Gross Anatomy 1: Midterm 1

Gross Anatomy

Study of structures that can be seen with the naked eye

Histology

the study of the microscopic structure of tissues

Embryology

study of embryos and their development

Morphology

study of form/shape

Comparative Anatomy

the study of similarities and differences in the anatomy of different species

Surface Anatomy

The study of the surface projections of anatomical structures

Systemic Approach to Anatomy

-the study of individual body systems

-may not take body region into account

-irrespective of relationships with structures of other systems

Regional Approach to Anatomy

-study of all anatomical structures within a specific region of the body

-emphasize three-dimensional and functional relationships between structures

-approach taken in gross anatomy

Anatomical Position

Standing pose, head and eyes are forward, arms are by the side with palms facing forward (supinated), legs are together and toes are facing anteriorly

Sagittal Plane

a vertical plane that divides the body into right and left parts

Midsagittal Plane (Median)

divides the body into equal right and left halves

Parasagittal Plane

Divides body into unequal right and left sides

Coronal Plane

divides body into front and back

Horizontal (Transverse) Plane

divides the body into superior and inferior sections

Superior

toward the head

Inferior

Lower on the body, farther from the head

Cranial

toward the head (on quadrepeds)

Caudal

toward the tail (on quadrepeds)

Anterior (Ventral)

Towards the front of the body

Posterior (Dorsal)

toward the back of the body

Medial

Toward the midline of the body

Lateral

Away from the midline of the body

Proximal

Closer to the point of attachment

Distal

away from the point of attachment

Superficial

near the surface

Deep

away from the surface; more internal

External

Located outside the structure

Internal

Located within the structure

Central

Center of the transverse cut

Peripheral

Towards the sides of a transverse cut

Parietal

pertaining to the outer wall of the body cavity

Visceral

pertaining to the internal organs

Rostral

toward the forehead or nose

Cephalon

head (cephalic)

Ipsilateral

on the same side of the body

Contralateral

on the opposite side of the body

Flexion

decreasing the angle between two bones

Extension

Increases the angle between two bones at a joint

Abduction

Movement away from the midline of the body

Adduction

Movement toward the midline of the body

Circumduction

the circular movement at the far end of a limb

Rotation

Pivot around a long axis, in limbs medical and lateral

Pronation

turning the palm downward

Supination

movement that turns the palm up

Inversion

turning the sole of the foot toward the midline (medially)

Eversion

turning the sole of the foot away from the midline (laterally)

Plantar Flexion

bending of the sole of the foot by curling the toes toward the ground

Doris Flexion

bends the foot upward at the ankle

Protraction

moving a body part forward

Retraction

moving a part backward

Structure of the Skeletal System

bones, cartilage, ligaments, tendons

Function of Skeletal System

support, protection, movement, storage, blood cell production

Storage for Minerals of Skeletal System

-calcium and phosphorous

-highly vascular = rapid exchange of minerals between bone and blood

Site of blood cell production (hematocytopoeisis)

-red marrow is where blood cells are produced

-occurs in vertebrae, ribs, sternum, scapulae, clavicles, pelvis, cranium, proximal femora and humeri in adults

-yellow marrow is found in proximal ends of extremities and is used for fat (energy) storage

Connective Tissue

A body tissue that provides support for the body and connects all of its parts

Loose connective tissue

-found throughout the body

-no characteristic form

-high proportion of cells in ECM

-fat (adipose)

Dense Connective Tissue

-regular, irregular, elastic

-tendons and ligaments

-high proportions of ECM to cells

Bone

-made up of hydroxyapatite crystals

-collagen fibers in bone matrix arranged in organized, specific structure

-highly vascular

Cartilage

-collagen fibers randomly arranged (except for fibrocartilage)

-avascular

Hyaline Cartilage

-most common type of cartilage

-very fine collagen fibers

-precursor to most bones

-found at synovial joints and growth plates

Fibrocartilage

-large amounts of collagen fibers

-structural and not found in bone

-found in joints (annulus fibrosis of intervertebral discs)

Elastic Cartilage

-large amounts of protein (elastin)

-found in external ear and nose

-small amount associated with skeletal system (in some ligaments)

Mineral Phase of Bone

-make up 65-70% of bone

-calcium phosphate and calcium carbonate make up hydroxyapatite

-gives bones it rigidity

Organic Phase of Bone

-30-35% of bone

-amorphous ground substance made up proteoglycans and glycoproteins in which collagen fibers are embedded

Long Bones

-tubular shaft with expanded ends

-bones are longer than they are wide

-found in the limbs (humerus, ulna, radius, femur, tibia, fibula)

Short Bones

- "cuboid" in shape

-lots of spongy bone; no real shaft

-found in carpals and tarsals

Flat Bones

-plate-like

-"sandwich" of two outer dense bones (cortical bone) with spongy-like bone (trabecular) between them

