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An arteriovenous ___ is a route by which blood flows from an artery to a vein without passing through capillaries

Arteriovenous Anastomosis

The middle layer of a blood vessel is called the ___.

tunica media

. In ___ capillaries, there are numerous filtration pores through the endothelial cells.

fenestrated

The lowest arterial blood pressure observed during the cardiac cycle is called the ___ pressure.

diastolic

. The ability of a tissue to control its own blood supply is called ___.

autoregulation

The stretch receptors in the cardiovascular system are called ___.

baroreceptors

In the process of ___, an endothelial cell imbibes a fluid droplet by pinocytosis on one side and releases it by exocytosis on the other side.

transcytosis

The skeletal muscle pump assists blood flow in small, low-pressure arteries. True or False?

False

All capillaries reabsorb about the same amount of fluid as they release. True or false?

False

The only force favoring capillary reabsorption is the colloid osmotic pressure of the blood. True or False?

True

Perfusion of the digestive tract drops during heavy exercise. True or False?

True

Blood cannot get from an artery into a vein without passing through at least one capillary bed. True or False?

False

Distributing arteries are larger than resistance arteries. True or False?

True

Blood cannot flow from point A to point B in a vessel unless the pressure is higher at A than at B. True or False?

True

The inferior vena cava has one-way valves that ensure the upward flow of blood toward the heart. True or False?

False

Which term can be described as the route in which blood flows through two capillary beds in series before returning to the heart?

Portal system

. Which term describes a hormone that is a strong vasoconstrictor?

angiotensin II

Which term can be described as the small blood vessels that perfuse the larger blood vessels?

Vasa Vasorum

Which term can be described as the category that includes neurogenic and anaphylactic shock?

circulatory shock

Which term can be described as the function of blood viscosity, vessel length, and vessel radius?

peripheral resistance

Which term described the promotion of the upward flow of blood in the inferior vena cava?

thoracic pump

Veins are called ___ vessels because they can hold a large amount of blood.
A. capacitance
B. resistance
C. storage
D. compliance
E. hemodynamic

A. capacitance

Blood flow is directly proportional to

A. blood viscosity.
B. vessel length.
C. vessel radius.
D. erythrocyte count.
E. peripheral resistance.

C. vessel radius.

56. Blood flow equals the pressure difference (P) between two points divided by
A. arterial diameter.
B. osmotic pressure.
C. resistance.
D. hydrostatic pressure.
E. blood volume.

C. resistance

Peripheral resistance is directly proportional to
A. blood viscosity.
B. vessel diameter.
C. cardiac preload.
D. systolic contraction force.
E. pulse pressure.

A. blood viscosity.

. If a person's arterial blood pressure measures 130/85, the mean arterial blood pressure is
A. 85 mmHg.
B. 100 mmHg.
C. 107.5 mmHg.
D. 128.3 mmHg.
E. 130 mmHg.

B. 100 mmHg.

Blood flow will decrease if
A. vessel radius increases.
B. viscosity increases.
C. p increases.
D. pressure increases.
E. afterload increases.

B. viscosity increases.

The net filtration pressure of a blood capillary is the difference between
A. colloid osmotic pressure and oncotic pressure.
B. blood and interstitial hydrostatic pressures.
C. blood pressures at the arterial and venous ends.
D. net hydrostatic pressure and oncotic pressure.
E. interstitial pressure and oncotic pressure.

D. net hydrostatic pressure and oncotic pressure.

Blood solutes can pass through the walls of continuous capillaries by passing through either the endothelial cell or

A. the thoroughfare channels.
B. the intercellular clefts.
C. the filtration pores.
D. the sinusoids.
E. the fenestrations.

