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Human Biology: Unit 3 > Chapter 7 - The Body Can Affect Itself From Infection > Flashcards

Chapter 7 - The Body Can Affect Itself From Infection Flashcards

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1
Q

Define Pathogens

A

A disease-causing organism; AKA pathogenic organism

eg. Bacterium/Virus

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2
Q

What is a communicable/Infectious disease?

A

A disease that can be transmitted/passed from person to person by infection with micro-organisms.
AKA Infectious/Transmissible disease

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3
Q

What are some pathogens which affect the human body?

A
  • Bacteria
  • Viruses
  • Fungi
  • Animal parasites
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4
Q

What is BACTERIA?

A
  • Prokaryote: unicellular organisms with a simple internal structure
  • Lack in nucleus
  • DNA either floats freely in cytoplasm or is in the form of circular plasmids
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5
Q

Define Plasmids

A

In a bacterial cell, small circular strands of DNA distinct from the main bacterial genome; composed of only a few genes and able to replicate independently.

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6
Q

What is a Prokaryote?

A

a single-celled organism lacking a distinct nucleus or specialised organelles.

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7
Q

Draw a diagram of bacteria and label and understand

  • Slime layer
  • cell membrane
  • flagella
  • cytoplasm
  • capsule
  • DNA
  • Cell Wall
A

Slime layer
- around the outside of some bacteria

Cell Membrane
- similar to that of other cells

Flagella

  • For movement; may be one or many
  • not found in all bacteria

Cytoplasm

  • appears granular due to the presence of ribosomes.
  • Bacteria do not have membrane-bound organelles such as Mitochondria or Golgi apparatus

Capsule
- form of complex carbohydrates by some bacteria for protection

DNA

  • there is no nuclear membrane so the DNA forms a tangle inside the cell.
  • Some of the DNA is in the form of loops called plasmids that can be exchanged during reproduction.

Cell Wall
- Composition varies but often made of PEPTIDOGLYCAN, a combined carbohydrate-protein

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8
Q

Are all bacteria harmful to humans?

- do they live on humans?

A
  • majority of bacteria are harmless to humans
  • they are non-pathogenic
  • Huge numbers of bacteria live on our SKIN, ALIMENTARY CANAL, and in other PARTS of the Body.
  • These bacteria have NO-ILL EFFECT ON HEALTH

eg.
- armpit of an adult male, there are more than 2 million bacteria per square cm of skin surface.
- intestines: bacteria so numerous that they form a major part of the digestion process

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9
Q

Why are bacteria essential for life on earth? (2)

A
  • ROLE in DECOMPOSITION of organic material and CYCLING of the elements
  • some bacteria are used fro INDUSTRIAL PURPOSES
    EG. lactobacilli - used to make yoghurt and sauerkraut
    The flavour of cheeses depends on the types of bacteria used in their production.
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10
Q

When are bacteria bad?

A

There are some bacteria that may cause illness or death when PRESENT IN RELATIVELY LARGE AMOUNTS.

  • Bacteria affect the body DIFFERENTLY, depending on SPECIES.
  • Effects may include PRODUCING TOXINS or INDUCING an ALLERGIC RESPONSE.
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11
Q

Explain the general structure of bacteria and how to view them.

A

very small

  • with an average diameter ranging from 0.5 to 2.0 micrometers
  • length ranging from 1 - 10 micrometers

ONLY SEEN THROUGH A LIGHT MICROSCOPE
- about all that can be seen is the shape of their cells which used to classify them

  • To identify a bacterium, it is first GROWN on an AGAR PLATE or GROWTH MEDIUM in SPECIFIC CONDITIONS
  • Then it can be STAINED and viewed under a light microscope.
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12
Q

What are the shapes of classification of bacteria?

A
  1. COCCI
    - coccus (sing.)
    - SPHERICAL CELLS
    - that may occur singly
    - in pairs (diplococci)
    - in clusters (staphylococci)
    - in chains (streptococci)
  2. BACILLI
    - bacillus (sing.)
    - with flagella
    - have ROD-SHAPED cells
    - many have flagella for movement
  3. SPIRILLA
    - spirillum (sing.)
    - have TWISTED CELLS
  4. VIBRO
    - CURVED RODS
    - shaped like a curved comma
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13
Q

What is a Virus?

A

An infectious agent, too small to be seen with a light microscope, consisting of a protein sheath surrounding a core of nucleic acid: viruses are totally dependent on living cells for reproduction.

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14
Q

Explain the general structure of viruses

A

-subsequent studies showed that viruses had distinctive structures and differing sizes

SIZE: 20-750 nanometres

  • too small to be seen with a microscope with an ordinary light microscope.
  • need an ELECTRON MICROSCOPE to see
  • ALL were found to have CONTAIN GENERIC MATERIAL in the form of a MOLECULE of EITHER DNA OR RNA
  • NEVER CONTAINS BOTH
  • NOT LIVING THINGS AS THEY DO NOT REPRODUCE ON THEIR OWN/BY THEMSELVES
  • Viruses DIFFER in the TYPE of CELL they INVADE, therefore the SYMPTOMS SHOWN RELATE TO THE TISSUE THAT IS AFFECTED.
  • Has a LIPID OUTER MEMBRANE
  • PROTEIN COAT
  • LIPOPROTEIN ENVELOPE
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15
Q

Explain the process in which a virus will infect a host/body.

A

A virus will INFECT A LIVING CELL by piercing with its Viron and entering the body.

  1. Virus’ DNA/RNA INDUCES THE CELL TO MANUFACTURE MORE VIRUS PARTICLES
  2. new particles are then ABLE TO LEAVE the HOST CELLS TO INFECT OTHERS.
  3. DURING THIS PROCESS THE CELLS BECOME DAMAGED/CHANGED OR DIE
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16
Q

What are bacteriophages?

