Receptors/Fibers/Joints

Question 1

Muscle Spindles

Answer 1

Muscle spindles distributed throughout belly of muscle.

Send info to nervous system about muscle length/rate of change of its length

Important for control of posture with help of gamma system/involuntary movements

Question 2

Golgi Tendon Organ

Answer 2

Sensory receptors - muscle tendons pass immediate beyond attachment to muscle fibers.

Sensitive to tension when produced from an active muscle contraction

Function: transmit info about tension or rate of change of tension w/in muscle

Question 3

Free Nerve Endings

Answer 3

Location: Joint Capsule, ligaments, synovium, fat pads

Sensitivity: One type to non noxious mechanical stress. One type is sensitive to noxious mechanical or biochemical stimulus.

In ALL JOINTs

Question 4

Golgi Ligament Endings

Answer 4

Location: ligaments, adjacent to ligaments bony attachments

Sensitivity: Tension or stretch on ligaments

Majority of joints

Question 5

Golgi Mazzoni Corpuscles

Answer 5

Location: Joint Capsule

Sensitivity: Compression of joint capsule

Distribution: Knee joint, joint capsule

Question 6

Pacinian Corpuscles

Answer 6

Location: Fibrous layer of joint capsule

Sensitivity: high frequency vibration, acceleration and high velocity changes in joint position.

ALL JOINTS

Question 7

Ruffini Endings

Answer 7

Location: Fibrous layer of joint capsule

Sensitivity: Stretching of joint capsule; amplitude and velocity of joint position

Distribution: Greater density in PROXIMAL joints, in capsular regions

Question 8

Type I fibers classification

Answer 8

Aerobic
Red
Tonic
Slow Twitch 
Slow-oxidative

Question 9

Type II fibers classification

Answer 9

Anaerobic
Red/White (IIa red, IIb white)
Phasic
Fast Twitch

Question 10

Type I characteristics

Answer 10

Low fatigue
High capillary density 
High myoglobin content
Smaller fibers
Extensive blood supply 
Large amount of mitochondria 
Ex: Marathon, Swimming

Question 11

Type II characteristics

Answer 11

High fatigue
Low capillary density
Low myoglobin content
Less blood supply
Fewer mitochondria
Ex: high jump, sprinters

Question 12

Types of joints

Answer 12

Fibrous (synarthroses)
Cartilaginous (Amphiarthroes)
Synovial (diarthroses)

Question 13

Fibrous joints

Answer 13

Synarthroses

Suture - immovable joint (Sagittal suture of skull)

Syndesmosis - Very little motion. Bone to bone by dense fibrous cord (tib and fib w/ interosseous membrane)

Gomphosis - 2 bony surfaces connect as peg in hole (Tooth in socket)

Question 14

Cartilaginous Joints

Answer 14

Amphiarthroses

Hyaline cartilage/fibrocartilage that connects one bone to another - slightly moveable

Synchondrosis - HYALINE, Sternum/rib articulation. Provides stability

Symphysis - midline of body. 2 bones connected with hyaline or fibrocartilage (pubic symphysis)

Question 15

Synovial Joints

Answer 15

Diarthorses

Free movement between joints: Joint cavity, articular cartilage, synovial membrane, synovial fluid, fibrous capsule - most vulnerable to injury

Uniaxial - Single axis in one plae motion (hinge/ginglymus - elbow; pivot/trochoid - Atlantoaxial joint)

Biaxial - 2 planes 2 axes of movement (Convex/Concave: Condyloid - metacaropharlageal joint of a finger; saddle - thumb)

Multi-axal joint - Movement occurs in 3 planes and around 3 aces (Plane/gliding: carpal joints; ball and socket - Hip joint