B. the intercellular clefts.

Identify the net filtration pressure in a capillary under the following conditions: interstitial hydrostatic pressure, -2 mmHg; colloid osmotic pressure (COP) of the tissue fluid, 6 mmHg; COP of the blood, 29 mmHg; blood hydrostatic pressure, 32 mmHg.
A. 1 mmHg
B. 5 mmHg
C. 8 mmHg
D. 11 mmHg
E. 65 mmHg

D. 11 mmHg

In autoregulation, all of the following chemicals tend to increase blood flow except
A. nitric oxide.
B. carbon dioxide.
C. thromboxane A2.
D. histamine.
E. lactic acid

C. thromboxane A2.

The common route for blood flow is heart ---> arteries ---> arterioles ---> capillaries ---> venules ---> veins ---> heart. There are exceptions to this route, notable portal systems and anastomoses. In a portal system blood flows from one _____ to another, while in the anastomoses blood flows from one _____ to another.

A. capillary bed; artery or vein
B. artery or vein; capillary bed
C. artery; vein
D. vein; artery
E. vein; capillary bed

A. capillary bed; artery or vein

The outer wall of an artery or vein is called the _____ and in large arteries and veins contains the _____.
A. tunica media; smooth muscle
B. tunica externa; vasa vasorum
C. tunica externa; valves
D. tunica intima; endothelium
E. tunica intima; basement membrane

B. tunica externa; vasa vasorum

You would expect to find the thickest tunica media in a

A. small artery.
B. small vein.
C. large artery.
D. large vein.
E. capillary.

C. large artery.

The renal vein has a larger diameter than the renal artery with the renal vein having a larger _____ but a smaller _____.

A. tunica externa; lumen
B. lumen; tunica media
C. tunica media; lumen
D. tunica intima; tunica media
E. lumen; tunica intima

B. lumen; tunica media

. A short vessel, which links to capillaries, and does not have a continuous tunica media but rather individual muscle cells spaced at short distances apart is a(n)

A. muscular artery.
B. arteriole.
C. precapillary sphincter.
D. metarteriole.
E. venule.

D. metarteriole.

Arteries like the aorta, pulmonary arteries, and common carotid arteries maintain pressure on blood during ventricular diastole and lessen the fluctuations in blood pressure. These are _____ arteries.
A. distributing
B. resistance
C. elastic
D. muscular
E. conducting

C. elastic

The major vessels that control the relative amounts of blood directed to the various tissues are
A. muscular arteries.
B. resistance arteries.
C. conducting arteries.
D. capillaries.
E. veins.

B. resistance arteries.

The most common capillary beds in the body are
A. continuous capillaries with tight junctions and intercellular clefts.
B. continuous capillaries with filtration pores that allow for rapid passage of small molecules.
C. fenestrated capillaries with tight junctions and intercellular clefts.
D. fenestrated capillaries with filtration pores that allow for rapid passage of small molecules.
E. fenestrated capillaries with gap junctions that allow for rapid passage of small molecules.

A. continuous capillaries with tight junctions and intercellular clefts.

The capillaries that form the blood-brain barrier in the brain resemble
A. continuous capillaries without fenestrations.
B. continuous capillaries without intercellular clefts.
C. fenestrated capillaries without fenestrations.
D. fenestrated capillaries without intercellular clefts.
E. fenestrated capillaries with intercellular clefts.

B. continuous capillaries without intercellular clefts.

Valves are found in
A. veins and lymphatic vessels.
B. veins.
C. veins and arteries.
D. arteries.
E. capillaries.

A. veins and lymphatic vessels.

. In the arterial blood pressure reading, for example in a young adult, the ratio is written 120/75. The 120 reading is in _____ units and refers to ______.


A. inches of water; peak arterial pressure during systole
B. millimeters of mercury; lowest arterial pressure during systole
C. milliliters of water; lowest arterial pressure during systole
D. millimeters of mercury; peak arterial pressure during systole
E. pounds of pressure; lowest arterial pressure during systole.

