SABS 1 Exam 1 pt2 and final material

When a B cell encounters its antigen, that antigen provokes the humoral immune response in which antibodies specific for that antigen are made

• True
• false

What is true about the activation and differentiation of B cells?

• naïve B cells activate when matching antigens bind to is surface recptors and cross-link adjacent receptors together
• antigen binding is followed by receptor mediated endocytosis of the cross-linked antigen-receptor complex
• clonal selection is followed by proliferation and differentiation into effector cells
• usually interactions with T cells are required to help B cells achieve full activation
• most clones differentiate into plasma cells but some become long-lived memory cells

What is true about plasma cells?

• they are the anti-body secretingcells of the humoral response
• develop elaborate internal machinery (rough ER) needed to secrete 2000 antibodies/second
• function for 4-5 days and then dies
• the secreted antibodies circulate in the blood/lymph where they find free antigens marking them for destruction by the innate or adaptive immune system

What is true about memory B cells

• clone cells that do not differentiate into plasma cells
• mount an almost immediate huoral response if they encounter the same antigen again
• capable of secreting antibodies
• only live 4-5 days

The primary immune response occurs only for when the body first sees an antigen/pathogen, which of the following is true about the primary immune response

• typically has a lag period of 3-6 days after antigen exposure
• there is a lag as the few B cells specific for that antigen proliferate and for the clones to become B cells
• after the mobilization period, plasma antibody levels rise and reach a peak in about 10 days then decline
• immune responses are more prolonged

What is true about the secondary immune response?

• describes when a person is re-exposed to the same antigen whether it is the 2nd or 22nd time
• immune responses are faster
• immune responses are more prolonged
• immune responses are more effective since the immune system has already been primed/sensitized
• memory cells are on high alert and ready to respond

Memory cells provide what is commonly called (a)   memory

What is true about immunological memory?

• within hours of recognizing the old enemy antigen a new army of plasma cell is being generated
• memory cells persist for long period in humans and many retain their capacity to produce powerful secondary humoral responses for life
• within 2-3 days the antibody titer has risen steeply to reach much higher levels than in the initial response
• secondary response antibodies bind with higer affinity but remain elevated for weeks to months
• with appropriate chemical signals plasma cells can function for longer than 4-5 days

The same events occur in the cellular immune response as the humoral :A primary response sets up a pool of effector cells and generates memory cells that can mount secondary responses

• True
• false

How is active immunity acquired?

• naturally acquired when an individual gets an infection
• artifically acquired when a person receives vaccines
• through antibodies passed from mother to fetus (placenta) or mother to infant (milk)