Lecture Outline #22: CV: Circulation Flashcards
BV 3 layers
1) tunica interna - thin endothelium
2) tunica media - smooth muscle
3) tunica externa - CT sheath around outside of vessel
lumen
opening in BV, where blood flows
arteries (function, lumen, appearance, 3 layers)
function: carry blood from heart to tissues
lumen: always open
appearance: round, thick walls
TI: internal elastic membrane
TM: thick middle layer
TE: collagen & elastic fibers - for contraction/expansion, few restriction because it is slippery
veins (function, lumen, appearance, 3 layers)
function: return blood to the heart from tissues
lumen: closed when no blood is within
appearance: not always round, has thin walls
TI: smooth walls, no elastic membrane
TM: thin muscle layer
TE: collagen fibers, few elastic fibers
lymphatics
function: return lymph (interstitial fluid) to heart
appearance: very thin-walled vessels with small valves
capillary beds (appearance)
very small so only 1 RBC is allowed to go through at a time, plasma is lost here.
lymphatics - edema
a chronic disease that occurs when the body’s lymphatic system is unable to properly remove excess fluid from tissues
Blood composition
Total: 1.2 - 1.8 gallons depending on body size
1/3 of blood is arterial while 2/3 of blood is venous (deep and superficial veins)
15% heart & lungs
20% brain, capillaries, arteries
65% skin, gut, liver, veins
how does the tunica media control blood flow
the tunica media is smooth m. that adjusts BV diameter (ANS controls lumen size)
- vasoconstriction (decrease in diameter)
- vasodilation (increase in diameter)
blood flow control - fight/flight response
dilation of capillary beds in m.s which increases O2 delivery aka shunting blood away from cap beds
restriction of blood supply to gut redistributing blood
blood flow control - rest/digest response
dilation of capillary beds in gut, shunting/bypassing blood, redistributing blood to gut (increase food absorption)
passing out (BVs)
parasym - GI vasodilation of vessels
sym - peripheral vessels & m.s vasodilate
arteries - types
1.elastic a. - lots of elastin, absorbs pressure fluctuations
2. Muscular a. - lots of smooth m., expand/control to control blood flow
3. Arterioles - distribute blood from larger a.s to caps
4. continuous capillary - continuous endothelial cell lining, least permeable (only small solutes can pass)
5. endothelial cells - inner single cell lining in BVs, regulates exchange btw blood & tissues
veins - types
- Large v. -
- medium v. -
- venule - smallest v.s, blood from caps to larger v.s
- fenestrated capillary - contain pores, more permeable (allow exchange of bigger molecules)
- endothelial cells - inner single cell lining in BVs, regulates exchange btw blood & tissues
general structure of a.s & v.s
a.s - branch into smaller and smaller arteries
v.s - combine into larger and larger veins
aorta structures
unpaired
ascending aorta
aortic arch
descending aorta
aortic arch
branches -
1. brachiocephalic a.
a. right common carotid a.
b. right subclavian a.
2. Left common carotid a.
3. left subclavian a.
descending aorta branches
1) thoracic aorta
- intercostal a.s (paired) vertebrae, spinal cord
2) abdominal aorta
- renal a.s (paired) kidneys
- gonadal a.s (paired) testes or ovaries
- lumbar a.s (paired) vertebrae, spinal cord, ab wall
3) common iliac a.s (paired)
- external iliac a.s (paired)
- internal iliac a.s (paired) inside pelvic cavity
anastomoses
where two a.s run into each other without a capillary bed
Ex: epigastric a.s, palmar loop, planter loop
collateral circulation
mainly at large joints
extra arteries that run along side of joint & main artery.
Ex: when flexing arm, main anterior a.s are ‘compressed’ posterior arteries keep arm bloodified.
palmar loop
in hand
ulner a.s are superficial and radial a.s are deep
2 palmar a.s
1 dorsal a.
when does femoral a. become the femoral a.
when the external iliac a. crosses the inguinal ligament, branches into deep femoral (goes to posterior side) and femoral a. (along femur)
when does popliteal become own artery
when the femoral artery passes through the adductor hiatus
what a.s does the popliteal a. split into?
splits in anterior tibial and posterior tibial arteries. The posterior tibial a. has the fibular a. branching off of it (lateral side)
venous drainage of inferior vena cava
phrenic v.s
hepatic v.s
renal v.s
lumbar v.s
gonadal v.s
common iliac v.s
venous drainage around spinal cord/throax area
Azygos v. - runs right side of vertebral column & drains intercostal v.s 1-12. Dumps into posterior aspect of superior vena cava
Accessory hemiazygos - runs left side adn drains intercostal v.s 1-7
Hemiazygos v.s - runs left side and drains intercostal v.s 8-12
Accessory + hemiazygos v.s drain into azygos v.
superficial v.s in superficial fascia of arm
- Cephalic v. - lateral side, dumps into axillary v. which immediately becomes subclavian v.
