Human Anatomy: General Anatomy, Skeletal System, and Arthrology

Vocabulary practice flashcards covering human anatomy fundamentals, planes, directions, osteology, bone structure and metabolism, joints, axial skeleton, and upper and lower limb bones.

Human Anatomy (Humánní anatomie)

The scientific discipline dealing with the shape, structure, and development of the human body as a whole and its individual parts; its name derives from the Greek word for dissection (anatomnein), and it became an established science in $1543$ with Andreas Vesalius' work illustrated by Calcar.

Anatomical Position (Anatomická poloha)

The standard reference posture in which the human body is upright with the head erect, upper limbs freely hanging alongside the trunk, and palms turned forward.

Anatomical Axes (Orientační osy)

The three reference axes of the three-dimensional human body: the vertical axis (from vertex to coccyx through the center), the anteroposterior axis (from the anterior abdominal wall to the dorsal back surface), and the transverse axis (from the right lateral to the left lateral body surface).

Median Plane (Mediánní rovina)

The vertical reference plane passing through the longitudinal axis of the body that divides it into two symmetrical right and left halves.

Transverse Plane (Transverzální / Příčná rovina)

A reference plane perpendicular to the longitudinal axis of the body that divides the body into superior (upper) and inferior (lower) parts.

Frontal Plane (Frontální / Čelní rovina)

A vertical reference plane parallel to the forehead that divides the body into anterior (front) and posterior (back) sections.

Directional Terms of the Trunk

Superior (cranial) points toward the head, inferior (caudal) points toward the lower end of the body, anterior (ventral) points toward the front, and posterior (dorsal) points toward the back.

Directional Terms of the Limbs

Proximalis denotes structures closer to the trunk; distalis denotes structures farther from the trunk (closer to the digits); medialis denotes lying closer to the median plane; lateralis denotes lying farther from the median plane.

Forearm and Leg Directional Terms

On the forearm: radialis (outer/lateral) and ulnaris (inner/medial); on the leg: tibialis (inner/medial) and fibularis (outer/lateral); on surfaces: palmaris (palm), plantaris (sole), and dorsalis (dorsum).

Oralis and Aboralis

Directional terms used in the digestive system: oralis indicates direction toward the mouth; aboralis indicates direction away from the mouth.

Trunk Regions (Krajiny trupu)

The trunk (truncus) accounts for $46\%$ of total body mass and includes the thorax (pectus), abdomen (venter), pelvis, and back (dorsum); its anterior abdominal wall is subdivided into epigastrium (upper), mesogastrium (middle), and hypogastrium (lower).

Skeletal System (Kosterní soustava)

The passive locomotor apparatus composed of approximately $220$ bones weighing about $11\text{ kg}$ ($1/5$ to $1/7$ of total body weight); provides soft-tissue support, attachment bases for muscles and ligaments, protective cages for organs, mineral storage for calcium and phosphorus, and blood cell formation.

Classification of Bones by Shape

Includes long bones (ossa longa, consisting of a diaphysis shaft and proximal/distal epiphyses), short bones (e.g., vertebrae, carpal bones), flat bones (e.g., cranial vault bones, sternum), irregular bones (e.g., mandible), and pneumatic bones containing mucosal cavities (e.g., ethmoid bone).

Periosteum (Okostice)

A vascularized and richly innervated fibrous membrane covering the external bone surface; consists of an outer fibrous layer (rich in collagen, poor in cells) and an inner cambium layer (cell-rich, carrying vessels through Volkmann canals and anchoring via Sharpey's fibers); critical for fracture healing and bone grafts.

Compact Bone vs. Spongy Bone

Substantia compacta forms a dense outer shell of lamellae arranged into Haversian systems under the periosteum; substantia spongiosa fills bone ends and inner compartments with branching trabeculae aligned precisely along lines of maximal tensile and compressive stress.

Bone Remodeling Cells

Osteoblasts initiate ossification and synthesize basic bone matrix; osteocytes are mature resting bone cells embedded in matrix; osteoclasts are multinucleated giant cells that resorb and break down bone tissue throughout life.

Bone Marrow (Medulla ossium)

Tissue filling the medullary cavities and spongy trabecular spaces totaling about $2600\text{ g}$ in an adult; red marrow ($1300\text{ g}$) is hematopoietic reticular tissue; yellow marrow contains fat cells occupying long bone shafts from age $20$; gray marrow develops in advanced age through lipid loss.

Adult Sites of Red Bone Marrow

Maintained in the spongiosa of long bone articular ends, short bones (vertebrae, carpus, tarsus), ribs, pelvic bones, the sternum, and flat bones of the skull; clinical access includes sternal puncture and iliac crest trephine biopsy.

