Immovable joints, allow little or no movement between bones
Def of cartilagenous joint
Slightly movable joints
Def of synovial joint
Freely movable joint. Contain a synovial (joint) cavity.
What are the three types of fibrous/synarthrotic joints?
What are the two types of cartilagenous/amphiarthrotic joints?
What are the six types of synovial/diarthrotic joints?
Def of suture joint:
Type of fibrous joint. Bones held together by very short dense fibrous connective tissue fibers that penetrate into bones. Ossification occurs in adulthood, so become syntoses.
Def of syndesmosis joint:
Type of fibrous joint. Bones held together by a short ligament or sheet-like interosseous membrane.
Example of suture joint:
Fibrous joint, joint between cranial bones.
Example of syndesmosis joint:
Type of fibrous joint. Joint at distal end of tibia and fibula, and between radius and ulna.
Def of gomphosis:
Type of fibrous joint. Tooth anchored in socket by the periodontal ligament.
Def of symphysis joint
Type of cartilagenous joint. Broad, flat disc of fibrocartilage connected two bones.
Example of symphysis joint
Found between two pubic bones (pubic symphysis) and vertebral bodies (intervertebral disks)
Def of synchondrosis joint
Type of cartilagenous joint. Two bones united by a bridge or plate of hyaline cartilage.
Examples of synchondrosis joints
Between ribs and sternum (costal cartilage), and epiphyseal plates of long bones.
Def of plane/gliding joint
Type of synovial joint. Articular surfaces of bones are flat or slightly curved. Allows movement in one or two planes (back and forth or side to side).
Examples of plane/gliding joints:
Intercarpal and intertarsal joints, sternum and clavicle joint, scapula and clavicle joint, superior and inferior articular facets of vertebrae.
Def of hinge joints:
Type of synovial joint. A rounded or convext process of one bone fits into a concave surface or groove of another bone to allow movement in one plane, usually flexion and extension.
Example of hinge joints:
Elbow and knee joints
Def of pivot joints:
Type of synovial joint. Rounded or conical surface of one bone articulates with a shallow depression or foramen of another bone to allow movement in just one plane.
Examples of pivot joints
Atlas and axis
Radius and ulna
Def of ellipsoidal/condyloid joints
Type of synovial joint. Oval condyle of one bone fits into ellipsoidal depression in another bone. Allows bi-axial (two-way) movement (side to side and back and forth).
Examples of condyloid/ellipsoidal joints:
Radius and carpals (wrist)
Metacarpals and phalanges (knuckles)
Occipital condyles and atlas
Def of saddle joint:
Type of synovial joint. Articulating surface of one bone is concave (saddle-shaped) and the reciprocal surface of the other bone is convex. Allows side to side and back and forth movement.
Example of saddle joint:
Metacarpal of thumb and trapezium
Def of ball-and-socket joints:
Type of synovial joint. Ball-shaped head of one bone fits into cup-like depression of another bone. Allows multi-axial movement (in all directions).
Examples of ball-and-socket joints:
Six important features of synovial joints:
Def of joint/articular capsule:
Encloses the joint/synovial cavity. Consists of 2 layers: fibrous capsule and synovial membrane.
Two layers of joint/articular capsule
Def fibrous capsule:
Part of synovial joint. Layer of joint capsule. Outermost layer composed of dense, fibrous connection tissue. Encloses joint surfaces. Continuous with periosteum. May be reinforced by ligaments.
Def synovial membrane:
Part of synovial joint. Layer of joint capsule. Innermost layer, lies interior of joint capsule, except for articular surfaces. Comprised of loose connective tissue and produces synovial fluid.
Def synovial fluid:
Produced by synovial membrane in synovial joints. Acts as lubricant to reduce friction, provide nourishment, and contains phagocytic cells to remove microbes and debris.
Def joint/synovial cavity:
Fluid-filled cavity between articulating bones.
Def articular cartilage:
Contained in synovial joints. Composed of hyaline cartilage which covers articulating surfaces of bones forming the joint.
Some synovial joints. Fluid-filled sacs that cushion and reduce friction in areas where tendons, ligaments, or muscles cross bone. Walls of bursae composed of dense connective tissue and lined by synovial membrane.
Some synovial joints. Both intrinsic and extrinsic. May be present to reinforce the fibrous capsule.
Four properties of muscle:
Def exitability of muscle
The ability to receive and respond to a stimulus
Def contractility of muscle
Ability to shorten
Def extensibility of muscle
The ability to be stretched
Def elasticity of muscle
The ability to return to the original length after contraction or extension
Four functions of muscle
Def muscle movement
Skeletal muscle contractions pull on tendons which then pull on bones
Def muscle maintain posture
Due to constant contraction of opposing pairs of muscles
Def muscle stabilizing joint
The tendons of many muscles extend over joints and contribute to their stability
Def muscle heat production
Muscle contraction generate heat and helps maintain body temperature. Approximately 85% of the heat produced by the body is from muscle contraction.
Connective tissue sheath surrounding muscle fiber, outside of sarcolemma
cell membrace of muscle cell, surrounds muscle fiber and is covered by endomysium
As muscles are exercised, hypertrophy occurs. This is due to the increase in number of _____ and not the number of ________.
Types of myofilaments
Type of thick filament in muscle
Def Sarcoplasmic reticulum
specialized ER of skeletal and cardiac muscles consisting of lacy, sleeve-like network of tubules that surrounds each myofibril
specialized structure called triad is located at Z-discs. Each triad consists of t-tubule flanked by terminal cisternae on each side
t-tubule is invagination of sarcolemma
Fxn sarcoplasmic reticulum
Stores and, on demand, releases Ca+ ions. Ca+ ions control muscle reactions. It knows when to release when nerves send electricity down t-tubule as nerve impulse
Ach function in muscles
After release from the synaptic head via synaptic vesicles,Ach triggers depolarization of the sarcolemma when it binds to the receptors of the sarcolemma
Sliding Filament Mechanism Steps (12):
1) Ca+ ions are released from the SR
2) Ca+ binds to troponin
3) Troponin changes shape
4) Tropomyosin is moved into the groove between 2 actin strands, exposing the binding sites on actin
5) Myosin heads bind to the binding sites on actin = cross bridge attachment
6) Myosin heads change shape - from its high energy (upright) configuration to its low energy (bent) configuration. When the myosin head bends toward the center of the sarcomere, the attached thin filament also moves toward the center.
7) At the same time ADP + Pi from the previous cycle are released from the myosin head.
8) A new ATP immediately binds to the myosin head.
9) The binding of the ATP to the myosin head causes it to release the binding site on actin (cross bridge detachment).
10) ATP is hydrolyzed into ADP + Pi by myosin head ATPase enzyme.
11) Energy from ATP hydrolysis causes myosin head to become "cocked" in the high energy configuration once again.
12) The myosin head is now ready for a new cycle to begin again.
Muscle Fiber Characteristics
Def motor unit
Motor neuron + muscle fibers it innervates
Isometric twitch graph
How smooth muscle different from striated in organization:
Smooth muscle contraction is involuntary.
Smooth muscle lacks striations due to different proportion and organization of myofilaments
Ratio of thick to thin is 1:13 instead of 1:2 in striated
No sarcomeres, no interdigitating thick and thin filaments. Instead, small parallel group of thick and thin groups are arranged in spiral configuration
Contain intermediate filaments attached to dense bodies
Thin filaments are attached to dense bands, which are analagous to the Z discs of striated muscle
How smooth muscle is same as striated in contraction:
Actin and myosin interact by sliding filament mechanism