Exam 1

Review Sheet

Standard Anatomical Position

• Standing Looking forward

•  Feet together and pointing forward 

• Arms alongside trunk 

• Palms facing forward  

Sagittal or Midsagittal

• Divides the body into symmetrical right and left halves. 

• Normally passes through craniometric point bregma

Craniometric point bregma

• Intersection of coronal and sagittal sutures.

Parasagittal

Plane parallel to sagittal that does not pass through midline of body (bregma)

Coronal (aka frontal

Divides body into anterior and posterior halves.

Passes through the bregma

Paracoronal

Plane parallel to coronal that does not pass through bregma. 

Transverse (aka horizontal, axial)

• Placed at right angle to sagittal and coronal planes.

• Passes through the body at any height 

Frankfort Horizontal

• - is analogous to transverse plane

  • Is a transverse plane 

  • Resting (neutral) plane of skull 

  • Approximately parallel to ground surface when walking 

  • Approximately parallel to the lateral semicircular canal plane in the inner ear 

  • Defined by line passing through: 

    • 1) superior margin of the external auditory meatus (ear canal) 

    • 2) inferior margin of the eye orbit  

Right & Left

sides of the bodies when divided by sagittal plane

Superior

• Towards the head end 

• aka Cephalic, Cranial = Toward the head 

• Superior border of parietal bone in skull is the sagittal suture. 

Inferior

• Away from the head end 

• Opposite of superior Aka Caudal = Toward the tail 

• Inferior surface of calcaleus (heel bone) is in contact with the ground.  

• Anterior

• Towards the front of the body. 

• aka Ventral = Towards the belly 

• Sternum is anterior to the vertebral column

• Posterior

• Towards the rear of the body 

• aka Dorsal = Towards the back 

• Occipital bone is on the posterior and inferior end of the skull.  

• Medial 

• Toward the midline. 

• Sternum is medial to adjacent ribs

• Lateral 

• Away from the midline. 

• The thumb occupies a lateral position relative to the little (pinky) finger in standard anatomical position 

• Proximal

• Nearest the axial skeleton. 

• Usually used for long and short bones in the limbs. 

• Proximal end of humerus articulates with scapula in shoulder joint. 

• Distal 

• Away from the axial skeleton. 

• Distal end of the terminal foot phalanx is the tip of the toe.  

• External

• closer to the surface. 

• aka Outer 

• Internal

• Away from the surface 

• aka Inner 

• Internal surface of the parietal bone is marked by grooves for blood vessels that lie external to the brain.  

• Endocranial 

• Inner surface of the cranial vault. 

• Brain fills the endocranial cavity.

Ectocranial

• Outer surface of the cranial vault. 

• Temporal line, for attachment of temporalis muscle, is on the ectocranial surface of the parietal 

Palmar

• Palm side of the hand. 

• Palmar surfaces of the fingers bear fingerprints.

Plantar

• Sole side of the foot. 

• Plantar surface of the foot contacts ground during normal walking.

Superficial:

Refers to a structure that is closer to the surface of the body. For example, the skin is superficial to the muscles.

Deep:

Refers to a structure that is further away from the surface of the body, often closer to the internal organs. For example, the bones are deep to the muscles.

Teeth: Mesial

• toward the midline point of the dental arch 

• where the central incisors contact each other. 

• Note this point falls on the sagittal (midline) plane of the body. 

• The anterior face of the molar and premolar crowns and the medial face of the canines and incisors are the mesial surfaces 

Teeth: Distal

• Away from the midline point of the dental arch where the central incisors contact each other. 

• Distal half of a premolar is the posterior half of the tooth. 

• The mesial surface of the canine tooth touches the distal surface of the second incisor, while the distal surface of the canine tooth touches the mesial surface of the first premolar 

Buccal:

Refers to the surface of a tooth that is closest to the inner cheek. This term is usually applied to the premolars and molars in the posterior region of the mouth.

