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Central nervous system- brain and spinal cord Peripheral nervous system- nerves that connect CNS to organ systems Spinal cord nerves

The Nervous System Central Nervous System (CNS) receives and processes information; initiates action Peripheral Nervous System (PNS) transmits signals between the CNS and the rest of the body Brain receives and processes sensory information; initiates responses; stores memories; generates thoughts and emotions Spinal Cord conducts signals to and from the brain; controls reflex activities Motor Neurons carry signals from the CNS that control the activities of muscles and glands Sensory Neurons carry signals to the CNS from sensory organs Somatic Nervous System controls voluntary movements by activating skeletal muscles Autonomic Nervous System controls involuntary responses by influencing organs, glands, and smooth muscle Sympathetic Division prepares the body for stressful or energetic activity; “fight or flight” Parasympathetic Division dominates during times of “rest and rumination”; directs maintenance activities

Meninges- layers of protective tissue which surround the brain Fluid between the meninges cushions the brain Cerebrum- interprets signals from body and forms responses Cerebral cortex- interprets information from sensory organs Cerebellum- coordinates movement Brain stem- connects brain to spinal cord and performs basic activities required for life (midbrain, pons and medulla oblongata)

The heart Atrium (2) receive the blood Ventricles (2) pump the blood Valves- prevent blood from flowing backward SA node (pacemaker) controls beating of the heart

Pulmonary circuit- carries blood to lungs Systemic circuit- carries blood to rest of body Path of blood- enters right atrium, right ventricle, pulmonary artery, lungs, pulmonary vein, left atria, left ventricle, aorta, body

Pathogens and Human Illness Germ Theory- Louis Pasteur proposed that microorganisms caused disease Pathogens- disease causing organisms Joseph Lister- used weak acid to clean his operating tools (number of deaths from infection dropped to near zero) Robert Koch- developed four steps needed to prove a pathogen caused a disease (Koch’s postulates) Pathogens include bacteria, viruses, fungi, protozoa and parasites

Immune system- fights off infection and pathogens Skin is first line of defense White blood cells- find and kill pathogens There are 6 types T cells- destroy body cells that are infected B cells- produce proteins that inactivate pathogens

Proteins help fight off invading pathogens (complement proteins, antibodies and interferons) Passive Immunity- occurs without the body undergoing an immune response (passed between generations through DNA and between mother and child) Active Immunity- occurs when your body produced a response to a specific pathogen (due to illness or vaccinations)

Inflammation- nonspecific response characterized by swelling, redness, pain, itching and increased warmth Fever- low fevers stimulate production of interferons and activity of white blood cells by increasing rate at which they mature (high fevers are dangerous) Antigens- protein markers on pathogens which help body recognize them as foreign

Memory cells- remember a pathogen and result in a rapid second response (why vaccinations work) Cellular immunity- depends on T cells Humoral immunity- depends on antibodies

Antiseptics- chemicals that kill pathogens Antibiotics- medicines which target bacteria and fungi by preventing them from multiplying Antibiotic resistance- when bacteria mutates and is no longer affected by antibiotics Vaccine- weakened or dead version of pathogen which is injected into the body to stimulate active immunity

Leukemia- cancer of the bone marrow White blood cells are produced in the bone marrow therefore leukemia indirectly affects the immune system HIV- retrovirus which invades T cells AIDS- condition of having a worn out immune system

ovaries- where eggs produced Uterus- holds developing baby Fallopian tube- what the egg travels through to reach the uterus, where fertilization occurs Estrogen- female steroid hormone which controls development of female characteristics, to mature egg cells, and prepare uterus for pregnancy

Testes- where sperm are produced Scrotum- holds testes, keeps sperm at cooler temperature Epididymis- where sperm mature Vas deferens Urethra- transports both urine and sperm to outside of body Testosterone- male steroid hormone which controls development of male characteristics and stimulates production of sperm

Fertilization of egg by sperm results in zygote Zygote becomes a hollow ball of cells called a blastocyst (stage where implantation occurs) Once the germ layers form it is called an embryo Amniotic sac- fluid filled sac which protects embryo Placenta- connects mother and child and where nutrients/waste are exchanged

Umbilical cord- connects embryo to placenta Pregnancy is divided into trimesters First- differentiation of cells occur, brain and body structures begin to form Second- increased growth and development Third- lungs complete development, final growth and development