Biology Test 2

• Cell


  The basic structural, functional and biological unit of any living organism .
• Tissue


  A group of cells of the same type which work together and carry out the same specialized function.
• Organ


  Tissues which work together and carry out a particular function. form an organ.
• system


  A set of organs working together to carry out an important function.
• organism


  A living thing that consists of a series of systems that work together to enable it to function independently.
• cellular respiration


  Occurs inside every cell within structures called the mitochondria. Glucose is broken down using oxygen.
• peripheral nervous system


  Includes all of the nerves that carry messages to and from the central nervous system and other parts of your body.
• central nervous system


  Includes the brain and spinal cord.
• motor neuron


  Have the opposite function of sensory neurons. and work to carry nerve messages away from the CNS and towards effectors.
• sensory neuron


  Carries messages from cells in the sense organs towards CNS.
• spinal cord


  Assists the brain to communicate with different parts of the body. And mostly, involved in reflex actions.
• cerebrum


  Controls intellectual functions of reasoning your voluntary movements. And receives sensory messages from all body parts.
• cerebellum


  Coordinates fine muscle movements and balance.
• brainstem


  Controls body's vital functions like breathing, blood pressure and heart rate.
• reflex


  extra-rapid responses to stimuli which involve that nervous system but bypass the brain eg. touching something very hot.
• stimulus


  an environmental change eg. heat, noise, light, pain
• receptor


  groups of specialized cells at nerve endings that can detect changes in the environment. Located in sense organs - ears, eyes, nose, tongue and skin
• effector


  the muscles, glands or organs that will put the response into effect. Muscles respond by contracting and glands respond by releasing a hormone.
• negative feedback


  helps our body to keep it's internal conditions stable so that you can function effectively - if it gets too cold and your body temperature decreases the negative feedback kicks in to keep it at 37 degrees.
• vasodilation


  blood vessels close to the skins surface to widen.
• vasoconstriction


  narrowing of the blood vessels near the surface of the skin
• shivering


  a nerve impulse is sent to the muscles which start contracting or shaking.
• homeostasis


  the process of maintaining a constant internal environment - 37 degrees
• edocrine system


  system where messages are passed on by chemicals via the blood stream.
• hormone


  the chemical messengers, adrenaline - can increase heart rate.
• endocrine gland


  secretes hormones - pituitary gland (master gland) controls all other glands

  kidney - regulates water and salt levels
• disease


  a condition that causes your body to stop working properly - cancer
• pathogen


  causes infection or disease - bacteria, virus or fungus
• Lines of defense against pathogens

  1st line - physical barriers, skin and mucous membranes

  2nd line - inflammation and fever, the body attacks the pathogen in the one area - a cut, mosquito bite.

  3rd line - immune system, white blood cells destroy pathogen.
• bacteria


  - single celled

  - no nucleus, many shapes and sizes, multiply rapidly

  - decomposers (useful bacteria)

  - whooping cough (harmful or pathogenic bacteria)

  - can spread via air, animals, food and water

  - eg. tuberculosis, strep throat, typhoid fever, salmonella and cholera.
• Virus


  - many times smaller than bacteria

  - genetic material encased in protein coat

  - can only multiply inside a host and attacks specific cells

  eg. infectious diseases - influenza, measles, hepatitis B, polio
• fungi


  - can be singular or multicellular

  - some are large eg. mushrooms

  - some are small eg. yeast

  - many live on plants and animals

  - eg. tinea, thrush and ringworm
• antibiotic


  a medicine that inhabits the growth of or destroys microorganisms eg. penicillin
• antigen


  a non-self-marker on a pathogen which is foreign to your body eg. a disease-causing organism such as bacteria, viruses, fungi and parasites
• phagocytosis


  the process by which phagocytes engulf and destroy foreign organisms eg. bacteria
• pandemic


  is an epidemic of an infectious disease that spreads through human populations across a large region, like a continent and affects a very high proportion of the population.
• epidemic


  disease outbreak that is concentrated in a particular region and exceeds the expected incidence rate.
• vaccine


  a medicine that inhabits the growth of or destroys microorganisms eg. penicillin
• herd immunity


  is a form of indirect protection that applies only to contagious disease, it occurs when a sufficient percentage of a population has become immune to an infection, whether through previous infections or vaccination, thereby reducing the likelihood of infection for individuals who lack immunity.

  eg. small babies
• antibody


  small proteins made by white blood cells that fight pathogens