A

A virus that infects and multiplies in bacterial cells, causing the death of the bacterium

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17
Q

Example of a Virus and how it affects a cell

  • Diagram on page 157
A

HIV - human immunodeficiency viruses

  1. virus binds to the receptor of a T-Lymphocyte.
  2. Uncoated RNA from the virus enters the lymphocyte
  3. Virus Contains an enzyme that enables it to make a DNA copy of Its RNA.
  4. Host Cell DNA in Nucleus
  5. DNA copy of HIV RNA integrates with HOST CELL DNA
  6. NEW VIRAL RNA PRODUCED
  7. BUDDING OF NEW VIRUS PARTICLE FROM LYMPHOCYTE
  8. NEW HIV able to INFECT OTHER CELLS
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18
Q

Examples of Bacteria

A
  • bubonic plague
  • cholera
  • chlamydia
  • dental caries (tooth decay)
  • Gonorrhoea
  • leprosy
  • pneumonia
  • syphilis
  • tuberculosis
  • typhoid
  • whooping cough

more in pge 158

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19
Q

Examples of Viruses

A
  • HIV/AIDS
  • Chickenpox
  • EBOLA
  • COVID-19
  • Mumps
  • smallpox
  • Hepatitis A,B,C,D
  • Shingles
  • Cold sores (herpes)
  • Cold
  • Influenza
  • Flu
  • Genital Herpes

more in pge 158

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20
Q

Examples of Fungi

A

ringworm

thrush

tinea

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21
Q

Examples of animal parasites

A
  • protozoans
  • malaria
  • sleeping sickness
  • amoebic meningitis
  • malaria
  • Toxoplasmosis

LICE
SCABIES (MITES)
TICKS
ARTHROPODS

Nematodes (roundworms)
Hookworms
roundworms
threadworms

Platyhelminthes (flatworms)
- Blood flukes 
live flukes 
tapeworms
hydatids
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22
Q

What is a communicable disease?

A

The disease may spread by the transmission of the pathogenic organism from one person to another

  • some are said to be Contagious
  • other are said to be VECTORS
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23
Q

Define Contagious

A

the disease is passed directly from one person to another

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24
Q

define Vector

A

disease spread from person to person by Vectors = by INTERMEDIATE HOSTS OF THE PATHOGEN (mosquitoes or fleas)

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25
Q

List, explain, example - the transfer of disease between people (6)

A
  1. TRANSMISSION BY CONTACT - involves the spread of actual PHYSICAL CONTACT
    - DIRECT - actually touching an infected person
    - INDIRECT - touching an object that has been touched by an infected individual
    EXAMPLE - SKIN INFECTIONS AND SEXUALLY TRANSMISSIBLE INFECTIONS
  2. INGESTION of food/drink CONTAMINATED with PATHOGENS may result in disease.
    EXAMPLE DYSENTERY, TYPHOID FEVER, SALMONELLA FOOD POISONING
  3. TRANSFER OF BODILY FLUIDS - from one person to another can result in the transmission of a number of infections
    - when BLOOD and other BODY FLUIDS from an infected person come into CONTACT WITH MUCOUS MEMBRANES (nose, mouth, throat, and genitals), or bloodstream of uninfected via a NEEDLE, STICK, BREAK-IN SKIN.
    Then pathogens may enter the body
    EXAMPLES - HIV, HEPATITIS B&C
  4. INFECTION BY DROPLETS - Tiny droplets of moisture-containing pathogenic organisms are emitted when breathing, talking, sneezing, or coughing.
    - maybe breathed in by others, or may settle in food/utensils to be later ingested with food.
    - EXAMPLES COVID-19, EBOLA, MUMPS, COLDS, INFLUENZA
  5. AIRBORNE TRANSMISSION
    - MOISTURE in EXHALED droplets evaporates, many bacteria are killed but VIRUSES AND SOME BACTERIA REMAIN VISIBLE AND CAN CAUSE INFECTION WHEN INHALED.
    - these particles are LIGHTER, they remain viable for a greater distance than those transmitted by droplets
    MEASLES, MUMPS, AND CHICKENPOX
  6. TRANSMISSION BY VECTORS
    - transfer of pathogens by other animals such as insects, ticks, or mites
    - some transfer DIRECTLY, others INDIRECTLY (HOUSE FLIES) - may spread by the pathogen to food and water, which is ingested.
    - many vectorborne diseases are spread by a specific vector
    EXAMPLE
    - MALARIA AND DENGUE FEVER ARE SPREAD BY MOSQUITOES,
    TRYPANOSOMIASIS (African sleeping fever) is spread by the TSETE FLY
    - LYME DISEASE is spread by TICKS,
    - BUBONIC PLAGUE - FLEAS FROM RATS, MICE
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26
Q

Why does the body have defenses?

A

The body has several defences that protect it against invasion by pathogenic micro-organisms

ALLOWS :

  1. PREVENTS ENTRANCE
  2. DEALT WITH: BEFORE INVASION CAUSES ISSUES (illness and sickness from infection and disease spread)
  3. IF ILL, the. RECOVER without medical intervention
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27
Q

What are the two categories of Body Defence systems based on what pathogen it is against

A
  1. Non-specific: works on/against all pathogens
    - 1st line in defense
  2. Defence directed at a particular pathogen
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28
Q

LIST THE NON-SPECIFIC DEFENCES OF THE BODY

A
  1. EXTERNAL DEFENCES
  2. PROTECTIVE REFLEXES
  3. INTERNAL NON-SPECIFIC:
    - PHAGOCYTOSIS
    - INFLAMMATORY RESPONSE
    - FEVER
  4. LYMPHATIC SYSTEM
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29
Q

Explain External defenses

A
  • All non-specific
  • act as BARRIERS
  • stop pathogens and foreign particles from entering the body
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30
Q

