Biology 2 - 2Nd Exam Dr. Alaie Hunter

Front 1

What is the hormone cascade pathway in response to cold?

Back 1

1. Cold (is a Stimulus that is sensed by the Sensory Neuron that sends a message to the
2. Hypothalamus (receives the signal from the Hypothalamus and through its neurosecretory cells: secretes)
3. Thyrotropic releasing hormone (TRH) – Through the blood vessel, these molecules travel to the:
4. Anterior Pituitary, which then secretes the thyroid-stimulating hormone:
5. Thyrotropin (or TSH) which travels through the blood stream and reach the:
6. Thyroid Gland (endocrine) which ten releases
7. T3 and Thyroxine T4 branches outthrough the blood vessels to… (through negative feedback shuts off anterior pituitary and hypothalamus)
8. Target tissue, increases metabolic rate (this is the Response)

Front 2

How long does signalling in the nervous system take?
How long does signalling in the endocrine system take?

Back 2

Nervous system signalling can take a miliseconds while
Endrocrine system signalling can take minutes to several hours

Front 3

What is the role of hormones? What must they maintain?

Back 3

Hormones are fulfilling the same general role : they are coordinating activities of diverse groups of cells in response to changes in the external and internal environment. We work to maintain an internal balance of many parameters: temperature, blood pH, blood sugar levels, blood composition, blood pressure, hydration, etc.

Front 4

What are the constant conditions that our body needs to maintain?

Back 4

: Temp 37 degrees C, pH of about 7.25 and blood sugar level of about 0.1%.

Front 5

What stimulatates the release of hormones?

Back 5

1. The Nervous System: Both hypothalamus and the adrenal medulla stimulate hormones in response to stimulation from the nervous system (neurons have released) neurotransmitters onto cells of the hypothalamus and adrenal medulla)
2. Hormones can stimulate release of other hormones
3. Chemical change in the blood. Concentration of certain ions or sugars can lead to the release of hormones

Front 6

What is the link between the nervous and endocrine sytems?

Back 6

The hypothalamus is the major integrating link between the nervous & endocrine systems. It receives input from the brain (neural transmitter signals) and it responds by releasing hormones. The hypothalamus also receives sensory signals from other internal organs. It controls our response to fear, hunger, thirst, sexual desires…..

Front 7

How is glucose homeostasis maintained in our system?

Back 7

Through insulin produced by the beta cells of the pancreas and through glucagon produced by the alpha cells of the panreas.

Front 8

Describe the process by which our bodies make insulin and glucogon in order to control the glucose levels in our blood?

Back 8

1. Stimulus: Blood glucose level rises (after eating a sugary meal)
2. Beta cells of pancreas release insulin into the blood
3. Body cells take up glucose through their plasma membranes (which? Most cells outside of the brain) Specifically, the Liver takes up glucose and stores it as glycogen
4. Blood glucose level declines
5. Homeostasis: Blood glucose level (about 90/mg/100ml)
1. Stimulus: blood Glucose level falls (for instance after skipping a meal
2. Alpha cells of pancreas release glucagon into the blood
3. Liver breaks down glycogen and releases glucose into our blood
4. Blood level rises
5. Homoeostatis: Blood glucose level (about 90/mg/100ml)

Front 9

Hormones that create opposite effects to each other?

Back 9

Antagonists Hormones

Front 10

How to non liver cells take in glucose

Back 10

They insert glucose transporters into their plasma membranes to increase glucose uptake!

Front 11

Why doesn't the release of insulin or glucagon affect muscle cells.

Back 11

Because they do not have the receptors for it.

Front 12

As a result of low blood sugar, the alpha cells of the pancreas release glucagon, what is the target cell?

Back 12

Liver cells hydrolyze glycogen molecules and release glucose into the blood.

Front 13

What are symptoms of Hyperthyroidism?
What is the most common disease with this symptom called?