-found in the cranial vault, sternum, and ribs

Diploe

spongy bone in flat bones

Irregular Bones

-irregular shapes that don't fit any other category

-found in vertebrae, bones of the face and sides of skull

Sesamoid Bones

-develops in the tendons of muscles

-function is to move tendons away from the center of joints, increasing the movement of muscles

-found in the patella and possibly in gastrocnemius tendon in calf

Diaphysis

shaft of a long bone

Epiphysis

-expanded area at the proximal or distal end of a long bone

-multiple growth centers that take part in joint function

Apophysis

Site of muscle insertion

Metaphysis

growth zone between the epiphysis and the diaphysis during development of a long bone

Periosteum

a dense layer of vascular connective tissue enveloping the bones except at the surfaces of the joints.

Osteogenic Layer

-inner layer that creates new layer of bones

-composed of bone lining cells derived from osteoprogenitor cells that differentiate into osteoblasts

Fibrous layer

-outer lay that anchor muscles and ligaments

-make up of dense irregular connective tissues

-Sharpey's fibers extend into the bone matrix

Medullary Cavity (marrow cavity)

-cavity inside the diaphysis of bone that contains marrow

-where yellow bone marrow is located

Endosteum

-membrane lining the medullary cavity of a bone

-similar to osteogenic layer of periosteum

-lines the internal surface of cortical bone separating it from the bone marrow

-helps to supply osteoblasts for fracture repair and for formation of Haversian systems in bone remodeling

Periositis

-inflammation of the tissue beneath the periosteum

-caused by infection, injury, or stress

-common site is in the tibia and other areas close to the skin

Osteomyelitis

-advanced inflammation of bone and bone marrow

-necrosis occurs

-development of a involcrum, sequesterum, and an cloaca occurs in affect area

Nutrient Artery

Passes through compact bone into the medullary cavity via nutrient foramen

Blood supply in Bone Matrix

-Haversian canals: network of small channels parallel to long axis of bone

-transversely connected via Volkmann's canals

Woven Bone (Primitive)

-collagen fibers are arranged in a haphazard manner without preferred orientation

-type of bone laid down in bony callus following fracture

-not as strong as mature bone

Lamellar Bone

Mature bone in sheets called lamellae. Fibers are oriented in one direction in each layer, but in different directions in different layers for strength.

Compact Bone (Cortical Bone)

the dense, hard, and very strong bone that forms the protective outer layer of bones

Trabecular (Cancellous) Bone

-series of intersecting spicules

-support articular ends

-greater elasticity prevents overlying cartilage from being excessively compacted during high bio mechanical loading'

-red marrow lives in spongy bone

Circumferential Lamellar Bone (Primary Osteons)

-mature compact bone

-lamellae extends around the circumference of the shaft of bone in layers just deep of the periosteum

-collagen fibers are parallel in each lamellae

-lacunae occupy osteocyte within each layer of lamellae

Lamellae

Bone layers in which collagen fibers have a specific orientation

Lacunae

small cavities in bone that contain osteocytes

Canaliculi

minute canals connecting osteocytes of an osteon that allow communication of osteocytes with blood vessels

Compressive Strength

The ability to bear weight

Tensile Strength

The ability to resist tension

Haversian Bone (Secondary Osteons)

-forms in already existing bone to repair micro fractures and other damage

-form within a resorption space carved out by osteoclasts

-blood vessels enter resorption space and bring osteoblasts

-Haversian canal contains arterioles and venules and parallel with long axis of bone

-Volkmann's canals lie perpendicular to Haversian canals

Volkmann's Canals

-transmit blood vessels and nerve fibers between adjacent Haversian canals

-not lined by concentric lamellae

Modeling

-the process of forming new primary osteosarcoma

-formation of bone from the anlage through ossification of model

-formation of circumferential lamellar bone

Remodeling

-the process of changes that occur after ossification

-bone gets resorbed and new bone forms

Osteoblasts

-synthesize, deposit, and mineralize bone matrix

-mononuclear cells

-single cell layer of cells on surface of growing or remodeling bone

-arise from osteoprogenitor cells (found beneath the periosteum or endosteum)

Osteoclasts

-removal of bone matrix

-polymorphous, polynucleated cells

-surfaces of bone undergoing active resorption in "Howships lacunae"

-mechanism is unknown

-originate from fusion of mononuclear cells in bone marrow

-respond to changes in parathyroid gland and vitamin D levels

Osteocytes

-principle type of cells in bone matrix

-derive from osteoblasts that have ceased production of bone matrix

-retain connections and blood vessels via canaliculi

-sit in lacunae

-maintenance of bone (repair of fractured trabeculae, death of osteocytes = resorption by osteocytes)