Lab Q4

Question 1

What are three types of connective tissue in the skeletal system?

Answer 1

Bones: hard elements of the skeleton
Ligaments: consist of dense fibrous connective tissue
Bind bones to each other
Cartilage: specialized connective tissue consisting primarily of collagen and elastin in a gel-like fluid called ground substance
Reduces friction in joints

Question 2

What do ligaments do?

Answer 2

Attach bone to bone

Give strength to certain joints while still permitting movement

Question 3

Cartilage?

Answer 3

Is a flexible connective tissue found in the joints between bones, the rib cage, the ear, the nose, the bronchial tubes and the intervertebral discs.
It is not as hard and rigid as bone but is stiffer and less flexible than muscle.

Question 4

3 types of cartilage?

Answer 4

Fibrocartilage: consists primarily of collagen fibers arranged in thick bundles
Withstands pressure and tension
Examples: intervertebral disks, knee joint-menisci
Hyaline cartilage: smooth almost glassy cartilage of thin fibers
Forms embryonic structures that later become bones
Covers the ends of mature bones in joints: smooth low-friction surface
Elastic cartilage: mostly elastin fibers, very flexible
Lends structure to the outer ear and epiglottis

Question 5

Chondrocytes?

Answer 5

Specialized cells.
Does not contain blood vessels.
Grows and repairs slowly.

Question 6

Matrix?

Answer 6

Composed of different fibers and ground material.

Question 7

Bones (complex tissue)-

Answer 7

-living cells and long twisted collagen fibers.
-Extracellular deposits of calcium minerals
-These are supported by crystals of hydroxyapatite (mineral: Ca, P, and H20).
This combination of flexible and rigid gives bones an amazing combination of strength, rigidity, and resistance to impact.
Bone tissue undergoes constant replacement, remodeling & repair

Question 8

Epiphysis?

Answer 8

-Distal or Proximal ends of long bones.
-At the joint the epiphysis is covered with articular cartilage.
-Filled with red bone marrow, which produces erythrocytes (red blood cells).
-Compact bone covers each end.
Spongy bone tissue: Provides strength & support with minimal weight.

Question 9

Metaphysis-

Answer 9

• includes the growth plate/epiphyseal plate or line
• Wide portion of a long bone between the epiphysis and the narrow diaphysis.
• It is considered a part of the growth plate, the part of the bone that grows during childhood and as it grows, it ossifies near the diaphysis and the epiphyses.

Question 10

Diaphysis-

Answer 10

Middle section of a long bone.
Composed of compact bone.
The inside is hollow: contains the yellow bone marrow
Yellow bone marrow: primarily fat, can be utilized for energy

Question 11

Periosteum

Answer 11

Periosteum: outer surface of the bone

Question 12

Osteoprogenitor cells?

Answer 12

Are the only bone cells that divide. They differentiate and form the Osteoblasts, which form the new bone tissue

Question 13

Osteoclasts?

Answer 13

type of bone cell that resorbs bone tissue.
Their function is critical in the maintenance and repair of compact bones.
They are involved in the mobilization of calcium and the destruction of the bone matrix.
Found on bone surfaces and are important in the normal growth, maintenance and repair of bone.

Question 14

Osteoblasts-

Answer 14

Osteoblasts: Bone forming cells.
Found on all bone surfaces.
Are enlarged and active at all sites of bone repair and growth.
As they secrete bone matrix they surround and isolate themselves.
Eventually become Osteocytes.

Question 15

5 major function s of the skeleton?

Answer 15

Support
Protection of organs
Muscle attachment
Blood cell formation: bone marrow produces blood cells
Mineral and fat storage: Minerals include Calcium & Phosporous

Question 16

Osteocytes-

Answer 16

When the area surrounding an osteoblast calcifies, the osteoblast becomes trapped and transforms into an osteocyte.
Mature, resting bone cells trapped in bony matrix.
They function to maintain the surrounding bone tissue, dealing with the metabolic requirements, waste products, mineral homeostasis etc.

Question 17

Bone cell overview?

Answer 17

Osteoclasts and osteoblasts are instrumental in controlling the amount of bone tissue: osteoblasts form bone, osteoclasts re-absorb bone.
Bone tissue is formed by osteoblasts, maintained by osteocytes and broken down by osteoclasts.
Bone is a dynamic tissue that is constantly being reshaped by osteoblasts, which are in charge of production of matrix and mineral, and osteoclasts, which break down the tissue.

Question 18

X section of the bone?

Answer 18

Compact bone

Question 19

Haversian canal?
Lamellae?
Lacunae?
Osteon?

Answer 19

Haversian canal: Central canal through which nerves and blood vessels flow.
Lamellae: concentric layers of bone tissue that surround a central canal.
Lacunae: small space containing an osteocyte in bone. Connected to one another by small canals called canaliculi.
Osteon: Haversian system. Fundamental functional unit of compact bone.

Question 20

Osteocytes cell?

Answer 20

Osteocytes: branched cell found in lacunae. Long lived cells that do not divide but are involved in maintaining mature bone tissue.

Question 21

Ossification?

Answer 21

Ossification: Process of replacing most of the cartilage by bones.

Question 22

Active skeletal growth is controlled by three factors-

Answer 22

Active skeletal growth: begins in the embryo and continues until age 25.
This growth is controlled by 3 factors:
1) Growth hormone
2) Combination of stresses: exercise and gravity
3) Levels of circulating calcium in the bloodstream

Question 23

Epiphyseal plates?

Answer 23

Epiphyseal plates (growth):
New cartilage is continuously produced and steadily replaced by new bone tissue.

Question 24

Embryo?

Answer 24

Nearly the entire skeleton is made out of cartilage.