Chondrogenic vs. Desmogenic Ossification

Chondrogenic ossification forms bone from a pre-existing hyaline cartilage model (long bones, vertebrae, pelvic bones, cranial base); desmogenic ossification forms bone directly from embryonic mesenchymal connective tissue (facial bones, clavicle, cranial vault).

Bone Growth Mechanisms

Longitudinal growth occurs at epiphyseal growth plates where cartilage cells divide and are replaced by bone until closing between ages $18\text{--}23$; growth in thickness occurs appositionally by deposition of new bone layers beneath the periosteum.

Hormonal Regulators of Bone Growth

Growth hormone (anterior pituitary) and thyroxine stimulate growth; adrenal corticosteroids inhibit growth; parathyroid hormone activates osteoclasts to demineralize bone and elevate serum calcium; sex steroids and vitamin D regulate mineralization (post-menopausal decline risks osteoporosis).

Nutrient Artery (Arteria nutricia)

The principal artery entering the diaphysis obliquely through a nutrient canal at the original site of ossification initiation; directs toward the less active growth cartilage during development and anastomoses with vessels of the Haversian canals.

Types of Cranial Sutures (Suturae)

Fibrous cranial joints categorized by morphology: sutura serrata (serrated/toothed, e.g., sagittal suture), sutura squamosa (overlapping scale-like, e.g., temporal squama with parietal bone), and sutura plana (smooth straight margins between small facial bones).

Continuous Bone Connections (Synarthroses)

Immovable or slightly movable junctions: syndesmosis (fibrous joint: sutures, interosseous membranes, gomphosis), synchondrosis/symphysis (cartilaginous joint: hyaline cartilage or fibrocartilage, such as intervertebral discs and pubic symphysis), and synostosis (complete bony fusion, such as the sacrum).

Synovial Joint (Articulatio synovialis)

A discontinuous articulation between two or more cartilage-covered bone ends enclosed by an articular capsule and separated by a joint cavity containing viscous synovial fluid rich in hyaluronic acid and mucoalbumin.

Joint Auxiliary Structures (Pomocná zařízení kloubu)

Specialized intra- and periarticular formations including fibrocartilaginous labra (articular lips deepening sockets), articular discs and menisci (cushions compensating surface curvature differences), reinforcing ligaments, synovial bursae (fluid sacs reducing friction), and capsule-inserting muscles.

Angular Joint Movements

Flexion (bending/decreasing angle), extension (straightening/increasing angle), abduction (movement away from median plane), adduction (movement toward median plane), rotation (turning around the bone's longitudinal axis), and circumduction (conical circular movement combining all primary planes).

Morphological Types of Synovial Joints

Classified by surface geometry into ball-and-socket (free in shoulder, restricted in hip), hinge/ginglymus (humero-ulnar), pivot/trochoid (proximal radio-ulnar), saddle (carpometacarpal joint of the thumb), ellipsoid/condylar (atlanto-occipital), and plane/rigid (amphiarthrosis, sacroiliac joint).

Vertebral Column (Columna vertebralis)

The bony central axis of the trunk constituting one-third of adult body height and protecting the spinal cord; composed of $33\text{--}34$ vertebrae divided into $7$ cervical ($\text{C1--C7}$), $12$ thoracic ($\text{Th1--Th12}$), $5$ lumbar ($\text{L1--L5}$), $5$ sacral ($\text{S1--S5}$ fused into os sacrum), and $4\text{--}5$ coccygeal ($\text{Co1--Co4/5}$ fused into os coccygis).

Physiological Curvatures of the Spine

Four anteroposterior curves comprising two forward convexities called lordoses (cervical at $\text{C4--C5}$, lumbar at $\text{L3--L4}$) and two posterior convexities called kyphoses (thoracic at $\text{Th6--Th7}$, and sacral); transitional protrusion at $\text{L5--S1}$ is termed the promontorium.

General Structure of a Vertebra

Consists of an anterior vertebral body (corpus vertebrae), a posterior vertebral arch (arcus vertebrae) enclosing the vertebral foramen (foramen vertebrale), and seven processes: one spinous, two transverse, and four articular (two superior, two inferior).

Atlas (C1) and Axis (C2)

The atlas (C1) lacks a body and spinous process, consisting of anterior and posterior arches with lateral masses; the axis (C2) features an upward vertical projection called the dens axis (odontoid process) bearing an apical point that articulates with the anterior arch of the atlas.

Thoracic Vertebra (Vertebra thoracica)

Characterized by a round vertebral foramen, heart-shaped body with costal facets (foveae costales superior and inferior) for rib head articulation, elongated steeply downward-sloping spinous process, and transverse process facets (fovea costalis processus transversi) for rib tubercles.

