

  • H zone, m-line, z-disc, A and I bands

4. Characteristics of actin and myosin

`5. Chacteristics of tropomyosin and troponin

6. Characteristics of titin, nebulin, and myomesin

7. Function and location of SR, T-tubules, Triads

D. Physiology of a SkeletalMuscleFiber

1. Neuromuscular Junction

a. Identify the parts of an axon and contents (vesicles with neurotransmitters; axon endings; exocytosis and neurotransmitters; synapse; receptors on the muscle sarcolemma)

b. Know that a nerve transmission causes a vesicle filled with ACh neurotransmitter fuse with the axon membrane and release contents into the synapse.

c. Know the function of ACh

d. Know what occurs when ACh binds to a receptor site on the membrane of the muscle sarcolemma

e. Know how an action potential is produced.

f. Know the role of acetylcholinesterase

2. Generation of an ActionPotential

a. Know how an action potential is produced at the motor end plate (sarcolemma of the muscle fiber)

  • Know the role of sodium and potassium ions in producing an action potential

b. Relate polarization, depolarization and repolarization to the production of an action potential.

  • Know the charge or membrane potential of a polarized or resting membrane

c. Know why a refractory period is important

3. Excitation-ContractionCoupling

a. Know all events that occur during EC coupling

  • T-tubule and action potential
  • Release of Calcium ions from SR
  • Calcium role in cross bridge formation
  • Reuptake of Calcium into the SR

4. MuscleFiberContraction

a. Know the steps of muscle fiber contractions

  • Cross-bridge formation
  • Power Stroke
  • Cross-bridge detachment
  • Cocking of myosin head
  • Role of ATP and ADP
  • Rigor mortis

5. MuscleContraction

6. MotorUnit

a. Know what a muscle unit consists of

b. Number of units in fine and course muscle control

7. MuscleTwitch and GradedResponse

a. Know the function of a myogram

b. Define the parts of a single twitch

  • Latent period; period of contraction; period of relaxation

c. Know what a graded muscle response is

d. Wave summation’

e. unfused and incomplete tetanus

f. fused tetanus

g. recruitment of muscle fibers

h. threshold and maximal stimulus

i. Treppe

9. MuscleTone

a. isotonic vs isometric contractions (characteristics)

10. MuscleMetabolism

a. Production of ATP – Direct phosphorylation of Creatine phosphate

  • CP and ADP
  • Advantages and disadvantages

b. Anaerobic respiration

  • Lactic acid fermentation
  • ATP production (net)
  • Glycolysis
  • Lactic acid production
  • Conversion of lactic acid into pyruvic acid or glucose

c. Aerobic respiration

  • Glycolysis
  • Pyruvic acid
  • Krebs Cycle
  • ETC
  • Other macromolecules that can be used: fatty acids and amino acids
  • Products of aerobic respiration
  • Location
  • Net ATP

11. Force of MuscleContraction

a. Factors that determine the force of a contraction

12. Velocity of Contractions

a. Slow fibers vs fast fibers (characteristics)

b. effects of load and recruitment

III. SmoothMuscle

A. Microscopicstructure

a. lack of connective sheaths

b. size

c. location

d. peristalsis in digestive system

e. varicosities

f. diffuse junctions

g. dense bodies

B. Contraction

a. Role of gap junctions

b. role of caveolae

c. role of calmoudlin

d. kinase

C. Comparison with skeletalmuscle

a. body location

b. cell shape and nuclei

c. connective tissue

d. T Tubules

e. gap junctions

f. regulation of contractions

g. sources of Ca

h. site of calcium regulation

i. speed of contractions

j. rhythmic contractions

k. respiration