Exam 3 Flashcards
1MM rule
Diffusion is an effective means of transporting substances only when the distance is < 1 MM
A______ Functions in both digestion and distribution of substances throughout the body
Gastrovascular cavity Note: some animals lack a circulatory system.
List 3 features of a circulatory system
circulatory fluid, set of interconnecting vessels, muscular pump(heart).
The circulatory system connects the fluid that surrounds cells with the organs that exchange_______ , _______ and _______
gases, absorb nutrients, and dispose of wastes
What type of circulatory system is this? The heart pumps the hemolymph through the vessels into interconnected sinuses, spaces around organs.
open circulatory system. Note: Any cell is within 2 cell thicknesses of Hemolymph
What type of circulatory system is this? The circulatory fluid is called blood.
Closed circulatory system
What type of circulatory system is this? Has a one chambered heart, one artery to gill capillaries, one artery to body capillaries and one vein back to the heart.
Single circulation: fish
What type of circulatory system is this? Has a two chambered atrium heart with a single ventricle chamber. Pulmocutaneous circuit, systemic circuit
Double circulation: amphibian
What type of circulatory system is this? Has two atrium and ventricle chambers of the heart. pulmonary circuit and a systemic circuit
Double circulation: Mammal
The __________ separate each atrium and ventricle
atrioventricular (AV) valves
The _________ control blood flow to the aorta and the pulmonary artery
semilunar valves
Backflow of blood through a defective valve causes a
heart murmur
The ________, or pacemaker, setsthe rate and timing at which cardiac musclecells contract
sinoatrial (SA) node
Some cardiac muscle cells are _______, meaning they contract without any signal fromthe nervous system
autorhythmic
Impulses that travel during the cardiac cyclecan be recorded as an________.
electrocardiogram(ECG or EKG)
The pacemaker is regulated by two portions ofthe nervous system: the ______ and _______ divisions.
sympathetic(speeds up) and parasympathetic (slows it down)
A vessel’s cavity is called the_____.
central lumen
The epithelial layer that lines blood vessels is called the ______.
endothelium( smooth & minimizes resistance)
Thin walls =
more gas exchange
Capillaries are only slightly _____ than a red blood cell
wider
Systolic pressure
High pressure
Diastolic pressure
low pressure
The recoil of elastic arterial walls plays a role in maintaining _____.
blood pressure
Precapillary sphincters
Can be shut off to redirect the flow to the main circulatory system.