LIST THE 9 EXTERNAL DEFENCES OF THE BODY

A
  • BARRIERS
    1. SKIN
    2. MUCUS
    3. HAIRS
    4. CILIA
    5. MOVEMENT OF FLUIDS
  • CHEMICAL MEDIATORS
    6. ACIDS
    7. LYZOZYMES
    8. CERUMEN
    9. SALIVA
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31
Q

Explain why the skin is an external barrier

A

EXAMPLE IMPERVIOUS MEMBRANE OF THE SKIN

  1. COVERING THE OUTSIDE OF THE BODY
  2. STOPPING ENTRY OF MICRO-ORGANISMS: PROVIDED IT IS NOT BROKEN BY CUTS AND ABRASIONS
  3. AT OPENINGS OF THE SKIN (mouth, eyes, nose, anus) SPECIAL PROTECTION is PROVIDED, by other defenses
  4. Huge NUMBER OF BACTERIA LIVE ON THE SKIN ALL THE TIME - normal healthy bacteria occupy the area so POTENTIAL PATHOGENS find it DIFFICULT to BECOME ESTABLISHED

Other protective mechanisms

  1. Oily SECRETION = CEBUM
    - is antiseptic
    - produced in the oil glands in the skin
    - contains substances that kill some pathogenic bacteria
  2. SWEAT
    - secreted onto the skin
    - contains salts + fatty acids
    - prevents growth of many micro-organisisms
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32
Q

Explain Mucous membranes as an external barrier

A

Mucous membranes

  1. Lines the cavities of the body that open to the exterior
  2. secretes mucous
  3. traps particles; inhibits entry of microorganisms to organs

FOUND IN digestive, reproductive, urinary tracts TO BE PROTECTED

  • VAGINA
  • STOMACH
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33
Q

Explain Hairs as an external barrier

A

Found in the NASAL CAVITY (NOSE) AND EARS

  • in nose hairs + a layer of mucus trap 90% of particles inhaled when breathing
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34
Q

Explain Cilia as an external barrier

A
  1. Tiny hair-like projections from cells that are capable of a BEATING MOTION
  2. FOUND - MUCOUS MEMBRANES lining the NASAL CAVITY, TRACHEA + OTHER AIR PASSAGES
  3. THE BEATING CILIA MOVES MUCUS, CONTAINING TRAPPED PARTICLES AND MICRO-ORGANISMS TOWARDS THE THROAT, WHERE IT MAY BE COUGHED UP OR SWALLOWED
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35
Q

Explain Acids as an external barrier

A
  1. Stomach juices
    - strongly acidic to kill bacteria taken in from food or those contained in mucous swallowed from nose/windpipe
    - gastric mucosa prevents it from eating itself up and prevents infection
  2. vagina acid secretions which reduced the growth of microorganisms
    - acidic lining and mucous plug protects
  3. urine and sweat on the skin is also acidic
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36
Q

Explain Lysozyme as an external barrier

A
  1. enzyme that kills bacteria
  2. found in the eyes: protected by the flushing action of tears which contain this enzyme
  3. Also found in the saliva, sweat, secretions of the nose, and tissue fluid
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37
Q

Explain CERUMEN as an external barrier

A

EARWAX
1. protects the outer ear against infection by some bacteria

  1. slightly acidic + contains lysozyme enzyme
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38
Q

Explain saliva as an external barrier

A

in the mouth cavity, has pH that is non-neutral (6.2ish - weak base)
to kill pathogens via corrosion

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39
Q

Explain the Movement of fluid as an external barrier

A
  1. Flushing actions of bodily fluids helps keeps some areas relatively clean/free of pathogens
  2. eg. urine flowing through urethra has cleaning action
  3. prevents bacterial growth and helps to stop bacteria reaching the bladder and kidney
  4. Women have shorter urethra than men, so they are more prone and ten to suffer more bladder infections
  5. EXAMPLES = TEARS, SWEAT, SALIVA, URINE
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40
Q

What is a Protective Reflex?

A

A reflex is AUTOMATIC, INVOLUNTARY RESPONSE TO A STIMULUS

  • against injury (Blink reflex)
  • infection (vomiting)

There are 4 reflexes to help protect against infection.

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41
Q

LIST THE 4 REFLEXES which help the body to protect itself from infection and explain them.

A
  1. Sneezing - stimulus is IRRITATION OF NASAL CAVITY
    - may be CAUSED BY NOXIOUS FUMES OR DUST PARTICLES which are likely to be carrying microorganisms
    - It is the FORCEFUL EXPULSION OF AIR FROM THE LUNGS CARRYING MUCUS, FOREIGN PARTICLES, AND IRRITATIATING GASES OUT THROUGH NOSE AND MOUTH.
  2. Coughing - stimulus is IRRITATION in the LOWER RESPIRATORY TRACT - the BRONCHI and BRONCHIOLES
    - similar to sneezing in manner: air forced from the lungs to try to remove the irritant
    - AIR DRIVES MUCUS + FOREIGN MATTER UP THE TRACHEA THROUGH THE NOSE AND MOUTH
  3. VOMITING - psychological stimulus: excessive stretching of the stomach and bacterial toxins can all induce vomiting
    - contraction of muscles in the abdomen and the diaphragm, (not stomach) expels the stomach contents up to and out via mouth.
  4. Diahorria - stimulus is the irritation of the small +large intestines by bacteria, virus, or protozoans
    - causing increased contractions of the muscles of the wall of the intestines so that the irritant is removed as quickly as possible
    - material does not stay in large intestines for long, enough for water to be absorbed, so faeces are very watery.
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42
Q

What are Internal non-specific defenses?

A

if pathogens get bast external defenses, there are internal non-specific defenses that work to eliminate them

includes

  • Phagocytosis
  • Inflammatory response
  • Fever
43
Q

What is Phagocytosis?

A

The process eliminates many pathogens before the infection has a chance to take hold.
- organisms that penetrate our external defences are attacked

44
Q

DEFINE PHAGOCYTES.

