bone unit ap

describe between totipotent, pluripotent, and multipotent stem cells

Totipotent: can become any cell type of the embryo and extra embryonic tissue (umbilical cord and placenta

Pluripotent: can become any cell type of the embryo, but cannot become extra embryonic tissues

Multipotent: can become a limited number of cell types, such as erythrocytes, leukocytes, and lymphocytes

What are the 5 layers of the epidermis and describe them?

Stratum corneum: top layer made of dead keratinized skin cells

Stratum: lucidum found only in thick skin and is a clear thick layer

Stratum granulosum: contains anti microbial and lipid granules that provide extra defense and waterproof the skin

Stratum spinosum: contains keratinocytes that keratinize cells to make them waterproof and melanocytes that produce melanin

Stratum basale: basement layer that contains melanocytes and lies just above the dermis

Describe the structure of the dermal layer

• collagen fibers

• Eccrine sweat glands

• Sebaceous glands that produces sebum

• Hair follicles

• Aprocrine sweat glands (armpits and groin) produces sugar rich sweat what makes them stink

• Mammary glands (modified sweat glands) that produce milk

• arrector pili muscles that raise hairs in response to cold or treats

Describe the rules of nines and why it’s used

The rule of nines is used by medical professionals to quickly calculate how much a persons body has been burned. Each body region equals 9% of the body surface area EXCEPT the groin which is 1%. (Head, chest, abdomen, upper back, lower back, right arm, left arm, right anterior leg, right posterior leg, left anterior leg, left posterior leg, groin)

What are the six degrees of burns and describe them?

First Degree - skin is red, swollen, and painful

Second degree - blisters with red painful swollen skin

Third degree - dermis is destroyed and the burn is painless

Fourth degree - burns with the hypodermis and chars adipocytes

Fifth degree - burns the muscle layer

Sixth degree - chars the bone

Why are skin grafts rejected?

Skin grafts are rejected because T cells recognize the graft as “non-self” proteins displayed on the major histocompality complex (MHC) and destroy cells. Immunosuppressive drugs are used to reduce rejection.

Describe what osteoblast and osteoclasts do.

Osteoblasts are formed from osteoprogenitor cells, build bone matrix, become osteocytes, and are active during bone growth and repair

Osteoclasts break down bone matrix, remodel bone after healing, and come from a red bone marrow lineage.

How do bones grow in length via epiphyseal plate?

Bones grow in length through the epiphyseal plate, which has three cartilage layers (resting cartilage, proliferating cartilage, hypertrophic cartilage) as a child grows, cartilage is slowly replaced with calcified bone. In Adulthood, the epiphyseal plate becomes the epiphyseal line.

Explain the bone break and repair mechanism.

A bone break and repair begins when a hematoma forms at the injury site, followed by a vascular spasm and the conversation of the prothrombin to thrombin and fibrinogen to create a clot which is then replace by a soft callus that later becomes a bony callus, and finally osteoclasts remodel the bone to restore its original shape.

What does UV light do to dna?

uv light causes dna strand to break and causes thymine dimmers by bonding two neighboring thymine bases together. If damage is extensive and not repaired it could result to cancer.

How is blood calcium maintained and kept at homeostasis?

Blood calcium is maintained in homeostasis by the thyroid gland releasing calcitonin when calcium levels are high, which activates osteoblasts to build bone, and by the parathyroid gland releasing parathyroid hormone (PTH) when calcium levels are low, which activates osteoblasts to break down bone and increase blood calcium levels.

What is the significance of vitamin d?

Vitamin d is a fat soluble vitamin derived from cholesterol that is necessary to incorporate calcium into bones.

Explain what a stnarthrosis joint is, what are 3 different types? Describe them.

(synthrosis joints are mostly immovable joints with no flexibility)

• sultural joints: bones of the skill are held together by thousand of tiny ligaments (no movement)

• Sydesmosis: ulna/radius and tibia/fibula are connected by interosseous membranes, allow slight movement

• Gomphosis: teeth are attached to jaw by periodontal ligaments. Periodontal ligaments can break and reform (makes braces possible)

What is a ligament and tendon?

Ligament: structural protein that attaches bone to bone

Tendon: structural proteins that attaches muscle to bone

What are the sign that a mole has become skin cancer?

If a mole is asymmetrical, bleeding, crusting, oozing, or changing colors, it can be cancer.

malignant malanoma has a high risk of metasis, meaning cancer spreads through the blood and forms new tumors.

Describe where you find amphiarthrosis joint. What’s is it?

Amphirathosis joints are joints that allow a slight degree movement and are found in places such as the intervertebral discs between vertebrae and the costal cartilage of the ribs

What are functions for the skeletal system?

The skeletal system functions to support the body and allow movement with muscles, protect vital organs, store calcium in bone matrix and lipids in yellow bone marrow, and produce blood cells in red bone marrow including erythrocytes, lymphocytes, leukocytes, and megakaryocytes.

What are functions for the skeletal system?

The skeletal system functions to support the body and allow movement with muscles, protect vital organs, store calcium in bone matrix and lipids in yellow bone marrow, and produce blood cells in red bone marrow including erythrocytes, lymphocytes, leukocytes, and megakaryocytes.