Chapter 6 & 11

Connective Tissues and

Skeletal System

Objectives To be familiar with the different connective

tissues. To explain how fat cells grow. To differentiate cartilage from bones. To compare the three kinds of cartilage. To identify the different bones of the body. To compare & contrast axial from

appendicular skeleton. To understand how the skeletal system

works.

Connective Tissue

FunctionsConnect, bind,

support, transport, fight infection and store materials

CharacteristicsCells are far apart in

arrangementComposed of large

amount of intercellular material also known as matrix

Types of Fibers Composing the Matrix of Connective Tissues

Collagenous FiberElastic FiberReticular fiber

Collagen Fiber

-Long, wavy and arrange parallel to each other

Collagenous Fiber

Locations: tendons and ligaments

Functions: strong flexible support

ELASTIC Fiber

The light pink in this tissue is smooth muscle.

Elastic tissue has numerous bundles of elastic fibers with interspersed flattened fibroblasts and collagen fibers.

Location: large arteries, bronchial tubes

Function: Elastic fibers can stretch l 1/2 times their length and then recoil. These fibers will provide elasticity to tissues.

ELASTIC Fiber

RETICULAR FIBER

Reticular tissue supplies the supporting framework for bone marrow and lymphoid hematopoitic (blood cell making) organs.

Locations: spleen, lymph nodes, liver

Function: gives support to soft organs

Classification of Connective Tissue

A. LOOSE CONNECTIVE TISSUE Areolar Reticular Adipose Elastic

1. AREOLAR CONNECTIVE

Locations: beneath the skin and around blood vessels, muscles and nerves

Functions: binds one tissue to another (as skin connects to muscle), protection and nourishment to the organs and structures it binds, and stores "body fluid"

Cells found in the matrix of Areolar Tissue

Fibroblast or Fibrocytes – active in repair and synthesis of fibers and protein.

Macrophage – agent of defense, engulf foreign bodies present in the tissue.

Mast Cells – produce heparin and histamine.

Plasma cell capable of forming antibodies.

Mesenchymal cell- developed into LCT, aka embryonic LCT cell

2. ADIPOSE TISSUE

The cells appear empty. Cells are filled with fat globules (B).

Locations/functions:-- Anywhere there is an empty space in the body fat is stored as a source of energy and may provide insulation.--The kidneys are correctly positioned and cushioned by adipose tissue.

--The eye is cushioned in the orbit by adipose.

Adipose Tissue

is localized to certain depots within the body but may accumulate anywhere.

In men it normally represents some 15-20% of body weight and in women, 20-25% of body weight.

Subcutaneous adipose tissue helps to shape, cushion and insulate the body. It also helps to hold some organs in place.

Almost all adipose tissue in adults is the called yellow adipose tissue

3. RETICULAR TISSUE

4. ELASTIC TISSUE

B. DENSE CONNECTIVE TISSUE

Dense connective tissue has many collagen fibers arranged in bundles and fewer cells. It is stronger and less flexible than loose connective tissue.

Dense irregular connective tissue, as seen in the dermis, has abundant collagen fibers in bundles with no particular orientation. This allows the tissue to handle stress from any direction.

Dense regular connective tissue, as found in tendons and ligaments, is characterized by collagen bundles being oriented in the direction of prolonged maximum stress. Both types of dense connective tissue have a shiny white sometimes translucent appearance in the natural state.

1. Dense Regular connective tissue

Location : Tendon - connects muscle

to bone Ligament – connects bone

to bone Aponeurosis - connect

muscle to muscle Fascia – covers the whole

muscle & hold them together Membrane – covers organs

and cavities

2. Dense Irregular Connective Tissue

Location :Dermis of the skinSheaths of nerves,

muscles and tendons

C. SUPPORTIVE CONNECTIVE TISSUE

Characterized by dense, rigid and firm matrix with cells that are far apart and locked up fluid filled spaces.

1.Cartilage

Cartilage is specialized to bear mechanical stress without permanent distortion.

Consist of protein called CHONDRIN. Avascular Perichondrium – membrane that

covers the matrix of cartilage

Cartilage

As was true with the connective tissues proper, these tissues contain various amounts and types of matrix, fibers and cells. Included here are:

Hyaline Cartilage Fibrocartilage Elastic Cartilage

a.HYALINE CARTILAGE

The chondrocytes (A) are located in lacunae (C). The matrix (B) contain collagen fibers that are so fine they are not visible in tissue preparations.

Locations: "C" rings in the trachea, nose, articular ends of bones, fetal skeleton

Function: precursor to bone, support

Hyaline cartilage is found in the fetus where it forms the fetal skeleton that is later ossified and becomes bone

b. ELASTIC CARTILAGE The chondrocytes (A) are

contained in lacunae (C). The matrix (B) contains abundant elastic fibers.These fibers give great flexibility to this tissue.

