Lecture Quiz #3

Question 1

Besides supporting the other tissues of the body, what else do bones do?

Answer 1

Protection of vital organs (skull, etc)
Leverage to move the body around in it’s environment
Storage sites for minerals, particularly calcium
Blood cell formation, i.e. hematopoiesis

Question 2

What are the hormones that regulate/act as cashiers at the calcium bank?

Answer 2

Cacitonin from the thyroid prevents hypercalcemia

Parathyroid hormone from the parathyroid gland prevents hypocalcemia by withdrawing calcium from bones

Question 3

What is the matrix of bone made of? Why is it so hard?

Answer 3

Matrix is the intercellular substance in which bone is embedded. It is hard because calcium and
phosphate crystals are deposited in it

Question 4

Describe cancellous bone

Answer 4

Cancellous bone consists of tiny spicules of bone randomly arranged w/lots of spaces btw . In life, the spaces btw spicules are occupied by bon marrow. To the naked eye,the many spicules and spaces give cancellous bone its spongy appearance. It is light, but amazingly strong and
helps reduce the weight of the bones of the skeleton without significantly reducing their
strength. The organization of the spicules of cancellous bone may appear random, but spicules are actually arranged to stand up to the forces bone is subjected to

Question 5

Describe compact bone

Answer 5

compact bone is very heavy and dense. It is composed of tiny, tightly compacted cylinders of bone called haversian systems Each haversian system runs lengthwise along the bone and
consists of a laminated (multilayered) cylinder composed of concentric layers of ossified bone matrix arranged around a central canal. The haversian canal contains blood and lymph vessels and nerves that supply the osteocytes. The osteocytes are located at the junctions between the layers of bone that makeup each haversian system

Question 6

Why does the body need these two different types of bone?

Answer 6

Dense compact bone for hardness on the outside of the bone and cancellous bone to reduce the weight of the skeleton without significantly reducing strength.

Question 7

What is the difference between a haversian canal and a Volkmann’s canal?

Answer 7

Haversian canals are part of the haversian system of compact bone. They run lengthwise with
the bone and consist of a laminated (multilayered) cylinder composed of concentric layers of ossified
bone matrix arranged around a central canal. The haversian canal contains the blood,lymph, and nerve supply for the osteocytes.
Volkmann canals are channels through which blood vessels travel to supply bones. They penetrate the periosteum at right angles to the long axis of the bone and at right angles to haversian canals. The blood vessels in the Volkmann canals join with the blood vessels in haversian canals to bring nutrients to the osteocytes in the haversian systems

Question 8

By which mechanism of bone formation do most of the bones in the animal body develop before
birth, and how does the process take place?

Answer 8

Endochondral bone formation. The body creates a cartilage “template” and that is subsequently replaced by bone. Most bones start out as rods of cartilage in the developing fetus.

Question 9

What is the difference between the primary growth center of a bone and a secondary growth center?

Answer 9

Primary growth centers are in the diaphysis of the cartilage rod and most are bone by the time of birth. Secondary growth centers are two plates of cartilage between the shaft and ends or epiphyses and called epiphyseal plates or growth plates and allow the bone to grow longer as the animal grows.

Question 10

Where would you find an epiphyseal plate and what would you find it doing?

Answer 10

Epiphyseal plates (growth plates) are two areas of a long bone that remain as cartilage when an animal is born.Located between the shaft (diaphysis) of the bone and the ends (epiphyses) of the bone,they are the sites where the creation of new bone allows the long bones to lengthen as
an anima grows

Question 11

What is bone marrow and what is the difference between the red kind and the yellow kind?

Answer 11

Yellow bm is located in the cavity of long bones that is primarily for fat cell storage. When you are born all of the marrow is red; however, as you grow older the red marrow in the long bones is replaced by yellow. YBM is used as fat reserve in extreme cases of starvation or it can revert back to red if extra blood cell production is needed. it is the spongy tissue inside some of your bones, such as your hip and thigh bones. It contains immature cells, called stem cells.and produces RBC

Question 12

What is synovial fluid and why is it important to the functioning of a synovial joint?

Answer 12

viscid lubricating fluid secreted by the membrane lining joints and tendon sheaths etc. It lubricates the joints and permits smooth movement. It also provides important nutrients to them.

