SKELETAL SYSTEM Flashcards
What does the skeleton provide?
Protection of internal organs
The site of blood cell production
Mineral store
Skeleton
What does it provide attachments for?
What does it act as?
Provides attachments for the muscular system.
It acts as the levers and pivot points to create movement.
Give examples of flat bones.
What do they do?
Sternum, ribs, cranium and pelvis.
Protect internal organs but also act as suitable sites for muscular attachment.
Give examples of long bones.
What do they act as?
Femur, humerus, radius, tubes and phalanges.
Acts as leavers for movement and act as sites for blood cell production
Give examples of irregular bones.
What does it protect?
The vertebrae.
Protects the spinal cord.
Give examples of short bones.
What do they do well?
Carpals and tarsals
Bear weight well
Give an example of a sesamoid bone.
What do does it do?
The patella
Which ease joint movement and resist compression.
Name the Axial skeleton bones.
There are 4
Sternum
Rib cage
Vertebral column
Cranium
Name the Appendicular skeletal bones.
There are 10
Pelvic girdle
Scapula
Humerus
Uina
Radius
Carpals
Femur
Tibia
Fibula
Talus
What is the definition of a joint?
An area of the body where two or more bones articulate to create human movement
What is the definition of a ligament?
A tough band of fibrous, slightly elastic connective tissue that attaches bones to bone
What is the definition of articular cartilage?
Smooth tissue which covers the surface of articulating bones to absorb shock and allow friction-free movement
What are the 5 common features of a synovial joint?
The structure of them?
The function of them?
Ligament - A tough band of slightly elastic connective tissue- connects bone to bone and stabilises joints during movement.
Synovial fluid- Lubricating liquid contained within the joint cavity- reduces friction and nourishes articular cartilage
Articular cartilage- Smooth tissue which covers the surface of articulating bones- absorbs shock and allows friction free movement
Joint capsule - A fibrous sac with an inner synovial membrane- encloses and strengthens the joint secreting synovial fluid
Bursa - A closed, fluid filled sac found where tenons rub over bones- reduces friction between tendons and bones
What is the definition of Plane of movement?
The description of three dimensional movements at a joint.
Movement patterns?
A description of the actions taking place at a joint- for example flexion and extension
What is flexion?
Movement which decreases the joint angle, usually to the front of the body.
Identify the two different parts that make up the skeleton.
Axial and appendicular
What is extension?
Movement which increases the joint angle, usually to the back of the body.
What is dorsiflexion?
Movement at the ankle joint as the tones move up.
What is Plantar flexion?
Movement at the ankle joint as the toes move down.
What are the two bones connected with the head/ neck joint? (2)
Cranium
Vertebral column
Shoulder joint bones? (2)
Scapula
Humerus
Chest region bones? (2)
Ribs
Sternum
Elbow region bones? (3)
Humerus
Radius
Ulna
Hip joint bones? (2)
Femur
Pelvis
Knee joint bones? (3)
Femur
Patella
Tibia
Ankle joint bones? (3)
Fibula
Tibia
Talus
The skeleton is divided into two parts, what are they called?
The axial skeleton
The appendicular skeleton
Axial skeleton (3)
Skull
Thoracic girdle
Vertebral column
Appendicular skeleton?
Shoulder girdle and upper limbs
Pelvic girdle and lower limbs
What are the 4 types of joints that help prevent injuries?
Cartilage - prevents ends of bones rubbing together
Synovial fluid- lubricates the joints allowing the parts to move feely
Ligaments - these retough, elastic fibres that link bones to bones
Tendons- these connect muscle to bones
What is a ball and socket joint?
An example.
Ball and socket joints allow movement in all directions and is the most mobile joints in the body.
Examples: Shoulders and hips - tennis serve
What is a hinge joint?
An example.
Hinge joints - only allow forwards and backwards movement like the hinge on a door.
Examples: knee and elbow - knee drive during 100m sprint
What is a pivot joint?
An example.
