Presentation is loading. Please wait.

Presentation is loading. Please wait.

Chapter 5 Skeletal System. Functions of Bone - How do bones contribute to homeostasis? - Protection -Support -Movement -Storage- store fat & minerals.

Similar presentations


Presentation on theme: "Chapter 5 Skeletal System. Functions of Bone - How do bones contribute to homeostasis? - Protection -Support -Movement -Storage- store fat & minerals."— Presentation transcript:

1 Chapter 5 Skeletal System

2 Functions of Bone - How do bones contribute to homeostasis? - Protection -Support -Movement -Storage- store fat & minerals -Blood cell formation- blood cells are formed within the marrow cavities of certain bones

3 Anatomy of Bone

4 Types of Bone Compact Bone: -Dense -Smooth Spongy Bone: -Composed of small pieces of bone -Lots of space All bones fall under these two basic types: How many bones make up our skeleton?!? -206!

5 Types of Bone Long Bone Flat Bone -thin, flattened -usually curved -made up of layers of spongy bone squished between 2 compact bones -longer then they are wide -mostly compact bone After a bone is classified as either compact or spongy they are further classified according to their shape -4 types of shape:

6 Types of Bone Cont’d Irregular Bone Short Bone -bones that don’t fit into the other categories -cubed shaped -mostly spongy bone

7 Classification of Bones - Take a few minutes to classify the bones of the skeleton

8 Closer look at long bones -important structures of long bone: in the picture your femur -diaphysis -periosteum -epiphyses -articular cartilage -epiphyseal line -epiphyseal plate

9 Closer look at long bones -important structures of long bone: -diaphysis : AKA the shaft -makes up the bone’s length -covered in protective fibrous connective tissue called periosteum epiphyses : ends of long bone - covered by protective cartilage, articular cartilage

10 Closer look at long bones -important structures of long bone: -epiphyses: 2 ends of the bone -proximal epiphyses -remember what proximal means? -closer to trunk/torso -distal epiphyses -distal is the opposite, further away from the trunk/torso

11 Closer look at long bones -important structures of long bone: -epiphyseal line: found in adult bones -remnant of epiphyseal plate -which is seen in young growing bones -cause growing of long bones -end of puberty hormones stop growth of long bones, the plate is replaced by bone leaving a line to mark its location

12 Microscopic look at long bones -important structures of compact bone that is only visible under a microscope: -riddled with passageways carrying nerves, blood vessels & provide living bone cells with nutrients -osteocytes: mature bone cells -found in tiny cavities within the matrix called lacunae -lacunae arranged in circles called lamellae around central canals -each complex contains a central canal & matrix rings are known as osteon or Haversian system

13 -osteocytes: mature bone cells -found in tiny cavities lacunae -lacunae arranged in circles called lamellae around central canals -each complex contains a central canal & rings are called osteon or Haversian system

14 Red & Yellow Bone Marrow Yellow Marrow -middle cavity of a long bone shaft stores yellow marrow, AKA medullary cavity -made of adipose fat tissue Red Marrow -in infants middle cavity forms blood cells & red marrow -in adults red marrow is confined to the cavities in spongy none - Found in flat bones (ribs, vertebrae, pelvic bones)

15 Hyaline Cartilage Abundant cartilage fibers hidden by a rubbery matrix with glassy blue-white appearance

16

17 Bone Growth and Formation Babies -Embryo: hyaline cartilage -Infant: cartilage replaced by bone Fibrous membranes connecting flat bones Adults -Almost entirely bone -Isolated cartilage remains (nose, ear, etc) Flat bones replace connective membranes

18 Bone Growth and Formation -bones use cartilage as “models” during bone formation (ossification) -ossification happens in two steps: 1.Hyaline cartilage model is superficially covered with bone matrix by osteoblasts 2.Hyaline cartilage is broken down, leaving behind an empty, medullary cavity.

19 Ossification

20 Ossification Cont’d After birth, only two regions of cartilage remain: articular cartilages and epiphyseal plates -articular cartilage covers ends of long bones

21 https://www.youtube.com/watch?v=p-3PuLXp9Wg

22 Bone Remodeling Bones change as the body grows. Why is this necessary? As the body changes in size and weight, our bones must compensate for the additional mass. Additionally, bones become thicker & form projections where bulky muscles attach

23 Bone Remodeling occurs in response to two factors: Blood Calcium Levels - Healthy balance must exist between Ca stored and excreted -Proper [Ca] is controlled by endocrine system Calcitonin- storing calcium Parahormone- release calcium into bloodstream Pull of gravity and muscles on the skeleton Determines where skeleton is remodeled

24

25

26 Axial & Appendicular Skeleton Axial Skeleton: -divided into 3 parts: -skull -vertebral column -bony thorax Appendicular Skeleton: -composed of 126 bones of the limbs -pectoral & pelvic gridle Our skeleton is divided into two parts:

27 Axial Skeleton Skull, vertebral column, bony thorax

28 Appendicular Skeleton Bones of the limbs and girdles

29 Joints in our body Place where two bones come together Classified by the amount of movement they allow -immovable -slightly movable -freely movable

30 Joints in our body 4 types of joints in our body: 1. Hinge- only one single action is allowed -similar to opening & closing a door Ex: -our elbow & fingers 2. Ball & socket- rounded curved shape surface of one bone fits into concave, cup shaped surface of another bone -allows for 360 degree movement Ex: - our hip & shoulder bone

31 Joints in our body 4 types of joints in our body: 3. Pivot- movement occurs in a half circle, rotation of one bone around another Ex: 4. Plane/gliding- surfaces are flat, only sliding & twisting movements are allowed without any circular movement Ex: -carpals in our wrist, tarsals in our ankle -joint between the axis & atlas of neck

32 Healing a Bone Occurs in 4 Steps: 1.Hematoma is formed 2.Break is splinted by fibrocartilage 3.Bony callus is formed 4.Bone remodeling occurs


Download ppt "Chapter 5 Skeletal System. Functions of Bone - How do bones contribute to homeostasis? - Protection -Support -Movement -Storage- store fat & minerals."

Similar presentations


Ads by Google