Locations: ear, auditory canal, epiglottis

Functions: flexible support

Elastic cartilage contains many elastic fibers giving it a yellowish color. it can be found in the auricle of the ear, ear canal, and epiglottis.

c. FIBROCARTILAGE

Locations: pubic symphysis, intervertebral discs

Functions: supports, withstands compression

Fibrocartilage contains a perichondrium in fibrocartilage

2. BONE

In the center of the osteon is the central canal (A) which hold the blood vessels and a nerve. These canals are surrounded by concentric rings of inorganic matrix, the lamellae (B). Between the lamellae are bone cells, the osteocytes (C) located in lacunae. Nutrients diffuse from cell to cell through the canaliculi (D).

Location: skeleton Function: framework,

protection

LOVE, LOVE, LOVE

Happy Valentines Day

SKELETAL SYSTEM

Functions ; Support Protection Helping in movement Storage of minerals Production of red blood cells Chemical energy storage

There are 206 bones in the body and these bones and cartilages help provide the support and points of attachment to many soft tissues, muscles and ligaments in the body.

Vitamins and Hormones that regulate bone formation and growth

1. Vitamin D – increase the rate of calcium absorption from the intestine.

Deficiency would cause rickets in children and osteomalacia in adults.

Vitamins and Hormones that regulate bone formation and growth

2. Vitamin A – important in the synthesis of collagen that makes the bone resilient.

Night Blindness is the first sign of Vit. A

deficiency

3. Vitamin C – stimulates the release of enzymes that stimulate bone resorption activity.

Bone resorption is the process by which osteoclasts break down bone and release the minerals, resulting in a transfer of calcium from bone fluid to the blood.

Vitamins and Hormones that regulate bone formation and growth

Vitamins and Hormones that regulate bone formation and growth

4. Thyroxin- a hormone secreted by the thyroid gland that increase the rate of bone replacement & important in the synthesis of other growth hormones.

Vitamins and Hormones that regulate bone formation and growth

6.Calcitonin & parahormone – that regulate the release of calcium from bone.

Bone remodeling, or renewal, recycles as much as 18% of bone matter.

This allows the body to regulate how much calcium in concentrated in our blood.

Parathyroid hormone increases calcium concentrations in the blood and calcitonin has the opposite effect.

. 5. Estrogens & Androgens – are respectively female & male hormones that promote ossification & maintenance of the bone matrix.

Estrogen can increase osteoblasts and that is why women, whose estrogen levels are diminishing in menopause, suffer bone loss.

Stress that encourages bone growth is not a bad thing, walking, strength training and jogging all encourage stronger bone growth

Bone Formation

1. Hematoma forms at break

2. Fibrocartilaginous callus will fill the space

3. Bony callus formed by osteoblasts.

4. Osteoblasts build new compact bone and osteoclasts create new medullary cavity.

Skeletal System The skeleton contains 99% of the body's

total calcium. Inorganic portions of the bone matrix

represents about 50% of bone by weight. Calcium, phosphorus, magnesium, citrate, potassium, and sodium are found there but the substance that gives bone its hardness is hydroxyapatite made from calcium and phosphate.

Hydoxyapatite crystals are associated with collagen in bone giving it its strength and resistance.

Classification of Bone According to Shape

Long – humerus, femur, tibia, fibula, radius & ulna

Short – clavicle, metacarpals & metatarsals

Flat – scapula, cranial, ribs & pelvic

Irregular – carpal, tarsal, vertebrae & auditory ossicles

Membrane Covering of Bones

Periosteum – outer covering of the bone

Endosteum – lines the cavities and haversian canal

Axial Skeleton:

Skull spinal column sacrum Ribs sternum ear ossicles hyoid bone

Appendicular Skeleton

composed of 126 bones.

shoulder girdle:claviclescapula

arms:humerusulnaradiuscarpalsmetacarpalsphalanges

appendicular skeleton

pelvic girdle:pelvis

legs:femurpatellatibiafibulatarsalsmetatarsalsphalanges

Homology

PECTORAL GIRDLE PECVIC GIRDLE

Clavicle PubisScapula IliumCoracoid IschiumHumerus FemurRadius -Ulna Tibia-FibulaCarpals TarsalsMetacarpals MetatarsalsPhalanges Phalanges

Difference between Male & Female Skeleton

MALE More shallow Longer and denser Squarer chin Skull has a small bulge at the

back. external occipital protuberance

male brow is more pronounced Men have one fewer rib than

women, IS NOT TRUE

Female Lower & Wider Shorter Chin rounded or

oval Rounded

Exam next meeting…