Back 13

High body temp, pofuse sweating, weight loss irritability and high blood pressure (speeds up metobolic processes)
Also bulging eyes caused by the fluid accumulation behnd the eyes
Graves' Disease.

Front 14

In graves disease, how is the cascade pathway effected?

Back 14

The immune system produces antibodies that bind to the receptor for TSH and activate sustained thyroid hormone production

Front 15

What is a common cause of hypothyroidism? What are the symptoms?

Back 15

A common cause is diet's deficient in iodine. Symptoms are weight gain, lethargy and intolerance to cold

Front 16

How does hypothyroidism effect the cascade pathway?

Back 16

without sufficient iodine, the thyroid gland cannot synthesize adequate amounts of t3 and t4 and the resulting low blood levels of t3 and t4 cannot exert the usual negative feedback on the hypothalamus and anterior pituitary gland. As a result the pituitary continues to secrete TSH. Too much TSH in the blood can enlarge the thyroid and reult in goiter (swelling of the neck)

Front 17

What hormone is involved in diabetes insipidis? What does the word mean
What hormone is involed in diabetes mellitus?
What does the word mean

Back 17

1. DI is caused by the lack of the antidiuretic hormone (vasopressin) or the kidney's inability to respond to this hormone. The word means Bland Urine
2. diabetes mellitus involves insulin, either the production of it or the ability to take it in. The word means Sweet Urine

Front 18

What are the characterisitcs of Diabetes Mellitus Type I

Back 18

– Insulin dependent
-Autoimmune disorder, immune system attacks beta cells, body cells are still receptive to insulin if it’s there.
- Antibodies attack and destroy beta cells in the pancreas
- Early Age Onset (Younger people get it. )

Front 19

What are the characterisitcs of Diabetes Mellitus Type II

Back 19

- Non-insulin dependent
- Cells (receptors) no longer properly respond to insulin
-Older onset

Front 20

In reproduction, where does diversity arise from?

Back 20

1. diversity arises from recombination during meiosis I, in prophase
2. from chromosomal alignment of the spindle during metaphase 1 and metaphase 2

Front 21

What is a basic overview of oogenesis?

Back 21

1. Human females are born with all the eggs that they will ever have.
2. The germ cell in the embryo differentiates and forms an oogonium in mitotic division.
3. The primary oocyte is formed before the woman is born, between 3 and 8 months of gestation.
4. At puberty, under the influence of a rise in gonadotropin-releasing hormone from the hypothalamus, the anterior pituitary starts releasing its gonadotropic hormones (Follicle Stimulating Hormone, Luteinizing Hormone).
5. These hormones allow 1 cell per month to finish meiosis 1 and get arrested in meiosis 2’s metaphase. 6. It will be released from the ovary in ovulation. If this cell is not fertilized by a sperm, it will never complete meiosis 2 and will be released from the body during monthly menses. If a woman has not had an egg fertilized, no egg has ever completed meiosis 2.

Front 22

Is cytokinesis symetrical in females?

Back 22

Cytokinesis is asymmetrical during gametogenesis in females. Cytoplasm is to be given to one egg and the other “polar bodies” degenerates.

Front 23

What are the cyclical changes in the ovaries:

Back 23

1. Formation of primary oocytes within follicles
2. Follicle growth
3. Maturation of follicle
4. Ovulation
5. Degeneration of corpus luteum – what is left after the secondary oocyte leaves is a “yellow body” that dies.

Front 24

Discuss hormones involved in the follicular phase

Back 24

-In the first half of a cycle, the follicular phase, Follicle Stimulating Hormone (FSH) helps the oocyte-containing follicle to grow.
-Estrogens are produced as the follicle grows, to repair the uterine lining and stop the blood release, in preparation for the egg to enter it.
-Estrogen also inhibits the anterior pituitary from releasing FSH, preventing another follicle from growing.
-Estrogen simultaneously positively regulates LH production, causing a luteal surge which gives the final push for the egg to leave in ovulation into the uterus, after which the empty follicle degenerates. This is the midpoint of the cycle.

