CH 17, 18, 19 a&p

Which lymph organs do not contain mucosa-associated lymphatic tissue?

Absent from bones, teeth, bone marrow, and CNS

All or nothing contraction of the heart muscle.

All cardiomyocytes contract as unit, or none do

Result of depriving heart muscles of normal blood supply.

Angina pectoris-Thoracic pain caused by fleeting deficiency in blood delivery to myocardium Cells weakened Myocardial infarction (heart attack) Prolonged coronary blockage Areas of cell death repaired with noncontractile scar tissue

Where do you place the stethoscope to ausculate the 4 heart valves?

Aortic valve sounds heard in 2nd intercostal space at right sternal margin. Pulmonary valve sounds heard in 2nd intercostal space at left sternal margin Mitral valve sounds heard over heart apex (in 5th intercostal space) in line with middle of clavicle Tricuspid valve sounds typically heard in right sternal margin of 5th intercostal space

Relate B cells to plasma cells to antibodies?

B cells are made from plasma cells, plasma cells create antibodies

What provides long-term response to blood pressure?

Baroreceptors quickly adapt to chronic high or low BP so are ineffective Long-term mechanisms control BP by altering blood volume via kidneys Kidneys regulate arterial blood pressure Direct renal mechanism Indirect renal (renin-angiotensin-aldosterone) mechanism

What is the relationship between cardiac output and cardiac return?

CO is Determined by venous return, and neural and hormonal controls

CH18 What are the 3 main factors regulating blood pressure?

Cardiac output (CO) Peripheral resistance (PR) Blood volume

Which chemicals/hormones regulate blood pressure?

Cause increased blood pressure Epinephrine and norepinephrine from adrenal gland increased CO and vasoconstriction Angiotensin II stimulates vasoconstriction High ADH levels cause vasoconstriction Cause lowered blood pressure Atrial natriuretic peptide causes decreased blood volume by antagonizing aldosterone

How does aldosterone affect blood pressure?

Cause lowered blood pressure Atrial natriuretic peptide causes decreased blood volume by antagonizing aldosterone

What is a heart block

Few (partial) or no (total) impulses reach ventricles Ventricles beat at intrinsic rate - too slow for life caused by defective AV node

How does the lymph leave the lymph node?

Lymph propelled by Milking action of skeletal muscle Pressure changes in thorax during breathing Valves to prevent backflow Pulsations of nearby arteries Contractions of smooth muscle in walls of lymphatics through efferent vessels

CH19 List lymphatic structures

Lymphatic capillaries Collecting lymphatic vessels Lymphatic trunks and ducts

What factors aid venous return?

Muscular pump: contraction of skeletal muscles "milks" blood toward heart; valves prevent backflow Respiratory pump: pressure changes during BREATHING move blood toward heart Valves: under sympathetic control pushes blood toward heart prevents back flow

What is the purpose of the right lymphatic duct and the left lymphatic duct?

R side drains right side of head and thoracic L side drains rest of body

Elements of the conduction system of the heart.

Sinoatrial node SA atrial muscles Atrioventricular node AV Atrioventricular bundle (bundle of His) Right and left bundle branches Subendocardial conducting network (Purkinje fibers) APEX

In which organs are lymph capillaries present?

Structures include spleen, thymus, tonsils, lymph nodes, and other lymphoid tissues

Why are arterioles known as resistance vessels?

The contraction and relaxation of the smooth muscle in their walls can change their diameter Control flow into capillary beds via vasodilation and vasoconstriction

Compare skeletal muscle and cardiac muscle.

Three differences from skeletal muscle: 1 ~1% of cells have automaticity (autorhythmicity) Do not need nervous system stimulation Can depolarize entire heart 2 All cardiomyocytes contract as unit, or none do 3 Long absolute refractory period (250 ms) Prevents tetanic contractions Three similarities with skeletal muscle: 1 Depolarization opens few voltage-gated fast Na+ channels in sarcolemma Reversal of membrane potential from -90 mV to +30 mV Brief; Na channels close rapidly 2 Depolarization wave down T tubules SR to release Ca2+ 3 Excitation-contraction coupling occurs

What is the role of norepinephrine on the heart?