Question 13

Membranes are composed of what two tissue types?

Answer 13

Epithelial and connective tissue

Question 14

Where are mucous membranes found?

Answer 14

Mucous membranes, or mucosae, are always found lining the organs with connections to the
outside environment. These organs are part of the digestive, respiratory, urinary, and reproductive
tracts and include the mouth, esophagus, stomach, intestines, colon, nasal passages, trachea, bladder,
uterus, and others

Question 15

What functions do mucous membranes perform?

Answer 15

With the exception of the mucosae of the urinary tract, mucosae in general can produce large quantities of protective and lubricating mucus. Goblet cells or multicellular glands maybe found throughout the tissue. These structures are responsible for the production and secretion of
mucus, which consists primarily of water, electrolytes, and a protein called mucin. Mucus is slippery and therefore can decrease friction and assist with the passage of food or waste. Because of its rich supply of antibodies and its viscous consistency, mucus is also helpful in the entrapment and disposal of invading pathogens and foreign particles. This is particularly apparent in the nasal passages, where microorganisms and debris are inhaled and trapped by mucus. Some mucosae can also absorb as well as secrete.
The mucosa therefore plays an important role in monitoring and controlling what enters the body, and mucous membranes form an important barrier between the outside environment and the delicate inner workings of the body. The secretory and absorptive qualities of mucosae make them
particularly well suited for this role.

Question 16

What is the definition of a mucous membrane?

Answer 16

A membrane lining all body passages that communicate with the air, such as the respiratory and alimentary tracts, and having cells and associated glands that secrete mucus. Also called mucosa

Question 17

What is Active Transport?

Answer 17

Active transport is the movement of all types of molecules across a cell membrane against its concentration gradient (from low to high concentration). In all cells, this is usually concerned with accumulating high concentrations of molecules that the cell needs, such as ions, glucose and amino acids. If the process uses chemical energy, such as from adenosine triphosphate (ATP), it is termed primary active transport. Secondary active transport involves the use of an electrochemical gradient. Active transport uses cellular energy, unlike passive transport, which does not use cellular energy.

Question 18

what is required for Active Transport to occur and what is not needed?

Answer 18

For active transport to occur, energy is needed in the form of ATP.

Question 19

What is the Na K+ pump?

Answer 19

The Na+/K+ pump illustrates “active transport” since it moves Na+ and K+ against their concentration gradients. That is because there is already a high concentration of Na+ outside the cell and a high concentration of K+ inside the cell. In order to move the ions (Na+ and K+) againts their gradients, energy is required. This energy is supplied by ATP (adenosine triphosphate). An ATP molecule floating inside the cell, binds to the pump transferring some energy to it. As the energy is used, the ATP falls off and having lost its energy it is converted into ADP (adenosine diphosphate).

Question 20

What is endocytosis? Exocytosis?

Answer 20

Endocytosis is a process for moving items that are outside of the cell into the cytoplasm of the cell.
Exocytosis is a process for moving items from the cytoplasm of the cell to the outside.

Question 21

What is meant by the membrane potential?

Answer 21

the electric potential existing on the two sides of a membrane or across the cell wall.

Question 22

What is the definition of a cutaneous membrane?

Answer 22

The cutaneous membrane is skin. Skin consists of a layer of stratified squamous epithelium (epidermis) firmly attached to a thick layer of dense connective tissue (dermis). It differs from other membranes because it is exposed to air and is dry.

Question 23

What is the definition of a mucous membrane?

Answer 23

The mucous membranes (or mucosae) consist of epithelial tissue (usually stratified squamous or simple columnar epithelia) on a layer of loose connective tissue called the lamina propria (from the Latin, meaning “one’s own layer”). The mucosae line the body cavities that open to the exterior, such as the digestive, respiratory, reproductive, and urinary tracts. These membranes are kept moist by bodily secretions

Question 24

What is a synovial membrane? Where is it found? Describe its structure

Answer 24

Synovial membranes are composed of connective tissue. They surround the cavity of joints, filling the space with the synovial fluid that they make. The synovial fluid lubricates the ends of the bones allowing them to move freely.