Chapter 50-The Circulatory System Flashcards
Function of the Circulatory System
- transport-gases, nutrients, wastes, hormones, antimicrobial cells and proteins
- Body defense against pathogenic microorgansims
- Thermoregulation-helps regulate body tempurature
- Osmoregulation-helps regulate body fluids
Components of circulatory system
- Heart
- Blood vessels
- Blood
2 types of circulatory systems
closed-excpet for injury, whole blood does not leave blood vessels
Open
at times, in certain places, whole blood leaves vessels and contacts tissue
Blood
type of connective tissue composed
- fluid matrix called plasma
- formed elements (cells and cell fragments)
Plasma proteins
- albumin (7%)
- Globulins (38%)
- fibrinogens (7%)
Other solutes in blood
- electrolytes
- nutrients
- gases
- regulatory substances
- waste products
Where do blood cells and cell fragments develop from
red bone marrow
Hematopoeisis
blood cell production
- produces lymphoid stem cell-lymphocytes
- produces myeloid stem cell-all other blood cells
Erythrocytes
red blood cells
Hemaglobin
in red blood cells of vertebrates, binds to and transports oxygen and sometimes CO2
Leukocytes
White blood cells
- larger than erythrocytes, have nuclei
- protect against foreign microorganisms and materials; protection against cancer
Platelets
cell fragments that pinch off from larger cells in the one marrow
-function in the formation of blood clots
Sponge circulatory system
circulate water using many incurrent pores and one excurrent one
Hydra circulatory system
circulate water through a gastrovascular cavity (also for digestion)
Nematode circulatory system
digestive tract can also be used as a circulatory system
Invertebrate circulatory system
directly related to sixe, complexity, and lifestyle of the organism
Hemolymph
in an open circulatory system, no distinction between circulating and extracellular fluid. Fluid-hemolymph
fish have how many heart chambers
2
amphibian circulatory system
double circulation (second pumping circuit)
- pulmonary and systemic circulation, similary to mammals
- 3 chambered heart (2 atria, 1 ventricle)
- additional oxygen through skin
- incomplete separation of systemic and pulmonary systems
Vertebrate circulatory systems
Mammals, birds, and crocodilians
-4 chambered heart
Right side of the vertebrate heart
reveices deoxygentated blood from the body and delivers it to the right venrtrivle, which pumps it to the lungs
Left side of the vertebrate hearts
left atrium receives oxygentated blood form the lungs and delivers it to the left ventricle, which pumps it through aorta to rest of the body
Edocardium
lines chambers, edothelial tissue mostly
myocardium
middle, cardiac muscle layer
epicardium
outside of heart, connnective tissue and other
pericardium
tissue that surrounds heart for protection
tricuspid valve
prevents backflow of blood from right ventricle into atria
Bicuspid valve
prevents backflow from left ventricle into left atria
Pulmonary (semilunar) valve
prevents backflow from pulmonary artery into right ventricle
Aortic (semilunar) valve
prevents backflow from aorta into left ventricle
Diastole
ventricles relaxed and filling
systole
ventricles contracted and pumping
Sinoatrial node (SA)
located in wall of right atrium
-SA node acts as pacemaker, initiates an action potential which will cause cardiac muscle to contract
EKG
electrocardiogram
-measures hearts electrical activity
arteries
carry oxygen rich blood to rest of body
-exception=pulmonary artery
veins
carry oxygen depleted blood to lungs/heart
-exception=pulmonary veins
steps of circulation
- deoxygentated blood enters right atria through vena cavas
- right atria pumps blood to right ventricle
3 right ventricle pumps blood to lungs through pulmonary artery - returned to left atria through pulmonary veins
- oxygentated blood is then pumped to left ventricle, enters body through aorta
blood pressure
force of blood/walls of blood vessels, written as a ratio of systolic over diastolic pressure
systolic pressure
peeak pressure at which ventricles are contacting
diastolic pressure
minimum pressure between heartbeats at which the ventricles are relaxed
Normal blood pressure?
120 mm/75mm
Hypertension
high blood pressure (diastole over 75 mm)
hypotension
low blood pressure (diastole less than 70 mm)
arteriols
smaller arteries entering organs and tissues and ending in capillaries
venules
smaller veins leaving organs and tissues
capillaries
smallest blood vessel, in tissues and organs
4 basic tissue layers of arteries and veins
- endothelium
- elastic fibers
- smooth muscle
- connective tissue
the lymphatic system
fluid that does not return to capillaries is returned to circulation by the lymphatic system
-most fluid leaves at arteriole end of capillary and reutrns to venule end
Lymphatic system consists of..
lymphatic capillaries, lymphatic vessels, lymph nodes, and lymphatic organs (spleen and thymus)
atherosclerosis
accumulation of fatty material within arteries, impedes blood flow
autonomic nervous system in relation to heart
modulates heart rhythm and force of contraction
Medulla oblongata in relation to heart
modulates heart rate
- norepinephrine, from sympathetic neurons, increases heart rate
- acetylcholine, from parasympathetic neurons, decreases heart rate
