Destroy and remove foreign bodies from lymph (to filter lymph) as part of the immune system
Lymph is cleaned by lymph nodes which are important for immune function
One way lymphatic vessels :
picks up lymph
delivers nutrients
removes waste
What is in lymph?
Lymph is full of white blood cells- lymphocytes
which release antibodies and activate T-cells
Also transport absorbed lipids from intestine and drain excess fluid back into blood
Structure of lymph node
Sinus- top left
Capsule- centre left
Valve to prevent backflow- bottom left
Nodule- top right
Hilum - centre
Afferent lymphatic vessels- top
Efferent lymph vessels- bottom
Vasodilation
When animal is too hot
Blood vessels expand and blood flows closer top surface of skin and heat then leaves the skin through radiation
If animal has sweat glands then glands will be stimulated by increased blood flow.
This causes animal to sweat.
Water has a specific heat capacity so when it evaporates it transfers a lot of heat with it.
Endothermic are animals that regulate their own internal body temperatures whereas ectotherms are animals which rely on external sources of heat to regulate body temperature