Pivot joints have a ring of bone that fits over a bone sticking out. Pivot joints allow rotation only.
Examples found in the body: The joint between the atlas and axis in the neck which allows turning and nodding of head - breathing during a swimming stroke
What is a gliding joint?
An example.
Gliding joints occur between the surfaces of two flat bones that are held together by ligaments.
Examples found in the body: The bones in your wrists and ankles as well as the spine-a kicking or catching action or a boxing slip
What is a fibrous joint?
Joints that are fused together and do not move (Immovable joints).
Found in the cranium,
Cartilaginous joints
The two bones are attached together with cartilage. Little movement can occur at these joints (slightly movable joints).
Found in the vertebrae.
Synovial joints
The most common joints in the body and have a lubricating liquid inside which aids these highly movable joints (freely movable joints).
Found in the elbows, shoulders, knees, etc.
Frontal plane
The frontal plane cuts vertically through the body.
It splits the body into the anterior and posterior.
Sagittal plane
The sagittal plane also cuts the body vertically.
It splits the body into left and right from the midline.
Transverse plane
he transverse plane cuts the body horizontally.
It splits the body into the superior and inferior.
Skeletal movements FRONTAL PLANE
Adduction
Abduction
Skeletal movements SAGITTAL PLANE
Flexion Extension Dorsi-flexion Hyper-extension Plantar-flexion
Skeletal movements TRANSVERSE PLANE
Horizontal extension Horizontal flexion Rotation Medial Rotation Lateral Rotation
What is an agonistic pair?
Muscles are arranged in antagonistic pairs. As one muscle contracts (shortens) the other relaxes (lengthens).
What is an agonist?
Agonist – the contracting muscle responsible for causing movement.
What is an antagonist?
Antagonist – relaxing + lengthening muscle which allows the movement. (The muscle that works in opposition to the agonist)
What are isometric contractions?
Example?
Isometric contractions – These are muscle contractions that DO NOT create movement.
Isometric contraction is when the muscle contracts
without lengthening or shortening. The result is that no movement occurs.
To hold the body in a
particular position (e.g.
scrum).
What is an isometric contraction?
Isometric contractions happen when a movement is still/stationary or held.
What is an isotonic contraction?
Isotonic contractions – A muscular contraction which changes the length of the muscle.
What is a concentric contraction?
Concentric contractions – Concentric contraction is when the muscle shortens under tension.
What is an eccentric contraction?
Eccentric contractions – Eccentric contraction is when the muscle lengthens under tension (and does not relax).
When a muscle contracts eccentrically, it acts as a brake to help control the movement of the body part during negative work.
e.g. when landing from a standing jump quadriceps muscles are contracting eccentrically.
What is adduction?
Adduction - Movement towards midline of the body
What is abduction?
Abduction - Movement away from midline of the body
What is horizontal flexion?
Movement of the arm across the body in the horizontal (transverse) plane.
What is horizontal extension?
Movement of the arm away from the body in the horizontal (transverse) plane
Examples of articulating bones in action= Types of joint= Movement= Agonist= Antagonist= Contraction=
Articulating bones = Humerus/Ulna/Radius
Type of Joint = Hinge Joint.
Movement = Extension
Agonist = Triceps Brachii Antagonist = Biceps Brachii Contraction = Concentric
What is the shoulder joint?
What does the structure allow?
The shoulder is a ball and socket joint where the head of the humerus fits into a cavity on the scapula.
Its structure also makes it one of the least stable joints, so it is heavily reliant on ligaments and muscles to increase its stability.
The following muscles listed are the agonists responsible for the movement pattern for the shoulder joint.
Can you name all 4?
Flexion = Anterior deltoid
Extension = Posterior deltoid
Adduction =Latissimus dorsi
Abduction = Middle deltoid
What joint is the elbow joint?
What bones does it articulate?
The elbow is a hinge joint, with the distal (far) end of the humerus articulating with the proximal (near) end of the radius and ulna.
What plane is the elbow joint?
Sagittal plane
What joint is the wrist joint?