Lumbar Vertebra (Vertebra lumbalis)

Features a large kidney-shaped vertebral body, a small triangular vertebral foramen, a broad quadrilateral horizontally oriented spinous process, and split transverse processes forming mammillary, accessory, and costal processes (rudimentary ribs).

Sacrum (Os sacrum)

A large triangular bone formed by the fusion of five sacral vertebrae ($\text{S1--S5}$); features a superior basis with promontory, an inferior apex, a smooth concave pelvic surface with four pairs of anterior sacral foramina, and a rough dorsal surface with median, intermediate, and lateral sacral crests surrounding the sacral hiatus.

Intervertebral Disc (Discus intervertebralis)

Twenty-three fibrocartilaginous pads placed between adjacent vertebral bodies from $\text{C2--C3}$ to $\text{L5--S1}$ that absorb shock and permit flexibility; each consists of a tough peripheral anulus fibrosus surrounding a gelatinous central nucleus pulposus.

Spinal Ligaments (Ligamenta columnae vertebralis)

Longitudinal bands including the anterior longitudinal ligament (along anterior vertebral bodies) and posterior longitudinal ligament (inside the vertebral canal); short elastic bands include ligamenta flava (between arches), interspinalia, intertransversaria, and supraspinale (expanding cranially into ligamentum nuchae).

Sternum (Breastbone)

An anterior flat bone consisting of three parts: the superior manubrium sterni (with jugular and clavicular notches), the elongated corpus sterni (bearing costal notches for ribs), and the inferior processus xiphoideus; the junction between manubrium and body forms the sternal angle (angulus sterni).

Classification of Ribs (Costae)

Twelve pairs of elastic bones divided into true ribs ($\text{costae verae}$, pairs $1\text{--}7$, attaching directly to sternum via costal cartilages), false ribs ($\text{costae spuriae}$, pairs $8\text{--}10$, connecting to cartilage of rib $7$), and floating ribs ($\text{costae liberae}$, pairs $11\text{--}12$, terminating freely in the abdominal muscular wall).

Anatomy of the First Rib (Costa prima)

A flat, horizontally oriented, curved bone with an inner margin and an outer margin; its superior surface displays a tuberculum costae, a neck, a head, a tubercle for scalene muscle, and distinct grooves for the subclavian vein (sulcus venae subclaviae) and subclavian artery (sulcus arteriae subclaviae).

Fontanelles of the Newborn Skull (Fonticuli)

Unossified membranous gaps between cranial bones in neonates; the anterior fontanelle (fonticulus major) is diamond-shaped at the junction of coronal and sagittal sutures (closes around $24$ months), and the posterior fontanelle (fonticulus minor) is triangular at the sagittal and lambdoid sutures (closes around $3$ months).

Neurocranium vs. Splanchnocranium

The skull comprises $22$ bones divided into the neurocranium ($8$ bones enclosing the brain: frontal, sphenoid, ethmoid, occipital, and paired parietal and temporal bones) and splanchnocranium ($14$ facial bones providing support for the face, mastication, and sensory organs).

Principal Cranial Sutures

Includes the coronal suture (sutura coronalis between frontal and parietal bones), sagittal suture (sutura sagittalis between the two parietal bones), lambdoid suture (sutura lambdoidea between parietal and occipital bones), and squamosal suture (sutura squamosa between squamous temporal and parietal bones).

Frontal Bone (Os frontale)

Forms the forehead and roofs of both orbits; features an extensive vertical squama frontalis, bilateral orbital plates (partes orbitales), superciliary arches (arcus superciliares), a smooth median depression called glabella, and paired paranasal frontal sinuses (sinus frontales).

Sphenoid Bone (Os sphenoidale)

A central butterfly-shaped cranial base bone containing the sella turcica (hypophyseal fossa housing the pituitary gland), greater and lesser wings (alae major and minor), pterygoid processes, sphenoidal sinuses, and key apertures (foramen rotundum, ovale, spinosum, and optic canal).

Temporal Bone (Os temporale)

A complex paired lateral skull bone consisting of a squama, a tympanic part (surrounding external acoustic meatus), and a petrous part (pyramid housing the inner and middle ear structures, carotid canal, and facial nerve canal), with styloid and mastoid processes projecting inferiorly.

Mandible (Mandibula)

The only freely movable skull bone; consists of a curved horizontal body (corpus mandibulae) with an alveolar arch and mental protuberance, and bilateral vertical rami (ramus mandibulae) ending in an anterior coronoid process (for temporalis muscle) and a posterior condylar process (articulates with temporal bone).

