BIO 150 Final Ch 13-15

What are common targets of the defense system?

• Pathogens

• Cancer cells

What are pathogens?

Disease-causing bacteria, viruses, prions, protozoans, fungi, parasitic worms

What are cancer cells?

once-normal body cells whose genetic changes cause unregulated cell division

What are the three lines of defense?

1. Physical and chemical surface barriers

2. Internal cellular and chemical defenses

3. Immune response

What makes up the first line of defense?

Physical barriers

• skin

• mucous membranes

Chemical barriers

• sweat and oil glands of skin

• lining of stomach

• urine

• saliva and tears

What are characteristics of the first line of defense?

• Nonspecific

• Keep foreign organisms or molecules out (moat)

What are characteristics of of the second line of defense?

• nonspecific

• attack ant foreign organism or molecule that has gotten past the surface barriers

What are characteristics of the third line of defense?

• specific and learned

• destroy specific targets and remember them

What makes up the second line of defense?

• Phagocytes (WBCs that engulf pathogens)

• Natural killer (NK) cells

• Interferons

• Complement system

What are phagocytes, and what is every type responsible for?

WBCs that engulf pathogens

Neutrophils - arrive first

Macrophages - develop from monocytes that leave circulatory system
Eosinophils - attack pathogens too large for phagocytosis, such as parasitic worms

What are natural killer (NK) cells?

A type of WBC that searches out abnormal cells, including cancer cells + kill them

What are interferons?

small proteins secreted by cell infected by virus; attract macrophages and NK cells, stimulate neighboring cells to make proteins to prevent viruses from replicating

What is the complement system?

group of proteins that enhance both nonspecific and specific defense mechanisms, destroy pathogens, enhance phagocytosis, stimulate inflammation

What is the purpose of inflammation?

destroys invaders and helps repair and restore damaged tissue

What are the factors of inflammation?

• Redness

• heat

• swelling

• pain

Why does redness occur from inflammation?

Mast cells release histamine, causes blood vessels to dilate; blood flow increases, delivering defensive cells and removing dead cells/toxins

Why does heat occur from inflammation?

temperature rises due to increased blood flow, speeds healing and activities of defensive cells

Why does swelling occur from inflammation?

histamine causes capillaries to become leaky, and fluid seeps into tissues

Why does pain occur from inflammation?

can be caused by excess fluid, bacterial toxins, or Prostaglandins

What is a fever, and what causes it?

An abnormally highboy temperature caused by pyrogens, which are chemicals that reset the brain’s thermostat to a higher temperature

What makes up the third line of defense?

the adaptive immune response, which is the body’s specific defenses

What are the characteristics of adaptive immune response?

specificity - directed at specific pathogen

memory - remembers pathogen an attacks it quickly so illness does not result upon second exposure

what are Major histocompatibility complex (MHC) markers?

molecules found on our cells that label cells as “self,” used by immune system to distinguish cells of body against foreign invaders

What are antigens?

a non-self substance that triggers immune response; usually large molecules (proteins, polysaccharides, nucleic acids)

What are lymphocytes?

WBCs responsible for specificity and memory of adaptive immune response

Where are B lymphocytes (B cells)?

form and mature in bone marrow

Where are T lymphocytes?

form in bone marrow and mature in thymus gland; recognize MHC self markers

how do lymphocytes distinguish self from non-self?

programmed to recognize particular type of antigen; when antigen fits into receptors, the body targets that antigen

What are effector cells?

short-lived cells that attack the invader

What are memory cells?

long-lived cells that remember invader and mount a quick response when invader is next encountered

What are antibody-mediated immune responses?

Responses that defend against antigens that are free in body fluids

(effector B cells use antibodies to neutralize antigen)

What are cell-mediated immune responses?

Protect against cancer cells and cells that have become infected with viruses or other pathogens

(cytotoxic T cells cause cancer cells and infected body cells to burst)

What are the overall steps of the adaptive immune response?

