2.82 communication

describe how responses can be controlled by nervous or by hormonal communication and understand the differences between the two systems.


1st way.
-in first diagram there is a motor nerve, orange part will be connected to the spine and the other end will be connected to the effector- most likely a muscle.
-the electrical impuse or the nerve impulse is carried along inside the nerve along the orange structure from the cell body to the synaptic knob where it connects to the muscles- can be a meter long. (single cell shown in orange)
-long structure is the axon.
-in mammals the axon is surrounded by a second kind of cell called a schwann cell- contains lots of fat and they form a myelin sheath- increase speed of nerve conduction.
-one way of linking coordinator or receptor to an effector.

2nd way.

-endocrine system .

- involves the endocrine gland produces chemical called hormones. (hormones can be proteins or steroids- different kinds)

-produced in the endocrine gland example would be Adrenal gland.

-the hormone is secreted into the blood- hormone travels into the blood.

-we would be secreting adrenaline from the adrenal gland into the blood. this will travel into the blood stream and arrive at the organ that will have an effect on called the target tissue or target organ which it will have an effect on.

-contrast with the nerve system it is possible that hormones can have multiple targets and effects.

comparison between communication based on nerves and communication based on hormones.

- nerve impulses are fast and hormones are relatively slow.