LIST THEM

A

specialized white blood cells or LEUCOCYTES that ENGULF AND DIGEST MICRO-ORGANISMS AND CELL DEBRIS

  1. MONOCYTES AND MACROPHAGES
  2. NEUTROPHILIS
  3. DENDRITE CELLS
45
Q

List and explain the phagocytic cells

A
  1. MONOCYTES AND MACROPHAGES
    - when the tissue becomes infected or inflamed MONOCYTES leave the bloodstream and enter the tissue
    - they differentiate into macrophages which are phagocytic cells
    * ** some move through tissues looking fro and destroying pathogens
    * ** others are situated in one place and only deal with the pathogens that come to them
  2. NEUTROPHILS
    - described as granulated leucocyte due to granules visible in the cytoplasm.
    - lobulated nucleus
    - most abundant (55-70%) of all leucocytes
    - short life span and dies after a few days
    - dead cells make a large portion of PUS that form after INFECTION
    - during cell infection, the neutrophils are the FIRST CELL to move into the tissue to destroy the pathogen
    - PARTICULARLY IMPORTANT IN KILLING PATHOGENS INSIDE CELLS
  3. DENDRITE CELLS
    - CHARACTERISED BY PROJECTIONS FROM THE CYTOPLASMAM
    - slightly different from macrophages and neutrophils as their FUNCTION GOES BEYOND PHAGOCYTOSIS
    - then use INFORMATION ABOUT INGESTED PARTICLE TO ASSISTS IN SPECIFIC IMMUNITY
46
Q

What are the steps of the process of phagocytosis

A
  1. Phagocye captures invading pathogen by moving to it
  2. It changes shape so it completely encloses bacterium
  3. LYSOSOMES contain destructive enzymes
  4. enzymes released and destroy the pathogen
  5. Harmless particles are released from phagocyte
47
Q

What is INFLAMMATION

A

is a response to any damage to the tissues

Damage to tissues stimulates a series of steps in the inflammatory response
- some of these steps are assisted by proteins in the Complement system that are produced by liver cells and macrophages

48
Q

What is the purpose of inflammation?

A
  1. Reduce the spread of any pathogens
  2. Destroy pathogens and prevent the entry of additional pathogens
  3. Begin repair of damaged cells and tissue
49
Q

Examples of the inflammatory response…

A

words ending with ‘itis’ indicate INFLAMMATION of specific organs/tissue

  • Tonsilitis - inflammation of the tonsils
  • Meningitis - is inflammation of the meninges, the membranes around the brain
  • Laryngitis - is inflammation of the larynx
50
Q

What are the four signs of inflammation?

A

eg. when there is a mozzie bite or cut, able to identify every 4 signs of the inflammation
1. REDNESS
2. SWELLING
3. PAIN
4. HEAT

51
Q

What are the steps of the inflammatory response

A

Step 1.

  • mechanical damage or local chemical damage
  • causes specialized leukocytes called MAST CELLS to be ACTIVATED BY COMPLEMENT PROTEINS
  • Results in the RELEASE OF HISTAMINE, HEPARIN and other CHEMICALS INTO THE TISSUE

Step 2.

  • HISTAMINE (vasodilator) increases blood flow through the area due to VASODILATION
  • making BLOOD CAPILLARY WALLS MORE PERMEABLE
  • more FLUID MOVES THROUGH CAPILLARY WALLS INTO THE TISSUE
  • The increased blood flow causes REDNESS AND HEAT
  • ESCAPE of the fluid from the blood CAUSES SWELLING; more fluid/liquid in an area

Step 3.

  • HEPARIN RELEASED FROM MAST CELLS prevents clotting, IN IMMEDIATE AREA OF INJURY
  • A clot of the fluid forms around the damaged area, which slows the spread of the pathogen into healthy tissues

Step 4.

  • Complement system protein and some chemicals released by the MAST CELLS ATTRACT PHAGOCYTES
  • PARTICULARLY NEUTROPHILS: They actively consume micro-organisms and debris by the phagocytosis

STEP 5.
- the abnormal conditions in the tissue stimulate pain receptors and so the person feels pain in the inflamed area

STEP 6.

  • the phagocytes, filled with BACTERIA, DEBRIS, AND DEAD CELLS BEGIN TO DIE.
  • the dead phagocyted and tissue fluid from a yellow liquid called PUS.

STEP 7.
- NEW cells are PRODUCED BY MITOSIS AND REPAIR OF THE DAMAGED TISSUE TAKES PLACE.

  • PAIN RECEPTORS - PAIN WHEN STRETCHED
52
Q

What is the complement system

A

A system of proteins that are produced by liver cells and macrophages
- enhances the activity of antibodies and phagocytes

  1. series of more than 20 proteins, many of which are normally active
  2. when initiated, one protein activates the next activating the next, and so on…
53
Q

What is fever?

A

An elevation of body temperature (heat)
- accompanying an infection (common cold, influenza)

  • change in body temperature is due to a RESETTING of the BODY’S THERMOSTAT controlled by the HYPOTHALAMUS to a HIGHER LEVEL THAN NORMAL
54
Q

Explain the onset of FEVER in 8 steps

A
  • Presence of an infection
    1. CHEMICALS CALLED PYROGENS are RELEASED FROM THE WBCs during INFLAMMATORY RESPONSE
  1. Acts on the HYPOTHALAMUS
    - change in body temperature is due to a RESETTING of the BODY’S THERMOSTAT controlled by the HYPOTHALAMUS to a HIGHER LEVEL THAN NORMAL
  2. When a person has a fever the TEMPERATURE IS STILL REGULATED IN RESPONSE TO HEAT/COLD
  3. ***SET POINT IS TO A HIGHER VALUE
  4. Person’s thermoreceptors detect the body temperature and the hypothalamus recognizes that it is lower than the new, higher set point.
  5. Consequence is VASOCONSTRICTION AND SHIVERING
    - CONSERVE HEAT AND INCREASE HEAT PRODUCTION TO DRIVE THE BODY TEMPERATURE UP RAPIDLY.
  6. When fever BREAKS, THE POINT CALLED ‘CRISIS’: reset the body thermostat to normal
  7. In this situation, the PERSON WILL FEEL HOT and appear FLUSHED, as SWEATING AND VASODILATION takes place.
55
Q

What is an example of a Pyrogen?