Cranial Sexual Dimorphism

Male skulls typically feature a distinct nasofrontal angle, prominent superciliary arches, larger mastoid processes, a more prominent external occipital protuberance, and a squarer chin; female skulls show a smooth nasofrontal transition, rounded chin, and rounded occiput.

Scapula (Shoulder Blade)

A flat triangular bone on the posterolateral thoracic wall; features medial, lateral, and superior borders, a prominent spine (spina scapulae) terminating in the acromion, supraspinous and infraspinous fossae, a coracoid process, and a shallow pear-shaped glenoid cavity (cavitas glenoidalis).

Clavicle (Clavicula)

An S-shaped long bone measuring $12\text{--}16\text{ cm}$ connecting the sternum to the shoulder girdle; features a medial sternal end (extremitas sternalis) articulating with the manubrium, a shaft (corpus claviculae), and a flattened lateral acromial end (extremitas acromialis) articulating with the acromion of the scapula.

Humerus (Arm Bone)

The long bone of the arm; proximally features a rounded head (caput humeri), anatomical neck, greater and lesser tubercles separated by the intertubercular groove, and a surgical neck (common fracture site); distally features the capitulum, trochlea, radial and coronoid fossae anteriorly, and olecranon fossa posteriorly.

Radius and Ulna (Forearm Bones)

The forearm skeleton: the radius is situated laterally (carries head, neck, radial tuberosity, and styloid process distally); the ulna is situated medially (features a prominent proximal olecranon and coronoid process, and ends distally in a smaller head with styloid process).

Carpus, Metacarpus, and Phalanges

The hand skeleton consists of $8$ carpal bones arranged in proximal and distal rows, $5$ metacarpal bones (each with base, shaft, and head), and $14$ phalanges ($2$ in the thumb/pollex, $3$ in each of the remaining four digits: proximal, middle, distal).

Hip Bone (Os coxae)

A large paired pelvic bone formed by the synostotic fusion of three individual bones meeting at the cup-shaped acetabulum: the ilium (os ilium), the ischium (os ischium), and the pubis (os pubis); encloses the large obturator foramen (foramen obturatum).

Pelvic Sexual Dimorphism

The female pelvis is adapted for childbirth with a wider, rounded inlet, a lower pubic symphysis, a wider sacrum, a more mobile coccyx, and a rounded pubic arch (arcus pubicus); the male pelvis is heavier and narrower with an acute subpubic angle (angulus pubicus).

External Pelvic Diameters (Zevní rozměry pánve)

Standard obstetric dimensions measured externally: distantia bispinalis ($26\text{ cm}$, between anterior superior iliac spines), distantia bicristalis ($29\text{ cm}$, between widest points of iliac crests), distantia bitrochanterica ($31\text{ cm}$, between greater trochanters), and conjugata externa ($18\text{--}20\text{ cm}$, from L5 spine to upper symphysis).

Obstetric Pelvic Planes (Roviny malé pánve)

The four internal birth canal planes: pelvic inlet (aditus pelvis), pelvic plane of greatest dimensions (amplitudo pelvis), pelvic narrow (angustia pelvis, the narrowest plane), and pelvic outlet (exitus pelvis); dimensions dictate the internal rotation of the fetal head during birth.

Conjugata diagonalis

The only pelvic inlet diameter directly measurable clinically per vaginam; the distance measured between the inferior margin of the pubic symphysis and the promontory, normally measuring $12.5\text{--}13\text{ cm}$.

Femur (Thigh Bone)

The longest and strongest bone in the human body; proximally features a spherical head (caput femoris with fovea capitis), a neck (collum femoris) forming a collodiaphyseal angle of about $125^\circ$, and greater and lesser trochanters; the shaft bears a posterior linea aspera and terminates distally in medial and lateral condyles.

Tibia and Fibula (Bones of the Leg)

The shin and calf skeleton: the tibia is the medial, weight-bearing bone carrying proximal medial/lateral condyles, intercondylar eminence, tibial tuberosity, and the medial malleolus distally; the fibula is the slender lateral stabilizing bone carrying a proximal head and the lateral malleolus distally.

Patella (Kneecap)

The largest sesamoid bone in the human body; an oval, flat bone embedded within the terminal tendon of the quadriceps femoris muscle that glides over the patellar surface of the distal femur.

Bones of the Foot (Ossa pedis)

Divided into seven tarsal bones arranged into a medial column (talus, navicular, three cuneiforms) and a lateral column (calcaneus, cuboid), five metatarsal bones, and fourteen phalanges of the toes (two in hallux, three in remaining digits).