Front 25

Describe the steps in the ovarian cycle

Back 25

the reproductive cycle begins with:
1. the release from the hypothalamus of GnRH, which
2. Stimulates the anterior pituitary to secrete small amounts of FSH and LH
3. Follicle-growth stimulating hormone stimulates follicle growth aided by LH
4. the cells of the growing follicle begin to produce estradiol. Low levels of estradiol inhibit LH and FSH while allowing the follicle and oocyte to mature.
5. Estradiol secretion by the growing follicle begins to rise steeply
6. FSH and LH levels increase markedly as a result of the high levels of the Estradiol stimulate the hypothalamus which produces GnRH which causes a surge in LH and FSH production. The result is the final maturation of the follicle.
7. The follicular phase ends at ovulation. , about a day after the LH surge. The follicle and adjacent wall of the ovary rupture, releasing the secondary oocyte. The luteal phase of the ovarian cyle follows ovulation
8. LH stimulates the follicular tissue left behing in the ovary to transform into the corpus luteum, a glandular structure, which is responsible for sectreting progesterone and estradiol, which exert negative feedback on the hypothalamus and pituitary reducing secreting onf LH and FSH to very low levels.

Front 26

Which immune system is considered the barrier defense. List the types

Back 26

The innate or non-specific immunity. The types of barrier defense are: Skin, Mucous membranes, secretions, phagocytosis cells, antimicrobial proteins, inflammatory response and natural killer cells.

Front 27

Which immunity has a rapid responce, which has a slow response

Back 27

Innate immunity is rapid while aquired (specific or adaptive) has a slower response (that gets quicker with subsequent exposure to antigens)

Front 28

What is the difference between the Humeral Responce and a Cell Mediated Response?

Back 28

Humeral response is referring to the antibodies defense against infection in the body while cell mediated is referring to the cytotoxic lymphocytes defense against infection in the body.

Front 29

Does the innate and adaptive immune systems communicate?

Back 29

Yes, activation of the innate immune system is required to activate the adaptive immune system but the adaptive system can alter the effectiveness of the innate immune system.

Front 30

Describe the Innate Immune system?

Back 30

- Barrier Defense
o Skin – low pH
o Tightly packed epithelial cellsTight barriers, tough cells held together with tight junctions
o Perspiration and tears containing lysosomes (antibacterial enzymes)
o Normal micro biota (like a hotel with no vacancy sign
- Mucus membranes
o Line respiratory, urinary and digestive tracts
- Acidic Environments
o Vagina
o Mouth
o Skin
o Stomach, etc.

Front 31

What is a complement protein of the immune system:
Name one

Back 31

Remember the Membrane Attach Complex (mac attack to continue) There are about 30 proteins ) circulating with blood and can be activated by either direct contact with a pathogen or by antibodies bound to pathogens. They insert themselves in the plasma membrane of pathogens causing cell lysis. (they make a funnel and fluid rushes in to pathogen and the cell bursts!

Front 32

Which immune system has cells that are:
-Always Acitve
-Repsond Fast
-Have a wide variety of receptors that recognize various pathogens
-Have compliment proteins

Back 32

The innate system

Front 33

What type of cell transports oxygen and CO2

Back 33

Red Blood Cell

Front 34

What type of cell fragment is involved in blood clotting

Back 34

Platlets

Front 35

What type of white blood cell (leukocytes) releases histamine and leukotrienes

Back 35

Basophils

Front 36

What type of white blood cell (leukocytes) releases enzymes / effective against parasitic worms

Back 36

Eosinophils

Front 37

What type of white blood cell (leukocytes) releases histamine / phagocytize bacteria

Back 37

Neutrophils

Front 38

White blood cells (leukocytes):
Monocytes develop into these cells that engulf and digest microorganisms; activate T and B cells

Back 38

macrophages

Front 39

What White blood cell (leukocytes) Presents antigens to T cells

Back 39

Dendritic cell

Front 40

What White blood cell (leukocytes) releases histamine and leukotrienes other than basophils

