mod8 Flashcards
albumin
most abundant plasma protein (54%) transports fatty acids in blood
globulins
38% plasma proteins; includes antibodies
fibrinogen
7% of plasma proteins; for blood clots
formed elements
make up 45% of volume of blood; RBCs, WBCs, and platelets
Hemopoeisis occurs in:
yolk sac of embryo, liver, spleen, and lymph nodes of fetus; later on red bone marrow becomes primary site
Myeloid stem cells
comes from pluripotent stem cells; begins in red bone marrow and differentiate into RBCs, platelets, eisonophils, basophils, neutrophils and monocytes
Lymphoid stem cells
comes from pluripotent stem cells; begins in red bone marrow but completes development in lymphatic tissues; differentiate into T and B lymphocytes and NK cells
Erythropoietin
a hormone that is produced by kidney that stimulates the maturation of red cell precursors in bone marrow (when RBC level is too low)
Reticulocytes
immature RBCs, released from bone marrow due to erythropoietin stimulation; become mature within 1-2 days
Bilirubin
the non iron portion of heme is converted into biliverdin (green pigment) and then into bilirubin (yellow-orange pigment); secreted by liver cells into bile
feedback of RBC production
Hypoxia stimulates release of erhythropoietin (EPO) from the kidneys
EPO stimulates Proerythroblasts in red bone marrow to mature into reticulocytes (immature RBC)
these enter circulation increasing # and thus increasing amount of O2 delivery
Agranular WBCs
lymphocytes and monocytes
granular WBCs
basophils
eosinophils
neutrophils
Neutrophils (60-70%)
first cell to move from blood to site of injury; effective against bacterial pathogens via phagocytosis
monocytes (3-5%)
respond to tissue infection; become macrophages once in cell and clean up debris
Basophils (0.5-1%)
secrete histamine, heparin and 5HT; inflammatory response
Eosinophils (2-4%)
produce enzymes for allergic reaction; fight parasitic infections
Lymphocytes
T cells- attack viruses
B cells- develop into plasma and produce antibodies
Major histocompatibility (MHC) antigens
from WBC plasma membrane; act as identity markers; unique to each person
life span of RBC vs WBC vs platelets
RBC is about 120 days, WBC is only a few days /few hours (during infection)
platelets: 5-9 days
Megakaryocytes
derived from myeloid stem cells; produce platelets
Fibrous pericardium
prevents overstretching of heart; provides protection and anchors heart in place
serous pericardium
forms double layer around heart; parietal layer connects to fibrous pericardium and visceral layer (epicardium) adheres to hearts surface
Epicardium
outer layer of heart wall composed of mesothelium and connective tissue
myocardium
middle layer of heart wall; pumping action; muscle fibers connect via intercalated discs and electrically via gap junctions
Endocardium
simple squamous epithelium lines inside of myocardium and covers valves and tendons of heart
Auricle
pouch like extensions at surface of each atrium, increase capacity of each atrium to hold greater volume of blood
Chordae tendineae/papillary muscles (only in AV valve)
in atrioventricular valves (AV); chords that are anchored to papillary muscle then to ventricle walls; these are slack when blood is moving into ventricle; contraction of papillary muscle tightens chordae and prevents valve from opening
SA node
main cardiac pacemaker located in RA; receives inputs from ANS; sends impulses to atria via gap junctions; initiates APs about 100X/min
AV node
in interatrial septum; receives AP from SA node; here the APs slow giving time for atria to empty
Bundle of HIS
receive AP from AV; within the interventricular septum; **only site where APs can conduct from atria to ventricle; then enter bundle branches
Purkinje Fibers
rapidly conduct AP from apex of ventricle then to remainder of ventricular myocardium
Arterioles
single layer of endothelium and very few muscle fibers, plays role in BP regulation via constriction and dilation
capillaries
consist of thin wall of endothelium and basement membrane
Capillary exchange (mention filtration and reabsoprtion)
capillary merges with arteriole: Bp is higher in capillary causing fluid to flow out of capillary and into interstitial fluid (filtration)
BP decreases in capillary as blood flows through but osmotic pressure increases (Due to large amount of proteins)
REABSORPTION then occurs when osmotic pressure exceeds BP and fluid leaves tissues and reneters capillary
difference btw vein and artery
veins are thinner (middle and inner layers)
lumen of vein is wider
inner layers of vein forms valves
pressure is much lower in veins that in arteries
2 mechanisms to ensure blood returns to heart
respiratory pump and skeletal muscle pump
respiratory pump
