2.5 d) Defence Against Parasitic Attack Flashcards
Immune response in mammals has both ___ and __-___ effects.
specific, non-specific
Non-specific defences of mammals include…
physical barriers,
chemical secretions,
inflammatory response,
phagocytes,
natural killer cells
Phagocytes and natural killer cells are examples of what.
non-specific defences in mammals
Epithelial tissue blocks…
the entry of parasites
Hydrolytic enzymes in ___, ___ and ___ destroy bacterial cell walls.
mucus, saliva, tears
What type of enzyme in mucus, saliva and tears destroys bacterial cell walls?
hydrolytic
The low __ environments of the secretions of the ___, ___ and ___ glands denature the ___ proteins of ___.
pH, stomache, vagina and sweat, cellular, pathogens
Describe the inflammatory response.
cells that are injured by cut/wound release signalling molecules, which increase blood flow to the site, bring more antimicrobial proteins and phagocytes.
Describe the inflammatory response.
When skin is damaged (eg cut or wound), damaged cells release signal molecules (called cytokines) which trigger an increase in blood flow to the area, bringing more antimicrobial proteins and phagocytes
What are phagocytes?
White blood cells with a non-specific role in defence
Phagocytes are ___ blood cells with a __-___ role in defence.
White, non-specific
Phagocytes arrive at the site of ___, and ___ parasites by enfolding their ___ ___ around the parasite.
infection, engulf, plasma membrane
Once engulfed, the parasite is brought into the ___ in a ___.
phagocyte, vacuole
Phagocytes contain, ___ (which are filled with ___ enzymes).
The lysosome ___ with the ___, and the parasite is ___.
This process is called ___.
lysosomes, digestive.
fuses, vacuole, digested.
*(parasite or pathogen or infected cell)
phagocytosis.
Describe the 3 steps to phagocytosis.
1.
2.
3.
- phagocytes arrive at the site of infection
- phagocytes engulf parasite by enfolding them with their plasma membrane
- lysosome fuses with vacuole and parasite is digested.
Natural killer cells can ___ and ___ to cells infected with ___, releasing ___ which induce ___.
identify and attach, viruses, chemicals, apoptosis
What do natural killer cells do? (2)
identify and attach to virus infected cells.
release chemicals that induce apoptosis
A wide range of ___ ___ cells constantly circulate, ___ the tissues.
white blood, monitoring
If tissues become ___ or are ___, then cells release ___ that increase ___ flow, resulting in both ___ and __-___ white blood cells ___ at the site.
damaged, infected, cytokines, blood, specific and non-specific, accumulating
What do cytokines do?
increase blood flow
(resulting in an accumulation of both specific and non-specific white blood cells at the site of infection)
When are cytokines released?
when cells are damaged/infected
Mammals contain different ___, each with a ___ on its surface, which can potentially recognise a ___ ___.
lymphocytes, receptor, parasite antigen
The binding of an ___ to a lymphocyte’s receptor causes ___ of that lymphocyte, creating a ___ ___.
antigen, replication, clonal population
How can lymphocytes fight pathogens? (2)
they can produce antibodies, or induce apoptosis in infected cells
Antibodies possess regions of great ___ in their amino acid sequences.
variation
The variable region of amino acids in an antibody’s amino acid sequence gives the antibody its ___ for binding ____.
specificity, antigens
When an antigen binds to an antibody’s activet site, the antigen-antibody complex formed can result in…
1…..
2….
- inactivation of the parasite, rendering it succeptible to an attack from a phagocyte.
- stimulation of a response which results in cell lysis
What is cell lysis?
the breakdown of a cell caused by damage to its outer membrane
Initial antigen exposure produces ___ ___ cells, which are specific to that ___, and can produce a secondary response should…
memory lymphocyte, antigen, the same, antigen enter the body for a second time
Should an antigen enter the body for a second time, ___ ___ cells will have been produced, which result in ___ antibody production, in terms of ___ of production, ___ in blood and ___.
memory lymphocytes, enhanced, speed, concentration, duration.
What does a natural killer cell do?
What does an antigen-antibody complex do?
What do lymphocytes do?
- identify and attach to virus infected cells and release chemicals that induce apoptosis.
- Inactivation of the parasite or cell lysis
- release chemicals which induce apoptosis or produce antibodies - after being cloned
Which three things do memory lymphocytes enhance/improve during the secondary response to a pathogen?
increased concentration in blood of antibodies, increased duration, and increased speed of production
