Chapter 6 - Bones and Skeletal Tissue

Question 1

Cartilage; Fibrous Membrane

Answer 1

Most get replaced by bone, those that remain will be where flexibility is needed
A. Structure of cartilage – some variety of cartilage tissue (water which gives it its resistance; has no blood vessels or nerves and is surrounded by perichondrium layer
1. Perichondrium – dense irregular connective tissue and it contains blood vessels from which nutrients defuse through the matrix; it acts as a girdles to resist outward expansion when cartilage is expressed.

Question 2

Hyaline Cartilage

Answer 2

Most abundant

a. Structure – composed of spherical condrocytes and fine collagen fibers which are not detectable microscopicly
b. Function – provide support, flexibility and resilience
c. Types of hyaline cartilage
i. Articular cartilage – cover the ends of most bones at movable joints
ii. Costal cartilage – connects the ribs to the sternum (breastbone)
iii. Respiratory cartilage – forms the skeleton of the larynx (voicebox)
iv. Nasal cartilage – external nose

Question 3

Elastic Cartilage

Answer 3

a. Structure – looks like hyaline, but contains more stretchy elastic fibers
b. Function – stand up to repeated bending and maintain shape
c. Locations – external ear and epiglottis

Question 4

Fibrocartilage

Answer 4

a. Structure – highly compressible and has great tensile strength and looks like parallel rows of chondrocytes alternating with thick collagen fibers
b. Function – withstands heavy pressure and stretch
c. Locations – in knee menisci (in between joint; between vertebrae and pubic symphysis)

Question 5

Bone: Functions

Answer 5

1. Support – provides framework that supports the body (legs act as pillars to hold up the rest of the body)
2. Protection – fused bones of the skull protect the brain; vertebra protect the spinal cord and the organs in the thorax
3. Movement – they work with tendons and muscles and they are used as leavers to move other parts
4. Mineral storage – deposits mineral stored (calcium and phosphate) and bone is going to release them into the blood stream
5. Production of blood cells – process of producing blood cells is called hematopoiesis; fat is stored in bone cavities which can be used as a source of energy

Question 6

Bones: Classification of the Skeleton

Answer 6

206 divided into:

1. Axial skeleton
   a. Bones – skull, vertebral column, and rib cage
   b. Functions – protecting, supporting or carrying other body parts
2. Appendicular skeleton
   a. Bones – bones of upper and lower limbs and the girdles (shoulder bones and hip bones that attach the limps to the axial skeleton)
   b. Functions – locomotion (moving) and manipulate the environment

Question 7

Bones: Classification of Bones

Answer 7

1. Long bones
   a. Description – elongated shape and NOT their overall size; longer than they are wide and have a shaft two end
   b. Examples – all limb
   bones except the patella and wrist and ankle bones
2. Short bones
   a. Description – are roughly cube shape; sesamoid – special type of short bone that form in a tendon (patella)
   b. Examples wrist and ankle bones
3. Flat bones
   a. Description – thin, flattened, and usually a bit curved
   b. Examples – sternum, scapula bones, ribs, and most of the skull bones
4. Irregular bones
   a. Description – have a complicated shape
   b. Examples – vertebrae and the hip bones

Question 8

Structure of Bones

Answer 8

1. Bones as organs – two or more tissues; bone tissue dominates the tissue but there are nervous tissue, cartilage, fibrous connective tissue, muscle and epithelia tissue in the blood vessels.
2. Gross anatomy of bones – bone as whole with the naked eye
   a. Bone markings – surface of bone is very rarely smooth; this will serve attachments or as joint surfaces or as con do it’s for blood vessels

Question 9

Bone Projections that Attach to Muscles (TTCLETSP)

Answer 9

1. Tuberosity – large rounded projection that may be roughened or may have a rough appearance to it
2. Tubercle – small rounded projection or a process
3. Crest – narrow ridge of bone which is usually prominent
4. Line – narrow ridge of bone that is less prominent than a crest
5. Epicondyle – raised area on or above a condyle
6. Trochanter – very large, blunt, irregularly shaped process
7. Spine – sharp, slender, often pointed projection
8. Process – any bony prominence

Question 10

Bone Projections that form Joints (HCRF)

Answer 10

1. Head – boney expansion, carried on a narrow neck
2. Condyle – rounded articular projection
3. Ramus – arm like bar of bone
4. Facet – smooth, nearly flat articular surface

Question 11

Bone Depressions (FG)

