AGENDA May 27 Objective: Explain the relationship between populations of predators and prey 1. Complete “Lynx Eats the Hare Lab” 2. Ecology Test / Quiz on Friday 3. STUDY YOUR NOTES 4. Rest of Week – Vertebrates/Invertebrates Human Body Systems

AGENDA May 30 Objective: Describe the structure and functions of human body systems. 1. Ecology Test / Quiz on Friday 2. Begin reading Chapter Human Body Systems – Nervous System Endocrine System Immune System

HUMAN BODY SYSTEMS

Chapter 35: Nervous System Controls and coordinates functions throughout the body and responds to internal and external stimuli. Messages carried are electrical impulses. Neurons are cells that transmit these impulses. 1. Sensory – carry impulses from sense organs to spinal cord and brain 2. Motor – carry impulses from brain and spinal cord to muscles and glands 3. Interneurons – connect sensory and motor neurons

Structure of a Neuron Cell Body – contains nucleus and cytoplasm Dendrite - carry impulses from environment or from other neurons to cell body Axon – carries impulses away from cell body Myelin sheath – insulating membrane Nodes – gaps in axon membrane Axon terminal – contains vesicles filled with chemical neurotransmitters used to transmit impulse Synapse – location where impulse is transferred from one neuron to the next

Nerve Impulses Resting potential – electrical charge across cell membrane of a neuron in its resting state Uses a sodium – potassium pump to maintain resting potential Na pumped out of cell and K pumped into cell Action potential – inside of cell membrane becomes more positive than the outside Produces a nerve impulse Threshold – minimum level of a stimulus required to activate a neuron

Central Nervous System Relays messages, processes information, and analyzes information. Brain and spinal cord wrapped in three layers of protective tissue called meninges. Cerebrum – largest part of brain responsible for voluntary actions Left hemisphere processes right side of body Right hemisphere processes left side of body Cerebellum – located at back of skull coordinates and balances the actions of muscles

Central Nervous System Brain Stem – connects brain and spinal cord Two regions – Pons and Medulla oblongata Controls blood pressure, heart rate, breathing, and swallowing. Thalamus – receives messages and relays them to proper region of cerebrum Hypothalamus – control center for hunger, thirst, fatigue, anger, and body temperature

Peripheral Nervous System Sensory division transmits impulses from organs to CNS. Motor division transmits impulses from CNS to muscles or glands. Subdivided into two parts Somatic Nervous System regulates conscious or voluntary activities. Muscle control and reflexes Autonomic Nervous System regulates automatic or involuntary activities.

Endocrine System Chapter 39

Delivering Messages Glands release their products into bloodstream delivering messages throughout the body. Hormones are chemicals released in one part of body Travel through bloodstream. Affect activities of cells in other parts of body.

Hormone Action Exocrine glands release secretions through ducts. Directly to organs that use them. Endocrine glands release their secretions through the bloodstream.

Hormone Action STEROID HORMONES Lipids that cross cell membrane into nuclei of cells. 1. Binds receptor proteins of target cells 2. Hormone-receptor complex enters nucleus 3. Binds directly to DNA control sequence 4. mRNA produced and protein synthesis occurs NONSTEROID HORMONES Require receptors on cell membranes to enter cell. 1. Binds receptor 2. Enzyme activates on inner surface of cell membrane 3. Secondary messengers carry message inside cell.

Steroid Hormone Mechanism

Control of Endocrine System All cells except for red blood cells produce prostaglandins. Modified fatty acids that generally affect localized cells and tissues. System is regulated by feedback mechanisms that function to maintain homeostasis. Pituitary Gland – produces 9 hormones to regulate body functions Hypothalamus – controls secretions of Pituitary Gland Thyroid Gland – regulates body’s metabolism

Endocrine Glands Pancrea s – has both exocrine and endocrine functions Beta cells secrete INSULIN Stimulates cells to take glucose of out the bloodstream after eating TYPE I Diabetes Autoimmune disorder that results in little/no insulin production TYPE II Diabetes Cells produce insulin but interaction between insulin and receptors is insufficient Alpha cells secrete GLUCAGON Stimulates release of glycogen to increase blood sugar levels when levels drop Ovaries produce estrogen and progesterone Testes produce testosterone

IMMUNE SYSTEM CHAPTER 40

Germ Theory of Disease A disease is any change other than an injury that disrupts the normal functions of the body. Germ Theory – conclusion that infectious diseases were caused by different types of microorganisms. Based upon the work of Louis Pasteur and Robert Koch

Koch’s Postulates Rules developed to identify the microorganism that causes a specific disease. 1. Pathogen should always be found in body of a sick organism not a healthy one 2. Pathogen must be isolated and grown in pure culture in lab 3. Cultured pathogens should cause same disease when placed in new host 4. Injected pathogen isolated from second hose should be identical to original

Nonspecific Defenses 1. First Defense  SKIN 2. Second Defense  Inflammatory Response White blood cells (phagocytes) engulf and destroy bacteria Chemicals released to increase body temperature  FEVER Why is a fever beneficial to humans? Interferons are proteins that interfere with the growth of a virus

Specific Defenses Antigens (disease causing agents) trigger the immune response. Body produces B-lymphocytes and T-lymphocytes Humoral Immunity – B-cells produce plasma cells Plasma cells release protein antibodies specific to a type of antigen Memory B-cells now capable of quickly producing antigens for same antigen.

Specific Defenses Cell-mediated Immunity – primary defense against its own cells or infection from virus, protists, or fungi. Upon infection, T-cells divide into Killer T-cells  track down and destroy antigens Helper T-cells  produce memory T-cells

Diseases AUTOIMMUNE Diseases - The body attacks its own cells. IMMUNODEFICIENCY Disease – immune system fails to develop properly AIDS Virus destroys helper T-cells weakening immune system functions