Study Guide - Chapters 8 & 9

Question 1

What are the functional classifications of articulations?

Answer 1

The functional classifications of articulations are:
* Synarthroses (immovable joints)
* Amphiarthroses (slightly movable joints)
* Diarthroses (freely movable joints)

Examples include sutures (synarthroses), pubic symphysis (amphiarthroses), and shoulder joint (diarthroses).

Question 2

What are the structural classifications of articulations?

Answer 2

The structural classifications of articulations are:
* Fibrous joints
* Cartilaginous joints
* Synovial joints

Examples include syndesmoses (fibrous), synchondroses (cartilaginous), and knee joint (synovial).

Question 3

What is the function/location of articular cartilage?

Answer 3

Articular cartilage provides a smooth, lubricated surface for joint movement and is located at the ends of bones in synovial joints.

Question 4

What is the function/location of synovial membrane and fluid?

Answer 4

The synovial membrane secretes synovial fluid, which lubricates the joint and nourishes the cartilage; it is located inside the joint capsule.

Question 5

What is the function/location of bursae?

Answer 5

Bursae reduce friction between moving structures in joints; they are located around joints, especially where tendons and ligaments pass.

Question 6

What is the function/location of menisci?

Answer 6

Menisci absorb shock and stabilize the joint; they are located between the femur and tibia in the knee joint.

Question 7

What is the function/location of tendons?

Answer 7

Tendons connect muscles to bones and are located at the ends of muscles where they attach to the bone.

Question 8

What is the function/location of ligaments?

Answer 8

Ligaments connect bones to other bones at joints and are located within or around the joint capsule.

Question 9

What is the function/location of joint cavity?

Answer 9

The joint cavity contains synovial fluid and allows for movement in synovial joints; it is located between the articulating bones.

Question 10

List the major characteristics of synovial joints.

Answer 10

The major characteristics of synovial joints include:
* Articular cartilage
* Joint cavity
* Synovial membrane
* Synovial fluid
* Ligaments
* Bursae

These features contribute to the mobility and stability of the joints.

Question 11

What factors contribute to stability in joints?

Answer 11

Factors contributing to joint stability include:
* Shape of the articulating surfaces
* Ligament strength and number
* Muscle tone and activity

Stronger ligaments and more muscle tone enhance stability.

Question 12

List the 6 types of synovial joints.

Answer 12

The 6 types of synovial joints are:
* Hinge
* Pivot
* Ball-and-socket
* Saddle
* Condyloid
* Plane

Each type allows different ranges of movement.

Question 13

Describe the types of movements at hinge joints.

Answer 13

Hinge joints allow flexion and extension.

Example: Elbow joint.

Question 14

Describe the types of movements at pivot joints.

Answer 14

Pivot joints allow rotational movement.

Example: Atlantoaxial joint.

Question 15

Describe the types of movements at ball-and-socket joints.

Answer 15

Ball-and-socket joints allow multi-axial movement including flexion, extension, abduction, adduction, and rotation.

Example: Shoulder joint.

Question 16

Describe the types of movements at saddle joints.

Answer 16

Saddle joints allow movement in two planes, including flexion, extension, abduction, and adduction.

Example: Carpometacarpal joint of the thumb.

Question 17

Describe the types of movements at condyloid joints.

Answer 17

Condyloid joints allow flexion, extension, abduction, and adduction.

Example: Metacarpophalangeal joints.

Question 18

Describe the types of movements at plane joints.

Answer 18

Plane joints allow sliding or gliding movements.

Example: Intercarpal joints.

Question 19

What are the functions of muscular tissue?

Answer 19

The functions of muscular tissue include:
* Movement of the body
* Maintaining posture
* Producing heat

These functions are essential for daily activities and overall body function.

Question 20

What are the 3 connective tissue sheaths?

Answer 20

The 3 connective tissue sheaths are:
* Epimysium (surrounds the entire muscle)
* Perimysium (surrounds fascicles)
* Endomysium (surrounds individual muscle fibers)

Each sheath plays a role in muscle structure and function.

Question 21

What is the significance/role of sarcoplasm?

