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IB BIOLOGY 2017 EXAM > Animal Physiology > Flashcards

Animal Physiology Flashcards

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1
Q

pathogen

A

any causative agent of diesease;

  • certain virsues or bacteria
  • certain fungi, protists and worms
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2
Q

fundamental body immune respnse

A
  1. immune system attempts to eradicate pathogen when it enters body
  2. self and not self recognition used; leucocytes are capable to detecting plasma memebrane proteins which don’t belong (not self); e.g. antigens
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3
Q

example of not self detection

A
  • human blood plasma proteins on RBC
  • Rh blood type based on presence or absence of Rh protein (+ or -)
  • ABO blood types
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4
Q

steps of mammalian immune response

A
  1. B lymphocyte (plasma cells) can synthesize and secrete a specific antibody that binds to a specific antigen
  2. first type of leucocyte to encounter pathogen is macrophage; find ‘non self’ antigen and engulf phagocyte by phagotyosis and digest it
  3. helper t-cells recognize the antigen being presented and become activated; turn the immune response from non-specific to antigne-specific by chemically communicating and activating the specific B-Cell type that is able to produce the needed antibody
  4. activated B-Cell begins cells cloning so that there are many types of b cells to rpoduce antibodies
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5
Q

true immunity

A
  • when there is a memory cell produced during primary infection still circulating in the bloodstream that can quickly respond to the pathogen
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6
Q

what are antibodies?

A

y-shaped protein molecules procued by plasma cell leucosytes in response to a specific pathogen

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7
Q

how do antibodies help destroy pathogens?

A
  • at the end of the forks of the ‘Y’ there are 2 identical sequences of amino acids unique to that antibody that act as binding sites to the spefic antigen
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8
Q

types of cloned B-cells

A
  • plasma cells; help secrete antibodies to help fight off the primary infection
  • memory cells; don’t secrete antibodies but remain in bloodstream to prep for secondary infections
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9
Q

ANTIGENS;

A

ANTIGENS; unfamiliar surface molecules that can cause the production of antibodies (found on bacteria and viruses [pathogens])

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10
Q

Precipitation

A

– Solube pathogens become insoluble and precipitate

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11
Q

Mechanisms of AID IN PATHOGEN DESTRUCTION BY

A 
•  Precipitation 
•  Agglutination 
•  Neutralisation 
•  Inflammation
•  Complement activation
Mnemonic:  PANIC
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12
Q

Agglutination

A

Cellular pathogens become clumped for easier removal

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13
Q

Neutralisation

A

Antibodies may occlude pathogenic regions (e.g. exotoxins)

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14
Q

Inflammation

A

Antibodies may trigger an inflammatory response within the body

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15
Q

Complement activation

A

Complement proteins perforate membranes (cell lysis

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16
Q

BLOOD GROUP INHERITANCE

A

ABO blood type classification system uses the presence of absence of antigens on red blood cells to categorize blood into four types

Distinct molecules called ‘agglutinogens’ (a type of antigen) are attached to the surface of red blood cells; there are two types called type “A’ and ‘B”

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17
Q

BLOOD TYPING:

A

Antibodies (immunoglobulins) are specific to antigens
The immune system recognizes ‘foreign’ antigens and produces antibodies in response

Blood type O is a universal donor, as it has no antigens which the recipient immune system can react to
AB is a universal recipient as the blood has no antibodies which will react to A or B antigens

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18
Q

Agglutination;

A

Agglutination; when your body has the wrong blood in it so it attacks itself (blood starts to clot as a reaction)

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19
Q

IMMUNITY

A

IMMUNITY: having sufficient biological defenses against infection

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20
Q

ACTIVE IMMUNITY

A

: is immunity due to the production of antibodies by the organism itself after the immune response has been stimulated by a pathogen

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21
Q

PASSIVE IMMUNITY

A

is the acquisition of antibodies from another organism; in which active immunity has been stimulated. This includes artificial sources as well as via the placenta,
colostrum or direct injection of antibodies

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22
Q

helper T-cells

A

Helper T-cells are the major driving force and regulators of the immune defense

Primary task; to activate B-cells and T-Cells (there are many different types of Helper T cells and B-Cells which respond to different antigens)

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23
Q

B LYMPHOCYTE ACTIVATION:

A

The B cells then search for the antigen matching its receptors, finds it + attaches to it
B cell however needs proteins produced by helper -T cells to become fully activated

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24
Q

how do phagocytes alert helper t cells?

A
  1. engulf phagocyte
  2. express the antigens of the phagocytes on their surface
  3. phagocytes present antigen to helper t-cells
  4. helper t cells become activated
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25
Q

PLASMA CELL AND ANTIBODY PRODUCTION

A

Plasma cells are specialized in production a specific antibody that matches the B-cell receptor
They can produce many tens of thousands of antibodies per second

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26
Q

PATHOGEN DESTRUCTION AND MEMORY CELL FORMATION

A

T-cells can also produce memory cells with an even longer lifespan than B memory cells.
Subsequent infections by the same pathogen therefore provoke a much more rapid immune response
If little or no symptoms are experienced, the organism is said to be immune!

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27
Q

ANTIBODY FUNCTIONS

A

Neutralization
Opsonization
Agglutination
Complement activation

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28
Q

Neutralization

A

attachment stops toxins from affecting/entering cells, viruses from invading cells and bacteria from efficiently functioning and therefore attacking cells

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29
Q

Opsonization

A
  • through attachment antibodies mark the pathogens and make them easily identifiable by other immune cells. E.g. so macrophages can find + engulf + digest them
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30
Q

Agglutination

A

antibodies attach to each other causing a clumping of the pathogen (to enhance neutralization and opsonization)

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31
Q

Complement activation

A

antibodies ‘encourage’ other components to attach to the pathogen by attack it e.g. breaking the bacterial membrane and lysing the cell

Antigens can also cause inflammation in the affected area (this is an enhanced non-specific immune response to help combat the pathogen

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32
Q

HISTAMINE

A

is a small organic molecules produced by two types of leukocyte; basophils and mast cells

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33
Q

basophils

A

circulate and hence release histamine into the blood and cause symptoms at secondary sites

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34
Q

mast cells

A

found in connective tissues; if stimulated by an infection they release histamine in the infected area

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35
Q

effect of histamine

A

Key effect is the immune response in that it increases the permeability of the capillaries to white blood cells and some proteins (e.g. antibodies)

