B.1 Anatomy, Connective Tissues, Skeletal System, and Joint Biomechanics

Comprehensive practice flashcards covering connective tissue classifications, gross and microscopic bone anatomy, axial and appendicular divisions, synovial joint structures, biomechanical movements, and clinical conditions.

Loose Connective Tissue

A type of connective tissue containing fibroblasts separated by ground substance with loosely packed collagenous and elastic fibers.

Dense Connective Tissue

A connective tissue consisting of densely packed collagenous fibers and fibroblasts embedded in ground substance, forming tendons, ligaments, and the periosteum.

Hyaline Cartilage

A pliable connective tissue containing chondrocytes surrounded by ground substance that covers bone ends as articular cartilage, forms the nose framework, and connects the ribs to the sternum.

Elastic Cartilage

A flexible connective tissue containing chondrocytes and elastic fibers that provides an adaptable structural framework for the external ear (earlobe) and larynx.

Fibrocartilage

A rigid, avascular connective tissue with chondrocytes and collagenous fibers that heals slowly; found in the intervertebral disks, the knee meniscus, and the pubic symphysis.

Extracellular Matrix

The non-cellular component present in all connective tissues, composed of ground substance containing nutrients and minerals together with extracellular fibers.

Adipose Tissue

A specialized connective tissue composed of adipocytes (fat cells) that stores triglycerides for energy, found subcutaneously and within the yellow bone marrow.

Long Bones

Cylindrical bones featuring a tubular shaft and widened ends where they articulate with other bones, such as the femur, radius, and ulna.

Short Bones

Cube-shaped bones that articulate with multiple surrounding bones, exemplified by the carpals of the wrist and tarsals of the ankle.

Flat Bones

Bones that may be curved, thick, or thin, possessing broad surface areas for organ protection and muscle attachment, including the scapula, ribs, and sternum.

Irregular Bones

Bones with specialized, complex shapes that do not fit the long, short, or flat classifications, such as the vertebrae and facial bones.

Periosteum

The tough, fibrous outer covering of a bone composed of dense connective tissue that protects bone tissue and provides an anchor for tendons and ligaments.

Compact Bone

Dense, hard bone tissue located deep to the periosteum composed of structural subunits called osteons, which contain osteocytes, blood vessels, and nerves within lamellae.

Spongy Bone

Porous bone tissue composed of a network of trabeculae that houses red bone marrow and serves as the primary site of erythropoiesis.

Medullary Cavity

The hollow internal chamber within the diaphysis of a long bone that houses yellow bone marrow, blood vessels, and nerves.

Erythropoiesis

The physiological process of forming red blood cells (erythrocytes) within the red bone marrow of spongy bone.

Ligaments

Strong, flexible, non-elastic bands of dense connective tissue that connect bones to other bones, stabilising joints and preventing movement beyond the normal range.

Anatomical Position

The standardized body orientation in which an individual stands upright with feet together, arms at sides, and palms facing forward.

Superior and Inferior

Directional terms where superior indicates a structure positioned higher or closer to the head, and inferior indicates a position lower or closer to the feet.

Proximal and Distal

Directional terms used for limbs; proximal refers to being closer to the trunk or point of attachment, whereas distal refers to being farther away.

Axial Skeleton

The central structural core of the skeleton, comprising the skull, vertebral column, ribs, and sternum.

Sphenoid Bone

A butterfly-shaped bone situated at the anterior base of the cranium that houses and protects the pituitary gland.

Atlas (C1)

The first cervical vertebra, which lacks a body and spinous process, articulates with the axis, and permits the nodding 'yes' motion of the head.

Axis (C2)

The second cervical vertebra, which articulates with the atlas via a pivot mechanism to permit the side-to-side rotational 'no' motion of the head.

Vertebra Prominens (C7)

The seventh cervical vertebra, characterized anatomically by a long, prominent spinous process that serves as a palpable landmark.

True Ribs

Rib pairs $1$ through $7$, which connect directly to the sternum through their own individual costal cartilages.

False Ribs

Rib pairs $8$ through $10$, which do not attach directly to the sternum but rather connect indirectly through the cartilage of the rib above.

Floating Ribs

Rib pairs $11$ and $12$, which attach only posteriorly to the thoracic vertebrae and have no anterior attachment to the sternum.

Tendons

Inelastic, tough bands of dense connective tissue that connect skeletal muscles to bones, transmitting contractile force to move skeletal levers.

