Chp 12: Circulatory System Flashcards Preview

Comparative Anatomy Exam 3 > Chp 12: Circulatory System > Flashcards

Flashcards in Chp 12: Circulatory System Deck (30):
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Circulation = transport.
What is transported?

O2
CO2
Nutrients
Hormones
Urea (N waste)
WBC
RBC -> hemoglobin
Platelets
Proteins
Antibodies
Heat (in some)
Water
Dissolved ions

1

Evolution of heart: Fish hearts

4 undivided chambers
-primitive > "single-circuit pump" gills
-linear arrangement
-contract from caudal to cranial
-single stream of unoxygenated blood
-heart mass/body mass ratio low, why?
•bc they're ectotherms with low metabolism and also they breathe thru delicate gills which could burst the capillaries if the heart pumps too hard and damage the gills

2

4 chambers

Sinus venosus
-thin wall, receives blood from: common Cardinal veins, hepatic veins
Atrium
-large & thin wall
Ventricle
-responsible for pumping
-thick wall
Conus arteriosus
-short in bony fish and amphibians
-continuous w/ ventral aorta

3

Lungs changed circulation

Tetrapod lungs
•double circulation
-(right) low pressure pulmonary circuit (bc lungs are right there)
-(left) high pressure systemic circuit
•some chambers are partitioned

4

Transitional hearts

(Amphibians & lung fish)
Atrium division
-lung fish + salamanders = partial division
-frogs = complete division

Ventricle division
-lung fish = partial
-all amphibians = none (trabeculae; folding that helps direct blood)

Conus division
-lung fish + amphibians = partial division (spiral valve)

5

Reptile heart

Atrium
-completely divided
Ventricle
-partial division in many
-fully divided in crocodiles
-extra chamber in many
Conus = 3 channels
-pulmonary
-left systemic
-right systemic (left & right like aorta)

6

Crocodilian heart in air

Right ventricle pumps to pulmonary
Left ventricle pumps to both right and left aortic arches
-using foramen (hole) of panizza to connect them

7

Crocodillian heart diving

Right ventricle now shunts blood to body (systemic arches)
Left ventricle continues to pump to body

8

Bird and mammal heart

4 chambered heart
-2 atria & 2 ventricles ; complete divisions
-left ventricle especially muscular
Conus
-pulmonary + systemic circuit
•mammals, single left systemic arch
•birds, single right systemic arch

9

Mammal circulation through heart

Cranial and caudal vena cava> right atrium> tricuspid valve> right ventricle> pulmonary trunk> pulmonary arteries> lung> pulmonary veins> left atrium> bicuspid valve> left ventricle> aorta> systemic circulation

10

Blood vessels

Closed system -blood always in vessels
Capillaries- some plasma leaks
Lymph vessels
-collect leaked fluid
-return it to venous system into subclavian veins

11

Elephantiasis

Lymphatic filariasis
Nematode worms block lymph system

12

Circulatory system characteristics

Variability in anatomy
Flexibility
-transport a vein, it will act like an artery
-tie a part off, other parts enlarge
-five-fold variation in flow rate
-shunting (pre-capillary sphincter)

13

Capillaries

Tonica intima, loose epithelial cells one cell thick
Site of materials exchange

14

Arteries

Thick wall, small bore (lumen)
Tunica intima
Tunica media (smooth muscle + elastic)
Tunica adventitia (thick connective tissue)

15

Veins

Thin wall, large bore
Same as artery, only much thinner, no elastic
Valves to prevent backflow

16

Patterns of circulation

Arterial systems
-6 aortic arches (diff from pharyngeal (cartilage) arch)
-in embryo; differentiate into head arteries

17

Cartilage fish aortic arch

1st arch lost
Rest = branchial

18

Bony fish aortic arches

1st and 2nd arches lost
Rest = branchial

19

Lung fish aortic arches

Like bony fish
Pulmonary artery from 6th arch

20

Tetrapod aortic arches

1st and 2nd arches lost
Dorsal segment dropped b/w 3rd and 4th arches
Arch 3 now carotid complex: cc, ec, ic
4th = systemic (aortic arch)
-amphibs, reptiles, both R & L
-birds only right remain
-mammals only left remain
5th arch lost in most
6th arch -modified to pulmonary arch

21

Carotid complex

Internal carotid
-3rd arch extends to internal carotids
External carotid
-central aorta extension
Common carotid
-at central base b/w 3rd & 4th

22

Arterial systems

Dorsal aorta- large median vessel
Ventral branches
-celiac artery >stomach
-mesenteric arteries
Lateral branches
-renal, ovarian, testicular
Dorsal branches
-to muscles, skin
Posterior appendages
-iliac arteries
Anterior appendages
-subclavian arteries

23

Three venous systems

1. Subintestinal = hepatic portal bein in adult
-drains digestive organs, goes to liver
2. Cardinal
-drains head, body wall, kidney (renal portal system not in mammals)
3. Lateral abdominal
-drains posterior limbs, body wall

24

Portal systems

Veins drain organ and dump blood into other organ instead of heart
* hepatic portal

25

Hepatic portal system

Specialized
From embryonic sub intestinal
Drains capillary beds of intestine, stomach, spleen -> into liver
No need to go to heart first
Hepatic artery delivers O2
Hepatic vein delivers nutrients

26

Cardinal system

Primitive, drains head, tail
-anterior + posterior Cardinal veins (& sinuses- pockets of blood)
Subsystem: renal portal
-routes venous blood thru kidneys
-not in mammals
-tail capillaries --- renal portal --- post Cardinal (fish)
-tail capillaries --- renal portal --- post cava (Tetrapod)

27

Modifications to basic Cardinal venous system

-mammals lose renal portal
-pre-cava from right common Cardinal (to sinus venosus & right atrium)
-internal jugular from anterior Cardinal veins
-posterior vena cava from (lots of sources) parts of posterior cardinals & parts of renal portal
-azygous vein (very small) from right posterior cardinal

28

Lateral abdominal system

Drains posterior limbs and body wall

29

Fetal circulation

Foramen ovale
-opening b/w atria >bypass lungs

Ductus arteriosus
-connect pulmonary to aorta >bypass lungs

Umbilical arteries (2) -branch from iliac
-out to placenta with wastes

Umbilical vein (1)
-back to fetus with O2, nutrients

Ductus venosus
-in liver