Where produced?

A

INTERLEUKIN -1

  • predominantly produced by macrophages
  • also produced by other cells such as dendrite and epithelial
56
Q

Is fever GOOD OR BAD?

A

FEVER IS BENEFICIAL UP TO A POINT
1. inhibits the growth of some bacteria/virus

  1. speeds up chemical reactions which may in turn help body cells to REPAIR THEMSELVES QUICKLY DURING DISEASE
  2. Inhibit VIRAL REPLICATION by ALLOWING CHEMICALS CALLED INTERFERONS TO OPERATE MORE QUICKLY.

BAD

  • TEMP over 40 degrees
  • CONVULSIONS, DEATH OF CELLS, BRAIN DAMAGE, DENATURE ENZYMES
  • DEATH WILL OCCUR IF REACHES 44.4-45.5 DEGREES
57
Q

What are INTERFERONS?

A
  • RELEASED BY DYING CELLS

- CHEMICAL SIGNALS ARE SENT BY THEM TO NOTIFY OTHER CELLS ABOUT THE INFECTION

58
Q

What is the LYMPHATIC SYSTEM?

CONSISTS OF:

A

CONSISTS OF :
1. NETWORK OF LYMPH CAPILLARIES JOINED TO LARGER LYMPH VESSELS

  1. LYMPH NODES WHICH ARE LOCATED IN THE LENGTH OF SOME LYMPH VESSELS

FUNCTION:
1. collect some of the fluid that escapes from the blood capillaries and return it to the circulatory system

  1. Body’s internal defence against pathogenic organisms
59
Q

Explain how the lymphatic system is a non- specific internal defense.

A
  1. Lymph nodes occur at intervals along lymphatic vessels
  2. each node contains masses of lymphoid tissue
    - cells of which are CRISS-CROSSED by a NETWORK OF FIBRES
  3. LYMPH entering the lymph nodes contain CELL DEBRIS, FOREIGN PARTICLES and MICRO-ORGANISMS that have PENETRATED THE BODY’S EXTERNAL DEFENCES
    - some pathogenic, if not destroyed, can cause disease
    - larger particles eg. BACTERIA ARE TRAPPED in the MNESHWORK OF FIBRES as the LYMPH FLOWS THROUGH the spaces in the NODES
  4. MACROPHAGES INGEST/DESTROY THESE PARTICLES BY PHAGOCYTOCIS
  5. WHEN INFECTION OCCURS, the formation of LYMPHOCYTES INCREASES AND THE LYMPH NODES BECOME SWOLLEN AND SORE
    eg. infected finger = swelling and tenderness in the armpit, where there are large numbers of lymph nodes
  6. MOST LYMPHOCYTES ARE IMPORTANT IN SPECIFIC RESPONSE TO A PATHOGEN.
60
Q

What are specific defenses?

A

Defences of the body directed towards a particular pathogen

- PART OF THE IMMUNE SYSTEM

61
Q

WHAT IS THE IMMUNE SYSTEM?

PROTECTS AGAINST AND COMPOSED OF

A

DIFFERENT TYPES OF CELLS THAT OCCUR IN MOST ORGANS OF THE BODY AND PROTECTS AGAINST

  • FOREIGN ORGANISM,
  • ALIEN CHEMICALS,
  • ABNORMAL CELLS/CANCEROUS,

COMPOSED OF

  • CELLS
  • non-specific (phagocytes)
  • specific (T AND B CELLS)
  • PROTEINS
62
Q

What is an immune response?

A

A response triggered by foreign particles, substances or micro-organisms entering the body

It involves

    • B CELLS and the PRODUCTION OF ANTIBODIES
  • -T CELLS AND THE DESTRUCTION OF A CELL

It is a HOMEOSTATIC MECHANISM
- DEALS with INVASION and RESTORES the INTERNAL ENVIRONMENT to its NORMAL CONDITION

63
Q

What are lymphocytes?

A

A WBC that is responsible for the IMMUNE RESPONSE
- TWO TYPES = T&B CELLS (via maturation)

  • PRODUCED IN BONE MARROW and END UP IN LYMPHOID TISSUE
64
Q

What is the LYMPHOID TISSUE?

A

Tissue containing many lymphocytes and macrophages

  • MOSTLY found in the LYMPH NODES, but also found in the BONE MARROW, TONSILS, SPLEEN, AND THYMUS
65
Q

there are 2 parts of the immune response. what are they? define them.

A
  1. HUMORAL RESPONSE/ antibody-mediated response
    - involves B-cells (B-LYMPHOCYTES)
  • PRODUCTION OF ANTIBODIES
  • CIRCULATE AROUND THE BODY
  • ATTACK INVADING AGENTS IN THE BLOOD/FLUID PARTS OF THE BODY (HUMORAL PARTS)
  • TRIGGERED BY ANTIGENS
  1. CELL MEDIATED RESPONSE/cellular immunity
    - involves T-cells
    - ATTACH TO ANTIGENS TO DESTROY THEM
    - IN CELLS
66
Q

What are T-Lymphocytes?

A
  1. responsible for cellular immunity
  2. OCCURS in the same LYMPHOID TISSUE AS B-CELLS, BUT OCCUPY DIFFERENT AREAS OF THE TISSUE
  3. 1000S TYPES - SPECIFIC TO ANTIGEN
  4. ACTIVATED/SENSITISED when foreign particles enters the body
  5. PRODUCED IN BONE MARROW AND Matures in the THYMUS
  6. WBC
67
Q

WHAT ARE B- LYMPHOCYTES?