This allows the componenets of the immune system to engage with the pathogen early at the site of infection

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36
Q

Non specific immunity;

A

Non specific immunity; barriers, mucous membranes, clotting and phagocytosis

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37
Q

Specific immune response;

A

direct targetting of pathogen that has invade

If non specific immunnity fails, specific immunity must be produced by body

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38
Q

RESPONSE: (body to pathogen)

A

RESPONSE:
pathogen engulfed by macrophage

macrophage takes on antigen (Or epitope-cell surface protein)

Macrophage presents epitope to T-Cells

Complementary helper T-Cell is activated

Helper T-Cell stimulates appropiate B-Cell

B-Cell produces clones

Clones become either plasma cells or memory cells

Plasma cells produce antibodies

Memory cells remain as immunity to the pathogen

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39
Q

MONOCLONAL ANTIBODIES;

A

When an immune response occurs, antibodies specific to the pathogen are produced

are antibodies artificially derived from a single B cell clone (i.e. identical specific antibodies)

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40
Q

ADVANTAGE IN MEDICINE/BIOTECH of monoclonal antibodies

A

We can produce large numbers of antibodies in the lab to be used therapeutically and diagnostically

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41
Q

POLYCLONAL IMMUNE RESPONSE:

A

B-cells would respond to multiple epitoptes

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42
Q

what can monoclonal antibodies be used in?

A

CAN BE USED IN:
Therapeutic use of antibodies to treat rabies
Diagnostic use in pregnancy tests

Monoclonal antibodies are commonly used to provide immune protection for individuals who contract harmful diseases

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43
Q

PRODUCTION OF MONOCLONAL ANTIBODIES

A
  1. An animal (mouse) is injected with an antigen and in response produces specific plasma cells
  2. The plasma cells are harvested from the spleen of the animal
  3. Harvested plasma cells fuse with tumour cells (which are capable to endless division) forming hybridoma cell
  4. Hybridoma cells are screened to determine which ones are producing useful antibodies
  5. The selected hybridoma is allowed to divide to produce clones
  6. Hybridomas are then used to synthesise large quantities of a single (monoclonal) antibodies for use in diagnostic tests and treatments
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44
Q

how are monoclonal antibodies produced?

A

Monoclonal antibodies are produced by hybridoma cells;

Immune response is stimulated using the antigen;
specific B-Cells are harvested

B-Cell is fused with myeloma (tumor) cell

Hybridoma makes a large number of clones
Clones produce antibodies which are collected

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45
Q

how are monoclonal antibodies used to treat rabies?

A

Because the rabies virus can potentially be fatal, injecting purified antibodies functions as an effective emergency treatment

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46
Q

how are monoclonal antibodies used to treat cancer?

A

Monoclonal antibodies can be used to target cancer cells that the body’s own immune cells fail to recognise as harmful

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47
Q

how are monoclonal antibodies used to test for pregnancy?

A

Monoclonal antibodies can be used to test for pregnancy via the presence of human chorionic gonadotrophin (hCG) in urine

hCG is a hormone produced by women during foetal development and thus its presence in urine is indicative of pregnancy

Pregnancy tests use a process called ELISA (enzyme-linked immunosorbent assay) to identify a substance via a colour change

Free monoclonal antibodies specific to hCG are conjugated to an enzyme that changes the colour of a dye

A second set of monoclonal antibodies specific to hCG are immobilised to the dye substrate

If hCG is present in urine, it will interact with both sets of monoclonal antibody (forming an antibody ‘sandwich’)

When both sets of antibody are bound to hCG, the enzyme is brought into physicial proximity with the dye, changing its colour

A third set of monoclonal antibodies will bind any unattached enzyme-linked antibodies, functioning as a control

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48
Q

therapeutic monoclonal antibodies

A

Therapeutic monoclonal antibodies are named according to the source organism from which the antibodies were derived

Mice antibodies (‘-omab’) are easier to synthesise than human antibodies but are less likely to be tolerated by the patient

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49
Q

THE ELISA TEST

A

In the Elisa test, a tray is coated with antigens for a pathogen

Serum samples are taken from a patient, and if those samples contain the antibody; COLOR CHANGE occurs to show that he/she is carrying the pathogen and the body is trying to find it

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50
Q

EPIDEMIOLOGY

A

study of incidence, distrubtion and possible control of disease

Surveillance is critical to the control of MEASELES.

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51
Q

dentifying and confirming suspected measles cases allows;

A

Early detection of outbreaks
Analysis of transmission helps to create more effective vaccination measures

Estimation true measles incidence on reported data- reported incidence reflects a small proportion of the true number of incidences as many affected to not seek health care

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52
Q

what can epidemilogy be used for?

A

It can be used to compare the incidence of a disease over time (prior and following vaccination programme implementation)

It can be used to compare the incidence of a disease in different regions (both with and without vaccination programmes)

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53
Q

epidemic

A

substantially increased occurrence of a particular infection within a given region

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54
Q

pandemic

A

is an epidemic that has spread across a large geographical area (like a continent)

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55
Q

vaccinations

A

confers immunity to vaccinated individuals but also indirectly protects non-vaccinated individuals via herd immunity

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56
Q

herd immunity

A

Herd immunity is when individuals who are not immune to a pathogen are protected from exposure by the large amounts of immune individuals within the community

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57
Q

how can diseases be transmitted?

A

Direct contact – the transfer of pathogens via physical association or the exchange of body fluids

Contamination – ingestion of pathogens growing on, or in, edible food sources

Airborne – certain pathogens can be transferred in the air via coughing and sneezing

Vectors – intermediary organisms that transfer pathogens
without developing disease symptoms themselves

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58
Q

EDWARD JENNER + SMALLPOX VACCINE

A

1796; cowpox virus inserted into 8 year old boy; SUCCESS (he became immune to small pox)

Second line of defense; adaptive immunity (B cells and T cells; memory cells)

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59
Q

modern issues with edward jenner procedure

A

UNETHICAL;
No prior research done prior to human testing to measure effectiveness + side effects
Informed consent was not given (choice of a child who was to young to understand the dangers)

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60
Q

what do vccines do

A

Vaccines used to trigger adaptive immune system; allows an individual become immune without experiencing it (initiate primary immune response to motivate secondary response; memory cell creation remain in the body until actual infection happens so your secondary response is MUCH quicker)