1. Threat

2. Detection

3. Alert

4. Alarm

5. Building specific defenses

6. Defense

7. Continued surveillance

What happens in step six (defense): the antibody-mediated response

• Antibodies secreted by plasma cells are specific to antigen and eliminate it

• effector cytotoxic T cell releases peforins, cause holes to form in cells w/ antigen

What are immunoglobulins?

five classes of antibodies, each with a special role to play in protecting against invaders

What are the five types of immunoglobulins?

IgG

IgM

IgE

IgA

IgD

(GAMED)

What happens in step seven (continued surveillance) of the adaptive immune system?

Immunological memory allows for more rapid response on subsequence exposure to antigen

(primary + secondary response)

Primary response from adaptive immune response

Body’s first exposure with particular antigen; antibody concentration rises slowly

Secondary response from adaptive immune response

Subsequent encounter with antigens; strong and swift response due to number of memory cells programmed to respond to antigen

What is active immunity?

body produces memory B cells and T cells following exposure to antigen (can happen through infection or vaccination) long-lived

What is passive immunity?

results when a person receives antibodies that were produced by another person or animal (antibodies passed in breast milk or placenta) short-lived

What are monoclonal antibodies?

group of identical antibodies that bind to one specific antigen; used in research, clinical diagnosis, and disease treatment

Where are monoclonal antibodies derived from?

single B cells clone

How are monoclonal antibodies formed?

1. Animal gets injected with antigen and produces antigen-specific plasma cells

2. Plasma cells removed and fused w/ tumor cells capable of endless divisions

3. hybridoma cells capable of synthesizing large quantities of monoclonal antibody

What are autoimmune disorders?

occurs when immune system fails to distinguish between self and non-self and attacks tissues or organs of the body

What are the two classifications of autoimmune disorders?

organ-specific (problematic T cells) and non-organ-specific (problematic B cells)

How do allergies form?

overreaction by immune system to an antigen, which is usually harmless

What are the steps in an allergic reaction

First exposure: allergens cause plasma cells to release IgE antibodies, which mind to mast cells

Subsequent exposures: allergen combines w/ IgE attached to mast cells and causes release of histamine

what is anaphylactic shock?

An extreme allergic reaction that can be fatal, can cause pooling of blood in capillaries, which makes breathing difficult

How can allergens be identified?

injecting small amounts of suspected antigens and monitoring skin response

What are the treatments to allergens?

antihistamine, epinephrine, allergy shots

What are the functions of the respiratory system?

• providing the body with essential oxygen, needed to extract energy from food

• exhaling co2, helping to regulate acid-base balance of body fluids

What are the four main processes of respiration?

1. Breathing/ventilating

2. external respiration

3. gas transport

4. internal respiration

What are the two regions of the respirator system?

upper and lower

what makes up the upper region of the respiratory system?

nose and pharynx

what makes up the lower region of the respirator system?

larynx, epiglottis, trachea, bronchi, bronchioles, and lungs

What is the structure of the nose?

a nasal septum divides inside into two nasal cavities, and a mucous membrane covers the inner surface

What are the functions of the nose?

cleans incoming air, warms and moistens air, and provides sense of smell

What is the structure of the sinuses?

large air-filled spaces in the bones of the face, which connect to the nasal cavities

What are the functions of the sinuses?

lighten head, warm and moisten air, part of resonating chamber that affects voice

What is sinusitis?

inflammation of the mucous membranes of the sinuses

What is the structure of the pharynx (throat)?

space behind the nose and mouth, acts as a passageway for food, drink, and air

What is the structure of the larynx (voice box Adam’s apple)

A boxlike structure made primarily of cartilage, serves as an entrance to the lower respiratory system *source of voice

What happens in the action of swallowing?

larynx rises up and causes epiglottis to cover the glottis; Heimlich maneuver in case food/drink enters trachea

What are the vocal cords?

two thick strands of tissue stretched over the glottis, which vibrate and produce the voice

What is laryngitis?

inflammation of the larynx, where the vocal cords become swollen; makes voice deepen

What is the structure of the trachea (windpipe)?

