Notes

Disease
-Any condition that prevents the body from working as it should
-As a result the body may fail to maintain homeostasis
-Disease may result from pathogens, abnormal cells, carcinogens, poor nutrition, inherited disorder, or risky personal behavior.
Causes of Disease
-Inherited disorders
-Exposure to toxins/carcinogens
-Poor nutrition
-Organ malfunction
-High risk behaviors
Pathogens
-Microbes that can cause harm to an organism.
-Virus: particles compound of nucleic acid and protein. They reproduce when they invade living cells.
-Bacteria: are one called organisms
-Fungus: can be uni or multi cellular. Include yeasts and molds. They eat by absorbing organic substances.
-Parasites: can be uni or multi cellular. Survive and by living and feeding on other organisms.
Keeping Pathogens Out
-Skin is a protective barrier
-Sweat, tears, saliva, contains enzymes to destroy the cell membranes of certain bacteria
-Mucus membranes
-These line internal membranes that entrap pathogens that are then washed away or destroyed by chemicals.
Second Line of Defense
-Leukocytes: Phagocytes for short minor invasions and lymphocytes are for longer more serious invasions.
-Phagocytes rapidly trap, consume and completely destroy foreign material.
-The inflammatory response
-Damaged cells release histamine
Third Line Of Defense
-When the inflammatory response defense in insufficient the pathogen is targeted for destruction by the body's last line- IMMUNE RESPONSE
-It "remembers" each kind of pathogen that enters the body by producing antibodies.
Type Of Immunity
-Active Immunity:This is when the body produces its own antibodies to attack a particular antigen
-This is when you get a disease and make your own antibodies
-Therefore: memory cells stay within your body
-Passive immunity- you are given antibodies from either another person or animal.
-Passive immunity is only TEMPORARY and lasts only about a month or so because the body destroys the borrowed antibodies
Some Diseases
-Transplants are usually given to you from family members that have the same organs.

Homeostasis
-Homeostasis is the maintenance of a steady state in the body despite changes in the external environment.
-The steady state is the optimum level for the body functions.
-Enzymes work at an optimum ph level, which means that our body temperature 98.6 keeps enzymes working.
-Sensors to detect changes in the internal environment
-A comparator which fixes the set point of the system
-The set point will be the optimum condition under which the system operates
- Effectors which bring the system back to the set point
-Stimulus change in the environment
-Feed back control. Negative feedback stops the system over compensating
-A communication system to link the different parts together

-The endocrine system based upon hormones
-Uses glands and hormones
-Glands are specialized organs that release hormones
-The nervous system based upon nerve impulses
Hormones
-Organic substances
-produced in small quantities
-produced in one part of an organism (an endocrine gland)
-transported by the blood stream.
-To a target organ or tissue where it has a profound effect
Endocrine System
-The endocrine system produces chemical signals
-Each hormone is different and they travel relatively quickly through the blood stream all over the body.
-System a glands and chemicals that regulate metabolism, homeostasis, growth and reproduction.
Nervous System
-System of specialized cells to carry messages throughout body
-Impulses are sent by neurons to and from central nervous system
-receptors: structures that detect stimuli
-eyes, ears, skin all have sense receptors
-Receptors are also found on the outsides of cells and receive info from hormones and antigens
Stimulus->Receptors->Response
Reproductive Hormones
-Testosterone
-from testes
-sperm production and secondary sexual characteristics
Estrogen
-from ovaries
-egg production, preparing uterus for fertilized egg and secondary sexual characteristics
Male
-sperm production
-over 100 million produced per day
-2.5 million released per drop
Testicles
-produces sperm and hormones
-scrotum
-sac that holds testicles outside of the body
Epididymis
-where sperm matures
Female reproductive system
-Fallopian tubes are where fertilization occurs
-Ovaries
-produces eggs and hormones
-Uterus
-nurtures fetuses;lining builds up each month
-Cervix
-opening to uterus, dilates 10 cm for birthing baby
-Vagina
-Birth canal for birthing a baby
Menstrual Cycle
-controlled by interaction of 4 hormones
-fsh and lh
-estrogen
-progesterone
Placenta
-food and gases diffuse across blood vessels
-life line that keeps the baby alive
Fetal Alcohol Syndrome

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