Thyroxine increases heart rate; enhances effects of norepinephrine and epinephrine

What is the purpose of the chordae tendineae?

anchor cusps to papillary muscles Hold valve flaps in closed position

Cerebral flow is regulated by ?

baroreceotors

What affects the velocity of blood flow?

blood vessel diameter

What is the result of blockage of the lymphatic structures of a limb?

build up of intracellular fluid if R mastectomy node removal, more ceceptiable to infection, edema, doesn't cut off blood flow moves slowly in veins. lose ability to kill bacteria in cells

What is the most significant source of blood flow resistance?

capillaries

What is the function of the spleen?

cleans old RBC's out of blood, 42 days old then digest or salvage

Myocardium capillaries are part of the ______ arteries.

coronary arteries, w/ oxygenated blood

Compare the permeability of the blood capillaries with the lymphatic capillaries

lymphatic capillaries more permeable bc 1 cell layer thick

What is hypovolemic shock?

results from large-scale blood loss

Lymphoid tissue is predominately what kind of tissue?

reticular connective tissue

What are baroreceptors?

stretch receptors in arteries that respond to increase pressure Inhibits vasomotor and cardioacceleratory centers, causing arteriolar dilation and venodilation Stimulates cardioinhibitory center decreased blood pressure Decrease in blood pressure due to Arteriolar vasodilation Venodilation Decreased cardiac output

Tricuspid valve is closed and open during what phases of the heart cycle

systole

Why is left ventricular wall thicker than the right wall?

the left ventricle has thicker walls than the right because it needs to pump blood to most of the body while the right ventricle fills only the lungs. pumps w/ greater presssure

The lymphoid tissue of the mucosa of the oral cavity is called?

tonsils

What is the process of ventricular filling?

1. Blood returning to the heart fills atria, pressing against the AV valves. The increased pressure forces AV valves open 2. As ventricles fill, AV valve flaps hang limply into ventricles 3. Atria contract, forcing additional blood into ventricles AV valves open; atrial pressure greater than ventricular pressure 1.Ventricles contract, forcing blood against AV valve cusps 2.AV valves close 3.Papillary muscles contract and chordae tendineae tighten, preventing valve flaps from everting into atria. AV valves closed; atrial pressure less than ventricular pressure

causes of heart sounds

2 sounds lub dup. associated with closing of heart valves. 1st sound occur as AV (tri and bicuspid) valves close and signifies beginning of systole (contracts). 2nd sound occurs when SL (semilunar) valves close at the beginning of ventricular diastole (relax).

How do hydrostatic pressure and osmotic pressure affect fluid flow across capillary walls?

Due to fluid pressing against a boundary • HP "pushes" fluid across the boundary • In blood vessels, is due to blood pressure Due to nondiffusible solutes that cannot cross the boundary • OP "pulls" fluid across the boundary • In blood vessels, is due to plasma proteins

What increases the response to arteriolar blood flow?

Elasticity (compliance or distensibility) Volume of blood forced into them at any time

Where are large clusters of lymph nodes found?

Embedded in connective tissue, in clusters along lymphatic vessels Near body surface in inguinal, axillary, and cervical regions of body

When is the thymus most active?

Increases in size and most active during childhood

What do the QRS, T, and P waves represent?

P wave - depolarization SA node atria QRS complex - ventricular depolarization and atrial repolarization T wave - ventricular repolarization

What are Peyer's patches?

Peyer's patches Clusters of lymphoid follicles In wall of distal portion of small intestine Peyer's patches and appendix Destroy bacteria, preventing them from breaching intestinal wall Generate "memory" lymphocytes

What are the functions of lymphoid tissues?

Provide structural basis of immune system House phagocytic cells and lymphocytes cellular debris, viral and bacterial infections, protects against cancer cells

Which tunic of the artery is responsible for maintaining blood pressure?

Tunica media