D. millimeters of mercury; peak arterial pressure during systole

. Hypertension, or high blood pressure is a chronic resting blood pressure higher than _____ mmHg systolic or ______ mmHg diastolic.
A. 200; 100
B. 140; 90
C. 170; 60
D. 140; 100
E. 200; 90

B. 140; 90

Suppose a vessel with a radius of 1 mm had a flow of 1 mm/sec. The vessel dilated to a radius of 4 mm. Its new flow rate would be _____ mm/sec.
A. 4
B. 16
C. 32
D. 64
E. 256

D. 64

You have been exercising strenuously and decided to sit down and rest. In response to the effects of exercising, the baroreceptors stimulate the _____ center and inhibit the ____ center.
A. cardioinhibitory; vasomotor
B. vasomotor; cardioacceleratory
C. cardioinhibitory; cardioacceleratory
D. cardioacceleratory; vasomotor
E. cardioacceleratory; cardioinhibitory

A. cardioinhibitory; vasomotor

Which one of the following hormones reduces blood pressure?
A. angiotensin II
B. atrial natriuretic peptide (ANP)
C. aldosterone
D. antidiuretic hormone (ADH)
E. renin

B. atrial natriuretic peptide (ANP)

These two hormones are powerful vasoconstrictors: _____. Of these two hormones, ____ also stimulates an increase in heart rate.
A. NE and vasopressin; vasopressin
B. EP and angiotensin II; EP
C. NE and ANP; NE
D. EP and aldosterone; EP
E. EP and vasopressin; vasopressin

B. EP and angiotensin II; EP

Some water-soluble materials can cross the capillary in the kidney, small intestine, and many endocrine glands and either cross slowly or not at all in other areas of the body. These water-soluble materials most likely cross by
A. diffusing through the plasma membrane.
B. transcytosis.
C. diffusing through intercellular clefts.
D. diffusing through fenestrations.
E. exocytosis.

D. diffusing through fenestrations.

The highest pressure that moves substances out of a capillary is _____ pressure.
A. interstitial hydrostatic
B. blood hydrostatic
C. blood colloid osmotic pressure
D. interstitial fluid osmotic pressure
E. intracellular osmotic pressure

B. blood hydrostatic

The highest pressure that moves substances into a capillary is
A. blood hydrostatic pressure.
B. interstitial hydrostatic pressure.
C. blood colloid osmotic pressure.
D. interstitial fluid osmotic pressure.
E. intracellular osmotic pressure.

C. blood colloid osmotic pressure.

The most important force in venous flow is
A. the pressure gradient generated by the heart.
B. gravity.
C. the skeletal muscle pump.
D. the thoracic (respiratory) pump.
E. one way flow due to valves.

A. the pressure gradient generated by the heart.

A mean arterial pressure (MAP) below 60 mmHg can cause _____, and a MAP above 160 mmHg can cause _____.
A. syncope; cerebral edema
B. neurogenic shock; neurogenic shock
C. compensated shock; decompensated shock
D. syncope; neurogenic shock
E. neurogenic shock; syncope

A. syncope; cerebral edema

. The main chemical stimulus for cerebral autoregulation is changes in
A. K+.
B. H+ or CO2.
C. O2.
D. Na+.
E. Ca2+.

B. H+ or CO2.

what are Lipid soluble molecules? do they need the help of transport proteins? or expenditure of metabolic energy?

Oxygen and Carbon Dioxide, they do not need the help of transport proteins and do not expend metabolic energy

what are non-lipid soluble molecules? how are they trans-located across capillary walls?

Proteins, exocytosis

What are water soluble solutes and how do they diffuse from the capillary?

Amino acids and sugar diffuse through fluid filled clefts or fenestrations

What is arterial blood pressure? Delta P

Delta P= 65;Pulsatile
systolic-diastolic=measure of stress on small arteries
MAP-Diastolic pressure + 1/3 of pulse pressure

What is Capillary blood pressure? Delta P

Delta P=17
Capillaries are fragile
highly permeable,nutrient exchange

What is Venous blood pressure? Delta P

Delta P= 17

What is Hemodynamics?

Distribution of blood within the cardiovascular system and distribution of cardiac output within different tissues

Classic circulatory route?

through one capillary

Portal system?

