Immune System Nervous System Hormones and Endocrine Systems

Chapter 40: Immune System Pathogen – a disease causing agent 1st line of defense: Skin and mucous membranes 2nd line of defense: inflammatory response, temperature response, proteins and white blood cells (wbc)

Temperature response: body temperature increases to kill bacteria Temperature greater than 103oF are dangerous Temperature greater than 105oF are fatal

Macrophage – wbc that ingest and kill pathogens they encounter Cytotoxic T Cells – attack and kill infected cells B Cells – labels invaders for later destruction

Helper T cells – active cytotoxic T cells and B cells Antigen-substance that triggers an immune response Koch’s Postulates are a guide for identifying specific pathogens

Immunity – resistance to a particular disease Vaccine – solution that contains dead or modified pathogen that can no longer cause disease. A vaccine triggers an immune response without symptoms of infection.

You can get infectious disease through: Person to person contact Air Food Water Animal bites

Allergy-the body’s inappropriate response to a normally harmless antigen Autoimmune disease-body launches an immune response against its own cells attacking them as they were pathogens. They can no longer distinguish “self” from “nonself”.

HIV causes AIDS when the body can no longer fight off other infections because of the destruction of helper T cells. If a person’s blood contains antibodies to HIV they are HIV positive. HIV is transmitted through body fluids including blood. Can also be transmitted through sexual contact, breast milk, and needles.

Chapter 41: Nervous System

Neuron – nerve cell Neurons enable movement, perception, thought, emotion and learning.

Dendrites receive information FROM other cells.

Axon conduct (sends) nerve impulses TO other cells Nerves are bundles of axons.

Synapse – a junction at which a neuron meets another cell.

Central Nervous System (CNS) The CNS consists of the brain and spinal cord. The CNS interprets and responds to information from the environment and from within the body.

Peripheral Nervous System (PNS) Sensory neurons send information from sense organs. Example of a sense organ: skin, eyes, ears, nose, mouth Motor neurons send commands from the CNS to muscles and other organs.

Brain Body’s processing center. Contains about 100 billion neurons. Enables you to have thoughts, feelings, emotions, behavior, memories, and the ability to learn and process information.

Spinal Cord Dense cable of nervous tissue that runs through the vertebral column to a level just below the ribs. Links brain to the peripheral nervous system.

Somatic Nervous System Consists of most motor neurons that stimulate skeletal muscle. Reflexes, although involuntary, are also part of the somatic nervous system. A reflex is a self-protective motor response. Reflex – sudden, involuntary contraction of muscles in response to a stimulus

Autonomic Nervous System Consists of peripheral motor neurons that regulate smooth muscles such as heart rate, all the body systems, and secretions of glands. Has 2 divisions: Sympathetic – fight or flight response Parasympathetic – keeps body functioning when you are not active (able to breathe while sleeping)

Chapter 42: Hormones and the Endocrine System Hormones are substances secreted by cells that act to regulate the activity of other cells in the body.

Function: Regulating growth, development, behavior, and reproduction Coordinating the production, use, and storage of energy Maintaining homeostasis (temperature, regulation, metabolism, excretion and water and salt balance) Responding to stimuli from outside the body

Endocrine glands are ductless organs that secrete hormones directly into either the bloodstream or the fluid around cells. (extra cellular fluid) Organs include the brain, stomach, small intestine, kidneys, liver and heart.

Exocrine glands deliver substances through ducts (tubelike structures). Organs include sweat glands, mucous glands, and other digestive glands.

Target cell are a specific cell that a hormone binds to and acts on (carriers the message to) If high levels of hormones stimulate the output of even more hormone, the regulation is celled positive feedback. Negative feedback is a change in one direction stimulates the control mechanism to counteract further in change in the same direction.

Hypothalamus is the area of the brain that coordinates the activities of the nervous and endocrine systems. Controls many body functions including: Body Temperature Blood Pressure Emotions

Pituitary Gland is an endocrine gland suspended from the hypothalamus by a short stalk.

Insulin is a hormone that lowers blood glucose levels by promoting the accumulation of glycogen in the liver. Glucagon had the opposite effect of insulin; it raises blood glucose levels

Diabetes mellitus is a serious disorder in which cells unable to obtain glucose from the blood, resulting in high blood glucose levels. Type I – is a hereditary autoimmune disease (usually treated with insulin dose everyday) Type II – develops in people over 40 due to obesity and an inactive lifestyle