Unit 1-10 NotesMr. Hefti – Pulaski Biology

The Nervous and Endocrine

Systems (Coordination)

Nervous & Endocrine System Fun Facts1. There are more nerve cells in the human brain than there are stars in the Milky

Way!2. If we lined up all the neurons in our body it would be around 600 miles long.3. There are 100 billion neurons in your brain alone.4. The left side of human brain controls the right side of the body and the right side

of the brain controls the left side of the body.5. The total surface area of the human brain is about 25,000 cm2.6. Only 4% of the brain's cells work while the remaining cells are kept in reserve.7. The nervous system can transmit impulses as fast as 100 m/s.8. Potassium and sodium ions are vital to the proper functioning of the nervous

system.9. There are 30 hormones in the human body!10. The sense of thirst and hunger is triggered in our body by the hypothalamus

gland.11. The pineal gland induces sleep in our body. It produces a hormone named

melatonin which controls the sleep cycle of our body.

A neuron – the smallest functional unit of the nervous system!

Cell body (light blue)

Dendrites (light blue)

Nucleus (gray)

Axon (red)

Insulative coating (yellow)

Synaptic knobs (dark green)

Terminal branches (light green)

A

Cerebrum (white)

Brain stem (purple)

Cerebellum (orange)

Spinal cord (yellow)

Learning, thinking,

emotions, memory…

Involuntary

control of organsBalance

Reflexes

B

How do nerve cells carry messages?

Axon end (red)

Cellmembranes(orange)

Neuro-transmitters(blue)

Synaptic knob (dark green)

Synapse (tan)

Dendrite (light blue)

C

This is where neurons and muscles meet up… it is called a neuro-muscular junction!

Axon (red)

Junction (yellow)

Muscle (brown)

Axon end (red)

Neurotransmitters (blue)

D

Q: How do the hormones get into the blood?

A: Diffusion and active transport!!!

The endocrine system glands make hormones!

Pancreas (yellow)

Hypothalamus (black)

Pituitary (dark green)

Parathyroid (tan)

Thyroid (orange)

Thymus (light blue)

Adrenal (red)

Pineal (black)

Ovary (pink)

Testes (light blue)

E

Endocrine gland (such as adrenals – red)

Hormone (such as adrenaline - blue)

Non-target cells(yellow)

Target cell (orange)Receptor

(black)

Active site (black w/

blue)

Receptors (green)

How do hormones work?

Response!F

Make connections…

• Which organelle performs a similar role to the one provided by the nervous and endocrine systems?– Nucleus

• If these organ systems are the ones that regulate, why do they need the other organ systems?– They require a tremendous supply of nutrients and

oxygen and generate wastes that must be removed.