Back 40

What is a Mast call

Front 41

What White blood cell (leukocytes) attack and lyse abnormal body cells

Back 41

What is a Natural Killer (NK) Cell

Front 42

List all white blood cells (leukocytes) of the innate immune system:

Back 42

1. Basophils
2. Eosinophils
3. Neutrophils
4. Monocytes
5. Macrophages
6. Dendritic cells
7. Mast cells
8. Natural Killer (NK cells)

Front 43

List cells of the adaptive (specific) immune system also called Lymphocytes:

Back 43

1. B Cells which differentiate into
2. Plasma Cells
3. Helper T (CD4) cells
4. Cytotoxic T (CD8) cells

Front 44

What adaptive (specific) immune system Lymphocyte is responsible for:
Patrol of the blood and lymph

Back 44

B cells

Front 45

What adaptive (specific) immune system Lymphocyte is responsible for:
Secreting antibodies

Back 45

Plasma cells

Front 46

What adaptive (specific) immune system Lymphocyte is responsible for:
activation of B cells and Cytotoxic T cells

Back 46

Helper T (CD4) cells

Front 47

What adaptive (specific) immune system Lymphocyte is responsible for:
attacking and lysing virally-infected body cells

Back 47

Cytotoxic T (CD8) cells

Front 48

What is phagocytosis, which innate cells are capable of doing it?

Back 48

A cell with a variety of receptors on the plasma membrane recognizes and binds a pathogen, pathogen is taken in the cell via endocytosis, endocytotic vesicle (phagosome) fuses with a lysosome, hydrolytic enzymes destroy the pathogen.

- Macrophages
- Dendtric Cells
- Neutrophils

Front 49

1. What cells have MHC I?
2. What Cells recognice the MHC I?
3. Where does peptide presented in this MHC I come from?

Back 49

1. All nucleated cells
2. CD8 (Cytotoxic T cells)
3. Proteins made inside the cells (endogenously-derived) are broken down and loaded into MHC I)

Front 50

1. What cells have MHC I?
2. What Cells recognice the MHC I?
3. Where does peptide presented in this MHC I come from?

Back 50

1. Professional APC (antigen presenting cells):
- Dendritic
- B cells
- Macrophages
2. CD4 (Helper T)
3. Proteins form outside (exogenously-derived) are taken in, broken down and loaded into MHC II

Front 51

What does a neutrophil do?

Back 51

Before ingesting invasive bacteria, neutrophils can release a net of fibers called a neutrophil extracellular trap (NET), which serves to trap and kill microbes outside of the cell. When neutrophils ingest microbes, they release a number of proteins in primary, secondary, and tertiary granules that help kill the bacteria. They also release superoxide, which becomes converted into hypochlorous acid, or chlorine bleach, which is theorized to play a part in killing microbes as well.

Front 52

Which adaptive Immune system cell is capable of phagocytosis?

Back 52

B cell

Front 53

What is a major site of adaptive immune system activation?

Back 53

The Lymph nodes, there dendritic cells and macrophages can go and present their antigens.

Front 54

What is a piece of pathogen? an even smaller piece?

Back 54

an antigen is usually a piece of a pathogen that can be recognized by a macrophage for instance, once a pathogens are destroyed and pieces disperse into our fluid, these “antigen” will be floating around, even more specific, epitopes are smaller pieces connected to the antigen on the pathogen

Front 55

What happens in an inflammatory response

Back 55

-Direct interaction with bacteria or pathogen will trigger histamine which will make inflammatory reaction. (we should be fine using the term cytokines for this reaction)
-Mast cells and macrophages that are resident in the tissue, they are looking for situations like splinter with pathogens on it. Pathogen penetrates the skin and is now meeting cells of innate immune system. -Cytokines released from mast cells and macrophages reach target receptors on the outside of the capillaries. This causes vasodilation, this makes capillaries more leaky and receptors go up on the inside of the capillaries to catch leukocytes. (we will be catching basophils, eucinophils, activated b and t cells and big one, neutrophils)
-additional leukocytes (through the process called Diapedesis squeeze through the capillaries to the effected tissue) along with antimicrobial proteins and anitbodies enter the tissue with fluid
-Macrophages and dentdritic cells may enter lymph vessel to activate the adaptive immune system.