Answer 11

Allowing blood vessels and nerve to pass
A. Fossa – shallow, basin like depression in a bone, often serving as an articular surface
B. Groove – furrow (rut)

Question 12

Bone Openings (MFFNS)

Answer 12

Allowing blood vessels and nerve to pass
A. Meatus – canal like passageway
B. Fissure – narrow, slit like opening
C. Foramen – round or oval opening through a bone
D. Notch – indentation at the edge of a structure
E. Sinus – cavity within a bone, filled with air and lined with mucous membrane

Question 13

Compact Bone

Answer 13

External Layer

Question 14

Spongy Bone

Answer 14

Honey comb of small needle like or flat pieces called trabeculae

Question 15

Trabeculae

Answer 15

In spongy bone area and their tiny bone struts which help bone resist stree

Question 16

Long Bone Structure: Diaphysis

Answer 16

Diaphysis – a tubular or shaft forms the long axis of the bone; it’s constructed of thick compact bone layers that surround the central medullary cavity
A. Medullary cavity – contains fat – yellow bone marrow cavity

Question 17

Long Bone Structure: Epiphyses

Answer 17

Epiphyses – are the bone ends and are formed of compact and spongy bone; joint surfaces are covered by articular or hyaline cartilage which cushions the opposing bone ends during joint movement and absorbs stress
A. Hematopoietic tissue – found within trebuclar cavities of spongy bone
B. Epiphyseal line – aka metaphysis – and is located between the diaphysis and the epiphyseal line and is the piphyesel plate or line – epiphyseal plate is a disc of hyaline cartilage that grows during childhood to lengthen the bone

Question 18

Long Bone Structure: Membranes

Answer 18

A. Periosteum – is a glistening white, double layer membrane, that cover the entire external surface of long bones except the joint surface
1. Fibrous layer – outer layer and is composed of dense irregular connective tissue
2. Osteogenic layer – inner layer and consists of ostoblasts (bone germinators)
3. Perforating fibers – aka sharpies fibers – they secure the periosteum to bone, tufts of collagen which extend from the fibrous layer of periosteum to the bone matrix
4. Nutrient foramen – openings in the periosteum which allow for the passage of nerve fibers, lymphatic vessels, and blood vessels
B. Endosteum – delicate connective tissue membrane which covers the internal bone surfaces, covers the trebucla and lines the canals

Question 19

Short, Flat and Irregular Bone Structure

Answer 19

Don’t have a shaft or an epipheyes, they have an active marrow, so they’re used for biopsy (sternum or coxyll – 3 bones fused together
i. Diploё – spongy bone in flat bone (resembles stiffened sandwich)

Question 20

Microscopic Anatomy of Compact Bone

Answer 20

Looks dense but contains passage ways for nerves and vessels, it is adapted to support weight and withstand tension stress

Question 21

Microscopic Anatomy of Compact Bone: Osteon

Answer 21

Haversian system – structural unit of compact bone
A. Lamellae – little plates; its hollow tube of bone matrix found surrounding the central canal (rings of the tree trunk)
B. Central canal – aka haversian canal – runs through the core of each osteon and contains small vessels and nerve fibers
C. Perforating canals – aka Volkmann’s canals – lie at right angles to the long axis of the bone and connect the blood and nerve supply of the periosteum to that in the central canal and medullary cavity
D. Lacunae – little hollow spaces at the junctions of the lamellae which contain ostocytes
E. Canaliculi – hair like canals that connect the lacunae to each other and to the central canal

Question 22

Microscopic Anatomy of Compact Bone: Interstitial Lamellae

Answer 22

Fill gaps between osteons

Question 23

Microscopic Anatomy of Compact Bone: Circumferential Lamellae

Answer 23

Found deep in the periosteum and superficial to the endosteum, extend around the entire circumference of the diaphysis and effectively resist twisting of the long bone

Question 24

Microscopic Anatomy of Spongy Bone

Answer 24

Looks like a poorly organized tissue; only a few cells thick and contains irregularly arranged lameua and osteocytes which are interconnected by caniliculi, it has no ostons and the nuetrins reach by defusing through canaliculi from capillaries that s in the endosteum surrounding the trabeculae

Question 25

Chemical Composition of Bones

Answer 25

Balance of the two components of bone maintain strong durable bones

a. Organic components – cells (ostocytes, ostoblasts, and ostoclass) and ostioid – ground substances and collagen fibers
b. Inorganic components – hydroxy appetites (mineral salts – largely calcium phosphates)