Circulation

Question 1

Whats the need for a circulatory system

Answer 1

transport of substances, removal of waste products, distribution of heat , immune response (antibodies to sickness), homeostasis,

Question 2

What is transported through circulation

Answer 2

Oxygen, Nutrients, CO2, Hormones, Waste products, Water+ Electrolytes, Immune Components

Question 3

Open Body Cavity

Answer 3

-internal organs are not completely enclosed or surrounded by a coelom (body cavity)
-insects, arachnids, crustaceans, arthropods

Question 4

Open Circulatory System

Answer 4

-found in certain invertebrates
-blood or hemolymph is not within vessels, its pumped by heart to open spaces called hemocoels
-arachnids, insects, mollusks, some crustaceans

Question 5

Closed Circulatory System

Answer 5

-in vertebrates and some invertebrates
-blood is contained within network of blood vessels and doesn’t directly bathe organs and tissues

Question 6

Sponges Circulatory System

Answer 6

Phylum Porifera
-water currents: filter feeders that rely on water currents to bring in food particles, oxygen, and other dissolved substances from environment
-

Question 7

Cnidaria Circulatory System

Answer 7

-water circulation for feeding and gas exchange
-diffusion across cells of gas

Question 8

Open Circulatory System0 Haemolypmh

Answer 8

-insects have a tubular heart located dorsally, it pumps hemolymph into body cavity (hemocoel) -this flows freely through bathing tissues and organs
-for nutrient transport, waste removal, gas exchange

Question 9

Open circulatory systems- Hemocyanin

Answer 9

-hameolymph contains
-respiratory pigment
-bind and transport oxygen in insects

Question 10

Closed Circulatory Systems

Answer 10

-a fluid; solutes in solution, cells in suspension
-pump moves the fluid
-vessels/ vascular system: carry the fluid between pump and body tissues
-all vertebrates and some invertebrates
-blood flows in continous circuit of tubes

Question 11

Single Circulation

Answer 11

-in fish
-undivided
-blood is oxygenated before going to the body
-higher BP than open system

Question 12

Parallel Circulation

Answer 12

-in amphibians
-heart is partially divided
-blood is still oxygenated before going to the body
-blood is mixed in heart
-single ventricle that isn’t fully divided, meaning hears are parallel as they pump same fluid in both vessels
BP=30/20

Question 13

Double Circulation

Answer 13

-in mammals, birds, crocs
-completely divided (double circuit)
-blood still oxygenated first
-two pumps= two BP
BP=30/20 (pulmonary)
BP=120/80 (symmetric)
-supports high rates of cellular respiration

Question 14

Mammalian Heart

Answer 14

-four chambered; 2 atria, 2 ventricles
-atrioventricular valves between atria and ventricles
-semilunar valves between ventricles and aorta/ pulmonary arteries
3 separate circuits’ [pulmonary circuit (right), Systemic circuit (left)

Question 15

Human Heart

Answer 15

Valves; open/ close due to pressure
-prevent backflow
-closing causes heart sounds
Atrioventricular+ outflow valves are passive

Question 16

Systolic and Diastolic

Answer 16

Systolic Pressure: contraction of ventricles pushes blood into arteries at 120mmHg
Diastolic pressure: between contractions, blood pressure in arteries falls to 80mmHg
-cardiac cycle

Question 17

Neurogenic vs Myogenic

Answer 17

Neurogenic hearts (some crustaceans): beat under control of nervous system
Myogenic hearts (all other animals): contractions initiated with hearts

Question 18

ECG

Answer 18

Electrocardiography: recording of Na+ gates (depolarization) and K+ ions (repolarization)

Question 19

Heart Rate

Answer 19

the number of heartbeats per unit of time, typically expressed as BPM
-resting 75bpm

Question 20

Cardiac Output

Answer 20

amount of blood pumped by each ventricle is 7560 litres per day
70ml/beat (SV) x 75bpm (HR) =5250ml/min

Question 21

Control of Heart Rate

Answer 21

-autonomic regulation of heart rate
-cardiovascular centre of medulla oblongata
-Sensory inputs; chemical changes in blood- chemoreceptors
;blood pressure changes- baroreceptors

Question 22

Arteries

Answer 22

carry blood away from the heart
-thick walls
-blood flows under high pressure
-pressure reservoirs

Question 23

Arterioles

Answer 23

(small branch of arteries): deliver blood to capillaries
-thick walls
-blood flows under high pressure
-pressure reservoirs

Question 24

Capillaries

Answer 24

exchange material with interstitial fluid
-walls are single cell (endothelial) layer
-are very near body cells
-most numerous vessel in body -10 billion in human body
-500-700m2
-highly regulated blood flow through ANS

Question 25

venules

Answer 25

collect blood from capillaries
-thinner walls
-blood flows under low pressure

Question 26

Veins

Answer 26

return blood to the heart
-thinner walls
-blood flows under low pressure
-valves in some prevent backflow
-“capacitance” vessels (60-75% of blood is in veins)
-return of blood to heart aided by limp muscle pumps and valves

Question 27

Lymphatic System Structure

Answer 27

vessels- collect excess interstitial fluid and returns it to venous blood
Includes: Lymph: lymphatic vessels, tissues, nodules, nodes
Tonsils, spleen thymus

Question 28

Functions of Lymphatic System

Answer 28

-helps maintain homeostasis
-fat absorption from digestive tract to venous circulation
-aids immune system