Two capillaries in a row

Arteriovenous anastamosis

Blood flows directly into vein (shunt)

Venous anastomosis

Alternate drainage, blockage is less serious

Arterial anastomosis

not common, more than one artery provides flow to an organ

nl not important for regulation but is pathological
n=pathological
l=Length
major player in turbulence

what is blood flow regulated by?

1-change in cardiac output
2- Modifying peripheral resistance
3-modifying blood pressure

What is the major purpose of blood flow?

Provide tissues with the appropriate amount of nutrients and remove toxic waste

3 types of mechanisms involved in Blood flow regulation?

1- Local control/autoregulation
2- Neural mechanisms
3-endocrine mechanisms

Local control/Autoregulation?

Occurs within a tissue and while cardiac output and Blood pressure are stable
*adjusts Peripheral resistance
Short-term- Vasoconstriction

Vasodialation occurs when- Low O2, High Co2, High potassium, too many H+ ions, Low nutrients

Vasoconstriction= decrease flow by constricting smooth muscle of arterial walls and spinctors- Endothelium, prostaglandins, thromboxines

Neural mechanisms

-ANS control C.O. and P.R.
Short term effect- Regulation of flow

Originates from cardiovascular center of medulla which has:
-Cardiac center
-Vasomotor center

Cardiovascular center

Cardiac center-Regulates C.O. thus Blood pressure
Vasomotor center- Regulates peripheral resistance to control flow. thus blood pressure

Composed of two subgroups of neurons
-vasoconstriction
-vasorelaxation- especially skeletal muscle

What controls the Vasomotor center?

Baroreceptors: Decrease in pressure stimulates cardioacceletory center and vasoconstriction
Increase in pressure inhibits cardioacceletory center and vasoconstriction center

Chemoreceptors
*sensitive to Co2 and acid mainly decrease in O2 and increase in Co2 stimulates cardioacceletory and vasoconstriction

Endocrine mechanisms "hormones"

-Epi and norepi
-ADH
-Angiotensin II
-Erythropoietin
-A.N.P

Epi and Norepi? ( short term)

Short term- Binds to alpha receptors and triggers vasoconstriction of non-vital tissues
-Binds to beta receptors and vasodialates vital tissues

Epi and Norepi increase C.O.

ADH?(short and long term)

Short term- Stimulates peripheral vasoconstriction in non-vital tissues

Long term- Stimulate water conservation by kidneys and increases blood volume and Blood pressure

Angiotensin II ( short and long term)

renin is released due to low renal B.P. Renin converts arculation angiotensinogen to angiotensin I. ACE coenzymes converts A-I to A-II

Short term- Powerful vasoconstriction to non-vital
-Positive Inotropic effect, increase C.O.
Long term-
-Stimulates release of ADH
-Stimulates Aldosterone
-Stimulates thirst

Erythropoietin

-released from kidney in blood pressure or O2 levels drop

Long term effect

increase RBC formation which increases blood volume and blood pressure

A.N.P
Short term
Long term

Short term- Weak vasodialator released from atrium due to stretch
Long term- Increases sodium loss
-reduces thirst
-Blocks release and action of ADH

Large Veins

Lower B.P. 10mmHg
thin walls/valves + High capacitance
valves aid skeletal muscle in upward blood flow

-Capacitance vessels contain 75% of total blood, veins of systemic circulation

Small veins

no valves

Venules

More porous than capillaries

Venus sinuses

thin walls, large lumens, no smooth muscle

types of capillaries

Continuous- Most common, have intercellular clefts

Fenestrated- Found in kindneys, small intestine, rapid absorption and filtration pores, still have clefts

Sinusoids- no longer continuous

Arterial system- four types of arteries

1- conducting/Elastic-Blood moves from A--->B, Balloon like
2- Distributing/muscular- blood to parts of body
3- Resistance or arterioles- Blood within specific organs
4- metarterioles- in capillary with precapillary sphinctors

Capillary exchange
Diffusion

-Requires a concentration gradient, and permeability
- small ions, water, glucose, amino acids
-works well only over short distances

Capillary exchange
transcytosis

-occurs in both directions
-minor mechanism
-used to move large molecules
-fatty acids
-albumin
-some hormones

Capillary exchange
filtration and reabsorption

-Allows movement of large amounts of fluid to be exchanged for dissolved nutrients

Due to
-Hydrostatic pressure
-Colloid osmotic pressure

Goal of cardiovascular regulation of flow?