A
  1. WBC
  2. PRODUCED IN BONE MARROW, MATURES IN BONE MARROW, END UP IN LYMPHOID TISSUE
    - BECOME PARTS OF LYMPHOID TISSUE
  3. ACTIVATED/SENSITISED WHEN ANTIGEN ENTERS
68
Q

What is an Antigen?

A

ANY SUBSTANCE CAPABLE OF CAUSING A SPECIFIC IMMUNE RESPONSE
- large molecules

ANTIGENS ACTIVATE B-CELLS BEFORE IT GETS TO THE CELL (INSIDE OF IT)

69
Q

EXAMPLES OF ANTIGENS

A

PROTEINS, CARBOHYDRATES, LIPIDS, AND NUCLEIC ACID

  • VIRUS PARTICLES
  • WHOLE MICRO-ORGANISMS (bacteria cell)
  • PART OF BACTERIUM (flagella, cell wall, capsule)
  • MOLECULES ON CELLS (blood cells)
  • EGG WHITES
  • POLLEN GRAINS
70
Q

self vs non-self antigens

How to distinguish

A

SELF ANTIGENS

  • large molecules produced in a person’s own body
  • does not cause an immune response

NON-SELF ANTIGENS

  • anti-self antigens
  • foreign compounds that trigger a immune response

THE IMMUNE SYSTEM BEFORE BIRTH BECOMES PROGRAMMED TO DISTINGUISH BETWEEN SELF-ANTIGENS AND NON-SELF ANTIGENS.
- from then on it will only attack non-self antigens

71
Q

What is an ANTIBODY?

A

A ‘Y’ SHAPED specialized protein that is produced by plasma cells in response to a non-specific antigen.

  • GROUP OF PROTEINS KNOWN AS IMMUNOGLOBINS
  • represented as ‘Ig’
  • there are 5 classes of antibodies that vary in their structure and are designated IgA, IgD, IgE, IgG, IgM
  • ANTIGEN PRODUCED IN RESPONSE TO AN ANTIGEN CAN COMBINE WITH THAT ANTIGEN TO FORM AN ANTIGEN-ANTIBODY COMPLEX
72
Q

WHAT IS ANTIGEN-ANTIBODY COMPLEX?

A

Antigen molecules have specific active sites with a particular shape

  • has a complementary shape, allowing 2 molecules to fit together like a key in a lock.
  • each particular antibody can combine with only one particular antigen

has

  • antigen
  • antigen - binding - site fragment
  • antibody y
73
Q

Plasma cell?

A

A cell that develops from a B-cell and produces antibodies

74
Q

What are antigen-presenting cells?

A

When a non-self antigen enters the body, specific cells recognize this and respond appropriately.

INCLUDES

  • DENDRITE CELLS
  • MACROPHAGES
  • UNDIFFERENTATED B-CELLS
75
Q

What are the properties of an antigen-presenting cell?

A
  1. detect the presence of a non-self antigen
  2. engulf the pathogen
  3. digest the pathogen, producing small fragments that move to the surface of the cell
  4. present the antigen to lymphocytes
76
Q

explain the process f humoral/antibody mediate response

A
  1. Antigen-presenting cells present the antigen to the SPECIFIC B -CELLS
  2. B-CELLS BECOME ACTIVATED (via detection of stimuli from their receptors)
    - SENSITISED, ENLARGE AND DIVIDE
  3. DIVIDE TO A GROUP CELLS = CLONE
  4. most clones become PLASMA CELLS: which secrete a specific antibody capable of attaching to the active site of the antigen
  5. THESE ANTIBODIES CIRCULATE THE BLOOD, LYMPH, AND EXTRACELLULAR FLUID TO REACH THE SITE OF INVASION
  6. REMAINING B-CELL CONES BECOME MEMORY CELLS
    - SPREAD TO ALL OF THE BODY TO ALLOW THE RESPONSE TO OCCUR MORE RAPIDLY SHOULD ANTIGEN ENTER THE BODY AGAIN
  7. ANTIGEN-ANTIBODY COMPLEX
  8. ONCE THE LEVEL OF ANTIBODIES REACHES A PEAK, IT BEGINS TO DECLINE
77
Q

primary vs secondary response

A

primary

  • first exposure
  • usually responds very slowly
  • often taking several days to build up a large number of antibodies
  • need time for b-cells to multiply and differentiate into plasma cells and secrete antibodies
  • once the level of antibodies reaches a peak, it declines
  • HOWEVER, THE PRIMARY RESPONSE LEAVES THE IMMUNE SYSTEM WITH A MEMORY OF THAT PARTICULAR ANTIGEN

secondary

  • subsequent exposure of the same antigen
  • MUCH FASTER due to MEMORY CELLS RECOGNSINSNG THE ANTIGEN MORE QUICKLY
  • PLASMA CELLS ARE ABLE TO FORM QUICKLY,

RESPONSE IS MUCH MORE INTENSE MAKING IT OCCUR FASTER

  • HIGHER LEVEL OF ANTIBODIES AND LAST LONGER
  • RESPONSE IS SO QUICK THAT THE ANTIGEN HAS LITTLE OPPORTUNITY TO EXERT ANY NOTICEABLE EFFECT ON THE BODY AND NO ILLNESS RESULTS
78
Q

How do antibodies work? (6)

A
  • INACTIVATE foreign enzymes or toxins by combining with them or inhibiting their reaction with other cells
  • BIND to the SURFACES of the VIRUSES AND PREVENT THEM ENTERING CELLS
  • COAT BACTERIA SO THAT THEY ARE MORE EASILY CONSUMED BY PHAGOCYTES
  • cause particles such as bacteria/virus/foreign BLOOD CELLS TO CLUMP TOGETHER, A PROCESS CALLED AGGULATION
  • DISSOLVE ORGANISMS
  • REACT WITH SOLUBLE SUBSTANCES TO MAKE THEM INSOLUBLE AND THUS MORE EASILY CONSUMED BY PHAGOCTYES
79
Q