Hallmarks of inflammatory response:
1. Swelling
2. Pain – pressure on the nerves and toxins cause pain
3. Redness – from increased pressure on nerves as well as due to toxins released by pathogens

Front 56

What are 4 characteristics of the adaptive immune system:

Back 56

1. Specificity – b & t cells are extremely specific for a particular epitope on an antigen
2. Massive numbers of B and T cells enables the ability to respond to a wide variety of pathogens
3. Ability to distinguish self from not self –
4. Immunological memory enables rapid responses to repeat infection

Front 57

Site of adaptive immune system activation (all the way from innate immune system)

Back 57

1. Macrophages and dendritic cells travel from sites of infection into lymphatic vessels
a. Local infection of tissues. Innate immunity
2. Macrophages and dendrites will travel to secondary lymphoid organs (lymph nodes, tonsils, spleen, MALT, GALT, etc.) Primary ThymusCD4 and TCells and Bone Marrow BCells
3. Pathogens and macrophages and dendritic cells will get trapped in lymph……

Front 58

Where do B cells mature in?
Where do T cells mature in?
FYI, mature does not mean non-naive

Back 58

B cells mature in bone marrow
T cells mature in thymus

Front 59

3 ways in which antibodies help us:

Back 59

By coating the bacteria (viral neutralization)
By opsonization (making other innate cells better able to take it in)
Activation of complement system and pore formation

Front 60

Which of our innate immune cells are only capable of circulating through our blood vessels to exit to tissue only at sites of infection, fighting the good fight and dying there?

Back 60

Neutrophils
Basophils
Eosinophils

Front 61

Which innate immune system cells are residents in our underlying tissue where pathogens may gain entrance and are reponsible for releasing chemicals to lure the neutrophils, basophils, eosinophils and adptive immune cells when they have encountered a pathogen?

Back 61

Macrophages and Dentritic Cells

Front 62

Which cells can circulate both blood vessels and also the lymphatics which is a series of vessels that runs parallel to the blood vessels

Back 62

B & T cells circulate continuously from blood to lymph to blood as part of their job

Front 63

What happens when a M0 or DC in the lymphatic system presents a antigen to a B or T cell?

Back 63

1. Lymphatic capillaries converge into larger lymphatic vessels and eventually the lymphatic fluid is dumped back into the blood.
2. However infection particles and pathogens & cells carrying such infectious particles & pathogens (like macrophages (M0) and DCs) are trapped in the lymph nodes.
3. B & T cells circulating through the lymph nodes check to see what is being presented by the innate cells.
4. If they can bind the shape of the molecule being presented, they are retrained in the lymph node and undergo division which is referred to as clonal expansion. (has specificity to that pathogen) Many clones with that specificity are made.

Front 64

Why do we call cells of the innate immune system non-specific?

Back 64

Because they possess receptors that can bind many common bacterial shapes and molecules

Front 65

M0 have many receptors for many pathogens, but what happens when a M0 encounters a pathogen that it doesn't have a receptor for?

Back 65

M0 for instance have many such receptors that can bind (and allow internalization and destruction) of a broad range of pathogens. Macrophages can be overwhelmed by sheer # of the pathogens present or they might not be able to recognize any portion of the pathogen. This means the adaptive or specific immune system is going to be rowing the heavy oar in order to remove this pathogen.

Front 66

What happens when a macrophage (M0) binds to a pathogen?

