RADANA-MIDTERMS-L1-SKELETALSYSTEM

-Bones

-Cartilage

-Joints

-Ligaments

Skeletal system is composed of?

SUPPORT

Hard framework that supports and anchors the soft organs of the body

PROTECTION

Surrounds organs such as the brain and spinal cord.

MOVEMENT

Allows for muscle attachment therefore the bones are used as levers

STORAGE

Minerals and lipids are stored within bone material

homeostasis

stability of the body

BLOOD CELL FORMATION

The bone marrow is responsible for blood cell production.

where:
• muscles, tendons, and ligaments attached
• nerves and blood vessels pass

What do bone markings reveal?

1. Projections or processes (protrude)

2. Depressions or cavities (fossa)

Bone marking may be ?

COMPACT BONE

➢ Outer layer of bone, very hard and dense.

➢ Organized in structural units called Haversian systems.

Ca salts (Ca carbonate and Ca phosphate)

Matrix is composed of what?

Osteocytes

living bone cells that live in matrix

POROUS ( SPONGY ) BONE

➢ Located in the ends of long bones.

➢ Many spaces that are filled with red bone marrow which produces bone cells

Trabeculae

needle-like threads of spongy bone that surround the spaces. Add strength to this portion of the bone

CARTILAGE

Matrix is a firm gel with chondrocytes suspended in the matrix

LONG BONES

➢ Typically, longer than wide

➢ Have a shaft with heads at both ends

➢ Contain mostly compact bone

Femur, humerus

Examples of long bones?

Carpals, tarsals

Examples of short bones?

Skull, ribs, sternum

Examples of flat bones?

Vertebrae and hip

Examples of irregular bones?

SHORT BONES

➢ Generally cube-shape

➢ Contain mostly spongy bone

FLAT BONES

➢ Thin and flattened

➢ Usually curved

➢ Thin layers of compact bone around a layer of spongy bone

IRREGULAR BONES

➢ Irregular shape

➢ Do not fit into other bone classification categories

DIAPHYSIS

◆ Shaft ( Body ) Middle Part

◆ Composed of compact bone

EPIPHYSIS

◆ Ends of the bone

◆ Composed mostly of spongy bone

PERIOSTEUM

➢ Outside covering of the diaphysis

➢ Fibrous connective tissue membrane

SHARPEY’S FIBERS

Secure periosteum and underlying bone

ARTERIES

Supply bone cells with nutrients

ARTICULAR CARTILAGE

➢ Covers the external surface of the epiphyses

➢ Made of hyaline cartilage

➢ Decreases friction at joint surfaces

MEDULLARY CAVITY

➢ Cavity of the shaft

➢ Contains yellow marrow (mostly fat) in adults

➢ Contains red marrow (for blood cell formation)

Hyaline cartilage

In embryos, the skeleton is primarily

CHANGES IN HUMAN SKELETON

➢ Cartilage remains in isolated areas

➢ Bridge of the nose

➢ Parts of ribs

➢ Joints

Epiphyseal plates

allow for growth of long bone during childhood

New cartilage

What is continuously formed

Older cartilage

what becomes ossified

Bones

are remodeled and lengthened until growth stops

gravity &muscle pull

Bones change shape by

through periostium

Bones grow in width

Osteocytes

Mature bone cells

Osteoblasts

Bone-forming cells

Osteoclasts

Bone-destroying cells

• Break down bone matrix for remodeling and release of calcium

Bone remodeling

is a process by both osteoblasts and osteoclasts

AXIAL DIVISION and APPENDICULAR DIVISION

What are the two divisions the skeletal system includes?

• Skull and associated bones
• Auditory ossicles
• Hyoid bones
• Vertebral column
• Thoracic cage (Ribs + sternum)

What bones are included in the axial division?

• Pectoral girdle
• Pelvic girdle

What bones are included in the appendicular division?

What bones are included in the axial skeleton?