Proprioceptors

Specialized sensory nerve endings situated within muscles and ligaments that constantly monitor joint position and tension to prevent overextension.

Nociceptors

Sensory nerve receptors that detect harmful mechanical, thermal, or chemical stimuli and transmit signals of pain when tissues are injured.

Gomphosis

An immovable fibrous joint where a peg-like bone fits into a socket, specifically the articulation of tooth roots within the alveolar sockets of the jaw.

Pronation of the Foot

A complex tri-planar movement occurring during normal gait that combines dorsiflexion, eversion, and abduction.

Supination of the Foot

A composite foot movement during walking that combines plantarflexion, inversion, and adduction.

Appendicular Skeleton

The portion of the skeleton consisting of the upper and lower limbs, the pectoral girdle, and the pelvic girdle.

Acetabulum

The deep, cup-like socket on the lateral aspect of the pelvic coxal bone that articulates with the rounded head of the femur.

Medial Malleolus

The bony prominence located at the distal, inner margin of the tibia that forms the inner bulge of the ankle.

Lateral Malleolus

The expanded distal terminus of the fibula that forms the outer prominence of the ankle joint.

Talus

The tarsal bone that directly articulates with the tibia and fibula to transmit full body weight to the foot.

Calcaneus

The heel bone, representing the largest of the tarsal bones, which functions to support body weight and serve as an attachment for calf tendons.

Saddle Joint

A biaxial synovial joint whose articulating bone faces possess complementary concave and convex surfaces, exemplified by the carpometacarpal joint of the thumb.

Osteoporosis

A systemic bone disease characterized by significant loss of mineral density and bone mass, predisposing the spine, hips, and wrists to compression and stress fractures.

Synovial Membrane

The specialized inner lining of an articular capsule that synthesizes and secretes viscous synovial fluid into the joint cavity.

Synovial Fluid

A thick, viscous fluid within the synovial cavity that lubricates articulating surfaces, cushions impact, and reduces friction between articular cartilages.

Bursae

Small fluid-filled fibrous sacs lined with synovial membrane that cushion and alleviate friction between skin, muscles, tendons, and bony prominences.

Meniscus

A crescent-shaped fibrocartilaginous pad situated between the articulating condyles of the femur and tibia that stabilizes the knee and disperses shock.

Hinge Joint

A uniaxial synovial joint that restricts movement to a single plane, permitting only flexion and extension, such as at the elbow and knee.

Ball and Socket Joint

A multiaxial synovial joint where a globular head articulates with a cup-shaped cavity, allowing flexion, extension, abduction, adduction, circumduction, and rotation (e.g., shoulder and hip).

Condyloid Joint

A biaxial joint featuring an oval-shaped condyle that seats within an elliptical socket, permitting flexion, extension, abduction, adduction, and circumduction (e.g., radiocarpal joint).

Pivot Joint

A uniaxial synovial joint in which a rounded bony process rotates within a ring formed of bone and ligament, as seen in the atlantoaxial joint.

Gliding Joint

A synovial joint composed of nearly flat articulating bones that allow limited sliding and twisting motions, such as between the carpals and tarsals.

Hypermobility

An extended joint range of motion beyond customary anatomical limits, which can compromise stability and predispose the joint to subluxations and dislocations.

Anthropometry

The scientific collection and study of quantitative physical measurements regarding the dimensions, geometry, and proportions of the human body.

Ergonomic Design

The engineering practice of designing equipment, apparel, and spaces according to human biomechanics and anthropometric data to optimize performance and prevent injury.

Leucocytes

Nucleated white blood cells within vascular tissue that safeguard the body by recognizing, engulfing, and neutralizing foreign pathogens.

Thrombocytes

Cellular fragments known as platelets present in blood plasma that initiate and facilitate the blood clotting cascade to seal vascular lesions.

Goniometer

A dual-armed protractor instrument used by clinicians and biomechanists to measure the precise angular range of motion available at a joint.

Ehlers-Danlos Syndrome

A group of hereditary connective tissue disorders characterized by defective collagen synthesis, hypermobile joints, and skin hyperelasticity.

Marfan Syndrome

A systemic genetic connective tissue disease that presents with hypermobility, elongation of long bones, and weaknesses in fibrous structural frameworks.

Inversion Ankle Sprain

The most common ankle injury, occurring when the sole of the foot turns excessively inward (inversion), stretching or tearing lateral ankle ligaments.