- basilic v. - medial side
- Median cubital - where cephalic & basilic v.s come together, place for drawing blood
superficial v.s in leg
- Great Saphanus v - anterior side of medial malleolus but runs on medial side of leg, dumps into femoral v. (if heart bypass needed, this vein is taken out)
- Small Sephanus v. - lateral side, dumps into popliteal v.
venous drainage of limbs & skin
2 brachiocephalic v.s that dump into superior vena cava, same v.s as a.s
medium & large v.s: valves
there is no pressure in veins to push blood so veins have valves. If there is movement, valve open superior to contracting muscles and valves closes inferior to contracting muscle.
varicose v.s or varicosities
veins swollen/distorted by valve failure
hemorrhoids
varicose/ruptured veins of the rectum & anus wall because of liver portal hypertension
caput medusae
cluster of swollen veins in the abdomen
arterial supply to head
skin & m.s supplied by external carotid a which turns into facial a.
brain tissue is supplied by branches of:
- internal carotid a.s via carotid canal off common carotid a.
- vertebral a.s via foreman magnum off subclavian a. Acts as a backup blood supply in transverse foramina
arteriosclerosis
abnormal thickening/ridging of a.s
vascular inflammatory response
If this happens to widow maker a. = death (anterior ventricular a.)
aneurysm
bulge/dilation in weakened arterial wall, plaque builds up
typically in descending aorta & external iliac a.
ischemia
restricted blood supply to an organ
infarction
localized cell/tissue death in an organ
CVA
hemorrhagic stroke - bleeding inside brain, blood fills subarachnoid spaces and pushes on brain
ischemic stroke - clot blocks blood flow
arterial circle (Circle of Willis)
anastomotic ring that encircles pituitary gland
formed by
- internal carotid a.s
- cerebral a.s
- basilar a. where vertebral & cerebellar a.s meet
blood-brain barrier
- Neural Tissue - must be isolated from circulation because chemicals have disruptive effects
- Astrocytes & endothelial cells - restricted permeability, control chemical exchange
exceptions to blood-brain barrier
- capillaries of the choroid plexus - permeable for secretion of CSF
- capillaries in hypo- & epithalamus - permeable for excretion of hormones into circulation from pituitary gland
venous drainage of head
most dural sinuses drain to internal jugular v.s
blood for BS drains to vertebral v,s
scalp, skin, m.s drain into external jugular v.s
retromandibular v. - connection btw internal & external jugular v.s
brachiocephalic v.s = vertebral + jugular + subclavian v.s
celiac trunk a.
- common hepatic a. to liver
- Left gastric a. to stomach
- splenic a. to spleen and 1/2 pancreas
superior mesenteric a.
- intestinal a. to 1/2 pancreas, small intestine, appendix
- mid-colic a. to transverse colon
- right colic a. to ascending colon
inferior mesenteric a.
- left colic a. to descending colon
- sigmoidal a. - sigmoid colon
- rectal a. to rectum
what is a portal v.
vessel system between 2 capillary beds
liver receives blood from what two sources`
- proper hepatic a. from common hepatic a. from celiac trunk
- hepatic portal v where superior mesenteric & splenic v.s (and inferior mesenteric) come together
liver function and drainage to heart
- filters/modifies substances in blood
- filters 25% of blood (25% by kidneys)
- drained by hepatic v.s (capillaries in liver) to inferior vena cava
veins contributing to hepatic portal v.
- Splenic v. - stomach, spleen, pancreas
- Superior mesenteric v. (mid-colic, right colic, intestinal v.s) - from small intestine & colon
- Inferior mesenteric v. (left colic, sigmoidalm rectal v.s) from rectum & descending colon, drains into splenic v.