Answer 21

Sarcoplasm is the cytoplasm of muscle fibers and contains organelles, myofibrils, and nutrients essential for muscle function.

Question 22

What is the significance/role of sarcolemma?

Answer 22

Sarcolemma is the plasma membrane of muscle fibers that regulates the entry and exit of substances and propagates action potentials.

Question 23

What is the significance/role of sarcoplasmic reticulum?

Answer 23

Sarcoplasmic reticulum stores calcium ions and releases them during muscle contraction to trigger the contraction process.

Question 24

What are the parts of a sarcomere?

Answer 24

The parts of a sarcomere include:
* Z-discs
* A-band
* I-band
* H-zone
* M-line

These components are crucial for muscle contraction.

Question 25

What makes up the thin filament?

Answer 25

The thin filament is primarily made of actin, along with troponin and tropomyosin proteins. ## Footnote Troponin and tropomyosin regulate muscle contraction.

Question 26

Describe the thick filament.

Answer 26

The thick filament is primarily made of myosin and contains heads that interact with actin during muscle contraction.

Question 27

Describe the steps involved in cross-bridge cycling.

Answer 27

The steps involved in cross-bridge cycling include: * Myosin head attaches to actin * Power stroke occurs * ATP binds to myosin * Myosin head detaches from actin * Hydrolysis of ATP re-cocks the myosin head ## Footnote This process is essential for muscle contraction.

Question 28

What is the role of Ca+2 in muscle tissue?

Answer 28

Ca+2 binds to troponin, causing tropomyosin to shift and expose binding sites on actin, allowing contraction to occur.

Question 29

What is the role of ATP in muscle tissue?

Answer 29

ATP provides energy for muscle contractions, allowing myosin heads to detach and re-cock during cross-bridge cycling.

Question 30

Trace the major steps involved in muscle contraction from the action potential arriving at the axon terminal to cross-bridge cycling.

Answer 30

The major steps include: * Action potential reaches axon terminal * Release of acetylcholine * Muscle action potential generated * Ca+2 released from sarcoplasmic reticulum * Cross-bridge cycling occurs ## Footnote This sequence is essential for muscle contraction.

Question 31

What is excitation-contraction coupling?

Answer 31

Excitation-contraction coupling is the process by which an action potential triggers muscle contraction through the release of Ca+2.

Question 32

Define motor unit in muscle.

Answer 32

A motor unit is defined as a motor neuron and all the muscle fibers it innervates.

Question 33

Describe the 3 phases of a muscle twitch.

Answer 33

The 3 phases of a muscle twitch are: * Latent period * Contraction phase * Relaxation phase ## Footnote Each phase represents a different stage of muscle response.

Question 34

What is spatial and temporal summation?

Answer 34

Spatial summation involves the recruitment of multiple motor units, while temporal summation involves increased frequency of stimulation of a single motor unit.

Question 35

What does spatial summation look like?

Answer 35

Spatial summation appears as a stronger muscle contraction due to the recruitment of additional motor units.

Question 36

How does recruitment of motor units affect strength?

Answer 36

Recruitment of motor units increases the strength of contraction by activating more muscle fibers.

Question 37

What are the differences between Type I and Type II muscle fibers?

Answer 37

Type I fibers are slow-twitch, fatigue-resistant, and used for endurance activities; Type II fibers are fast-twitch, fatigue-prone, and used for short bursts of strength.

Question 38

Define agonist, antagonist, and synergist in the context of muscle movement.

Answer 38

Agonist is the primary muscle that produces a movement, antagonist opposes the movement, and synergist assists the agonist.

Question 39

How do you distinguish an isometric contraction from an isotonic contraction?

Answer 39

Isometric contraction generates tension without changing muscle length, while isotonic contraction involves muscle shortening or lengthening.

Question 40

What is the difference between eccentric and concentric contraction?

Answer 40

Eccentric contraction occurs when the muscle lengthens under tension, while concentric contraction occurs when the muscle shortens under tension. ## Footnote Example: Lowering a weight (eccentric) vs lifting a weight (concentric).