Title: Anatomy / 3 Locomotor System

Q: differentiation
active and passive locomotor system
A: - passive: consist of the skeleton & joints;
- active: consist of the skeletal muscles, tendons (= Sehne) & auxiliary structures (= Hilfsstrukturen)

Q: head bones (subdivision & fontanels)
A: The head is subdivided into 2 main parts:
1. visceral part: Facial skeleton that forms the face and oral/nasal cavities;
2. cerebral part: encloses & protects the brain;
Fontanels: In newborn, these are soft, non-ossified gaps between the cranial bones → allow flexibility during birth

Q: Spine: curvature & parts
A: Parts & numbers
1. Cervical spine: C1-C7 → 7;
2. Thoracic spine: Th1-Th12 → 12;
3. Lumbar spine: L1-L5 → 5;
4. Sacrum: S1-S5 → 5 fused vertebrae;
5. Coccyx (=Steißbein): Tailbone;
Curvatures: provide flexibility, shock absorption and balance;
- cervical & lumbar curvature: Lordosis;
- thoracic & sacral curvature: Kyphosis

Q: Thorax: sternum & ribs
A: Thorax protects the heart and lungs;
Sternum: The breastbone, centrally in the front;
Ribs (Costea): There are 12 pairs of ribs in total:
- True ribs (1-7): directly attached to the sternum;
- Fals ribs (8-10): indirectly attached to the sternum;
- Floating ribs (11-12): which have no anterior attachment.

Q: diarthrosis
vs. synarthrosis
A: Synarthroses (= Knochenverbindung): immovable joints, where bones are connected in a continuous way without a joint cavity;
Diarthroses (Synovial joints) (= Gelenk): These are discontinuous joints characterized by a joint cavity between the bones, allowing for greater mobility.

Q: types
of synathroses with examples
A: Altfragen
- syndesmosis: fibrous joints connected by ligaments (e.g. distal tibiofibular joint);
- synchondrosis: cartilaginous joints connected by hyaline cartilage (e.g. epiphyseal plate, sternum-ribs);
- synostosis: bony fusion where bones completely fuse (e.g. sutures of the skull in adults, epiphyseal line);

Q: diarthrosis: characteristics, movement inhibition, ligaments, classification of
joints (types with examples)
A: Freely movable synovial joints; consisting of:
- joint capsule;
- joint cavity;
- synovial fluid;
- cartilage;
- ligaments;
Movement Inhibition: Movement in these joints can be limited by several factors:
- Ligaments (strengthen the capsule, guide movement and set limit to motion);
- Osseous factors (shape of the bones);
- Muscular factors;
- Soft tissue (surrounding skin or fat);
Classification of Synovial Joints:
- By axis and shape: uniaxial, biaxial, or multiaxial;
- By complexity: simple, compound, or complex;
Types of joints:
- Ball joint: Hip joint, shoulder joint;
- Saddle joint: Thumb saddle joint;
- Hinge joint: Elbow joint;

Q: muscles: definition of origin and insertion
A: - Origin (fixed): The stationary, usually proximal attachment point;
- Insertion (mobile): The moving, usually distal attachment point;
- Auxiliary Respiratory Muscles: Unique because they can switch their fixed and mobile points (e.g., using arm muscles to move the rib cage when the arms are braced).

Q: Synergist / Antagonist
A: - Synergists: Muscles that work together for the same movement. (e.g. biceps brachii & brachialis)
- Antagonists: Muscles that perform the opposite movement. (e.g. biceps- & triceps brachii)

Q: Auxiliary Structures (= Hilfsstrukturen) of the locomoter system
A: - tendon sheaths: protect tendons from friction;
- bursae (=Schleimbeutel): fluid-filled cushions at pressure points;
- sesamoid bones: small bones that improve the muscle's lever arm

Header: Upper extremity bones
Remarks: clavicula

Header: Upper extremity bones
Remarks: scapula

Header: Upper extremity bones
Remarks: shoulder joint

Header: Upper extremity bones
Remarks: humerus

Header: Upper extremity bones
Remarks: elbow

Header: Upper extremity bones
Remarks: radius

Header: Upper extremity bones
Remarks: ulnar

Header: Upper extremity bones
Remarks: wrist

Header: Upper extremity bones
Remarks: 8x carpals

Header: Upper extremity bones
Remarks: 5x metacarpals

Header: Upper extremity bones
Remarks: 5x phalanges with 4x3 + 1x2

Header: Lower extremity bones
Remarks: pelvis

Header: Lower extremity bones
Remarks: hip joint

Header: Lower extremity bones
Remarks: hip bone

Header: Lower extremity bones
Remarks: femur

Header: Lower extremity bones
Remarks: knee joint

Header: Lower extremity bones
Remarks: patella

Header: Lower extremity bones
Remarks: fibula

Header: Lower extremity bones
Remarks: tibia

Header: Lower extremity bones
Remarks: ankle joint

Header: Lower extremity bones
Remarks: 7x tarsals

Header: Lower extremity bones
Remarks: 5x metatarsals

Header: Lower extremity bones
Remarks: 5x phalanges with 4x3 + 1x2