Lesson objectives List and label the bones that make up the skull List and label the bones that make up the axial skeleton List and label the bones that make up the appendicular skeleton Describe the structure and functions of the skeleton

The Skull There are 22 bones in the skull 8 cranial 14 facial These bones protect the brain They also provide a surface for muscle attachment

Cranial Bones 1 x Ethmoid Bone 1 x Frontal Bone 1 x Occipital Bone 2 x Parietal Bones 1 x Sphenoid Bone 2 x Temporal Bones

Facial Bones 2x Turbinate Bones 2x Lacrimal Bones 1x Mandible 2x Maxillae (Singular = Maxilla) 2x Nasal Bones 2x Palatine Bones 1x Vomer 2x Zygomatic Bones

Side View of Skull

Front View of Skull Frontal Bone Nasal Bone Lacrimal Bone Ethmoid Bone Vomer Bone Turbinate Bone

Palatine Bones The palatine bone forms part of the nasal cavity and hard palate

Palatine Bones Palatine Bone

Sphenoid Bone A bone which forms the base of the cranium, behind the eye and below the front part of the brain It has two pairs of broad lateral ‘wings’ and a number of other projections, and contains two air-filled sinuses

Sphenoid Bone

Ethmoid Bone This is an unpaired bone in the skull that separates the nasal cavity from the brain It is located at the roof of the nose, between the two orbits

Ethmoid Bone

Lacrimal Bones Two small bones which form part of the eye sockets

Lacrimal Bones

Vomer Bone The vomer is one of the unpaired facial bones of the skull It is located in the midsagittal line, and joins with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones

Vomer Bone

Structure of Skeletal System Human skeleton is made up of 206 bones Babies born with over 300 bones Bones fuse together over time Bone is pound for pound stronger than steel

Structure of Skeletal System Human skeleton is made up of 206 bones Babies born with over 300 bones Bones fuse together over time Bone is pound for pound stronger than steel

Axial Skeleton Forms the core of the body Skull Spine Sternum Ribs

The Spine/Vertebral Column Provides support Protects spinal cord Comprises 33 bones 7 cervical - top 12 Thoracic - middle 5 Lumbar - bottom 5 Sacrum 4 Coccyx Sacrum and coccyx are fused, no movement 24 moveable bones

The Spine/Vertebral Column

Thoracic Cage Consists of the ribs, sternum and thoracic vertebrae Protects heart and lungs 12 pairs of ribs 7 true pairs attached to sternum 3 false ribs attached to cartilage of the 7th rib 2 pairs not attached (floating ribs)

Thoracic Cage

Appendicular Skeleton Shoulder girdle Upper Limbs Lower Limbs Pelvic girdle

Shoulder Girdle

A = Scaphoid B = Lunate C = Triquetral D = Pisiform E = Trapezium F = Trapezoid G = Capitate H = Hamate

Bones of Wrist 8 bones S = Sally - Scaphoid L = Left - Lunate T = The - Triquetral/Triquetrum P = Party - Pisiform T = To - Trapezium T = Take - Trapezoid C = Cathy - Capitate H = Home - Hamate

Pelvic Girdle Two hip bones joined together The each hip bone consists of three different bones: Ilium Ischium Pubis

Pelvic Girdle

Pelvic Girdle

Functions of Skeletal System The skeletal system has 7 major functions: Movement Support Shape Protection Muscle attachments Formation of blood cells Mineral storage

Muscle Attachment and Movement Muscles attach to bone by tendons Muscles contract Bones act as levers and help movement

Support and Shape Holds weight of the body Wouldn’t be able to stand up Bones gives shape to structures – skull, ribs etc.

Protection Helps protect body vital organs and structures Ribs – heart and lungs Cranium – brain Vertebrae – spinal cord

Formation of Blood Cells & Mineral Storage Important minerals (calcium) stored in bone marrow Blood cells created in bone marrow

Structure of Bone Bone is made from special cells Osteoblasts Different types of bone tissue: Compact Cancellous or Spongy bone Marrow

Compact Bone Gives bones hardness Protects spongy bone Provides framework for the bone and body

Cancellous/Spongy Bone Lighter in weight than compact bone Sponge-like appearance Web like structure, consists of red bone marrow Contains blood vessels which carry oxygen and nutrients

Bone Marrow Found inside bone Main function is the production of blood cells Two different types: Red bone marrow Yellow bone marrow

Red Bone Marrow Responsible for producing blood cells Babies bones made up of mostly red marrow Within a few years red marrow will change to yellow marrow Mainly found in flat, irregular and sesamoid bones

Yellow Bone Marrow Consists mainly of fat cells Can be used as energy in extreme starvation conditions Can be converted into red marrow within 2 hours

Bone Types Long Short Flat Irregular Sesamoid

Long Bones Characterised by a shaft Longer than they are wide Made of mostly compact bone with little spongy bone Usually found in the limbs, fingers and toes

Short Bones Usually more cube shaped Thin layer of compact bone covering more spongy bone Usually found in the wrist and ankle

Flat Bones Thin, usually curved bones Two thin parallel layers of compact bone sandwiching a layer of spongy bone Found in the skull, scapula and sternum

Irregular Bones Thin layer of compact bone surrounding spongy bone Irregular shape Can be found in the vertebrae

Sesamoid Bones Bones embedded in tendons Increase the distance between a tendon and a joint Increase the leverage of the muscle Example - Patella