Anatomy And Physiology Exam 3

Front 1

Long-term autoregulation

Back 1

Long term oxygen deficient deficit can lead to increased growth of blood vessels

Front 2

Capillary blood pressure

Back 2

Blood pressure low , vessels fragile

- pressure important to control filtration pressure.

Front 3

Neural short-term mechanism (chemoreceptor reflexes)

Back 3

Decrease in blood oxygen or pH, or increase in CO2 causes chemoreceptors to stimulate vasomotor center

Front 4

Chemical short-term mechanisms

Back 4

1. NE and E increase cardiac output and cause vasoconstriction except in skeletal and cardiac muscle
2 . Atrial Natriuretic peptide
- from atria, causes kidneys to excrete sodium, decreases BV and BP
3. ATH can enhance BV
4. Angiotensin II - phase of construction, causes release of aldosterone and ADH
5. Endothelium derived factors: endothelium causes vasoconstriction, PDGF causes vasoconstriction, nitric oxide causes vasodilation

Front 5

Venous system

Back 5

Walls are thinner and the lumen is larger
- contain one way valves
- capacitance vessels
-veins contain up to 65% of body's blood

Front 6

Long term mechanisms (Renal)

Back 6

- BP related to BV: kidneys important in BV regulation
- kidneys regulate several ways
- when BV increases filtration rate increases
- renin-angiotensin= low BP causes renin release

Front 7

Maintaining blood pressure: cardioinhibitory vs cardioaccelatory

Back 7

BP = cardiac output × peripheral resistance
- cardio inhibitory center (parasympathetic) - controls resting heart rate
- stroke volume controlled by EDV
- cardioacceleratory (sympathetic) - increases HR and stroke volume (increasing contractility and decreasing ESV)
- results in increased stroke volume

Front 8

Structure of vessel walls

Back 8

3 Layers
- Tunica intima (internal) : contains endothelial cells and connective tissue
- tunica media: smooth muscle + elastin
- tunica adventitia (external) : collagen fibers

Front 9

Velocity of blood flow

Back 9

Fastest in arteries, slowest in capillaries

Front 10

Venous blood pressure

Back 10

-Blood pressure is steady and changes little
-Factors aiding venous flow = respiratory and muscle "pumps"

Front 11

sinusoidal capillaries

Back 11

- only found in liver, bone marrow, lymphoid tissues, and some endocrine organs
- irregularly shaped lumens, fenestrated
- even blood vessels can leave

Front 12

Autonomic regulation - sensors and response

Back 12

1. Processing center - medulla
- cardio inhibitory center (parasympathetic)
- cardio stimulatory center ( sympathetic)

2. Sensors - baroreceptors
- carotid sinus - feedback increase, P gets stimulated
- aortic reflex is similar

Front 13

Three types of vessels

Back 13

- arteries
- capillaries
- veins

- venuoles carry blood from capillaries to veins
-arteriols carry blood from arteries to capillaries

Front 14

Fluid movement through capillaries

Back 14

Filtration pressure = hydrostatic pressure inside capillary minus hydrostatic pressure in interstitial fluid

- opposed by inwardly directed oncotic pressure

Front 15

Neural short-term mechanism: baroreceptors initiated reflex

Back 15

- receptors located in aortic arch, carotid sinus and large blood vessels in neck and thorax
- increase in BP causes:
- inhibition of vasomotor center ( vasodilation)
- causes Cardiac Center to stimulate parasympathetic and inhibit sympathetic nervous system

Front 16

Autoregulation (metabolic)

Back 16

1. NO attaches to hemoglobin and is delivered with O2 causing vasodilation
2. Other local substances cause vasodilation including:
- potassium, adenosine lactic acid, histamines and kinins

Front 17

Fenestrated capillaries

Back 17

Endothelial cells have pores or fenestrations

Front 18

Continuous capillaries

Back 18

- endothelial cells form uninterupted lining
- although tight junctions present, usually contain intercellular clefts

Front 19

Capillaries and types

Back 19

- smallest blood vessels
- large number
- contain only tunica intima
- RBCs pass single file

