Chapter 8 - musculoskeletal system Flashcards
Contractile proteins
- refers to
- size
- example
Refers to myofilament proteins within muscle cells that are responsible for muscle contraction. They never get smaller they just change how over lapped they are which contracts the myofibril.
Myosin and Actin
Agonist
Muscle that causes the desired action. Referred to as the prime mover.
Antagonist - example
Muscle that has an action opposite to the prime mover. Antagonist to the triceps is the biceps
Antagonist pair
Muscles are always grouped in pairs called antagonists as they have opposite actions to enable them to produce coordinated and controlled movements around joints.
Belly
Fleshy portion in the middle of a muscle
Cardiac muscle
- function
Muscle that forms the wall of the heart. Heart beating that pumps the blood in the heart
Connective tissue
Tissue that provides support for body organs
Characteristics of skeletal muscle
Excitable – stimulated to do something through nerve impulses
Contractible – able to shorten to generate force
Extensible – can be stretched out of shape without damage
Elastic – after stretched out of shape it will return to original length
Fixator
Type of synergist. It is a Muscle that contracts to immobilize a joint
Flexion
Movement that decreases the angle between articulating bones.
Insertion
End of a muscle fixed to a movable bone
Involuntary muscle
Not under conscious control
Joint
Connection between two bones
Ligament
Fibrous tissue that attaches one bone to another
Muscle tone
- maintains posture
Maintaining partial contraction of skeletal muscles. At any time some muscle fibres are contracted while others are relaxed. Fibres take turns to contract which means the contractions can be kept up for long periods of time. Posture is maintained by the muscle tone in the back and neck.
Myofibril
- made up of
- striations
- allows
Long cylindrical structures made up of repeating units called sarcomeres. The arrangement of thick and thin myofilaments gives myofibrils stations with allows it to be divided into sarcomeres
Myofilament
- referred to as
- size
Referred to as the contractile proteins within muscle cells- Threads of protein that are the actual units involved in the contraction of muscles
They never get smaller they just change how overlapped they are.
Origin
End of a muscle that is fixed to the stationary bone
Posture
Way a person holds their body when sitting or standing
Sarcolemma
Cell membrane of muscle cells
Sarcomere
- responsible for
- bounded by
Responsible for the contraction and relaxation of muscles. Shorted in muscle contractions from the overlap of thick and thin filaments sliding past one another. Bounded by Z lines.
Sarcoplasm
Cytoplasm of muscle fibres
Skeletal muscle
- function
To attach to the bones in the skeleton through tendons to provide movement
Sliding filament therory
Theory that explains muscle contractions. When muscles contract the sarcomeres shorten as the actin and myosin filaments slide over one another. The sarcomeres length corresponds to the relaxed position, semi contracted or maximally contracted.
Smooth muscle
- function
Not under conscious control, found in the walls of internal organs.
- to move the organs to perform function like churning of the stomach
Synergist
Assist action of the agonist by STABILISING a joint in a particular movement OR producing the same movement as the agonist.
Tendon
Fibrous tissue that attached muscle to bone
Extension
Lengthening of a muscle
Role of connective tissue in muscles
The bundles of muscle fibres are surrounded by various types of connective tissue that provide support. At the end of the muscle, the connective tissue layers merge to form dense fibrous band called tendon.
Muscle bundles
Make up the muscle. Bundles of muscle fibres.
Cross bridges
Structures formed by the heads of the myosin filaments interacting with the actin filaments to bind and pull along during muscle contraction
Z lines
Structural proteins that separate sarcomeres within a myofibril
H zone
Region where there is no overlap of myofilaments. Central zone in A band where there is just myosin
A band
Length of myosin filament. A band length does not change as the length of myofilaments dont change. Makes up dark band.
I band
Distance between successive thick filaments which contains only actin. Light bands. In shortening of the sarcomere the band size decreases.
Myofibril
Long cylindrical structures within the sarcoplasm of each muscle fibre. Arrangement of thick and thin myofilaments within myofibrils gives myofibrils striations, which allows it to be divided up into its repeating units called sarcomeres
Thick myofilament
Myosin
Thin myofilament
Actin
Abduction
Movement of a limb away from midline of the body
Adduction
Movement of a limb towards the midline of the body
Appendicular skeleton
Made up of bones of upper and lower libs and shoulder and pelvis
Articular cartilage
Covers the surfaces of bones at a joint
Articular capsule
Envelope in cavity of synovial joint - made of fibrous capsule and synovial membrane.
Articular disc
Also called meniscus. Purpose is shock absorption, lubrication from distributing synovial fluid, improves fit between articulating bones
Articulation
Connection of bones at a joint.
