Anatomy and Physiology

• Anatomy is the study of the body's structure and the relationship between its parts.
• Physiology is the study of how the body functions and the processes within it.

The Musculoskeletal System

• The skeletal system provides structure and support.
• It protects vital organs.
• It works with muscles to enable movement.
• The muscular system enables body movement and supports posture.

Anatomical Position

• Anatomical position is the standard reference for describing the location of body parts.
• In this position, the body is upright, facing forward, with arms at the sides and palms facing forward, and feet slightly apart or together.

Body Planes

• The sagittal plane divides the body into right and left halves.
• The frontal plane divides the body into anterior (front) and posterior (back) sections.
• The transverse plane divides the body into upper (superior) and lower (inferior) parts.

Anatomical Terms

• Superior refers to a position above or higher than another body part; the head is superior to the neck.
• Inferior refers to a position below or lower than another body part; the feet are inferior to the knees.
• Anterior refers to the front of the body or towards the front; the chest is anterior to the spine.
• Posterior refers to the back of the body or towards the back; the spine is posterior to the chest.
• Medial refers to being closer to the midline or center of the body; the nose is medial to the eyes.
• Lateral refers to being further away from the midline of the body; the ears are lateral to the eyes.
• Proximal refers to a position closer to the point of attachment or the center of the body; the elbow is proximal to the wrist.
• Distal refers to a position further from the point of attachment or the center of the body; the fingers are distal to the wrist.

Long Bones

• Common examples include the femur and humerus, found in the arms and legs.
• Their curved shape helps absorb shock and distribute pressure.
• The diaphysis is the long shaft of the bone, covered by the periosteum membrane.
• The medullary cavity is the hollow space within the diaphysis.
• It contains red bone marrow in childhood and yellow bone marrow in adulthood.
• Epiphyses are the two end portions of the bone.
• They are covered with articular cartilage to reduce friction and absorb shock at movable joints.

Short Bones

• They are cube-shaped.
• Examples are found in the wrists, ankles, fingers, and toes.

Flat Bones

• They are flattened in shape.
• Examples include bones of the skull and the sternum (breastbone).

Irregular Bones

• They have unusual shapes that don't fit into other categories.
• Examples are vertebrae, facial bones, and the scapula (shoulder blade).

Sesamoid Bones

• They are embedded in tendons where pressure develops.
• An example is the patella (kneecap).

Sutural (Wormian) Bones

• They are found between the joints (sutures) of some cranial bones.
• Small bones found in the skull, between the parietal and occipital bones, are examples.

Axial Skeleton

• It provides a central support axis.
• It includes the skull, vertebral column, sternum, and ribs.

Appendicular Skeleton

• It is mainly involved in movement.
• It includes the bones of the limbs, the shoulder girdle, and the pelvic girdle.

Main Bones

• Head: Skull
• Mantle
• Chest: Ribs, Sternum
• Shoulder girdle: Scapula, Clavicle
• Spinal column: Cervical curve, Thoracic curve, Lumbar curve, Sacral curve, Sacrum, Coccyx
• Arm: Humerus, Radius, Ulna
• Hand: Carpals, Metacarpals, Phalanges
• Leg: Femur, Tibia, Fibula, Patella (Knee cap)
• Foot: Tarsals, Metatarsals, Phalanges

Vertebral Column

• The vertebral column has 33 bones with intervertebral discs between them.
• Cervical vertebrae (neck) consist of seven small vertebrae (C1–7).
• Thoracic vertebrae (upper back) consist of 12 vertebrae (T1–12).
• Lumbar vertebrae (lower back) consist of five large vertebrae (L1–5).
• The sacrum has 5 fused bones.
• The coccyx has 4 fused bones.

Joints

Immovable or Fibrous Joint

• No movement is possible.
• Examples include the bones of the cranium, fused in lines called sutures.

Slightly Movable or Cartilaginous Joint

• Permits limited movement.
• Examples exist in the vertebral column, where fibrous cartilage between discs allows a limited range of movement.

Freely Movable or Synovial Joint

• Allows maximum movement.
• Most joints in the body are synovial joints, such as the hip joint.