- Gastric v.s from stomach
fetal characteristics
lungs are non-functional, liver/kidneys somewhat functional, digestive tract has nothing to digest
fertilized egg compostition
70% placenta
30% you
placenta
mass of capillary beds, fetal & maternal capillaries do not touch so exchange of nutrients is through diffusion
unique features of fetal pulmonary circulation
foramen ovale - shunt/hole in the interatrial spetum to reduce amount of blood passing to right ventricle.
ductus arteriorsis - shunt/path btw pulmonary trunk & aorta for what blood has left right ventricle to go to lungs
unique features in fetal systemic circulation
- Umbilical a.s branch off internal iliac a.s bring deoxygenated blood to placenta
- Placenta exchanges gases, nutrients, wastes
- Umbilical v.s branch off placenta to return oxygenated blood to body
- Ductus venosus (shunt to bypass liver) where umbilical v. connects to inferior vena cava
circulatory changes at birth
- Loss of umbilical arteries/veins & ductus venosus
- Ductus arteriosus closes (separating pulmonary and systemic circuits)
- Infant breathes so pulmonary circuit starts
- Blood flows into left atria so foramen ovale closes = fossa ovalis
circulatory problems at birth
- foreman ovale doesn’t close
- ductus arteriosus doesn’t close
- Coarctation of aorta - aorta closes so it is critical to develop a collateral circulation
conotruncal defects
- Ventricle Septal Defect - hole between vents
- Transposition of great vessels - aorta & pulmonary artery are switched
- Tetralogy of Fallot - RV hypertrophy, ventricular septum defect, large aorta over-rides R/L vents
- Atrium septal defect - hole between atria
- Congenital heart defects - septal failures with stenosis
fetal structures to adult structures
- Umbilical v. - ligamentum teres
- Ductus venosus - ligamentum venosum
- Foramen ovale - fossa ovalis
- ductus arteriosus - ligamentum arteriosum
- R/L umbilical a.s - R/L medial umbilical ligaments
lymphatic system functions
- production, maintenance, distribution of lymphocytes
- return interstitial fluid from tissues to blood
- maintain osmotic balance in peripheral tissues (balanced pressure)
lymphopoiesis
production of lymphocytes, occurs in bone marrow, thymus, peripheral lymphoid tissues
neurovascular bundle
vein, artery, nerve, and lymphatic
lymph
fluid similar to plasma but with fewer proteins
lymph nodes
small lymphoid organ, widespread
have afferent & efferent lymph vessels
have a hilum, cortex, medulla, and capsule
filtering system for circulating lymph by removing 99% antigens before returning lymph to blood
location of macrophages
lymphatic vessels
contain valves for 1 way flow of lymph
vessels combine to form larger ducts
- R lymphatic duct - drains right appendage & head
- L lymphatic duct/thoracic duct - drains everything else
- both R/L drain to R/L subclavian veins
- Azygos duct - posterior wall of thorax
- cisterna chyli - swelling beneath diaphragm where all thoracic duct lymph beneath diaphragm meets up
- sentinel lymph nodes - biopsied to evaluate progress of metastasized cancer cells
chronic edema/elephantiasis nostras
extreme edema
wuchereria bancrofti/elephantiasis tropica
parasitic roundworm that blocks fluid in lymphatic system, get from skeeter bite
tonsils
encircle the openings of resp/dig system and identify pathogens from inspired air/indigested food
pharyngeal tonsil(adenoids)
roof of nasopharynx
with air inspiration, air hits this and immune response is sent if harmful particulates are within
palatine tonsils
(2) located in sides of mouth at rear of oral cavity
monitor inspired air/food
lingual tonsil
at root of tongue
monitors food intake
tonsillectomy
adenoidectomy
t - surgical removal of tonsils, typically palatine
a - surgical remove of pharyngeal tonsils
spleen
largest lymphoid mass/tissue
removes/recycles abnormal RBC/WBC
stores/recycles iron from RBCs
initiate immune responses to specific immunities by B&T cells
thymus gland
not in adults, kids need it to build immune system
contains lymphocytes: T-cells`
GALT
gut - associated lymphoid tissue
- immune response within GI tract
peyer’s patches
- lymphoid nodules in ileum to monitor what you eat
MALT
mucous - associated lymphoid tissue
- lymphomas in duodenum
ways to blood dope
- blood transfusions
- EPO (erythropoietin) creates new blood cells