Vaccines contain antigens; in various forms that shouldn’t cause symptoms in a healthy person

By initiating a primary immune reponse, resulting in the production of memory cells that can produce antibodies in response to the antigen
Can be given orally or injected
Vaccines contain antigens in various forms that should not cause symptoms in a healthy person

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61
Q

TYPES of vaccines

A

Life attenuated vaccines

Inactive/Weakened toxin vaccines

Subunit vaccine

DNA vaccine

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62
Q

Life attenuated vaccines

A

made of weak pathogen; can be difficult to make and are active

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63
Q

Inactive/Weakened toxin vaccines

A

dead pathogen

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64
Q

Subunit vaccine

A

made only of antigen or part of

pathogen carrying antigen; prompts responses

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65
Q

DNA vaccine

A

genes isolated of pathogen to create the

genes that make the immune response molecules (DNA encondes for antigens rather than the antigen itself)

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66
Q

SMALLPOX;

A

first infectious disease of humans to have been eradicated by vaccination
Caused by virus variola
WHO declared disease ‘dead’ in 1980
Cowpox is a mild viral infection of cows similar to small pox

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67
Q

other eradication programmes

A

Eradication programmes for other disease has reduced the number of cases, but has been less successful;
e.g. Polio and measles become contagious before symptoms are easily detected,

yellow fever has animal reservoir (also affects monkeys)
Immunity malaria not complete; can infect same person several times

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68
Q

species specific pathogens vs non. species specific

A

Some pathogens are species-specific (Polio, Measles and Syphilis are human specific)

Flu, Ebola and Salmonella can be transmitted between humans and other animals

Zoonosis is a diseases that is transmissible from vertebrate animals to humans

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69
Q

ALLERGEN:

A

environmental substance that triggers an immune reponse depite itself not being intrinsically harmful

Immune response tends to be localized on region of exposure (throat or eyes)

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70
Q

ANAPHYLAXIS

A

Severe systematic allergic reaction; ANAPHYLAXIS can be harmful if left untreated

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71
Q

allergen action

A

An allergic reaction requires a pre-sensitised immune state (i.e. prior exposure to the allergen)

When a specific B cell first encounters the allergen, it differentiates into plasma cells and makes large quantites of antibody (IgE)

The IgE antibodies attach to mast cells, effectively ‘priming’ them towards the allergen

Upon re-exposure to the allergen, the IgE-primed mast cells release large amounts of histamine which causes inflammation

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72
Q

WHAT CAUSES ALLERGIC REACTIONS?

A

The release of histamine from IgE-primed mast cells causes an inflammatory response that results in allergic symptoms

Inflammation
Vasodilation
Capillary permeability

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73
Q

symptoms of an allergic response

A

Redness, heat, swelling and localised pain

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74
Q

inflammation in allergy respone

A

improves leukocytes mobility to infected regions by triggering vasodilation and increasing capillary permeability

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75
Q

vasodilation in allergy reponse

A

is the widening of blood vessels to improve the circulation of blood to targeted regions
Vasodilation causes redness (as vessel expansion moves blood closer to the skin) and heat (which is transported in blood)

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76
Q

capillary permeability in allergy response

A

describes the capacity for leukocytes to leave the bloodstream and migrate into the body tissue
Increased permeability leads to swelling (more fluid leaks from the blood) and pain (swelling causes compression of nerves)

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77
Q

sensitization

A

(intial exposure to allergen)
1. allergen (e.g. pollen) enters bloodstream

  1. B Cells differentiate into plasma cells and make antibodies
  2. antibodies attach to mast cells
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78
Q

allergic reaction

A

(secondary exposure to same allergen)

  1. allergen binds to antibodies on mast cells
  2. histamine is released from mast cell
  3. alleric reaction ensues
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79
Q

lympathic system

A

Secondary transport system that protects and maintains the body by producing and filtering LYMPH

Absorbs fat from gut + other fluids (LIPID TRANSPORT + BLOOD PRESSURE)

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80
Q

LYMPTH:

A

a clear fluid that contains white blood cells + arises from the drainage of fluid from the blood and surrounding tissues

Filtered at points called lymph nodes (pathogens are removed before blood returns to circulation)

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81
Q

lymph organs

A
  • spleen
  • tonsils
  • tymus
  • adenoids
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82
Q

immune disorders

A
  • hypersensitivity
  • autoimmune disorders
  • immunodefiency disorders
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83
Q

hypersenstivity

A

Refers to excess immune response to inherently unharmful substance (allergen)

Such reactions require a pre-sensitized immune state with excessive reaction occurring upon re-exposure

E.g. allergic reactions (localized hypersensitive conditions), anaphylaxic (severe, systemic)

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84
Q

autoimmune disorders

A

Autoimmunity occurs when the immune system fails to recognize body cells as ‘self’ and target its own cells and tissues

Some pathogens try to invade immune detection by producing antigens similar to host markers (results in production of antibodies that recognize and target markers on body cells)

E.g. diabetes I, rheumatoid arthritis, multiple sclerosis

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85
Q

immunodeficiency disorders

A

State in which the immune system’s capacity to fight infection is compromised/absent

Some inherited; SCIDS

Pathogen in origin (AIDS

Drug treatments (cytotoxic drugs cause

immunosuppression; usually used in organ transplant to avoid organ rejection)

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86
Q

TYPES OF IMMUNITY;

A

active immunity

passive immunity

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87
Q

active immunity

A

involves production of antibodies by the body itself + subsequent development of memory cells

Results in long term immunity

Natural; producing antibodies in response to pathogenic infection

Artificial; use of vaccines (producing antibodies in response to the controlled exposure to an attenuated pathogen)

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88
Q

passive immunity

A

Passive immunity: results from the acquisitions of antibodies from another source and hence memory cells aren’t developed

Natural; receiving antibodies from another organism (e.g. fetus via placenta from mum/breastmilk)

Artificial; receiving manufactured antibodies via external delivery (blood transfusion of monoclonal antibodies)

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89
Q

Humoral immunity

A

describes the pathway by which antibodies are produced by B-lymphocytes to target exogeneous antigens

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90
Q

humoral immunity action

A

When macrophages engulf pathogens; they digest them within lysosomes to release antigenic fragments

These fragments are present on special surface recetprs (DENOTE MATIERAL AS BEING FOREIGN)

Antigens are presented to helper T-Cells which in turn secrete cytokines to activate B-Lymphocytes

Specific B-Lymphocytes divide + differentiate to form antibody producing plasma cells

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91
Q

Cell-mediated immunity:

A

describes a pathway that doesn’t result in antigen production but instead targets endogenous antigens

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92
Q

cell mediated immunity action

A

Cancerous + virus-infected cells involve the body’s own cells (thus aren’t recognized as foreign and evade normal detection

These cells may instead present antigenic fragments as self markers

When helper T-Cells identify these cells; they stimulate a second type of T-lymphocyte (Tc Cells; cytotoxic cells)

Tc Cells show specificity to a particular antigen + will bind to the presented antigen and release perforating enzymes

These enzymes cause the infected/cancerous cells to be lysed + prevent further infection

Virus infected cells can also be destroyed by nonspecific NK cells (respond to interferon released by infected cells)

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93
Q

diseases that can cross over species?