Back 66

1. The M0 internalizes the pathogen and fuses it’s endocytotic vesicle with a lysosome to unleash toxic hydrolytic enzymes on the pathogens.
2. The pathogen is destroyed and fragments of these pathogens can then be presented by these innate immune cells to the adaptive immune cells for purposes of activation of the adaptive immune cells.

Front 67

What is another name for a Red blood cell?
For a white blood cell?

Back 67

Erythrocyte
Leukocyte (all immune cells are leukocytes

Front 68

Leukocytes – White blood cells, all immune cells are leukocytes, then there are some subeatogonics:

Back 68

1. Lymphocytes – cells that circulate between blood and lymph fluid, (B & Ts) check out secondary lymphoid organs like lymph nodes.
2. Cytokines – proteins that after the behavior of target cells
3. Chemokine – alters the behavior of the target cell such that the cell moves towards the chemokine
4. Interleukine – signaling molecules sent out (after) between 2 leukocyes. Or between a leukocyte and a non-white blood cell.

Front 69

Adaptive or specific immune system has 4 key characteristics:

Back 69

1. Specificity : each B or T cell binds only one epitope (shape) of a foreign molecule
2. Because we have to many B and T cells, we can respond to an enormous diversity of foreign molecules and pathogens
3. Ability to distinguish our cells (self) from foreign proteins, pathogens (non-self)
4. Immunological memory: provides our immunity. Means that we have Long lived cells that remember what happened to us or what infections we had. They are in a half-activated state.

Front 70

What are the primary lymphoid organs: They are the site where what happens

Back 70

where B & T cells mature, bone marrow and thymus. Leave Bone marrow once mature, but naive.

Front 71

What is the secondary lymphoid organs:

Back 71

these are organs where B & T cells gain experience and become activated. If cells get activated in the 2nd lymphoid organ, they leave these organs changed: gene expression changes allows the cells to achieve an activated profile where they are making toxic chemicals or signaling molecules or tons of antibodies. They have an ability that they didn’t previously have.
The secondary lymphoid organs are where B & T cells meet up with cells of innate immune system (like Dendritic cells and macrophages) which stimulate the activation.

Front 72

What happens when a naive T cell meets up with a dendritic cell (and the antigen presented by the dendritic cell is a match for the receptor on the T cell)

Back 72

1. A T cell enter a lymph node, gets activated by interaction with a dendritic cell
2. Undergoes differentiation and clonal expansion.
3. Many activated clones of this T cell leave a lymph node and get dumped back into the blood
4. From there, these activated clones can exit out and fight where they are needed.

Front 73

1. What is a CD4
2. What is a CD8

Back 73

1. Helper T is also called CD4 since one of the receptors are the CD4 receptor.
2. The Cytotoxic T are sometimes called CD8 or Killer Ts, they have CD8 receptors.

Front 74

What does MHC stand for

Back 74

Major Histocompatibility Complex

Front 75

1. What can a T cell bind?
2. What can a B cell bind?

Back 75

1. T cell is restricted to binding its peptide antigen in an MHC molecule. MHC = major histocompatibility complex.
2. B cells can bind free-floating antigen. It can be a peptide or an oligosaccharide or nucleic acid it binds with its BCR

Front 76

What are the two types of MHC molecules:

Back 76

- MHC I (on surface of every nucleated cell)
- MHC II (Dendritic cells, Macrophages, and B Cells, only a few cells express this one)

Front 77

What does an MHC I do?

Back 77

MHC I (on every nucleated cell) gets loaded with peptides and makes it presentation to cytotoxic T cells. It loads pieces of proteins it made and broke down into these MHC molecules. Every nucleated cell is presenting peptides as part of their obligation to show their health of their protein production internally to CD8.
If the proteins are self proteins then the Cytotoxic T cell will not recognize the proteins (the cell gets to live), but if they are foreign, then they will be recognized the the Cytotoxic T cell and the cell will be destroyed!

Front 78

What does an MHC II do?