As the skeleton (bones) grow, new cartilage is added and the older cartilage is broken down and replaced by bone.

Question 25

Osteoporosis?

Answer 25

Osteoporosis is a disease in which bones become fragile and more likely to fracture. Bone mass declines slowly after age 30. In some elderly individuals mineral loss can so weaken bones so they break under minimal stress.
Occurs when the creation of new bone doesn’t keep up with the removal of old bone. (Changes in balance between bone production & Destruction)

Question 26

Causes of osteoporosis?

Answer 26

Causes: Your bones are in a constant state of renewal — new bone is made and old bone is broken down. When you’re young, your body makes new bone faster than it breaks down old bone and your bone mass increases. Most people reach their peak bone mass by their early 20s. As people age, bone mass is lost faster than it’s created.

Question 27

Symptoms of osteoporosis?

Answer 27

Back pain, caused by a fractured or collapsed vertebra
Loss of height over time
A stooped posture
A bone fracture that occurs much more easily than expected

Question 28

Treatments of osteoporosis?

Answer 28

Treatments:
Medications
Hormone replacement therapy
Changes in diet and exercise.

Question 29

Osteoporosis risk factors?

Answer 29

Risk factors:
Women are more likely to develop it than men are.
The older you get the more likely you will develop it.
Reduction of estrogen levels after Menopause is one of the strongest risk factors.
A lifetime lack of Calcium: Diet is very important
Lack of exercise.
Tobacco and alcohol use increase the risk of getting osteoporosis.

Question 30

Rickets-

Answer 30

Rickets: Children (Pre-plate closure)

Rickets is a deficiency of Vitamin D, phosphorus and/or Calcium. Causes defective mineralization of the bones (usually happen during childhood) before the bones stop growing.
It is one of the most frequent childhood diseases in many developing countries. Generally occurs in children suffering from severe malnutrition (famine or starvation).
Replacing calcium, phosphorus, or vitamin D that is lacking will eliminate most symptoms of rickets.

Question 31

How do bones heal?
Fracture hematoma-
Fibrocartilage callus-
Bony callus-
Remodeling-

Answer 31

How do bones heal?

Fracture hematoma: During injury to the bone blood fills the site. Forms a hematoma. Swelling and pain.
Fibrocartilage callus: After several hours the spongy bone fills in and forms a soft callus. New blood vessels form.
Bony callus: After a few weeks the bony callus replaces the soft callus. This callus is able to support the bone and the cast can be removed.
Remodeling: Months later the fracture site is remodeled and completely healed.

Question 32

Fibrous joint-

Answer 32

Fibrous joint: suture, immobile joint found only among the bones of the skull.
At birth, the skull is still partly cartilage and the sutures between the bones are slightly flexible. Allows the fetus’s head to flex as it squeezes through the birth canal.
During the next 18 months the skull solidifies and the edges of bones interlock together.
After bone growth stops the membrane lining is replaced by bone.

Question 33

Cartilaginous joints-

Answer 33

Joints between ribs and sternum: tight, scarcely moveable joints. Can move slightly during breathing but are ribs are firmly attached to the sternum.
Vertebrae in the spinal column: Designed for support and resilience, not for extensive movement and can be damaged if bent too far under pressure.
Ex. Herniated disk: lifting heavy weights with a bent back.

Question 34

Synovial joints-

Answer 34

known for their strength and movement.
Consists of a combination of tendons and ligaments that for a fibrous joint capsule. Helps hold the bones together.
Inside the capsule, bone surfaces are lined with resilient cartilage and “oiled” with synovial fluid.

Question 35

Bone shapes:
Long bones – 
Short bones –
Flat bones – 
Sesemoid bones –
Irregular shape -

Answer 35

Long bones – femur
Short bones – hand & foot bones
Flat bones – shoulder blade, pelvic bone
Sesemoid bones – patella
Irregular shape - vertebrae

Question 36

Axial skeleton?

Answer 36

Axial Skeleton:

Composed of the central supporting elements:
Includes the skull, the vertebral column, the ribs and the sternum.
Skull: cranial & facial bones
2 dozen bones
Protect brain and form the face
Vertebral Column: body’s main axis
33 irregular bones
Ribs: 12 pairs
Upper 7 attach via cartilage to sternum
8-10 joined by cartilage to 7th rib
11-12 floating ribs
Protects thoracic cavity
Also helps us breathe-muscles between ribs
Sternum: breastbone (3 fused bones)

Question 37

Appendicular skeleton

Answer 37

Appendicular Skeleton

Consists of the arm and leg bones, together with the pectoral and pelvic girdles.
Pectoral girdle:
Clavicles: collar bones
Scapulae: shoulder blades
Arms: humerus, radius, ulna
Radius swivels at the elbow.
Ulna swivels at the wrist.
Hands: carpals, metacarpals, phalanges
Pelvic girdle: hip bone
Created by fusion of paired bones
Includes ilium, ischium, pubis, sacrum
Legs: Femur, tibia, fibula
Feet: tarsals, metatarsals, phalanges

Question 38

Review:
Function of the skeletal system
How can we classify bones?
Bone development and growth
X-section of compact bone tissue: look at slides
Cartilage tissue: look under microscope
What are the 4 types of bone cells and what do they each do?
What are osteoporosis and rickets?
How do bones heal?
Joint structure and function
Axial Skeleton
Appendicular Skeleton

Answer 38

Function of the skeletal system
How can we classify bones?
Bone development and growth
X-section of compact bone tissue: look at slides
Cartilage tissue: look under microscope
What are the 4 types of bone cells and what do they each do?
What are osteoporosis and rickets?
How do bones heal?
Joint structure and function
Axial Skeleton
Appendicular Skeleton