A
  • HIV/Aids
  • ebola
  • SARS
  • H1N1
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94
Q

two problems in moncolonal antibody procedure?

A
  1. keeping B-cells alive for extended period of time

2. identifying B-cell type that produces the antibody that recognizes desired antigen

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95
Q

endoskeleton

A

internal skeleton (internal bones)

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96
Q

exoskeleton

A

an external skeleton that surrounds and protects most of the body surface of an animal e.g. crustaceans and insects
- made up of chitin instead of bone

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97
Q

species with good leverage potential

A
  1. asian weaver ant (Oceophylla smaragdina)

2. flea (Ctenocephalides felis)

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98
Q

how do bones and exoskeletons facilitate movements?

A

providing an anchorage for muscles and by acting as levers

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99
Q

levers

A

change the size and direction of forces; relative of these positions determine class of lever;

Effort force

Pivot Point (Fulcrum)

Resultant Force

Muscles are attached to the insides of exoskeletons but to the outside of bones

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100
Q

Movement of the body requires muscles to work in antagonistic pairs

A

Skeletal muscles occur in pairs; one contracts as the other relaxes (Antagonistic)

Antagonistic muscles; produce opposite movements at a joint
E.g. elbow; triceps extends the forearm while the biceps flex the forearm

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101
Q

insect leg antagonistic muscles

A

Grasshopper has three pairs of appendages; the hindlimb is specialized for jumping

Below the joint; tibia

At the base of the tibia another joint below is found called the tarsus

Above the joint; femur relatively massive muscles found there

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102
Q

grasshoper jumps;

A

When a grasshopper jumps;

Flexor muscles will contract bringing the tibia and tarsus into a position where they resemble the letter Z and the femur and tibia are brought closer together (FLEXING);

extensor muscles relax at this phase

When extensor muscles contract; the tibia extends= powerful propelling force

103
Q

humerus bone

A

to which biceps and triceps are attached

104
Q

example of synovial joint?

A

human elbow

105
Q

triceps

A

extends the joint

106
Q

biceps

A

flexes the join

107
Q

joint capsule

A

seals the joint and helps to prevent disolocation

108
Q

synovial fluid

A

lubriates the joint and prevents friction

- provides nutrients to cells of cartilage

109
Q

ulna bone

A

to which triceps are attached; acts as a leveer for triceps muslce

110
Q

cartilage

A

covers the bones and prevents friction and absorbs compression

111
Q

radius bone

A

to which the biceps are attached; acts as alever for biceps muscle

112
Q

what do synovial joints alllow?

A

for certain movements but not others

113
Q

knee joint

A

acts as a hinge joint to allow only two movements;
1. flexion (bending)

  1. extension (straightening)
  2. can act as a pivot point when flexed
114
Q

when does the knee have the greatest movement range?

A

when flex and extedned

115
Q

structure of a joint

A

The structure of a joint (including joint capsule + ligaments) determines possible movements

116
Q

hip joint

A

between pelvis and femur; is a BALL AND SOCKET joint
-has great range of movmenet than kneed joint in that it can flex, extend, rotate and move sideways and back (abduction and adduction)

117
Q

skeletal muscle fibres

A
  • are multinucleate

- contain specialised endoplasmic reticulum

118
Q

skeletal muslces

A

used to move the body and attached to bones

119
Q

striated muscles

A
  • there are clear trips (other muscles are smooth and cardiac)
  • composed of muscle cells called muscle fibres surrounded by plasma membrnae (SACROLEMMA)
120
Q

muscle fibres

A

Many nuclei present + muscle fibres are longer than typical cells; these features are due to the fact that embryonic muscle cells fuse together to form muscle fibres

  • contain sacropaslmic reticulum
  • contain many mitchondria for ATP for contraction etween myofibrils
121
Q

sacroplasmic retriculum

A
  • muscle fibres contain a modified endoplasmic reticulum
  • extends through muscle fibre and wraps around every myofirbril conveying the signal to contract to all parts of muscle fibre
  • also store calcium
122
Q

myofibrils

A

parallel, elongated structured

  • have alternating light/dark bands (gives striated muslce its stripes)
  • centre of each light band is disce shapped and called Z-line
  • muscle fibres contain many
123
Q

contracticle sacromeres

A
  • make up myofibrils
  • centre of light area called Z line
  • repeating units of light and dark bands due to arrangement of two types of proteins (thin actin and thick myosin)
124
Q

sacromere

A

(the part of the myofbiril between one Z line and next is called the sacromere; functional unit of myofibril)

125
Q

actin

A
  • thin

- attached to Z line at one end

126
Q

myosin

A
  • interdigitate diwth actin filaments at both ends
  • occupy qcenter of sacromere
  • thick
127
Q

how is the contraction of skeletal muscles achieved?

A
  • by the sliding of actin and myosin filaments
128
Q

mechanism of skeletal muscle contraction

A
  1. Myosin filaments pull actin filaments inwards towards centre of sarcomere; shortening the sarcomere + overall length of muscle fibre

2 Contraction occurs by the sliding actin and myosin filaments

  1. Myosin filaments cause this sliding; have heads that can bind to special sites on actin filaments creating cross bridges through which they exert force using ATP
  2. Heads are regularly spaced along myosin filaments
  3. Binding sites spaced regularly along the actin filaments; many cross bridges can form at once
129
Q

how is skeletal muscle contrcation controlled?

