Chapter 8 Keywords Flashcards
Mass transport system
Substances are transported in a mass of fluid with a mechanism for moving the fluid around the body
haemolymph
Insect blood. It doesn’t carry oxygen or CO2 (those are exchanged in the tracheal system)Just transports food and nitrogenous waste and cells involved in defence against disease
Haemocoel
Open body cavity of insects. Split by a membrane and the heart extends the length of the thorax and abdomen of the insect.
Elastic fibres
Compounds of elastin, a fibrous protein.
Can stretch and recoil
Providing vessel wall with flexibility
Smooth muscle
Contracts or relaxes
which changes the size of the lumen
Collagen
Provides structural support to maintain shape and volume of the vessel
Vasoconstriction
-smooth muscle contracts, vessel constricted and blood prevented from flowing into a capillary bed
Vasodilation
-smooth muscle of the arterioles relax, vessel dilated and blood flows through the capillary bed
Capillaries
Microscopic blood vessels that link the arterioles and the venules. RBC travel through them in single file
Platelets
55% is plasma. Most of Which is water
Fragments of large megakaryocytes founds in the red bone marrow.
Involved in blood clotting
Leucocytes
Wbcs
Many diff types with many diff functions
Plasma
Yellow liquid
carries dissolved glucose and a.a mineral ions, hormones ,rbcs, wbcs and large plasma proteins
-albumin
Important for maintaining osmotic pressure of the blood
-fibrinogens
Important for blood clotting
-globulins
Involved in transport and the immune system
All of these can pass thru cap walls except the large plasma proteins
Plasma proteins
Albumin
Fibrinogen
Globulins
Esp albumin have osmotic effect. Lower wp of the blood in the Capps so water moves in from surrounding fluid by osmosis.
Osmotic pressure is about -3.3kPa
Osmotic pressure
The tendency of water to move into the blood by osmosis
Hydrostatic pressure
As blood flows through the arterioles into the Capps it’s still under pressure from the surge of blood that occurs every time the heart contracts
Tissue fluid
Same composition as plasma but without the rbc and plasma proteins
Diffusion takes places between blood and cells through tissue fluid. 90% of the tissue fluid returns to Capps
Lymph
The 10% of tissue fluid that doesn’t return to the Capps. It drains into a system of blind ended tubes called lymph Capps. Similar composition to plasma and tissue fluid but with less O2 and fewer nutrients
- contains fatty acids that have been absorbed into the lymph from the villi of the small intestine
- lymph Capps join up to form larger vessels
- fluid is transported through them squeezing of the body muscles
- one way valves to prevent backflow of lymph
- eventually lymph returns to blood flowing into the right and left subclavian veins
Lymph nodes
- Found Along the lymph vessels.
- intercepts bacteria and other debris from the lymph
- ingested by phagocytes found in the nodes.
Lymphocytes build up in the lymph nodes when ness and make antibodies that are then passed into the blood.
Diastole
Heart relaxes
Atria and then ventricles fill with blood.
Vol and pressure increase as heart fills
Pressure in the arteries is at a minimum
Systole
Atria contract, then ventricle contract,
Drastic Pressure increase
Blood forced out of the right side to the lungs
Blood forced out of left side to the body
At the end vol and pressure low. In arteries pressure at the max
What are the heart sounds
First one
Blood forced against the AVV as ventricles contract
Second one
Backflow of blood closes the semilunar value in the aorta and pulmonary artery
What happens in atrial fibrillation
An example of an arrhythmia
Electrical impulses are generated in the atria
They contract very fast, but to 400times a minute.
Don’t contract properly tho and only some impulses passed onto the ventricles that contract much less often so heart nah pump very effectively
How does an ECG work
Electrodes are stuck painlessly to clean skin to get good contact needed for realiable results
Signals from each of the electrodes is fed into the machine which makes an ECG
Uses of the ECG
To measure the spread of electrical excitation through the heart. Measuring the tiny electrical differences in ur skin
Used to diagnose heart problems
Recognisable changes in the electrical activity of someone’s heart can tell you if they’re having a heart attack for example. From there you can diagnose and treat correctly and fast
Myogenic
Heart has its own intrinsic rhythm so bodies resources nah wasted maintaining heart rate at a basic level
Bundle of His
A bundle of conducting tissue that is made up of Purkyne fibres that penetrate thru the septum between the ventricles
