1. Basic Human Structure Health Science

3. MitosisMeiosis

4. Chromosomal Disorders Sometimes during meiosis to form sex cells or during the rapid mitosis after fertilization, chromosomal abnormalities may occur. These may include addition, deletion or rearrangement of chromosomes or parts of chromosomes. The result is a chromosomal disorder. Increased risk in very young or older mothers. Otherwise not necessarily linked to any particular behaviors by mother or father. Most pregnancies with these disorders end in miscarriage.

5. Chromosomal Disorders Trisomy 21 – Down’s Syndrome 1:1,300 @ age 25 1:35 @ age 45

6. Cancer Uncontrolled mitosis resulting in rapid growth of non-functional cells that invade surrounding structures and spread to other sites.

7. Stem Cells When an ova and sperm unite to form a zygote, rapid mitotic division begins. Within, 4-5 days a hollow ball of stem cells called a blastocyte is formed. The undifferentiated stem cells will go on to form all the different types of tissue in the body. Scientists hope to use stem cells to “grow” new tissues to treat diseases such as Parkinson’s or Diabetes or spinal cord and brain injuries. These stem cells come from the developing human embryo/fetus and extracting them for research will destroy the developing life. Some researchers want to used discarded fetal tissue from abortions or fertilized embryos that are not wanted in fertility clinics. Stem cells can also be successfully obtained from umbilical cord blood/ Adults have some stem cells in bone marrow and liver but they do not have the ability to develop into any type of tissue as the fetal cells do – they have, however, been successfully used to grow specific tissues. Some success has been had w/ genetically modifying adult cells to become “pluripotent” – or able to grow into many types of cells What do you think of this research?

8. How are we made?? Cells form tissues – tissues form organs – organs form systems – systems form a living organism.

9. Tissues Cells join together to form tissues. They are 60-99% water with dissolved substances. If there is not enough tissue fluid, it is called dehydration. If there is excess tissue fluid, it is called edema (swelling).

10. Four Types of Body Tissue

11. Epithelial Tissue Protect and Secrete Covers surface of the body and is main tissue in skin. Also forms lining of the intestinal, respiratory, circulatory and genitourinary tracts. Forms body glands to produce specific secretions.

12. Nerve Tissue Control and Communicate Nerves, brain and spinal cord are composed of nerve tissue. Cells are called neurons. Transmits messages to and from brain for the body.

13. Muscle Tissue Move and Protect Produces power and movement by contraction of muscle fibers. Three types – cardiac, smooth, skeletal. Cardiac is heart muscle. Skeletal is attached to bones for movement. Smooth is located inside blood vessels, respiratory, urinary and digestive tract.

14. Connective Tissue Support and Protect Supporting fabric of organs/body tissue Two types: soft and hard Soft includes adipose or fatty tissue (stores fat as energy reserve, acts as padding, insulates). It also includes fibrous such as ligaments and tendons.

15. Connective Tissue Bones and cartilage are hard connective tissue. Bones give rigid structure will cartilage is elastic & flexible found at ends of long bones, in larynx (voice box), nose & ears. Blood and Lymph Fluids are liquid connective tissue

16. Terms Osmosis – movement of water across semi-permeable cell membrane. Will always move from area of lesser concentration to greater concentration of solutes (dissolved particles) in order to have equal osmotic pressure on both sides of membrane. Osmotic pressure – the force with which the water is pulled across cell membrane.

18. Terms Isotonic solution – has same osmotic pressure as cell – will not cause movement of fluids across membrane Hypertonic solution – has greater osmotic pressure than cell (more solutes, less water) thus causes fluid to move out of cell. Hypotonic solution – has lesser osmotic pressure that cell (less solutes, more water) thus causes fluid to move into cell.