A
  • by calcium ions

- by proteins; tropomyosin and troponin

130
Q

tropomyosin

A
  • regulatory protein that blocks binding sites of actin in relaxed muscle
131
Q

calcium ion action in movement

A
  • motor neuron sends signal ot muscle fibre to contract
  • causes sacropaslmic reticulum to release calcium ions
  • calcium ions bind to protein (troponin) which causes tropomyoson to move and for the ACTIN filament binding sites to be exposed
  • myosin heads then and bind to the centre of the sacromere moving the actin filaments a smal distance
132
Q

role of ATP in sliding filaments

A

ATP hydrolysis and cross bridge formation needed for filaments to slide

133
Q

Sequence of stages of ATP role in sliding filanents

A
  1. ATP causes the breaking of the cross-bridges by attaching the myosin heads causing them to detach from the binding sites on actin
  2. Hydrolysis of ATP to ADP from phosphate; provides energy for the myosin heads to swivel outwards away from the centre of the sacromere; ‘cocking of the myosin head’
  3. New cross bridges are formed by the binding of myosin heads to actin at binding sites adjacent to the ones previously occupied (each head binds to a site one position further from the centre of the sarcomere)
  4. Energy stored in the myosin head when it was cocked causes it to swivel inwards towards the centre of the sarcomere moving the actin filament a small distance.
  5. This sequence of stages continues until the motor neuron stops ending signals to the muscle fibre
  6. Calcium ions are then pumped back into the sarcoplasmic reticulum so the regulatory protein movs and covers the actin binding sites= MUSCLE FIBRE RELAXES
134
Q

USE OF FLUORESCENCE TO STUDY CONTRACTION

A

Fluorescence has been used to study the cyclic interactions in muscle contractions.
- Fluocorscene can be detected by a light microscope and capture on film for analysis

135
Q

what does fluorenscne use portray?

A

ATP depedence of myostin-actin interaction

136
Q

nisella axillaris cells

A
  • researches cut open Nisella axillariss cells; unique in that they have a network of actin filaments underlying their membranes; researches attached fluorescent dye to the myosin muscles to show how myosin can ‘walk along’ actin
137
Q

acorn barnacles

A
  • Scientists have studied the contraction of the giant single muscle gibres on the acorn barnacle by injecting samples of the muscle with aeqourin (calcium sensitive protein ); bioluminscene resulted from the release of the calcium ions
138
Q

synovial joint

A

bone to bone joints where there is self contained capsule area that contains a lubricant called synovial fluid

139
Q

tendons

A

attach muscle to bone

140
Q

ligaments

A

connect bone to bone

141
Q

types of muscle tissue

A

smooth muscle
cardiac muscle
skeletela striated muscle

142
Q

sacroplasm

A
  • cytoplasm of muscle fibres
  • contain glycogen as energy reserve
  • contains myoglobin which provides and stores oxygen
143
Q

sliding filament theory of muscle contraction

A
  1. myosin heads are activated by splitting ATP; this causes a chane in the positions of the heads
  2. myosin heads are attracted to and attach to exposed binding sites of actin to form cross bridges
  3. as myosin forms cross brdiges, ADP is released and tme myosin bends tue to loss of energy; bending towards centre of sacromere and actin is moved inwards
  4. myosin binds to ATP and this allows for detachment of myosin heads from the actin attachement sites
144
Q

steps of muscle contraction

A
  1. motor neurone carries action potential unit it reaches the neuromuscular junction
  2. neurotransmitter (acetylecholine) released into synaptic gap between neurone end buttons and sacrolemma of muscle fibre
  3. acetylcholine binds to receptors on sacrolemma
  4. sacrolemma ions channels opens and sodium ions move through membrane
  5. resulting action potential moves through the T-Tubules causing teh release of caclium ions from sacropaslm
  6. released calcium ions flood onto sacroplasm
  7. myosin heads then attach to binding sites on actin
  8. myosin heads all flex towards sacromere centre
  9. entire sacromere shortens as Z lines move towards each other
  10. ATp binds to myosin head resulting in detachment of myosin from actin and awaiting new action potential from motor neurone
145
Q

excretion

A

removal of bodies waste products of metaolism

-carried out by kidney

146
Q

diuretic

A

caffiene and alcohol; increase passing of urine

147
Q

metabolic waste; nigrogen

A

fish and amphibians; constant access to water their flush their nitrogeneious waste as ammonia

mammalas; metabolize ammonia into molecules called urea

reptiles and birds;
package their nitrogenous waste as uric acid

148
Q

osmoregulators

A

tightly regulate their body osmolarity which always stays constant, irrespectve of their environment
- much more common in animal kingon

149
Q

kidney role in osmoregulation

A
  • regulating amount of water reabsorved

- a disadvantage as osmoregulation costs animals ATP

150
Q

osmoregulation in freshwater fish

A
  1. food enters fishs mouth along with ions (Na+, K+ Cl-) and water
  2. water absorved by skin too
  3. active ion uptake through gills
  4. dilute urine is expelled at end of fish
151
Q

osmoregulators

A
  • needs ATP
  • cost animals ATP
  • use kidney
  • tightly regulate their body osmolarity to keep it constant irrespective of environemnt
  • homeostasis
  • found in fish and other marine invertabres
  • ion control
152
Q

osmoconformers

A
  • no ATP
  • disadvatange as internal conditions must be sub optimal
  • maintain an internal conditions taht are equalt o the osmolarity of their environemnt
  • -homeostasis
  • found in fish and other marine invertabres
  • ion control
153
Q

ammonia

A
  • fish
  • requires little energy to produce
  • very toxic in blood and tissues; must be diluted and removed quickly by a lot of water
154
Q

urea

A
  • mammals
  • requires less enerty to produce compared with uric acid
  • toxic in blood and tissues
  • requires more energy than ammonia, only some water for dilution and removal from body
155
Q

uric acid

A
  • birds
  • relatively insoluble in aqueous solutions such as blood and cyoplasm
  • stored in specialized structures within animal eggs
  • little to not water for dilution and removal ob body
  • complex structure requires a great deal of eneryg ot produce
156
Q

nitrogenous waste execretion in insects

A
  • insecst have open circulatorysystem; so their blood is sometimes outside veseels
  • body cavities of insects have Malpighian tubules; tubes connecteed by distal and proximal ends
  • selective reabsorbtion occurs here
  • nitrogenous waste and excess water move thourgh Malpighian tubules to proximal end that empties into the gut so waste eliminated along with feacus
157
Q

how is the kidney like a dirty fridge?