The wrist is a condyloid joint, with the radius, ulna and carpals making up the joint.
What joint is the hip joint?
The hip is a ball-and-socket joint where the head of the femur fits into the pelvic girdle.
Flexion at the hip joint is created by what?
Action created by the Iliopsoas.
Extension at the hip joint is created by what?
Gluteus Maximus
Flexion at the wrist joint is created by what?
Wrist Flexors
Extension at the wrist joint is created by what?
Wrist extensors
Flexion at the elbow joint is created by what?
Bicep brachii
Extension at the elbow joint is created by what?
Tricep brachii
The hip joints adductors are?
Adductor longus
Adductor Brevis
Adductor Magnus
The hip joints abductors are?
Gluteus Maximus
Gluteus Minimus
Gluteus Medius
What joint is the knee joint?
The knee is classed as a hinge joint and allows flexion and extension only.
Describe flexion at the knee joint.
During the preparation for the action (backlift) the biceps femoris, semitendinosus and semimembranosus concentrically contract.
Describe extension at the knee joint.
The downward kicking action involves the contraction of the rectus femoris, vastus lateralis, vastus intermedius and vastus medialis.
What joint is the ankle joint?
The ankle is a hinge joint where the articulating bones are the tibia and fibula. The main muscles that control movement in this joint are the gastrocnemius, soleus and the tibialis anterior.
These muscles allow plantarflexion and dorsiflexion movement.
What movements is the hinge joints responsible for?
The hinge joint is responsible for these movements.
Flexion and extension of the wrist, elbow, shoulder and knee.
Dorsiflexion and plantar flexion at the ankle.
What movements are the frontal plane responsible for?
The frontal plane is also a vertical plane but this divides the body into front and back.
Adduction and abduction move articulating bones away or closer to the midline of the body.
What movements are the transverse plane responsible for?
The transverse plane is a horizontal plane that divides the body into upper and lower halves.
Horizontal flexion and horizontal extension occur with the limb is parallel to the ground and the arm or leg moves away or closer to the midline of then body.
What is the motor unit?
Muscle contractions occur when an electrical impulse travels down the spinal cord, along motor neurones to the muscle fibres.
The cell body processes the
information and sends an impulse down the axon. The motor neuron and its muscle fibres are called a motor unit.
How does the motor unit work?
The motor unit must carry nerve impulses from the brain and spinal cord to the muscle fibres.
The nerve impulse travelling to the muscle fibre is an electrochemical process which requires action potential. This wave of electrical charge moves down the axon to the motor end plate.
What happens when the impulse reaches the end of the axon?
As the impulse reaches the end of the axon, it triggers the release of acetylcholine (a neurotransmitter) at the neuromuscular junction.
This neurotransmitter is secreted into the synaptic cleft to assist the never impulse to cross the gap.
If enough neurotransmitter is present muscle action potential is created and a wave of contraction occurs.
Can one motor neuron stimulate a whole muscle?
No. One motor neurone cannot stimulate the whole muscle.
Instead, a motor neurone will stimulate a number of fibres within that muscle.
What is the all or none law?
The motor units exhibit an all-or-none response
Characteristics of a Motor Unit
A minimum amount of stimulation is required to start a muscle contraction.
If an impulse is strong enough then all the muscle fibres in a motor unit will contract.
However, if the impulse is less than the threshold required then no muscle action will occur.
What are the three main muscle fibres?
Type 1 (slow oxidative or SO) Type 2a (fast oxidative glycolytic or FOG) Type 2b (or 2x) (fast glycolytic or FG)
The relationship between muscle fibre type and force production are?
Small motor neurons stimulate a small number of fibres and creates slow amount of force but for a sustained period. Larger neurons produce high force but fatigue rapidly.
How quickly do SO muscle fibres recover?
Slow oxidative muscle fibres are recruited and recover very quickly, within 90 seconds.
Aerobic training should therefore have limited rest periods.
i.e. 3 x 800m set with 90 seconds rest.