during inspiration diaphragm will flatten, this causes blood to move from abdominal veins into thoracic veins and into RA (this pressure reveres on exhalation but valves prevent backflow)
skeletal muscle pump
skeletal muscles contract to help push blood toward atrium via MILKING (compression of muscle pushes blood through the valves closer to heart; while valves in uncompressed segment of vein close as blood pushes against it)
BP depends on: (2)
total volume of blood in body vascular resistance (increased resistance will increase BP)
3 factors of vascular resistance
lumen size (smaller lumen=greater R) Blood Viscosity: thicker=greater R Total blood vessel length: longer=greater R (increased fat cells cause increased number of vessels and thus greater resistance, therefore higher BP)
Cardiovascular (CV) centre and BP control
in medulla; receives inputs from higher brain regions (hypothalamus will send impulse if body temp rises); and receives inputs from 3 sensory receptors
3 sensory receptors that stimulate CV centre
proprioreceptors , baroreceptors and chemoreceptors
proprioreceptors
(monitor movement of joints and muscles); cause rapid increase in HR at beginning of exercise
negative FB of baroreceptors (pressure receptors)
BP falls and receptors are stretched less therefore sending impulse at slower rate to CV
CV decreases parasympathetic stimulation of heart and increases sympathetic
this increase BP causing receptors to stretch more (reverse for high BP; decrease sympathetic)
chemoreceptors
monitor blood level of O2, CO2, and H; in common carotid arteries and aortic body; send impulse to CV which produce vasoconstriction in arterioles and veins via sympathetic stimulation to increase BP
chemorecptors are stimulated by : (3)
hypoxia: lowered O2 in blood
acidosis: increased H concentration
Hypercapnia: excess CO2
Renin-Angiotensin-Aldosterone system to control BP
blood level falls; kidneys release RENIN
Renin combines with ACE to form ANGIOTENSIN II
Angiotensin II raises BP by causing vasoconstriction and stimulates ALDOSTERONE
aldosterone increases reabsorption of Na and H2O by kidneys thus increasing BP
Epinephrine/norepinephrine
from adrenal medulla; increase CO by increasing rate and force of contractions and via vasoconstriction of arterioles and veins
Antidiuretic hormone (ADH)
hypothalamus; released from posterior pit; responds to dehydration or decreased blood vol
causes vasoconstriction which raises BP
atrial natriuretic peptide (ANP)
from atria of heart; lowers BP by vasodilation and promoting salt loss in urine
Hepatic portal vein
union of splenic and superior mesenteric veins; receives blood from capillaries of digestive organs and delivers to sinusoids in liver
Splenic vein
collects from spleen, stomach, pancreas, and portion of Lg intestine
Superior mesenteric vein
collects from stomach, pancreas, SI, and protion of LI
three main functions of lymphatic system
drains excess interstitial fluid
transport dietary lipids
carries out immune responses
lymphatic capillaries are:
closed at one end and have extremely thin walls
located in spaces btw cells
slightly larger than blood caps
has structure allowing fluid to flow in but not out
movement of fluid into lymphatic capillaries
when pressure is greater INSIDE caps, lymph cannot escape
when pressure is greater OUTSIDE caps, interstitial fluid will enter
lymph nodes
600 along lymphatic vessels (mammary gland, axillae and groin); masses of T and B cells; lymph flows through the nodes; site for B cell maturation
thoracic duct
main lymph-collecting duct; receives lymph from left side of neck, chest and upper lumbs and enitre body below ribs; empties lymph into junction of left internal jugular and left subclavian veins
right lymphatic duct
drains lymph from upper right side of body into right jugular and right subclavian
2 pumps maintain flow of lymph
skeletal muscle pump, and respiratory pump (inhalation lymph flows from abdominal to thoracic region, valves prevent backflow on exhalation)
primary lymphatic organs and tissues
sites of stem cell division and dev of B and T cells; the bone marrow and the thymus
secondary lymphatic organs and tissues
sites where most immune responses occur; includes lymph nodes, spleen, lymphatic nodules
thymus
contains lg number of T cells that are maturing; 2% of T cells that mature in thymus leave via blood and are carried to lymph nodes, spleen and tissues
Spleen
largest lymphatic organ btw stomach and diaphragm; most vulnerable organ; contains white and red pulp
white pulp
consists mostly of lymphocytes and macrophages
red pulp
blood travels from white to red pulp; has venous sinusoids and chords of CT containing macrophages and lymphocytes
3 functions of red pulp
removes worn out RBCs and platelets
stores platelets
produces RBCs in fetus (not adults)