A
  • take out all contents in blood and filter them into water and non waste
158
Q

where are kidneys in the body?

A

Dark red, bean shaped on each side of the spine along the posterior wall, between the dorsal wall and the peritoneum (not in abdominal cavity where digestive system is)

159
Q

how do kidneys work?

A

Continuously filter blood; hold 20% of total blood volume
Branching into capillaries, each with filtering units (NEPHRONS)

  1. Filtration, reabsorption and excretion
160
Q

renal/bowmans capsule

A

ultrafiltration

161
Q

glomerus

A

delivers blood

162
Q

proximal convulated tubule

A

selective reabsorbtion

163
Q

distal convulated tube

A

secretion of toxins into urine

164
Q

loop of henle

A

osmoregulations

165
Q

collecting duct

A

delivers urine to pelvis

166
Q

nephrons

A

carry out ultrafiltractions, reabosrbtion and secretion in the production of urine

167
Q

ultrafiltrations

A
  • nearly all the substances (water and other molecules such as drugs and glucose) are filtered out of the blood exept blood cells and proteins
  • enter through pailiary wall to bowmans capsule from glomerus
168
Q

capilary wall

A

-has
fenestrated pores
-basement membrane has these pores to allow passage of small molecules and block large molecules from leaving plasma
-passive process

169
Q

podocytes

A

provide support to capillaries

170
Q

basement membrane

A

act as filter to only allow certain sized molecules into bowmans capsule

171
Q

capillary endothelium

A

pores found in capillary endothelium which allow certain size molecules to pass through

172
Q

process of ultrafiltration

A

Ultrafiltration occurs in the renal artery, in the cortex of the kidney

  1. Blood enters through the afferent arteriole and leaves the efferent arteriole
  2. The afferent arteriole is much larger than the efferent arteriole; this causes high pressure in the renal artery
  3. Water, glucose, amino acids and solutes are forced out of blood (including metabolic wastes) through fenestrated capillaries and basement membrane
  4. Podocytes acts as filters; plasma proteins and blood are large so they remain in blood stream
  5. Glomerular filtrate is carried through the nephron where selective reabsorption takes places in the proximal convoluted tubule
173
Q

What is the difference between an osmoconformer and an osmoregulator?

A

Osmoregulators need ATP and use kidneys, whereas osmoconformers are passive

174
Q

glomerulus

A

Glomerulus; network of capillaries at beginning of nephron in bowman’s capsule
Aids in filtering process of blood

175
Q

what does the bowmans capsule do?

A

filters the glomerular filtrate into the proximal tube

176
Q

kidney renal corpuslce

A

composed of tangled clusters of blood capillaries, called a glomerulus, and a thin-walled, saclike structure called the Bowman’s capsule, which surrounds the glomerulus.

177
Q

bowmans capsule structure

A

The Bowman’s capsule is composed of two layers of cells:

an inner layer that closely covers the glomerulus, and an

outer layer that is continuous with the inner layer and with the wall of the renal tubule

178
Q

Proximal convoluted tubule:

A

The swirly one; the one that joins the bowman’s capsule to the loop of henle
Main job is reabsorption of ions, glucose and water
Contains microvilli for larger surface area
Pulls sodium ions back into blood stream

179
Q

loop of henle function

A

recovery of water and sodium chloride from urine

180
Q

firest segement of loop

A

descending limb; permeable to water so liquid reaches the bend of the blpoop is much richer than blood plasma in salt and urine
-liquid returns through ascending limb; sodium chlroide diffuses out of tubue into surrounding tissue where concentration is lower

181
Q

third segement of loop

A

tubuel wall, if needed, removes further salt against concentration gradient
(NEEDS ATP)

182
Q

strucutre of loops of hendle

A
  • long curly shape for max time for reabsorbtion

- starts in cortex, dips into medulla, back to cortex

183
Q

loops of henle primary task

A

-creates hypertonic environment in the medulle oaf th ekidneuy
drive reabsrobtion of water by creating salt concentration gradient

184
Q

collecting duct task

A

reasbortion of water; balacne water concentraiton in blood

185
Q

ADH in collecting duct

A
  • body uses negative feedback when body is dehydrated
  • hormone ADH causes aquaparines in channels in wall to factiliate osmosis
  • ADH released by pituitary gland increases permataiblity of walls in distal convulated tubule to increase body water amount
186
Q

homeostasis

A

the body’s ability to maintain a stable internal environment

187
Q

factors that affect osmoregulation

A
  • total volume of water ingested
  • pesperiation rate (influence by environmental tempearture and excersize)
  • ventilation rate
188
Q

proximal convulated tubule structure

A
  1. one cell thick
  2. ring of cells
  3. intertior is called lumen where the filtrate flows through
  4. tubule cells have microvilli to increase surface area for reabosrbtion
189
Q

what happens when ADh is present?

A

= collecting duct becomes permeable to water and water moves by osmosis out of collecting duct and into medulla intersittial fluid

190
Q

what happens when adh is NOT present

A
  • colelcting duct is impermeable to water

- so water stays in collecting duct and urine is more dilute

191
Q

adaptions to water consevation

A
  • longer loop of henle
  • wate rintake of kangaroo rats comes from foods they eat; only venture out at night when water is cooler to reduce water loss
192
Q

what changes to the kidneys make to the blood?

A
  • lower urea
  • lower salt ion
  • lower water amount
  • nearly identical amount og fluocse and proteins
  • no change to blood cells
193
Q

kidney failure

A
  • two options abailbe; kidney dialysis/ haemodulais

Kidney transplamt

194
Q

testing urine for chemical composition

A
  • glucose needs to be completly reabsrobed
  • no blood cells should by in urine
  • no proteins should not be in urine
  • no drugs should be in urine
195
Q

dehydration

A

sleepiness
contipation
dry mouth and skin
dizzines and headache

196
Q

overhydration

A

change in bheaviour/confusion
blurred vision
muscle cramps
nausea and vomitting

197
Q

haemodialysis

A
  • patients blood pumped into device with large surface area of a membrane
  • patiens blood on one side, dialysate solution on other
  • urea is small enough molecuel to diffuse out of membrane
  • basically balances water, salt, glucose and urea balancein body
  • repeated sessions needed every 1-3 days
198
Q

kidney transplant

A
  • transplated organs need to have matching donor-patient tissues in order to minimize rejection
  • usually family member used
  • after recieving transplated kidney; person must need immune suprresing drugs
199
Q

follicle cells

A

provide nutrients to support the early development of a fertilize d egg

200
Q

zone pellucida

A

conssits of a glycoprotein that protects the egg and prevents sperm entry

201
Q

1st polar body nucleus

A

not required; will break down

202
Q

nucleolus

A

haploid (n) contains 23 chromosomes to be passed from mother to child

203
Q

cytoplasm

A

contains nutrients to support early developments of fertilized egg

204
Q

cortical granules

A

make the zone pellcuidea impenetrable to sperm post-fertlization to prevent polyspermy