Types:
Continuous / fenestrated/ sinusoidal

Front 20

Function of blood flow

Back 20

- deliver oxygen / nutrients
- remove waste
- gas exchange in lungs
- urine formation in kidneys
- absorption of nutrients from GIT

Front 21

Capillary beds

Back 21

-Microcirculation
-Precapillary sphincter: surrounds root of the capillary at the metarteriole

Front 22

Alternations in blood pressure

Back 22

- hypotension:
- orthostatic hypotension
- Addison's disease
- hypertension:
- Primary (Essential) Hypertension: no known cause
- secondary: identifiable causes are arteriosclerosis, excessive renin secretion

Front 23

Reticular cell

Back 23

Produce reticular fiber stroma which supports other cells in lymphoid tissue

Front 24

MALT

Back 24

Mucosa associated lymphatic tissue

- includes Peyer's patches, appendix, tonsils, and lymphoid nodules in walls of bronchi

Front 25

Tonsils

Back 25

1. Ring of lymphatic tissue around pharynx: 3 pairs

Functions:
- filter pathogens from air / food
- yield immunity against many antigens

Commonly affected during childhood

Front 26

Lymphoid nodules

Back 26

1. Peyer's patches in wall of ileum; appendix - branch off cecum

Functions:
- destroy bacteria in intestine
- generate "memory lymphocytes" for long term immunity

Front 27

Lymph nodes

Back 27

Functions:
- filter lymph : macrophages
- activate immune system : lymphocytes monitor lymph for antigens

concentrated in centeral body regions

Front 28

Thymus

Back 28

1. bilobed: in lower neck region

function:
- T-cell maturation
- secretion of thymosin and thymopoietin

atrophy begins during adolescence

Front 29

Lymphocytes

Back 29

1. Formed from stem cells in bone marrow
2. mature into two types:
- T- cells provide cell mediated immunity
- B- cells provide humoral immunity
- give rise to plasma cells
- secretes antibodies against bacterial ( and some viral antigens)

Front 30

Lymphatic Vessels : Distribution and vessels

Back 30

1. one way flow towards heart
2. no lymph vessels in bone, teeth, bone marrow or nervous system

Front 31

Lymphoid Tissue

Back 31

- lymph nodes
- spleen
- thymus
- tonsils
- lymphoid nodules

Front 32

Lymphatic Vessels: Structural specialties

Back 32

Endothelial cells form valves at blind ends

Endothelial cells anchored to surrounding tissues

Front 33

Lymphatic Vessels : minivalves and central lacteals

Back 33

minivalves: large enough to allow entry of proteins, pathogens, cell debris, and cancer cells

central lacteals: in GIT mucosa; contain chyle which is milky because of lipids

Front 34

Lymphoid Cells

Back 34

lymphocytes
macrophages
reticular cells

Front 35

Macrophages

Back 35

1. Phagocytosis
2. Help to activate T-Cells

Front 36

Spleen

Back 36

Upper left abdominal cavity; suspended from stomach

Functions:
- Cleanses blood: phagocytes filter aged RBCs, foreign particles, and cell debris
- lymphocyte proliferation
- platelet storage
RBC production in fetus

Front 37

Lymphatic Vessels : Pathway

Back 37

Lymphatic Capillaries -> collecting vessels-> trunks -> ducts

- empties into subcalavian vein/internal jugular vein junctions

Front 38

Auto regulation (myogenic)

Back 38

decreased stretch of vessel causes vasodilation and increased blood flow
- reactive hyperemia

Front 39

Blood flow in: Skin

Back 39

Blood flow important to supply nutrients, control BT and act as blood reservoir

Sympathetic innervation causes vasodilation

sweating causes release of bradykinin which inceeases release of NO

Front 40

Blood flow in : Brain

Back 40

since located in a rigid case, needs a constant blood flow

Autoregulation controls flow:
- very sensitive to decreased pH or increased CO2

Front 41

Blood Flow in: Skeletal Muscle

Back 41

1. at rest only about 25% of capillaries open
2. during exercise, active hyperemia (hyperemia= increased blood flow)
3. vessels have A and B receptors
- at low levels, E and NE stimulate B receptors
- at high levels, stimulates A receptors