Back 78

MHC II: found only on professional antigen presenting cells. (APC) These are the Dentritic cells, macrophages and B cells: present peptide to CD4 Helper Ts in this loaded MHC II complex. So Peptide in MHC II comes from proteins engulfed by the antigen presenting cell (APC) (not made). Presentation in MHC II Complex is not an indication of the cell’s health, it is an indication of what is in the body. When recognized by a CD4’s TCR, the APC winds up activating the CD4 cell.

Front 79

What happens when a Cytotoxic T-cell encounters a cell with a foreign peptide on its MHC II?

Back 79

Cytotoxic T-Cells kill infected cells; perhaps by inducing the infected cell to commit suicide. The CD8 cells do this neatly killing only the cell they are indirect contact with.

Front 80

What do helper T cells do?

Back 80

They help to activate the other main subtypes of lymphocytes which are B cells & CD8 cells.
CD4 cell can activate a CD8 and a B cell. They are helper T cells. Aids virus attacks the helper T cells so in essence, this effects the production of CD8 and B cell. Before the CD4 cell can help activate a naïve B cell or a naïve T cell CD8, the CD4 cells must themselves be activated. No T cell (whether CD4 or CD8) leaves the thymus activated. They are all naïve.

Front 81

What can/can't a Naive cell do?

Back 81

Lymphocytes circulate as naïve cells until they are selected for activation and clonal expansion.
- Naïve CD8 do not make cytotoxic molecules
- Naïve CD4 do not make the signaling molecules (cytokines) that will allow them to activate either B cells or CD8 cells.
- Naïve cells do not sectrete antibodies

Front 82

How can a naïve CD4 Cell get activated

Back 82

1. Binds to a peptide presented in an MHC II complex it has specificity for (it’s TCR binds)
2. The professional antigen presenting cell secretes cytokines on the naïve CD4 cell causing the CD4 cell to change it’s expression profile
3. Interlocking of a second set of receptors: one on the professional antigen presenting cell, and one on the CD4 cell.
If a naïve B or T cell were to simply get one of the 3 signals, binding through the antigen specific receptors, they do not become activated. In fact, they can never be activated again even by normal professional APCs. They are anergic.

Front 83

How do we become immune to a pathogen?

Back 83

Through our memory cells.

Front 84

When we activate a cell, clonal expansion leads to 2 distinct populations are created

Back 84

1. The effector population (armed activated cells that fight the infection at that time and usually die)
2. Memory population (half activated and long lived) Should we ever see that pathogen again, it will be found sooner b/c many memory cells are circulating through the blood and exiting to check out the lymph nodes and secondary lymphoid structures, and these cells become activated sooner. They are sort of part way to the activated state already

Front 85

If a memory cell becomes activated from it's half activation state, what does it do?

Back 85

Be aware that memory cells upon activation expand and differentiate into 2 populations also: activated effector cells & more memory cells. This way, we sustain “immunity” over time.
Here is amplification upon 2nd exposure because more memory cells (as compared to first exposure) are activated and expand.

Front 86

How does a CD4 (Helper T) activate a Naive B cell:

Back 86

Once a CD4 Cell has been activated, it can activate a naïve B cell.
1. This B cell will have bound antigen (exogenously derived), processed it and presented it to the CD4 in an MHC II.
2. The CD4 cell can then release its cytokines onto the naïve B cell & this causes the differentiation & clonal expansion of the B cells.
3. An activated , effector population is produced, called plasma cells, and a population of memory cells is also produced.
4. Antibodies released by plasma cells protect us in all of our “humors” (blood, sweat, tears, milk) by neutralizing pathogens, encouraging a compliment system to lyse the pathogen since these proteins can recognize antibodies and make the pathogens more easily recognized by Macrophages to help in the cleanup of the pathogen.

Front 87

How do antibodies released from plasma cells protect us?

Back 87

a. neutralizing pathogens
b. encouraging a compliment system to lyse the pathogen since these proteins can recognize antibodies c. make the pathogens more easily recognized by Macrophages to help in the cleanup of the pathogen.

