BIOS 255 FINAL EXAM
1. Explain the difference between nonspecific and specific defense and the role of lymphocytes in each of
the immune response.
Nonspecific Resistance (Innate Immunity)
Present at birth ad includes defense mechanisms that provide general protection against invasion by a wide
range of pathogens
Immunity (Adaptive Immunity)
Involves activation of specific lymphocytes that combat a particular pathogen or other foreign substance
Lymphocytes provide specific defense. They respond to the presence of invading pathogens, abnormal body cells, and
foreign proteins by physical and chemical attacks.
2. Identify the major components of the lymphatic system and explain their functions.
Thymus – produces T-cells for immune response.
The spleen - largest single mass of lymphatic tissue in the body. The spleen destroy blood-borne pathogens and
worn-out red blood cells by phagocytosis
Lymph Nodes- produce lymphocytes that kill pathogens, harmful foreign particles and debris from lymph before it is
returned to the blood stream.
Lymph vessels -act as reservoirs for plasma and other substances including cells that have leaked from the vascular
system and transport lymph fluid back from the tissues to the circulatory system.
Tonsils - trap bacteria and viruses that are people breathe. Antibodies produced in the tonsils kill these bacteria and
viruses to prevent throat and lung infections.
, 3. List the body’s nonspecific defenses, and explain the function of two of them, also describe the
components and mechanisms.
Nonspecific Resistance (Innate Immunity)- Present at birth ad includes defense mechanisms that provide
general protection against invasion by a wide range of pathogens
Mechanical defenses
Epidermis of skin Forms physical barrier to entrance of microbes.
Mucous membranes Inhibit entrance of many microbes, but not as effective as intact skin.
Mucus Traps microbes in respiratory and gastrointestinal tracts.
Hairs Filter out microbes and dust in nose. Cilia Together with mucus trap and remove microbes and dust
from upper respiratory tract.
Lacrimal apparatus Tears dilute and wash away irritating substances and microbes.
Saliva Washes microbes from surfaces of teeth and mucous membranes of mouth.
Urine Washes microbes from urethra.
Defecation and vomiting Expel microbes from body.
Chemical defenses
Sebum Forms protective acidic film over skin surface that inhibits growth of many microbes.
Lysozyme Antimicrobial substance in perspiration, tears, saliva, nasal secretions, and tissue fluids.
Gastric juice Destroys bacteria and most toxins in stomach.
Vaginal secretions Slight acidity discourages bacterial growth; flush microbes out of vagina.
4. Discuss the types of T cells and the role played by each in the immune response, and explain the
1. Explain the difference between nonspecific and specific defense and the role of lymphocytes in each of
the immune response.
Nonspecific Resistance (Innate Immunity)
Present at birth ad includes defense mechanisms that provide general protection against invasion by a wide
range of pathogens
Immunity (Adaptive Immunity)
Involves activation of specific lymphocytes that combat a particular pathogen or other foreign substance
Lymphocytes provide specific defense. They respond to the presence of invading pathogens, abnormal body cells, and
foreign proteins by physical and chemical attacks.
2. Identify the major components of the lymphatic system and explain their functions.
Thymus – produces T-cells for immune response.
The spleen - largest single mass of lymphatic tissue in the body. The spleen destroy blood-borne pathogens and
worn-out red blood cells by phagocytosis
Lymph Nodes- produce lymphocytes that kill pathogens, harmful foreign particles and debris from lymph before it is
returned to the blood stream.
Lymph vessels -act as reservoirs for plasma and other substances including cells that have leaked from the vascular
system and transport lymph fluid back from the tissues to the circulatory system.
Tonsils - trap bacteria and viruses that are people breathe. Antibodies produced in the tonsils kill these bacteria and
viruses to prevent throat and lung infections.
, 3. List the body’s nonspecific defenses, and explain the function of two of them, also describe the
components and mechanisms.
Nonspecific Resistance (Innate Immunity)- Present at birth ad includes defense mechanisms that provide
general protection against invasion by a wide range of pathogens
Mechanical defenses
Epidermis of skin Forms physical barrier to entrance of microbes.
Mucous membranes Inhibit entrance of many microbes, but not as effective as intact skin.
Mucus Traps microbes in respiratory and gastrointestinal tracts.
Hairs Filter out microbes and dust in nose. Cilia Together with mucus trap and remove microbes and dust
from upper respiratory tract.
Lacrimal apparatus Tears dilute and wash away irritating substances and microbes.
Saliva Washes microbes from surfaces of teeth and mucous membranes of mouth.
Urine Washes microbes from urethra.
Defecation and vomiting Expel microbes from body.
Chemical defenses
Sebum Forms protective acidic film over skin surface that inhibits growth of many microbes.
Lysozyme Antimicrobial substance in perspiration, tears, saliva, nasal secretions, and tissue fluids.
Gastric juice Destroys bacteria and most toxins in stomach.
Vaginal secretions Slight acidity discourages bacterial growth; flush microbes out of vagina.
4. Discuss the types of T cells and the role played by each in the immune response, and explain the