Front 42

Coverings and Layers of the Heart

Back 42

Pericardium
-Fibrous peticardium
- Serous pericardium (epicardium)
Myocardium : the muscle tissue
Endocardium- endothelium + connective tissue

Front 43

Arterioles

Back 43

smaller

can vasocontrict and vasodilate dramatically

Front 44

Arteries (muscular)

Back 44

muscular/distributing
- deliver to specific organs
- smaller and more muscular: less elastic tissue, therefore little change in diameter, maintains pressure

Front 45

Arteriole Blood Pressure

Back 45

Reflect 2 factors:
- volume of blood
- compliance of arteries

Pulse pressure

pressure drops with increasing distance from heart

mean arteriole pressure (MAP) = diastolic press. + (pulse press./ 3 )

Front 46

Neural Short Term Mechanism: Vasomotor center

Back 46

controls diameter of blood vessels

cardiac center+ vasomotor center = cardiovascular center

sends impulses via vasomotor fibers (sympathetic efferents)
- NE
- Vasomotor Tone

Front 47

Arteries (elastic)

Back 47

elastic/conducting: elastin fibers along with the smooth muscle in Tunica media
- low resistance
- expand and recoil; keeping blood under pressure
- keeps blood flow constant
- when walls get hard, blood flow more intermittent

Front 48

Physiology of Circulation

Back 48

relationship between blood flow, BP, and resistance:

Blood Flow = ( change in P / peripheral resistance )
- resistance is most important

Front 49

characteristics of blood

Back 49

slightly alkaline : pH 7.35-7.45
~8% of body wt.

Front 50

Components of Blood

Back 50

Plasma : 55% vol.
- mostly water (92%)
- solids (8%)
- proteins (albumins, globulins, fibrinogen)
- other ( gases, electrolytes, metabolites, etc.)

Serum :
- plasma minus fibrinogen + clotting factors
- collected by ommitting the anticoagulant

Front 51

Homeostatic imbalance of cardiac output

Back 51

congestive heart failure
- low pumping efficiency of heart
- atherosclerosis, persistent hypertension, myocardial infarcts, cardio myopathy
pulmonary congestion: left side of heart fails
peripheral congestion: right side of heart fails

Front 52

Regulation of Heart Rate : Chemical

Back 52

E and thyroxine increase HR
Hypocalcemia: depresses the heart
- hypercalcemia: increase irritability
Hypermatremia: prevents calcium entry, blocking contraction
Hyperkalemia: lower RMP
- cardiac arrest
Hypokalemia: abnormal rhythyms

Front 53

Regulation of Heart Rate : Autonomic NS - Parasympathetic

Back 53

1. ACh
2. Hyperpolarizes membranes by opening k+ channels
3. Has little effect on contractility

heart generally exhibits vagal tone
tachycardia vs bradycardia

Front 54

Regulation of Heart Rate : Autonomic NS- Sympathetic

Back 54

NE + E act at B receptors to increase HR
- causing threshold to be reached quicker
- increases Ca ++ entry
- Bainbridge reflex: ^ venous return in atria stretches atrial wall resulting in increased HR and force

(sympathetic reflex)

Front 55

Afterload

Back 55

Increased atrial pressure can reduce the amount of blood ejected
-hypertension

Front 56

Negative Inotropic agents

Back 56

acidosis, increasing k+ levels, verapamil (Ca++ channel blocker)

Front 57

Positive Inotropic agents

Back 57

can be caused by Sympathetic NS, horomones (glucagon, thyroxine), and digitalis

Front 58

Contractility

Back 58

increase of contractile strength of muscle independent of stretch
- results from increased intracellular Ca++
results in decreased ESV and greater SV
NE increases contractility

Front 59

Frank Starling Law of the Heart

Back 59

stretch (fill): increased force of conctraction, therefore > output

increased EDV increases stretch
- ^ volume or speed of venous return (slower HR or exercise)