Axial skeleton
Part of skeleton that forms the central axis of the body. Skull, vertebral column, ribs and sternum
Ball and socket joint
Spherical bone fitting into cup like cavity of another bone. head of humerus fits into the scalpa
Bursa
Little sacs of synovial fluid found in friction points of a movable joint
Canaliculi
Canals in the matrix of compact bone, that run between the lacunae, projections from bone cells enter the chanel and make contact with adjacent bone cells to allow material to be passed between cells.
Cancellous bone
Bone contains many large spaces - appears spongy. Arrangement of trabeculae (thin bony plates)
Chondrocytes
Mature cartilage cell
Chondroblast
Forms the fibres and matrix of cartilage called chondrin
Cartilage
Type of connective tissue - contains fibres of collagen
Chondrin
Matrix in cartilage which collagen fibres are embedded.
Osteoarthritis
Deterioration of joint cartilage due to age or injury. Point where bone surfaces are not protected.
Cartilaginous joint
Slightly moveable joint. Held in place by cartilage.
Joints between vertebrae
Central canal
Central channel in an osteon of compact bone. Called Haversian canal. Occupied by nerves and blood vessles.
Compact bone
Dense hard bone found in outer layer of most bones
Fibrous capsule
External layer of an articular capsule
Condyloid joint
Called elipsoid joint. One surface of bone is slightly convex and fits into slightly concave depression in another bone. Metacarpals and phalanges.
Epiphysis
End of a long bone
Contraction
Shortening of a muscle
Fibrous cartilage
Contains parallel bundles of thick collagenous fibres. Forms pads of the body. Meniscus of knee joint, intervertebral disks in the spinal column.
Hyaline cartilage
rings trachea and bronchi
Fibrous joint
immovable joint . Bones held together by fibrous tissue. Suture joints between the bones in the skull
Extension
Lengthening of a muscle
Diaphysis
Shaft of a long bone, hollow shape surrounds medullary cavity (storage for yellow bone marrow)
Elastic cartilage
network of elastic fibres along with collagen fibres. Highly flexible. Ear, epiglottis
Gliding joint
Plane joint of two mostly flat bones. Glide past one another. Carpal bones
Functional classification of the different types of synovial joints
Based on its range of motion
Hinge joint
Movement in one plane only (flexion and extension). Head of one bone wraps around cylindrical head of another. Ulna and humerous
Meniscus
Cartilage disk found in the knee joint, divides the cavity into two parts
Osteon
Also called Haversian system. Unit of structure of compact bone. Central canal surrounded by concentric layers of hard matrix and bone cells.
Lacunae
Space in the matrix of bone occupied by a cell
Matrix
non cellular material between cells of a tissue
Osteocyte
Mature bone cell
Lamellae
Concentric rings that make up compact bone
Osteoporosis
Reduced bone density due to ageing results in increased risk of fractures.
Red bone marrow
Found in pores of cancellous bone, blood cell production takes place.
Periosteum
Dense fibrous outer layer covering of a bone. Attachment point for tendons and ligaments
Pivot joint
Allows rotation. Between radium and ulna
Perichondrium
Membrane that covers some types of cartilage
Rotation
Movement of a bone around its long axis
Saddle joint
Joint where thumb is attached to the palm.
Structural classification of joints
Based on the type of connective tissue holding the joint together
Synovial cavity
Space between articulating bones in a synovial joint.
Synovial fluid
Fluid that fills the cavity of a synovial joint.
Synovial joint
Freely moveable joint. Limited by ligaments, muscles, tendons and adjoining bones.
Synovial membrane
Inner layer of a capsule around a synovial joint.
Trabeculae
Bony plates that criss-cross to make up cancellous bone.
Yellow bone marrow
Region of a bone where fat is stored
sarcoplasmic reticulum
surrounds myofibrils where calcium ions are stored which are released during muscle contractions
articulating bones
bones that connect at a joint and move relative to one another
skeleton function
- scaffold to support the weight of the rest of the body
- facilitates movement from being points of attachment for muscles (when muscles contract, bones allow movement to take place)
- protects vital organs (heart and lungs are protected by the rib cage)
irregular bone
complex shape
long bone
tubular in shape, long, 2 ends that articulate with other bones. FEMUR
Irregular bone
complex shape VERTEBRAE
short bone
cube like shape TARSALS
sesamoid bone
unique shape lies within tendons PATELLA
flat bone
flat and thin and protects internal organs STERNUM
girdle
attachment point for limbs to the axial skeleton, facilitates movement of the limbs. Shoulder and pelvic girdles are made up of a group of bones.
connective tissue holding fibrous joint togrther
fibrous connective tissue
connective tissue holding synovial joint together
ligaments
connective tissue holding cartilagenous joint together
cartilage
Osteoporosis treatment
excersise to stimulate bone formation, increase calcium intake which is an element needed in bone formation, vitamin D
osteoarthritis treatmement
no cure, joint replacement surgery
osteoarthritis prevention
regular low impact excersise maintains cartilage health, strengthens supporting muscles which helps to stabilize and protect joints from injury and wear.
