16.1-16.11 Flashcards
6 goals of circulatory system
- Distribute nutrients (from digestion, liver, fat)
- Transport oxygen, eliminate CO2
- Remove metabolic waste (to kidneys)
- Transport hormones
- Maintain homeostasis of body temperature
- Blood clotting
capillaries
very thin, 1 cell thick
exchange b/t blood and tissues
arterioles
increasingly smaller arteries, with SMOOTH muscle on walls
endothelial cells (4 purposes)
INNER LINING of all blood vessels
capillaries are 1 SINGLE LAYER of endothelial cells
intracellular clefts make up the wall, allows for transport of nutrients wastes and WBCs
vasodilation/constriction
inflammation
angiogenesis (new blood vessels)
thrombosis (clot)
implicated in diseases like hypercholesterolemia, hypertension, bad clots, CAD, and atherosclerosis (!)
AV valve
prevents backflow to atrium
left is bicuspid - mitral
right is tricuspid
what is the valve leaving the ventricle called?
aortic and pulmonary SEMILUNAR valve
intercalated disks
the connections between cardiac muscle cells
muscle cell
ability to propagate AP across the surface.
diastole
when the blood is filling the heart
when dup and lub
systole
shorter, the space between lub and dup
functional syncytium
cytoplasm of two cells can communicate via GAP JUNCTIONS in the heart
NO CHEMICAL SIGNALING WITHIN HEART
cardiac muscle -> intercalated disks -> electrical synapse
Calcium goes down its gradient (MORE outside than inside)
Strength of contraction == extracellular concentration of Calcium
Phase 3: Outward K+ current through voltage-gated channels
atrial synctium is connected to the ventricles through…
cardiac conduction system
delayed as it passes through this CONDUCTION SYSTEM known as the AV NODE
two voltage-gated channels in heart
fast sodium channels (voltage gated) - cardiac muscle and neurons
slow calcium channel - calcium comes IN once change in membrane potential to the threshold voltage occurs
slow Ca channels allow passage of calcium DOWN ITS GRADIENT, longer depolarization than neurons
depolarization of membrane lasts *** in cardiac muscle
LONGER, therefore longer absolute refractory period
SA node
in right atrium
- PACEMAKER of the heart (has most Na leak channels)
- automaticity, divided into three phases: phase 0, 3 and 4
UNSTABLE RESTING POTENTIAL (-50-40 mV)
Phase 0: Inward Ca2+ current through VOLTAGE-GATED channels (DEPOLARIZATION due to Ca2+, NOT Na+ influx in myocytes and skeletal muscle cells); this is VERY GRADUAL
Phase 3: Repolarization: closure of Ca2+ channels and opening of K+ channels
Has the MOST Na+ leak channels, so reaches threshold voltage FIRST
RBC
NO NUCLEUS or other organelles like mitochondria
120-day lifespan
requires ATP for ion pumping and basic maintenance of structure
relies on glycolysis
large surface area with millions of hemoglobin
transfusion reaction
antibodies to A and B cause clumping and destruction of red blood cells with the wrong antigen
the immune system must be exposed before it produces antibodies for it
hemolytic disease of the newborn
anti-Rh antibodies can cross the placental barrier and destroy the Rh+ baby’s red blood cells
must inject with anti-Rh antibodies
which WBCs move by amoeboid?
macrophages, neutrophils
6 types of WBC
p. 420
what are magekaryocytes?
large bone marrow cells that produce platelets
what helps platelets
fibrin
plasma protein fibrinogen is converted into FIBRIN by a protein called THROMBIN when bleeding occurs. THROMBUS is a blood clot circulating the bloodstream
activated by CALCIUM
hemophilia X-linked recessive
cooperative binding
hemoglobin -> increased affinity for each oxygen
SIGMOIDAL CURVE
Bohr effect (3 factors)
- decreased pH
- increased CO2
- increase temperature
these factors stabilize TENSE hemoglobin, REDUCING oxygen affinity.
carbonic anhydrase
found in RBC enzyme
converts CO2 into carbonic acid (H2CO3)
carbonic acid -> HCO3- + H+
CO2 can be dissolved in blood
CO2 binds to OTHER sites on hemoglobin - STABILIZES tense hemoglobin
spaces between endothelial cells in capillaries
intercellular clefts
Liver
hepatic portal system: direct transport from intestine to liver
stores glucose / AAs
Pressure = Flow * Resistance
increase resistance, DECREASE flow
Pressure = Flow * Resistance
increase resistance, DECREASE flow
SNS controls precapillary sphincters that control peripheral resistance; SNS causes PSphincters in the gut to CONTRACT (reduce blood flow). Vasoconstriction reduces blood flow. SNS also causes PSphincters in skeletal muscles to relax.
More Q = higher blood pressure (!)
Vasodilation can also be regulated automatically by waste build up. (Local autoregulation). This affects coronary blood flow.
blood
transport of glucose lipoproteins - fats, cholesterol, carrier proteins - transport lipids urea - breakdown of amino acids bilirubin - breakdown of heme serum - lacks proteins for clotting
Chylomicrons
lipoproteins that PACKAGE fats, which enter lymphatic vessels in the intestinal wall called LACTEALS (draining into large vein in the neck, THORACIC duct). FAT BYPASS THE HEPATIC VEIN.
lipemia
chylomicrons are taken up by liver and converted to another lipoprotein, which carries fats to adipocytes for storage
adipocyte triglycerides are HYDROLYZED to release free fatty acids released in the bloodstream. they pass through capillary pores
Albumin
too large to fit through clefts, remains in capillaries and keeps water in the blood
pulmonary edema
Increased blood pressure, fluid is forced out of capillaries into surrounding tissues
pulmonary edema
Increased blood pressure, fluid is forced out of capillaries into surrounding tissues
surfactant
REDUCES surface tension (Type II alveolar cell)
partial pressure
portion of total pressure due to a particular gas
hyperventilation
INCREASES pH, while acidosis occurs with depressed respiration
lymphatic system
suction
WATER, PROTEINS, and Leukocytes
lympahtic ducts form the THORACIC duct
lymph nodes
millions of WBCs