1- alter flow at appropriate time
2- alter flow to appropriate organs
3- alter flow without drastically changing flow to vital organs

what is the systemic Delta P aka Blood pressure

90mmHg from aorta to right atrium

Vessel wall

Tunica interna- nonstick simple squamous endothelium, elastic recoil

Tunica media- smooth muscle, elastic innervated by ANS; allows contracting(vasomotion)

Tunica externa- loose connective tissue with vasa vasorum

Components of the lymphatic system

-Lymph- Fluid, little proteins
-lymphatic vessels- network that carries lymph from tissues to veins
-lymphocytes/phagocytes
- lymphoid tissue and organs found throughout the body

What are the main functions of the respiratory system?

-Provides for oxygen and carbon dioxide exchange between the blood and air
-helps control the PH of body fluids
-Lungs filter small blood clots from the blood stream and dissolve them, preventing clots from obstructing the more vital coronary,cerebral, and renal circulation
-carry out a step in the synthesis(A.C.E enzymes) of a vasoconstrictor called angiotensin II, which helps regulate blood pressure.

Henry's law

At the air-water interface, the amount of gas that dissolves in water is determined by its solubility in water and its partial pressure in the air (assuming a constant temp)

ex-smell of chlorine near a swimming pool. if it's partial pressure is greater in the air, it diffuses into the water

Solubility of the gasses

Carbon dioxide is about 20 times as soluble as oxygen, and oxygen is about twice as soluble as nitrogen. Even though the pressure of Oxygen is much greater than Carbon dioxide across the respiratory membrane, equal amounts of the two gasses are exchanged because carbon dioxide is much more soluble and diffuses more rapidly

Ventilation-perfusion coupling

Gas exchange requires not only good ventilation of the alveoli but also good perfusion of their capillaries.Ventilation perfusion coupling refers to the physiological responses that match airflow to blood flow and vice versa. For example if a part of a lung were poorly ventilated because of tissue destruction or an airway obstruction, it would be pointless to direct much blood to that tissue. Poor ventilation leads to a low Partial pressure of oxygen in that region of the lung, this stimulates local vasoconstriction, rerouting the blood to better-ventilated areas of the lung, where it can pick up more oxygen

Boyle's law

A pressure of a given quantity of gas is inversely proportional to it's volume(assuming a constant temp)

if you increase the volume the pressure decreases
if you decrease the volume the pressure increases

P1 x V1= V2 x P2

ex- (inhalation)P1=10 V1=10
(exhalation)P1=20 V2=5

Dalton's law

A total pressure of a gas mixture is equal to the sum of the partial pressure of its individual gases

Pressure and airflow

Flow of a fluid is directly proportional to the pressure difference between two points(deltaP) and inversely proportional to resistance(R)

atmospheric(barometric) pressure

The weight of the air above us. at sea level, this averages 760mmHg

Intrapulmonary pressure

intrapulmonary pressure falls below the atmospheric pressure, then air tends to flow down its pressure gradient into the lungs. Conversely, if intrapulmonary pressure rises above atmospheric pressure, air flows out. Therefore, all we have to do to breathe is to cyclically raise and lower intrapulmonary pressure

Composition of air?