Explain the process of CELL MEDIATED IMMUNITY

A
  1. ANTIGEN-PRESENTING CELL present the antigen to a particular type of T-CELL
  2. Specific T-lymphocyte is stimulated
    - SENSITIVE, ENLARGE SWELL to undergo rapid cell division
  3. EITHER WILL DEVELOP INTO MEMORY CELLS AND CLONE
  4. REMAINING WILL DEVELOP FURTHER, PRODUCING 3 DIFFERENT TYPES OF T-CELLS

1*** KILLER T-CELLS (cytotoxic cells)

  • migrate to the site of infection and deal with the invading antigen
  • attaches to invading cells and secrete a chemical that will destroy the antigen and then. in search of more

2*** HELPER T-CELLS

  • in humoral and cellular immunity
  • BIND TO THE ANTIGEN ON ANTIGEN-PRESENTING CELLS STIMULATING THE SECRETION OF CYTOKINES THAT:
  • ATTRACT LYMPHOCYTES TO THE INFECTION SITE, WHICH BECOME SENITISED AND ACTIVATES AND THUS INTENSIFYING THE RESPONSE
  • attract MACROPHAGES to the place of infection so that the macrophages can destroy the antigens by phagocytosis
  • intensify the phagocytic activity of macrophages
  • promotes the action of killer T-cells
  1. SUPPRESSOR T CELLS
    - act when the immunity activity becomes excessive or the infection has been eliminated.
    they RELEASE SUBSTANCES THAT INHIBIT T AND B CELL ACTIVITY, SLOWING DOWN THE IMMUNE RESPONSE
80
Q

WHAT DOES THE HELPER T CELLS DO SPECIFICALLY

A

HELPER T-CELLS ARE STIMULATED BY ANTIGEN-PRESENTING CELLS WHICH RELEASE CYTOKINES

  • ATTRACT LYMPHOCYTES TO THE INFECTION SITE, WHICH BECOME SENSITISED AND ACTIVATES AND THUS INTENSIFYING THE RESPONSE
  • attract MACROPHAGES to the place of infection so that the macrophages can destroy the antigens by phagocytosis
  • intensify the phagocytic activity of macrophages
  • promotes the action of killer T-cells

IN HUMORAL AND CELL MEDIATED

81
Q

What is immunity

A

resistance to infection by invading-microorganisms

  • presence of memory cells allows the body to respond quickly enough to deal with any pathogenic invasion,
    before symptoms of the disease occur
82
Q

NATURAL VS ATRIFIVAL IMMUNITY

A

NATURAL
- occurs without any human intervention

artificial
- results from giving people antibody or antigen

BOTH CAN BE PASSIVE OR ACTIVE

83
Q

WHAT IS PASSIVE IMMUNITY?

A

when a person receives antibodies produced by someone else
- meaning the individuals body plays no part in the production of the antibodies

eg. placenta, breast milk, injected with antibodies

IMMUNITY IS ESTABLISHED IMMEDIALETY

IS SHORT-LIVED - LASTS ONLY UNTIL THE ANTIBODIES ARE BROKEN DOWN AND EXCRETED

84
Q

WHAT IS ACTIVE IMMUNITY

A

THE BODY IS EXPOSED TO A FOREIGN ANTIGEN AND MANUFACTURES ANTIBODIES IN RESPONSE TO THAT ANTIGEN

  • AMOUNT OF ANTIBODIES DECREASES, THIS TYPE OF IMMUNITY LASTS LONGER DUE TO THE PRESENCE OF MEMORY CELLS
  • CAN develop from experiencing and recovering from injection with antigens or naturally transmitted infection
85
Q

What are immunizations?

A

programming the immune system so that the body can respond rapidly to infecting micro-organisms

DEVELOPING IMMUNITY

86
Q

WHAT ARE VACCINATIONS?

what are vaccines?

A

ARTIFICIAL INTRODUCTION OF ANTIGENS OF PATHOGENIC ORGANISMS SO THAT THE ABILITY TO PRODUCE THE APPROPRIATE ANTIBODIES IS ACQUIRED W/O THE PERSON HAVING TO SUFFER DISEASE

VACCINE = the antigen preparation used in artificial immunization

87
Q

What are the 4 types of vaccines and explain them

A
  1. LIVE ATTENUATED VACCINES
    - living attenuated micro-organisms are pathogens of REDUCED VIRUELNCE: reduced ability to produce disease symptoms
    - person cannot contract the disease but MANUFACTURES THE ANTIBODIES AGAINST ANTIGEN
    - EXAMPLES - RUBELLA, TUBERCULOSIS, POLIO, MEASLES, MUMPS AND YELLOW FEVER
  2. INACTIVATED VACCINES
    - DEAD MICRO-ORGANISMS
    - PRODUCE IMMUNITY THAT IS SHORTER LASTING THAN LAV
    - CHOLERA, TYPHOID, WHOOPING COUGH
  3. TOXOID VACCINES
    -used when immunizing for liberating effects of toxins produced by bacteria
    - INACTIVATED TOXINS = TOXOIDS are injected to a person so that they are not made ill AND YET DEVELOP IMMUNITY
    EXAMPLES - DIPHTHERIA, TETANUS
  4. SUB-UNIT VACCINE
    - fragment of an organism can be used to provoke the immune response e
    - examples GARDASIL = HPV, AND HEPATITIS B
88
Q

RECOMBINANT DNA METHOD?

A

insert DNA sequences from the pathogen into harmless bacterial cells
- chosen DNA sequence can cause the production of antigens that are characteristic of the pathogen

89
Q

DELIVERY OF VACCINES?