205
Q

spermatogensis

A
  • production of male gametes by meiosis
  • occurs in testes; in seminiferous tubules
  • each spermatogonium capable of mitosis/meisosis (germinal epithelial cells)
206
Q

mitosis and spermatogenia

A
  • to replish their numbers

- spermatozoa production starts at puberty and continues throughout life; mitosis replaces cells that become spermtozoa

207
Q

meiosis and spermatogenia

A
  • produce spermtazoa
  • reduction division of diploid to haploid number of chromosomes
  • spermatognia replicate DNA in diploid nucleus and then undergo cell growth in prep for cell division
208
Q

single chromosome

A

a pair of chromatids connected by a centromere

209
Q

steps of spermatogensis

A

interphase:
- DNA replication so each of the 46 chromosomes now exsit as a pair of chromatis

Meiosis I:
-two cells result weach with haploid number of chromosomes (each chromosome stile xists as a pir of chromatids)

Meisosis II;
- chromatids are seprate two produce four halpod cells created from original diploid

210
Q

what happens after meisosis in spertmagotenesis

A
  • each cell must differentiate into functioning, motile spermtazoon
  • cells remain in seminiferious tubule untill they form the cellulcular structural characteristics of sterm
211
Q

characteristic structures of spermtazoon

A
  1. flagellum for mobility

2. acrosome with enzymes for fertliziation

212
Q

what happens when spermatazoon have matured?

A
  • detach from the sertoli cell and move towards the lumen to the storage area of testis called epididmis
213
Q

oogensis

A

production of female gametes by mitosis
produces 4 cells as end products, but three aren’t used (polar bodies)
-fourth haploid cell produced is large and is the ovum

214
Q

events occuring before birth

A
  • cells called oognoia undergo mitosis to build up number of oogonia in ovaries
    0oocongia grow into primary oocytes
    –both oogonia and primary oocytes are idploid cells (undergo meisosis)
    -process of meisosis stops during prophase I
  • cells called follicle cells undergo mitosis to surround the primary oocyte (forming primary folliciles); remain unchange duntil girl in puberty
215
Q

oogensis process

A
  1. During fetal development large numbers of oogonia are formed by mitosis
  2. Oogonia enlarge and undergo meiosis, but stop in prophase I (until puberty). They are now termed primary oocytes and are held in primary follicles
    (AT PUBERTY) some follicles develop each month in response to FSH
  3. The oocyte completes the first meiotic division
  4. Division of the cytoplasm is unequal creating a polar body
  5. The secondary oocyte continues into meiosis II and halts at prophase II
  6. Secondary ooctyes develop along with the follicle. When the foolicle is masture it ruptures to release the secondary oocture with a small number of cells (the mature egg) into the fallipian tube. The reamining follicle cells remain in the ovary to form the CORPUS LUTEUM (which secretes progresterone)
  7. The oocyte completes meiosis II (forming the ovum) if the cell is fertilized and another polar body
216
Q

spermatogensiss contrast

A
  • occurs in testes
  • millions produced daily
  • released during ejactulation
  • beings at puberty
  • continues throughout life
  • 4 sperm made per meiosis
  • polar bodies not produced (equal division)
  • cytoplasm reduced in sperm
  • sperm are motile
217
Q

oogensiss contrast

A
  • occurs in ovaries
  • one/few produced monthly
  • released during ovultion
  • egg production beings before birth
  • production stops at menopause
  • only one egg produced per meiosis
  • polar bodies produced/uneven distribution of cytoplasm
  • cytoplasm not ehnahnced in eggs
  • eggs not motile
218
Q

spermatogensisis + oogensis compare

A
  • both start with germ gells
  • both start with mitosis to produce many cells
  • both involve cell growth before mitosis
  • both involve mieosis to produce haploid cells
219
Q

internal fertilization

A

most mammals; prevents dehydration of gametes

- parents must care for animals; childbirth and raising the child

220
Q

external fertilization

A

awuatic species ferlization (fish and amphibians); sucestible to environmental variation; large quantities of eggs produced to compensate loss;
parents dont provide parental care

221
Q

gestation period

A

period pf pregnancy

- humans have 9 month period

222
Q

fertliization producess

A
  1. sperm pushes through follicular celsl and bind to receptors in zona pellucida
  2. enzmes are relased from acrosome and digest glycoprotein based zona pellucida
  3. membranes of sperm and ova fuse
  4. exosytosis cortical granules release protease enzymes into zona pellucida to harden it and become impnetrable to sperm (prevent polyspermy)
  5. influx of calcium 2+ ions into ova to prompt meiosis II completion
  6. nucleus of sperm cell is deposited into ova’s cytoplasm to fuse wiht ova nucleus and form diploid zygote cell
223
Q

simple fertlization overview

A
  1. many sperm cell needed to achieve fertilization
  2. sperm cells push thorugh follicle cells
  3. first sperm to reach zona pellcudia uses acrosome enzymes
  4. acrosome enzymes allow for cell membranes of sperm and ovum to meet and fuse
  5. fusion of membranes result in cortical reaction
  6. haploid nucleus of sperm enters ovum; restores diploid number
224
Q

polyspermy prevention in sea urchings

A
  • revesr electrical charge upon first fertilization
    • sea urchin ova have negative charge inside, when first spermatazoon fertilizes ovum charge is made positive to repell further spermtazoa
225
Q

matierals exchaged between maternal and foetal blood in placenta

A

maternal blood to fetal blood:
- oxygen, glucose, lipids, water, amino acids, antibodies, hormones, drugs

foetul bloo to maternal blood;
carbon dioxide, urea, waste, water, hormones

226
Q

early development

A
  • implantation into endometrium by blastocystes

- fertilization stimulates zyogte to being mititoci division to create blastocyst

227
Q

blastocyte charactersitics

A
  1. surrounding layer of cells called the trophoblast which help the foetal portion of the placenta
  2. group of cells called inner cell mass which become the body of teh embryo
  3. bluid filled cavity
228
Q

why is the human ovum so large?