Air consists of about 79% Nitrogen and 21% oxygen

difference between the composition of air we inhale and the composition of air in the alveoli. what are the three influences

-it is humidified by contact with the mucous membranes, so it's PH2o is more than 10 times higher that that of inhaled air
-Freshly inspired air mixed with the residual air left from the previous respiratory cycle, so that its oxgygen is diluted and enriched with Carbon dioxide from the residual air.
-Alveolar air exchanges Oxygen and Carbon dioxide with the blood. Thus the Partial pressure of oxygen of alveolar air is about 65% that of inhaled air, and its Partial pressure of Carbon dioxide is more that 130 times higher

Muscles involved in respiration

Scalene, Pectoralis minor, serratus anterior, external intercostal muscles, sternoclydomastoid, diaphragm

Importance of surfactant

Importance of surfactant is especially apparent when it is lacking. Premature infants often have a deficiency of pulmonary surfactant and experience great difficulty breathing. The resulting infant respiratory distress syndrome can be treated by administering artificial surfactant

squamous type I alveolar cells

cover 95% of the alveolar surface area, allow for rapid gas diffusion between the air and blood
ex-

Great type II alveolar cells

Cover the other 5% of the alveolar surface, even though they cover less surface area, they considerably outnumber squamous Type I alveolar cells

Functions-
-Repair alveolar epithelium when the squamous cells are damaged
-Secrete pulmonary surfactant, a mixture of phospoholipids and protein that coats the alveoli and smallest bronchioles and prevent them from collapsing when one exhales. without surfactant alveolus would cling together like sheets of wet paper

Alveolar macrophages (dust cells)

Most numerous of all cells in the lungs that wander lumens of the alveoli and connective tissue between them, they keep alveoli free of debris by phagocytizing dust particles that escape entrapment by mucus in the higher parts of the respiratory tract.

What is the Delta P in the Alveoli

100mmHg

Oxygen-Hemoglobin dissociation curve

-Not linear relationship due to cooperation
-as PO2 increases more O2 is bound to hemoglobin
-as PO2 drops O2 is released from hemoglobin
-blood leaving the lungs is 98% saturated
-at tissue (PO2=40) blood is 75% saturated
-at PO2 of 70mmHg hemoglobin is saturated
-can survive high altitude and cardiopulmonary disease

Factors that influence the curve and enhance oxygen unloading at the tissues

-increase acidity
Bohr effect
-increase temp
-increase level of CO2
Haldane effect
- 2,3-biphosphoglycerate(BPG)(intermediate in respiration)
Produced during anaerobic respiration

Oxygen transport

Oxygen binds to hemoglobin.
Oxygen binds to iron so 4O2 to 1 hem =100% saturated

After binding with O2, hemoglobin changes shape to further uptake, 1st oxygen is hardest to get on, after shape change the 2nd,3rd, and fourth go on easily ( positive feedback cycle)

Carbon Dioxide transport-3 ways

-Dissolved in plasma 7%
-bound to hemoglobin 23%
-as bicarbonate ion in plasma- 70%

-CO2 + H2O<--->H2CO3<--->H+HCO3
^ ^
Enzyme CAH (carbonicanhydrase)

External respiration

- 1st 7% of Co2 will go straight into alvioli, then Co2 will come off HB into plasma into alveoli as long as there is a Partial pressure then Co2 sitting in blood cell will leave and equation will work backward. The HCO3 will reenter cell by exchange of Cl-( outward CL shift in lungs) HCL and gets rest from HB then O2 enters plasma then vessel and bind to Hb and then we are 98.5% saturated, 1 1/2% O2 dissolved in plasma

What are the two intrinsic defense systems of the body that deal with infectious agents?

Nonspecific- also known as innate defense system, always ready and waiting at 100%

Specific- also known as adaptive defense systems, Immune system waiting at 20%

Nonspecific body defenses( surface membrane barriers)

-unbroken epithelial linings
-acidity
-skin,vagina,stomach
-lysozyme (works on gram +)
-mucous
-iron chelators (makes iron available for bacteria)

NonSpecific body defenses

Phagocytes
-Macrophages
-Microphages
-Neutrophils
-NK cells

Nonspecific cells
-Phagocytes

Phagocyte
-Macrophage-->kills by phagocytosis
-Microphage(neutrophil)-->phagocytosis
-deregulate to release( hypochlorite,superoxide ions)
also produces hydrogen peroxide and cause a killing zone that kills the good and bad

Nonspecific cells
*Eosinophiles
*NK cells

Eosinphiles
-Very common in mucus membrane
-kill by phagocytosis
-degranulated to release superoxide anions and hydrogen peroxide