A tube held open by C-shaped rings of cartilage to prevent from collapsing; conducts air between environment and lungs

What is the structure of the bronchial tree?

network of progressively smaller air tubes

Two air tubes (bronchi) - bronchioles

What is asthma?

spasms of the bronchial muscles that severely restrict air flow; recurring attacks of wheezing and difficult breathing

What are potential causes of asthma?

allergies, respiratory infections, exercise; assisted through inhalers

What are alveoli?

minute sacs where o2 diffuses from inhaled air into blood; co2 diffuses from blood into alveolar air to be exhaled

What is surfactant?

phospholipid molecules that coat alveoli + keep open

What is Respiratory Distress Syndrome (RDS)?

insufficient production of surfactant; occurs in some premature babies

When does air move into the lungs?

pressure in the atmosphere is greater than pressure in the lungs

When does air move out of the lungs?

Pressure in the lungs is greater than the pressure in the atmosphere

What is inhalation (inspiration)?

air moves into the lungs when the thoracic cavity increases in volume due to contraction of diaphragm and intercostal muscles (active process involving muscle contraction)

What is exhalation (expiration)?

air moves out of the lungs when the diaphragm and intercostal muscles relax and the thoracic cavity decreases in volume (passive process without muscle contraction)

What is the tidal volume?

volume of air inhaled or exhaled during a normal breath

What is the inspiratory reserve volume?

Volume of air that can be inhaled in addition to a normal breath

What is the expiratory reserve volume?

Volume of air that can be exhaled in addition to a normal breath

What is the vital capacity?

the maximum volume of air that can be inhaled or exhaled in a single forced breath (tidal volume + inspiratory reserve volume + expiratory reserve volume)

What is the residual volume?

volume of air remaining in lungs after maximum exhalation

What is the total lung capacity?

total volume of air in lungs after maximal inhalation (vital capacity + residual volume)

What are the three processes to transport gases between the lungs and the cells?

1. External respiration

2. Gas transport by the blood

3. internal respiration

Where does external respiration occur?

alveoli, happens when o2 diffuses into blood and co2 diffuses from blood

Where does internal respiration occur?

tissues, happens when o2 diffuses out of blood and into cells, and co2 diffuses out of cells and into blood

how is most oxygen bound when transported between lungs and cells?

bound to hemoglobin; oxyhemoglobin

How can co2 be removed from the blood?

1. dissolved in blood plasma

2. carried by hemoglobin as carbaminohemoglobin

3. bicarbonate ion

How is the basic breathing pattern controlled?

breathing center located in the medulla; contains inspiratory and expiratory area

How can the breathing pattern be voluntarily altered?

through impulses originating in the cerebral cortex

What is the most influential chemical in breathing rate?

carbon dioxide (increased co2 increases breathing rate)

How much does oxygen influence breathing rate?

does not influence unless blood levels fall dangerously low

where are the chemoreceptors for carbon dioxide located?

the medulla, aortic bodies, and carotid bodies

where are the chemoreceptors for oxygen located?

aortic bodies and carotid bodies

what is the common cold?

caused by more than 200 viruses; typically lasts 1-2 weeks and is transmitted when a person handles a contaminated object and touches mucous membranes

what is influenza/flu?

Caused by three types of viruses (A,B,C), each w/ variants; symptoms are more serious than a cold and can become complicated by secondary infections

What is pneumonia?

an inflammation of the lungs, where fluid accumulates in the alveoli, reducing gas exchange and making breathing difficult through the bronchioles

what is strep throat?

caused by Streptococcus bacteria, leads to soreness, swollen glands, and fever

what is tuberculosis?

an infection caused by bacterium Mycobacterium tuberculosis, which is transmitted through respiratory droplets and results in fibrous tissue in the lungs

what is cystic fibrosis?

inherited lung disorder where a single mutation results in thick mucus that can clog air passageways and lead to lung infections