-VOCAB-

= VOCAB =
 * __28.2__**


 * homeostasis**- the regulation and maintenance of internal environment, such as: temperature, fluid, salt, PH, nutrients and gases-within the narrow ranges that support human life.


 * sensors**- also called receptors, gather information about conditions inside and outside of the body.


 * control center**- receives information from the sensors, if the condition is above or lower than the a set point, the control center responds by sending messages through a communication system.


 * Communication systems**- controlled by the nervous and endocrine systems, carry messages to all parts of the body in forms of nerve impulses or hormones.


 * feedback**- information from sensors that allows a control center to compare current condition to a set of ideal values.


 * negative feedback**- a control center counteracts any change in the body that moves conditions above or below a set point.


 * positive feedback**- a control center uses information from sensors to increase the rate of change away from the set point.


 * __29.1__**


 * stimulus**- something that cause a respond


 * nervous system**- a physical connected network of cells, tissues, organs that control thoughts, movements.


 * central nervous system (CNS)**- interprets messages and save


 * peripheral nervous system (PNS)**- transmit messages to the CNS and from the CNS to other organs in the body.


 * endocrine system**- a collection of physically disconnected organs that help to control growth, development, and responses to your environment.


 * __29.2__**


 * neuron**- a specialized cell that stores information and carries messages within the nervous system and between other body system.


 * dendrite**- branch like extensions of the cytoplasm and the cell membrane that receive messages from neighboring cell.


 * axon**- a long extension that carries electrical messages away from the cell body and passes them to other cells.


 * action potential**- charge distribution that triggers a moving electrical impulse.


 * terminal**- the part of the axon through which the impulse leaves that neuron contains chemical-filled vesicles.


 * neurotransmitter**- they bind to receptors proteins on the adjacent neuron and cause Na+ channels in that neuron to open, generating an action potential.


 * synapse**- tiny gap between the neurons.


 * __29.4__**


 * cerebrum**- the part of the brain that interprets signals from the body and forms responses.


 * cerebellum**- the part of the brain that coordinates your movements.


 * brain stem**- a structure that connects the brain to the spinal cord and controls the most basic activities required for life.


 * reflex arc**- are nerve pathways that need to cross only two synapses before producing a response.


 * somatic nervous system-** part of the nervous system that regulates all of the movements over which you have voluntary control.


 * autonomic nervous system-** part of the nervous system that control automatic functions that you do not have to think about.


 * sympathetic nervous system**- part of the autonomic nervous system that prepares the body for action and stress.


 * parasympathetic nervous system**- part of the autonomic nervous system that calms the body and helps the body to conserve energy.


 * __29.6__**


 * glands**- organs that make hormones.


 * hormones**- chemical signals made by the endocrine system.


 * hypothalamus**- a gland in the middle of the brain that release hormones that make other glands releasing their hormones.


 * releasing hormone**- hormones that stimulate other glands to release their hormones


 * pituitary gland**- a gland that is also in the middle of the brain and stimulate other glands to release their hormones. It also serve as a gateway for the hypothalamus hormones to enter the bloodstream.


 * __31.1 __**


 * pathogen- **Microorganisms that infiltrate into the body and causes diseases and infections.


 * 31.2 **


 * immune system- **A body system that fights infection


 * phagocytes- **A type of white blood cell that destroy the pathogens by consuming them


 * B cells- **A type of white blood cell that make antibodies


 * T cells- **A type of white blood cell that T Cells fight a foreign cell (T Cells)


 * antibodies- ** proteins created by B cells that make pathogens inactive


 * interferons- **<span style="font-family: Arial,Helvetica,sans-serif;">proteins preventing viruses to reproduce


 * <span style="font-family: Arial,Helvetica,sans-serif;">passive immunity- **<span style="font-family: Arial,Helvetica,sans-serif;">A type of immunity a person gets through by genetic make up

pathogen
 * <span style="font-family: Arial,Helvetica,sans-serif;">active immunity- **<span style="font-family: Arial,Helvetica,sans-serif;">Acquired only after <span style="font-family: Calibri,helvetica,sans-serif; font-size: 16px; font-weight: normal; line-height: 24px;">a person’s white blood cells encounter a


 * __<span style="font-family: Arial,Helvetica,sans-serif;">31.3 __**
 * <span style="font-family: Arial,Helvetica,sans-serif;">inflammation- <span style="font-family: Calibri,helvetica,sans-serif; font-size: 16px; font-weight: normal; line-height: 24px;">when white blood cells release chemicals that cause blood vessels to be leaky **


 * <span style="font-family: Arial,Helvetica,sans-serif;">antigens- **<span style="font-family: Arial,Helvetica,sans-serif;">protein markers on pathogen surfaces


 * <span style="font-family: Arial,Helvetica,sans-serif;">memory cells- **<span style="font-family: Arial,Helvetica,sans-serif;">These cells remember the pathogen for future encounters

antigens, they become activated and divide
 * <span style="font-family: Arial,Helvetica,sans-serif;">cellular immunity- <span style="font-family: Calibri,helvetica,sans-serif; font-size: 16px; font-weight: normal; line-height: 24px;">. When they encounter specific **

the B cell divides and matures
 * <span style="font-family: Arial,Helvetica,sans-serif;">humoral immunity- <span style="font-family: Calibri,helvetica,sans-serif; font-size: 16px; font-weight: normal; line-height: 24px;">When a T cell activates a B cell, **

Works cited: "28.2 Homeostasis." McDougal Littell, 2008. Web. 15 May 2011

"29.1 Communication." McDougal Littell, 2008. Web. 15 May 2011

"29.4 CNS and PNS." McDougal Littell, 2008. Web. 15 May 2011

"29.6 The Endocrine System and Hormones." McDougal Littell, 2008. Web. 15 May 201

"31.2 Immune System." McDougal Littell, 2008. Web. 15 May 2011

"31.3 Immune Responses." McDougal Littell, 2008. Web. 15 May 2011

"31.6 Diseases That Weaken the Immune System." McDougal Littell, 2008. Web. 15 May 2011