Front 88

What are antibodies made of?

Back 88

Antibodies are proteins made up of 4 polypeptide chains, two identical heavy chains and two identical light chains.

The antibody can bind the same shape twice since its antigen binding region is made up of the combo of 1 heavy and 1 light chains “variable” region. (image, doesn’t bind to the Y part, the left side binds something between the heavy and light chain and the right side binds something between its heavy and light chains)

Front 89

What is the constant region of an antibody?

Back 89

The constant region of the antibody determines where in the body the antibody can be found (and function) or on what cell types it can sit (ex. Mast cells can bind the IgE class since they have a receptor for constant region of the “E” class). The variable region of the antibody determines what antibody can bind to. What shape , antigenic determinant = epitope.

Front 90

Can plasma cells make antibodies of a variety of variable and "contstant" regions?

Back 90

The variable regions bind the epitopes/antigenic determinants on the antigens, while the “constant” regions determine where in the body these antibodies can be found. Any particular plasma cell sends out only one constant class at a time: either IgM or IgG or IgA or IgE and which one it is making is dependent on the particular cytokine stimulation that the Helper T cell released onto the B cell during its activation.
Some cells have receptors for the constant region of certain classes of antibodies enabling them to bind and engulf the antibody and whatever it is bound to (Macrophage) or to respond by releasing chemicals once the bound antibody catches an antigen (mast cells releasing histamine when their bound IgE antibodies bind their antigen)

Front 91

What's faster, a primary response or secondary response of the specific immune system?

Back 91

Primary responses of the specific immune system are slow to arise because the B & T cells have to first find the pathogen they are specific for and then they have to get activated : differentiated (activated) and multiply (clonal expansion), maybe up to 14 days to get a high concentration of antibodies and a large number of effector T cells.
Secondary Response: We now have many memory cells specific for that pathogen circulating in our bodies. They bind the displayed pathogen faster and since they are mid-way to activation already, they get activated quicker than a naïve cell. And there are many of them rather than just one. They may all respond. This means that our secondary responses are quicker and more robust.

Front 92

What is Transcription? What is reverse transcription? Which of our cells do reverse transcription?

Back 92

Transcription DNA to RNA
If you go backwards, then it’s reverse transcription. (We don’t have an enzyme that allows us to do reverse transcription) This function is not very precise so the HIV virus is always changing. The first drug for HIV targeted the revere transcription. HIV though, has adapted to this drugs so now, we give a cocktail.

Front 93

What is the coctail of drugs used to combat HIV called

Back 93

HAART

Front 94

What does the circulatory system do for large animals?

Back 94

Metabolic needs of larger animals are met by a circulatory system that: transports nutrients and respiratory gases and metabolic wastes throughout the body.

Front 95

What does a circulatory system minimize?

Back 95

Circulatory systems minimize the distance that substances must diffuse to enter or leave a cell
By transporting fluids, the circulatory system functionally connects the body cells to the organs that exchange gases, absorb nutrients and dispose of wastes.

Front 96

A circulatory system has three basic components:

Back 96

1. A circulatory fluid
2. A set of interconnecting tubes
3. A muscular pump (heart) – to put the fluid under pressure

Front 97

In the circulatory system, the fluid in the vessels in under pressure, what is this called?

Back 97

hydrostatic pressure

Front 98

What are the advantages over a closed circulatory system and and open one?

Back 98

Advantages of closed circulatory system over open circulatory systems (Humans and Earthworms):
1. Fluid can flow more rapidly through vessels than through intercellular spaces so transport of nutrients and wastes to and from cells is more rapid
2. Closed circulatory systems can be selective in directing blood to specific tissues
3. Specialized cells and large molecules that aid in the transport can be kept within the vessels but can drop their cargo to tissues where it is needed. (we can control the composition)

Front 99

What is the total length of blood vessels in the average human equal to?

Back 99

It is greater than twice Earth’s circumference at the equator. 24,900 miles x 2 = over 49, 800 miles