Lingual:

refers to the surface of a tooth that is closest to the tongue. This term is used for both the anterior (front) and posterior (back) teeth.

Occlusal:

Refers to the biting or chewing surface of the posterior teeth (premolars and molars). It's the surface that comes into contact with the teeth in the opposite jaw.

Cervical:

Refers to the area around the neck of the tooth, where the crown of the tooth meets the root. This region is near the gum line.

Apical:

Refers to the tip or apex of the root of the tooth. It's the most distal point of the tooth structure, located furthest from the crown.

Flexion:

A movement that decreases the angle between two body parts (e.g., bending the elbow).

Extension

A movement that increases the angle between two body parts (e.g., straightening the elbow).

Dorsiflexion:

Flexing the foot upwards towards the shin (e.g., walking on your heels).

Plantarflexion:

Flexing the foot downwards, pointing the toes away from the leg (e.g., standing on your toes)

Abduction

Moving a body part away from the midline of the body (e.g., raising your arm sideways).

Adduction

Moving a body part towards the midline of the body (e.g., lowering your arm to your side).

Circumduction

A circular movement that combines flexion, extension, abduction, and adduction. It describes a conical motion of a limb (e.g., circling the arm at the shoulder).

Pronation (Forearm)

Rotational movement of the forearm where the palm faces downwards or backwards

Supination (Forearm)

Rotational movement of the forearm where the palm faces upwards or forwards.

Synovial:

Freely movable joints with a fluid-filled joint cavity (e.g., knee, elbow).

Cartilaginous

Joints connected entirely by cartilage allowing limited movement (e.g., intervertebral discs).

Fibrous

Joints connected by dense connective tissue, allowing little to no movement (e.g., cranial sutures).

Axial Skeleton

Consists of the bones along the body's central axis, including the skull, vertebral column, and rib cage.

Appendicular Skeleton

Comprises the bones of the limbs and girdles (shoulder and pelvic girdles).

Cranial

Refers to the bones of the skull. hyoid and mandible

Postcranial (Infracranial)

Refers to all the bones of the body excluding the skull (i.e., everything below the head).

Bone

• A rigid connective tissue that forms the skeleton. It is composed of organic components (collagen fibers) and inorganic components (hydroxyapatite crystals).

Cartilage

 A flexible, avascular connective tissue that provides support and cushioning in joints. It comes in three types: Hyaline, fibrous, elastic

Hyaline Cartilage:

• The most common type, providing smooth surfaces for joint movement and support for respiratory structures.

Fibrous Cartilage (Fibrocartilage)

•  Contains dense collagen fibers, providing tensile strength and resistance to compression; found in intervertebral discs and menisci.

Elastic Cartilage

• Contains elastic fibers, allowing it to maintain shape after deformation; found in the ear and epiglottis.

Tendons:

• Tough, fibrous connective tissue that connects muscle to bone, transmitting the force of muscle contractions to bones.

Ligaments

•  Bands of fibrous connective tissue that connect bones to other bones, providing stability to joints.

-blast:

• uffix indicating a producer or precursor cell that forms tissue. For example: chrondroblasts & osteoblasts

Chondroblasts

• Cells that produce cartilage matrix.

Osteoblasts:

Cells that produce bone matrix.

-cyte

•  Suffix indicating a mature cell that maintains the tissue. For example: osteocyte

Osteocyte

 A mature bone cell embedded in the bone matrix, responsible for maintaining the bone tissue.

clast

• Suffix indicating a cell that breaks down or resorbs tissue. For example: osteoclasts

Osteoclasts

• Cells that resorb bone tissue, playing a key role in bone remodeling.

Collagen Fibers (Osteoid

•  The organic component of bone matrix, providing flexibility and tensile strength.

Hydroxyapatite Crystals

•  The inorganic component of bone, composed of calcium and phosphate, giving bone its hardness and strength.

Osteon (Haversian System):

• The fundamental structural unit of compact bone, consisting of concentric layers (lamellae) of bone tissue surrounding a central canal.