• Skull and associated bones
• Auditory ossicles
• Hyoid bones
• Vertebral column
• Thoracic cage
• Ribs + sternum

22 bones

How many bones are in the adult skull?

8 bones: frontal, occipital, 2 temporals, 2 parietals, sphenoid and ethmoid

How many bones are in the cranium?

14 bones: nasals, maxillae, zygomatics, mandible, lacrimals, palatines, inferior nasal conchae, vomer

How many bones are in the facial bones?

• Nasal cavity
• Orbits
• Paranasal sinuses mandible

• Auditory ossicles

What cavities does the skull form?

• Mandible

• Auditory ossicles

the only movable skull bone?

meninges

cranial bones also attach to membranes called?

outer surface

provides large areas for muscle attachment that move the head or provide facial expressions

meninges

what stabilize positions of the brain, blood vessels

cranial bones

The bones that make up the cranium, or skull.

are flat bones that protect the brain and provide a broad surface for muscle attachment

the frontal bone, parietal bones, occipital bone, temporal bones, ethmoid bone, and sphenoid bone

what includes the cranial bones?

Frontal bone (1)

forms the anterior third of the cranial dome, forms part of the cranial cavity as well as the fore head, the brow ridges and the nasal cavity

Parietal bones (2)

form the middle segment of the cranial dome, joined with each other along the midline by the sagittal suture. The left and right forms much of the superior and lateral portions of the cranium

Occipital bone (1)

forms the posterior portion of the cranial dome, curving inferiorly to the base of the cranium forms the posterior and inferior portions of the cranium.

Temporal bones (2)

at the sides of the cranium, extending inward to form part of the cranial floor. The left and right forms the lateral walls of the cranium as well as housing the external ear

Sphenoid bone (1)

is a butterfly shaped bone that forms part of the anterior floor and sides of the cranium. It forms part of the eye orbit and helps to form the floor of the cranium.

Ethmoid(1)

forms the middle portion of the anterior cranial floor, extending inferiorly between the eye orbits to also form the roof of the nasal cavity.

SUTURES

● Immovable joints that join skull bones together

● Form boundaries between skull bones

Coronal

between parietal and frontal

Sagittal

between parietal bones

Lambdoid

between the parietal and occipital

Squamous

between the parietal and temporal

Fontanels

usually ossify by 2 years of age

ORBITAL PLATES OF FRONTAL BONE

thin and irregular and separate the anterior cranial fossa from the orbital cavity

CRIBRIFORM PLATE OF THE ETHMOID BONE

thin depressed bone separating the anterior cranial fossa from the nasal cavity

CRISTA GALLI

superior perpendicular projection which is continuous below with the nasal septum on the frontal skull radiograph

SPHENOID BONE WITH LESSER WINGS ANTERIORLY, THE GREATER WINGS POSTERIORLY AND BODY

Houses the sphenoid sinuses and is grooved laterally by the carotid sulcus

ELEVATED SELLA TURCICA IN THE MIDLINE

Which houses the pituitary gland

MANDIBLE (1)

is the lower jawbone. It articulates with the temporal bones at the temporomandibular joints. This forms the only freely moveable joint in the head. It provides the chewing motion.

MAXILLA (2)

are the upper jaw bones. They form part of the nose, orbits, and roof of the mouth

PALATINE (2)

form a portion of the nasal cavity and the posterior portion of the roof of the mouth.

ZYGOMATIC (2)

➢ are the cheek bones. They form portions of the orbits as well.

NASAL (2)

form the superior portion of the bridge of the nose.

LACRIMAL (2)

help to form the orbits

VOMER (1)

forms part of the nasal septum (the divider between the nostrils)

NASAL CONCHAE (2 TURBINATES)

forms the lateral walls of the nose and increase the surface area of the nasal cavity.

● Frontal Sinuses

● Sphenoid Sinuses

● Ethmoid Sinuses

● Maxillary

what are the PARANASAL SINUSES

Sinusitis

is inflammation of the membrane (allergy)