A

VIA NEEDLE IT IS INJECTED USUALLY
- HPV, CHICKENPOX, MEASLES, MUMPS

ORAL VACCINES - IN SEET SUGAR SYRUP OR LUMPS OF SUGAR
- POLIO

OTHER FORMS IN RESEARCH = FINE SPRAY, PATCHES, INGESTION

90
Q

eliminated infection

A

SMALLPOX IS ELIMINATED

NEXT FOR WHO IS POLIO

91
Q

EXPLAIN THE VACCINATION SCHEDULE

A

BIRTH - HEPATITIS B
- due to risk of infection during birth

then later for the immune system to be activated because the placenta and breast milk provide antibodies to overcome disease

2-4 MONTHS
POLIO, WHOOPING COUGH, DIPHTHERIA, TETANUS, HEPATITIS B, HiB, pneumococcal

6MONTHS
- SAME

12 MONTHS - MEASLES, MUMPS, RUBELLA, HiB, MENINGOCOCAAL

18 MONTHS - MEASLES, MUMPS, RUBELLA, CHICKENPOX

4 YEARS - DIPHTHERIA, TETANUS, WHOOPING COUGH, POLIO, MEASELS, MUMPS, RUBELLA

10-15 YEARS - HEPATITIS B, CHICKENPOX, DIPHTHEERIA, TETANUS, WHOOPING COUGH, HPV

15 YEARS AND OVER - INFLUENZA, (ABOS), PNEUMOCOCCAL

50 YEARS AND OVER -N INFLUENZA, PNEUMOCOCCAL,

PREGNANT WOMEN - INFLUENZA

65 AND OVER - INFLUENZA ANNUALLY, PNEUMOCOCCAL

92
Q

herd immunity

A

aprox 70% (differsv to country pop and prox)

A proportion of individuals are immunized
when a large number of immune individuals in a population there is less chance the disease being transmitted between them

93
Q

WHAT CAUSES THE INABILITY TO BE VACCINATED?

A
  1. ALLERGIC REACTIONS
    - not from the vaccine itself from the medium the vaccine is produced in
    eg. INfluenza is cultured in the fertilized egg, egg protein allergic reaction
    Hepatitis B = yeast component
  2. PRESERVATIVES
    - certain chemicals are used as preservatives
    - thiomersal, phenol (carbolic acid), aluminum phosphate, formaldehyde
  3. IMMUNOSUPPRESSED PEOPLE
94
Q

LIST THE FACTORS TO CONSIDER WITH VACCINATIONS

A
  1. INABILITY TO BE VACCINATED DUE TO HEALTH ISSUE
  2. SOCIAL FACTORS
  3. CULTURAL FACTORS
  4. ECONOMIC FACTORS
95
Q

WHAT ARE THE SOCIAL FACTORS?

A
  1. ETHICAL CONCERNS WITH THE USE OF ANIMALS TO PRODUCE VACCINES
    - virus needs to be cultured in living cells to be reproduced, hence animal cells are used
    - worried about the treatment of animals
    EG INFLUENZA IN CHICKEN EMBRYO
  2. ETHICAL CONCERNS WITH THE USE OF HUMAN TISSUE TO PRODUCE VACCINES
    - EG RUBELLA
    - some virus does not grow well in other species tissue and this avoids cross-species
    - people would want to harvest human embryos, tissue
    - moral question on how the cells were obtained
  3. Ethical concerns with testing on animals
    - any problems with the treatment of animals and the harm they obtain from the problems of the virus
    - animals should not be used at all
  4. ethical concerns with informed consent
    - trial in countries with low standards of education and will perform in an experiment without knowing risks and become exploited
  5. concerns about promoting sexual activity between teenagers
    - against HPV likely encourage teenagers to be sexually active
  6. availability: may not available in all areas
96
Q

What are the cultural factors?

A
  1. religious beliefs
    eg church of the firstborns, and the, first church of christ
    are against because they contradict their beliefs
    believe in recovery through prayer, faith
    the way obtained may also be against the religion
97
Q

What are the economic factors?

A
  1. Cost of vaccine - too expensive for people to buy

2. commercialization - interests in commercial vaccines may affect their use

98
Q

What are antibiotics?

A

drugs that are used to fight infections of bacteria

99
Q

list some antibiotics and what they do

A

penicillin notaum - to stop the growth of the staphylococcus bacteria

streptomycin, erythromycin, neomycin, tetracycline, vancomycin - interferes with protein synthesis in the cell of target bacteria

cephalosporin - interferes with the synthesis of the cell wall
- less likely to produce allergic reactions

100
Q

BACTERISTATIC ANTIBIOTICS VS BACTERICIDAL ANTIBIOTICS

A

BACTERIOSTATIC
- prevents reproduction, usually disrupting protein synthesis

BACTERICIDAL
- KILLS BACTERIA BY CHANGING STRUCTURE OF CELL WALL OR MEMBRANE, DISRUPTING ACTION OF PARTICULAR ENZYMES

101
Q

BROAD SPECTRUM VS NARROW SPECTRUM ANTIBIOTICS

A

BROAD
- Affect a wide range of bacteria

Narrow
- specific to bacteria

102
Q

Multiple drug-resistant vs Total drug-resistant

A

Multiple

  • ‘super bugs’
  • resistant to most antibiotics

Total
- cannot be treated with current (any) antibiotics

103
Q

Antiviral Drugs

A
  • drugs used for treating viral infections
  • inhibits the development of the virus, otherwise dangerous for the host as the host cells are used for reproduction of the virus,
  • hard to produce
  • virus also leaved the host making hard to develop something for it

examples
- HIV HERPES, HEPATITIS B AND C, INFLUENZA A AND B

TAMIFLU AND RELENZA FOR INFLUENZA

HEPATITIS B, C, HERPES USE ZOVIRAX - MARKETING, OR ACYCLOVIR

ZIDOVUDINE FOR HIV (AZT)

Human Biology: Unit 3 (5 decks)

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