NK Cells
-destroy, bacteria, transplanted cells, and cells infected by virus or cancer
-release perforines and granzymes
granzymes disrupt enzyme systems and cause apoptosis

NK cells

NK cells attack human cells and your cells containing viruses. Really good at killing precancer cells
-attach to cell and make a hole. Local hormones are released (cytokines) and go through pores, go to heart of cell and activates suicide

Apoptosis= cell suicide

Non-specific defenses
antimicrobial proteins
aka complement
(arsenal)

30+ circulatory proteins that when activate
-split cells
-stimulate inflammation
-attracts phagocytes
-immune clearance
---> RBC carry Ab Ag complexes to macrophages, live in spleen, main way foreign antigen is cleared

Compliment system
---Splitting C3 into c3a +c3b
*classical pathway

require antibody:specific immunity
*bound antibody activates C1 (antibdy dependent)

Antigen-antibody complexes form on pathogen surface----->

reaction cascade compliment fixation----->

C3 dissociates to C3a+C3b

compliment system
*splitting C3 into C3a + C3b

*alternate pathway

*spontaneous breakdown of C3 to C3a+b
the products adhere to pathogenic cells.
when enough build up. activation of arsonal occurs(antibody independent)

C3 dissociates into fragments C3a+b
C3 binds to pathogen surfaces
reaction cascade and auto-catalytic effect then arsenal

complement system
*splitting C3 into C3 a + C3b

*Lectin pathway

*lectin pathway binds to microbial carbohydrase groups which trigger breakdown of c3 (antibody independent)

Lectin binds to carbohydrates on pathogen surface

Reaction cascade and arsonal

membrane attack complex
(cytolysis)

complement proteins form ring in plasma membrane of target cell and cause cytolysis

lipid inserts to membrane assembly ring of Ca and Cd rain out insides and cell swells and bursts

Nonspecific body defenses

Antimicrobial proteins
-interferons

Produced by own cells
-Virally infected cells
-macrophages
-lymphocytes

Effects
-attack NK cells
-stimulate macrophage activity
-trigger cells to make antiviral proteins

Nonspecific body defenses
antimicrobial proteins
-pyrogens

Exogenous pyrogens=surface
glycolipids of bacteria and viruses
-endogenous pyrogens= interleukins and interferions from leukocytes

*cause fever to promote wbc
*acts at hypothalamus to produde proteglandins, ez with triggers fever
-->stimulate liver and spleen to hoard up zinc and iron

inflammation
(non-specific)

-Triggers whenever tissues are injured
- purpose is to prevent spread, dispense of cellular debris and pathogens

Cardinal signs
-redness, swelling, heat, pain

-words ending with -itis denotes inflammation

Inflammation
Stage one

-vasodialation and increased permeability, this is due to inflammatory chemicals
Histamine, Kinins, prostoglandins, lymphocytes, mast cells

cause hyperemia (redness/swelling) and edema

Inflammation
Stage two

phagocyte migration and activation
margination: endothelial cells at injury site express selection(fish hooks that bind to phagocytes)
diapedsis; snagged phagocytes migrate through endothelial cells
-chemotaxis
-Neutrophils are quickest to responds
-machrophages and T-cells secrete colony-stimulating factor to develope lots of new cells (leukopoeisis)

Tissue cleanup
1. what are the primary agents of cleanup and when do they arrive?

