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64 Cards in this Set

  • Front
  • Back
What are pathogens?
any disease-causing organism
When is a pathogen contageous?
When it can be spread from one organism to another
When is a pathogen considered infectious?
when it finds a tissue inside the body that will support its growth.
What is a bacteria?
a group of single-celled organisms. Tiny, numerous. Prokaryotic and do not contain organelles. Surrounded by a cell wall that provides protection. Also have flagella dn pili which help tem pass genes and become mobile
Where is the DNA held in a prokaryotic cell?
the nucleoid region
What are plasmids?
small, circular extrachromosomal DNA.
How to bacteria reproduce?
Binary fission.
What happens in binary fission?
The single circular choromosome is copied and attached to another site of the plasma membrane then that section of the membrane grows around it until it becomes two daughter cells
What are toxins?
Symptoms of a disease arise dut to the effects of biological molecules secreted by the bacterial cells, called TOXINS
What are macrophages?
white blood cells which contain toxic chemicals that kill bacteria
What is a virus?
a nonliving organism that cannot replicate without the aid of a host cell. Viruses lack enzymes for metabolism and contain no ribosomes. They are basically packets of nucleic acid surrounded by a protein coat
Do viruses have to conain DNA?
No. A virus can be DNA or RNA, double stranded or single stranded, linear or cirular.
What is a capsid?
the protein coat that surrounds a virus
What is a latent virus and what is an emerging virus?
A latent virus enters a state of dormancy. An emerging virus is one that who incidence has increased in the past two decades
What is a parasite?
A paraiste is an organism that obtain nutrients and shelter required for growth and development from a different organism
What is a prion?
A prion is a normally occuring protein produced by brain cells that , when misfolded, causes spongiform encephalopathy
What is an epidemic?
a contagious disease that sprad rapidly and extensively among members of the population
What are some ways diseases are spread?
Exposure to infected body fluids, transmision through an intermediate host, Inhalation, Ingestion
What is the "first line of defense" in the immune system?
Skin and Mucus membranes.
What are nonspecific defenses?
Defenses that do not distinguish one pathogen from another, but defend against all
What is phagocytosis?
The ingestion of pathogens by cells.
What are natural killer celles?
cells that attack virus-invaded calls by penetrating them and causing them to burst.
What are Interferons?
they are proteins produced by virus-infected body cells to help uninfected cells resist infections
What is the inflammatory response?
a reaction producing redness, pain, swelling, and fever that is induced by chemicals released from macrophages
What is the third line of defense in the immue system?
What are lymphocytes?
Lymphocytes are white blood cells that travel throughout the body by moving through spacing between cells, etc
What is an antigen?
an antigen is a molecule that is foreign to the host and stimulates the immune system to react
What happens when an antigen is presen tin the body?
The production of B lymphocytes (B cells) and T lymphocytes (T cells) are enchanced.
What to B cells and T cells do?
they are concentrated in the spleen and lymph nodes. Both recognize and elminate antigens.
How do B cells eliminate antigens?
By secreting proteins called antibodies that bind to and inactivate antigens.
What is an antigen receptor?
Lymphocytes recognize foreign molecules based on the presence of proteins whose shape is complementary to a portion of the foreign molecule, called ANTIGEN RECEPTORS. They are either attached to the surface of the lymphocyte or secreted by it.
What types of antigens to B-cells recognize?
small, free-living microorganisms such as bacteria and the toxins they produce.
What types of antigens do t-cells recognize?
recognize and respond to body's cells that have gone awry, like cancer cells or cells invaded by viruses. also respond to fungi and parasitic worms.
How are lymphocytes made?
produced from stem cells. produced in bone marrow and released into the blood stream. B cells continue to develop in bond marrow. T cells take up residence in the thmus glad and devalop
B cells from BONE marrow

T cells from THYmus
What is humoral immunity?
b-cells encounter an antigen, clones itself to create a clonal popluation. some cells become memory cells
What are memory cells?
help respond more quickly if infected by same thing again.
What is cell-mediated immunity?
by T cells. directly attack other cells rather than secreting antibodies.
What is a cytotoxic T cell?
attack and kill body cells infected with a virus.
What are helper T cells?
boosters of the immune response. detect invaders and alter B and T cells that an infection is occuring. no helper T cells, no immuse system response.
What is a vaccine?
vaccines are mad eof coponents of the disease causing orgnaizms. The immune system resonds to the vaccine by producing the clonal populaiton of memory cells that will be prepared for a real infection
What is the endocrine system?
asystem of regulation and communication that involves hormones, glads and particular cells that respond to the hormones.
What are hormones?
chemicals that travel through the circulatory system and act as signals to elicit a response from target cells
What do you call organs that secrete hormones?
endocrine glands.
What does the thyroid glad do?
secretes hormones that stimulates metabolism
What does the hypthalamus do?
regulates body temp and affects hunger, thirst, reproduction. stimulates the activities of the gonads
What is GnRH?
moves through veins from teh hypothalamus to the pituitary glad.
What is the pituitar gland?
secretes many different hormones such as FSH and LH that produce sex differences.
What does FSH (follicle-stimulating hormones) do in males and females?
In females:stimulates egg-cell development
In males: stimulates sperm production.
What does LH (luteinizing hormones) do in males and females?
In females: stimulates the release of an egg cell during ovulation
In males: stimulates testosterone production.
What are the adrenal glands?
sit atop each kidney. secrete adrenaline in reponse to stress of excitement. also secrete androgens.
What do androgens do?
include masculinizing hormones like testosterone and feminine hormones such as estrogen.
What are endocrine disrupters?
chemicals that disrupt the actions of the hormone-producing endocrine system.
What are neurons?
specialized cells that carry electrical and chemical messages ack and forth betwen your brain and other parts of the body.
What are the components of the central nervous system?
the brain and spinal cord
What are effectors?
effectors are the responsive tissues that respond to verve signals.
What are nerve impulses?
electrical changes that carry information along nerves
What are the three categories of neurons?
1) sensory neurons-carry info towrad the CNS
2) motor neurons-carry info away from the CNS toward effector tissues
3)interneurons-located between sensory and motor neurons within the brain or spinal cord
What is the peripheral nervous system
the network of nerves that radiates out from the brain and spinal cord. not all organisms have one.
What ist he cerebrum?
the cerebrum fills the whole upper part of the skull. controls language, memory, sensations, and decision making.
What is the temporal lobe?
processing auditory information and some visual information, as well as memory and emotion.
What is the occipital lobe?
processes visual info from the eyes
What is the parietal lobe?
processes info. about touch and is involved in self-awareness
What is the frontal lobe?
processes voluntary muscle movements and is involved in planning and organizing future expressive behavior.