A

contains nutrients needed for early embryonic devvelopment that will be sued for metabolism

229
Q

placenta structure

A

The placenta is a disk shaped structure that nourishes the developing embryo
It is formed from the development of the TROPHOBLAST upon implantation and eventually invades the uterine wall

Umbilical Cord; connects the foetus to the placenta and maternal blood pools via open ended arterioles into intervillous spaces
Chorionic villi; extend into these spaces and facilitate the exchange of materials between the maternal blood and fetal capillaries

Nutrients, oxygen and antibodies will be taken up by the fetus, while carbon dioxide and waste products will be removed
The placenta is expelled from the uterus after childbirth

230
Q

functions of placenta

A
  1. production of estrogen and progesterone
  2. exchange of molecules between maternal and foetal blood
  3. maintaining pregnancy
231
Q

what do progesterone and estrogen do?

A

prevent menstratuion by building up the endometrium

232
Q

progestrone

A
  • helps maintain the highly bascular tissue characteristic of the uterus/placenta
  • suppresses contractions of smooth muscle of the uterus
233
Q

oestrogen

A
  • encourages muscle growth of the uterus
  • antagonizes action of progestrone to suppress urine contractions
  • stimulates mammary glad devvelopment late in pregnancy in prep for milk production
  • induces production of oxytocin receptors in uterine muscle late in pregnanacy
234
Q

placenta formation

A

The placenta begins to form when the fetus develops a villus, a finger-like growth into the uterus.

The number of villi increases steadily to meet the needs of the growing fetus.

Maternal blood flows out of capillaries into inter-villous spaces surrounding each villus.

Fetal capillaries are very close to the surface of each villus (within 5 µm of the maternal blood).

The cells separating fetal and maternal blood form a selectively permeable barrier known as the placental barrier.

Microvilli project from each villus to increase surface area, which allows rapid diffusion of molecules.

Nutrients and O2 diffuse from maternal blood to fetal blood, and carbon dioxide diffuses from fetal blood to maternal blood.

Fetal blood flows toward the placenta in the umbilical artery, and away from the placenta in the umbilical vein.

235
Q

ib response of placenta strcuture and function

A

During the first 2-4 weeks of development, the embryo obtains nutrients directly from the endometrium (the uterus lining).

Tissues grow out of the developing embryo and mingle with the endometrium to form the placenta.

Diffusion of material between the maternal and embryonic circulatory systems via the placenta provides nutrients, exchanges respiratory gases, and disposes of metabolic wastes from the embryo.

Blood from the embryo travels to the placenta through the arteries of the umbilical cord and returns through the umbilical vein.

The embryo secretes hormones that signal its presence and controls the mother’s reproductive system.

HCG acts like luteinizing hormone to maintain secretion of progesterone and estrogen.

Placenta is expelled from the uterus after childbirth

236
Q

oxytocin

A
  • postive feedback mechanism
  • hormone produced in hypothalmus and secreted by pituitary gland
  • when birth time ahs come, oxytocin will stimulate contractions in uterus to cause birth
237
Q

HCG role in early pregnancy

A

The endometrium is a blood rich environment in which an implanted zygote can grow and it is sustained by the hormone progesterone
If progesterone levels aren’t maintained then the endometrium will be sloughed away (menstruation)

A fertilized zygote develops into a blastocyst that secretes human chorionic gonadotrophin (hCG)

hCG maintains the corpus luteum post-ovulation so that the blastocyst can remain embedded in the endometrium and continue to develop

Gradually the placenta develops and produces progesterone (at around 8-10 weeks), at which point the corpus luteum is no longer needed

238
Q

HOW THE FETUS IS SUPPORTED + PROTECTED BY THE AMNIOTIC SAC/FLUID:

A

The fetus develops in a fluid-filled space called the amniotic sac

Amniotic fluid is largely incompressible and good at absorbing pressure; and so protects the child from impacts to the uterine wall

The fluid also creates buoyancy so that the fetus dos not have to support its own body weight while the skeletal system develops
Amniotic fluid prevents dehydration of the tissues, while the amniotic sac provides an effective barrier against infection

239
Q

Interstitial cells

A

Interstitial cells: produce testosterone

240
Q

Spermatogonia

A

Spermatogonia; divide to produce spermatocytes

241
Q

Sertoli cells

A

Sertoli cells: nourish developing spermatozoa

242
Q

Developing spermatozoa

A

Developing spermatozoa; almost complete sperm cells

243
Q

Germinal epithelium

A

Germinal epithelium: outer layer of cells in the ovary

244
Q

Primary follicle:

A

Primary follicle: contain the primary oocyte surrounded by a single layer of supporting follicle cells

245
Q

Mature follicle

A

Mature follicle: contains the secondary oocyte ready for ovulation

246
Q

Secondary oocyte

A

Secondary oocyte: haploid gamete; final stage of meiosis occurs after fertilization

247
Q

Medulla:

A

Medulla: central main body of ovary (blood vessels, lymph and nerves)

248
Q

Zona pellucida:

A

Zona pellucida: outer layer of ovum

249
Q

Troponin

A

Troponin: molecules are bound to tropomyosin and contain calcium ion binding sites

250
Q

Tropomyosin:

A

Tropomyosin: is wound around the actin

251
Q

Actin

A

at edge; form a helix of actin-subunits with a binding site for myosin heads
- has tropomyosin wrapped around it attached to troponin

252
Q

Myosin

A

Myosin thick and internal

Each ends in a myosin head contains ATPase; for muscle contraction ATP use

253
Q

sacromere muscle contraction

A

Ca2+ released from sarcoplasmic reticulum

Bind to troponin; cause tropomyosin to move

Actin filament myosin binding sites now free; Myosin cross bridge attaches the actin myofilament using ATPase

Power stroke; myosin head pivots and pulls on the actin filament sliding down the M line

New ATP attaches to myosin head and cross bridge detaches

ATP split back into ADP and Pi; cocking of myosin head occurs

IB BIOLOGY 2017 EXAM (11 decks)

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