Momocytes; arrive in 8-12 hours and become macrophages

-Edema, decreased venous flow, increased lymphatic flow that favors removal of bacteria and debris

Tissue repair

Blood platelets and endothelial cells in injured area secrete cytokine PDGF that stimulates fibroblasts to multiply and synthesize collagen(scars)

Facilitated by hyperemia that provides materials needed and heat that increases metabolism

-Fibrin clot may provide scaffold for repair

Mobilization of defenses

Leukocyte development
-Margination
-Selectins cause leukocytes to adhere to blood vessel walls
-Diapedesis(emigration) leukocytes squeeze between endothelial cells into tissue space

Immunity
(specific defense)
-forms of immunity

provided by the coordinated actions of T and B lymphocytes

A) innate immunity
B) Acquired immunity
-active acquired
-follows exposure to an antigen
-passive acquired
-transferred from another source

Forms of immunity

Cellular or cell mediated immunity
-T-lymphocytes
-directly kill abnormal cell by lysis
-indirect role by releasing chemicals that enhance
inflammation and attract/activate lymphocytes and macrophages

Humoral imminity
-B-lymphocytes and plasma cells
-defend against pathogen in fluids

Properties of immunity
Antigen specific
Systemic
memory
tolerance

-one virus/pathogen
-immunity spread through body
-childhood inoculation
-tolerance of own tissues

Target of immune system

Antigens (pathogens)
-any substance that can mobilize the immune system (foreign hopefully)

Substances that can be antigenic
-Proteins
-nucleic acids
-some lipids
-Some large polysaccharides(blood)

Haptens

-Haptens are small molecules that normally are not immunogenic
- they bind to a protein in the body and are now immunogenic

-Appears to be the basis for most allergies

Cell-mediated immunity
*key cell types involved

1. Cytotoxic T cells/CD8 T-cells
2. Suppressor T-cells (regulatory)/CD8 cells
3. Helper T-cells/CD4 cells
-each T cell can recognize only 1 antigen
4. Antigen presenters
-Macrophage cells and dendridic cells

Antigen presentation

Major histocompatibility complex

T and B cells only recognize antigens when they are bound to membrane bound glycoproteins called (MHC's)

*unique in everyone

Antigen presentation in all nucleated cells

Class 1/Class 2

All nucleated cells have class I MHC
Class I-made in golgi, as they migrate to plasma, they pick up small peptides(can be phagosome/virus) one then carry them to surface and present them

Class II
-found in phagocytes, connected to phagosome then we destroy bacteria. MHC takes it to surface and presents potential pathogen

Antigen recognition Step 1

CD is a marker that recognizes MHC only
-are marker receptors on surface of T-cells

-these T-cells via CD markers are constantly docking onto MHC proteins of cells

-All T-cells have CD3 marker
-Cytotoxic and suppressor have CD8
-helper T-cells have CD4

Antigen recognition Step 2

Each T-cell contains a receptor for one antigen (specific)

-antigen recognition occurs when an antigen presenting cell has a MHC complex containing an antigen that binds to the specific receptor for the same antigen on the T-cell

T-cell activation

T-Cell must bind the antigen being presented to its receptor and both a CD3 marker and a CD8 or CD4 marker must brind to the MHC protein on the antigen presenting cell before the immune response will continue

*called Costimulation---> multiple events need to occur
*serves as a safety

Role of activated CD8 T-cells

A.K.A suppressor and cytotoxic cells
-quickly produce large numbers of activated cytotoxic cells (mainly killers)
-memory T-cells slow metabolism and a small number
of supressor T-cells Wait and then take around 1 week to shut down

Activated Cytotoxic T-cells

Release
-Perforins=make hole in cell
-lymphotoxin=wrecks mitochondria/disrupts metabolism
-cytokines= interleukins, triggers apoptosis
-gama interferion=attacks and stimulates macrophages to killer status

Role of the CD4 helper T-Cells

*occurs at same time as CD8 cell activation and is similar
-docks to MHC II and sees what its holding, if it can recognize antigen, once activated, large numbers of helper cells occur and memory helper CD4 cells

Activated CD4(helper) T-cells

Secrete cytokines
-stimulate T cell division and maturation
-attract macrophages
-attact and stimulate NK cells
-Promote B cell division and plasma cell production leading to antibody production
-Stimulate B+T cells by helper T cell interleukins

Attack phase: role of helper T cells

*secrete interleukins which attack neutrophils, NK cells, and macrophages
-stimulates phagocytosis
-stimulates T and B cell mitosis and maturation

*coordinate humoral and cellular immunity

See More

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