Lamellae:

• Concentric rings of bone matrix within an osteon.

Lacunae

•  Small spaces within the bone matrix that house osteocytes.

Canaliculi:

• Tiny channels that connect lacunae, allowing communication and nutrient exchange between osteocytes.

Haversian (Central) Canal:

• The central channel in an osteon, containing blood vessels and nerves.

Volksmann’s (Transverse) Canal

• Horizontal canals that connect Haversian canals, allowing blood vessels and nerves to pass through compact bone.

Major Types of Bones

Tubular

Long

Short

Flat

Irregular

Seasmoid

Teeth

Tubular Bones:

• Long bones with a hollow shaft (e.g., femur).

Long Bones

•  Bones that are longer than they are wide, providing leverage and support (e.g., humerus, femur).

Short Bones

Bones that are as wide as they are long, providing stability with little movement (e.g., carpals in the wrist).

Flat Bones:

• Thin, flat bones that provide protection and a surface for muscle attachment (e.g., skull, ribs).

Sesamoid Bones

• Small, round bones embedded in tendons that reduce friction and modify pressure (e.g., patella).

Teeth

• Not bones, but calcified structures used for mastication; they are often discussed with bones due to their hardness.

Diaphysis:

• The long, cylindrical shaft of a long bone.

Epiphysis:

• The rounded end of a long bone, which forms a joint with adjacent bones.

Metaphysis

• The region between the diaphysis and epiphysis, containing the growth plate in growing bones.

Nutrient Foramen:

• A small opening in the bone through which blood vessels enter to nourish bone tissue.

Medullary Canal (Marrow Cavity):

• the central cavity within the diaphysis, containing bone marrow. red or yellow

Red Marrow:

• Bone marrow responsible for producing blood cells (hematopoiesis).

Yellow Marrow:

• Bone marrow primarily composed of fat cells, storing energy.

Periosteum:

• A dense layer of vascular connective tissue covering the outer surface of bones, except at the joints.

Endosteum:

A thin layer of connective tissue lining the inner surfaces of bones, including the medullary canal

Woven (Immature) Bone

• A type of bone tissue with a haphazard arrangement of collagen fibers; it is the first type of bone formed during development or repair.

Lamellar (Mature) Bone:

• Bone tissue with a regular, parallel arrangement of collagen fibers; it replaces woven bone and is stronger and more organized.

Compact Bone (Cortical)

• Dense bone tissue that forms the outer layer of bones, providing strength and rigidity.

Subchondral Bone:

• The layer of bone just below the cartilage in joints, supporting the cartilage and absorbing shock.

Cancellous Bone (Spongy, Trabecular, Diploë

• Porous bone tissue found at the ends of long bones and in the interior of other bones, providing structural support and flexibility without the weight of compact bone.

Trabeculae

• The small, rod-like structures that make up the spongy part of cancellous bone, providing strength and supporting bone marrow.

Ossification (Mineralization, Calcification)

•  The process of bone tissue formation, where osteoblasts deposit minerals like calcium and phosphate to create bone.

• Ossification Centers:

• primary

• secondary

• Epiphyseal

Primary Ossification Center: 

The first area of a bone to start ossifying, typically in the diaphysis.

Secondary Ossification Center:

• Areas in the epiphyses where bone formation occurs after the primary center, usually during childhood and adolescence.

Epiphyseal (Metaphyseal) Growth Plate:

• A hyaline cartilage plate at the ends of long bones, allowing for growth in length during development.

Bone growth types

Endochondral Bone Growth

Intramembranous (Dermal) Bone Growth

Endochondral Bone Growth:

• The process where bone forms by replacing hyaline cartilage, which acts as a template. This is how most bones, including the long bones of the limbs, grow.

Intramembranous (Dermal) Bone Growth:

• The process where bone forms directly within a layer of mesenchymal tissue, without a cartilage precursor. This is how flat bones like those of the skull and clavicle develop.