1. Human Body Systems

2. 12 Body Systems

3. Nervous and Endocrine System

4. KEY CONCEPT The nervous system and the endocrine system provide the means by which organ systems communicate.

5. The body’s communication systems help maintain homeostasis.
A stimulus causes a response.
Responses can be chemical, cellular, or behavioral.
The nervous and endocrine systems respond to stimuli.

6. The nervous system controls thoughts, movement, and emotion.
The endocrine system controls growth, development, and digestion.

7. The nervous and endocrine systems have different methods and rates of communication.
The nervous system works quickly, using chemical and electrical signals.
interconnected network of cells
signals move through cells
divided into central nervous system (CNS) and peripheral nervous system (PNS)
spinal chord
nerves

8. The endocrine system works more slowly.
only chemical signals
signals move through bloodstream
physically unconnected organs
target cell
hormone
bloodstream
receptor
not a target cell

9. Neurons are highly specialized cells.
A neuron has three parts.
cell body has nucleus and organelles 1
Cell body

10. Neurons are highly specialized cells.
A neuron has three parts.
cell body has nucleus and organelles
dendrites receive impulses 2
dendrites

11. Neurons are highly specialized cells.
A neuron has three parts.
cell body has nucleus and organelles
dendrites receive impulses
axon carries impulses 3
axon

12. Neurons have other structures to transmit signals.
Schwann cell

13. Neurons have other structures to transmit signals.
Schwann cell
synapse
synapse

14. Neurons have other structures to transmit signals.
Schwann cell
synapse
terminal
axon terminal

15. Neurons receive and transmit signals.
Resting potential means no signal is being transmitted.
more Na+ outside of cell
more K+ inside of cell

16. An action potential is a moving electrical impulse.
It is generated by a stimulus.
Na+ enters, and cell becomes positively charged.
K+ leaves, and area of positive charge moves.
area of detail

17. A chemical signal passes between neurons.
Impulse reaches terminal.
impulse

18. A chemical signal passes between neurons.
Impulse reaches terminal.
impulse

19. A chemical signal passes between neurons.
Impulse reaches terminal.
Neurotransmitters released into synapse.
synapse
impulse
neurotransmitter
vesicles
receptor

20. A chemical signal passes between neurons.
Impulse reaches terminal.
Neurotransmitters released into synapse.
Neurotransmitters stimulate next cell.
synapse
impulse
neurotransmitter
vesicles
receptor

21. Senses

22. KEY CONCEPT The senses detect the internal and external environments.

23. The senses help to maintain homeostasis.
Senses gather stimuli, and send it to the nervous system.
Nervous system responds to stimuli.
Pupils shrink when too much light enters the eyes.
Goose bumps when cold air touches skin.

24. The senses detect physical and chemical stimuli.
The eye contributes to vision.
Photoreceptors sense light.
Two photoreceptors work together: rod cells and cone cells.

25. The ear contributes to hearing.
mechanoreceptors called hair cells
bend in response to vibrations

26. Taste and smell use chemoreceptors.
Taste uses tongue, and smell uses nose.
Chemoreceptors detect chemicals dissolved in fluid.

27. The skin senses touch. Mechanoreceptors detect pressure.
Pain receptors detect damaged tissue.
Thermoreceptors detect temperature.
pain receptor
light pressure receptor
hair follicle
heavy pressure receptor

28. KEY CONCEPT The central nervous system interprets information, and the peripheral nervous system gathers and transmits information.

29. The nervous system’s two parts work together.
The CNS includes the brain, brain stem, and spinal cord.
The PNS includes four systems of nerves.

30. The CNS and PNS pass signals between one another.
Sensory receptor generates impulse.
PNS passes impulse to CNS.
CNS interprets impulse.
CNS passes impulse to PNS.
PNS stimulates a response.

31. The CNS processes information.
The brain has three parts.
cerebrum controls thought, movement, emotion
cerebellum allows for balance
brain stem controls basic life functions
Brain stem
midbrain
pons
medulla oblongata

32. The brain stem has three parts.
midbrain controls some reflexes
pons regulates breathing
medulla oblongata controls heart function, swallowing, coughing
midbrain
pons
medulla oblongata

33. The spinal cord controls reflexes.
sensory neuron sends impulse to spinal cord
spinal cord directs impulse to motor neuron
does not involve the brain
interneuron
motor neurons
sensory neuron

34. The PNS links the CNS to muscles and other organs.
The somatic nervous system regulates voluntary movements.
The autonomic nervous system controls involuntary, functions
sympathetic nervous system: “fight vs. flight”
parasympathetic nervous system: calms the body, conserves energy

35. KEY CONCEPT Scientists study the functions and chemistry of the brain.

36. New techniques improve our understanding of the brain.
Today, scientists study the brain without surgery.

37. There are three common technologies.
CT uses x-rays to view structure.
MRI uses magnetic fields and radio waves to view structure.
PET detects activity, where glucose is used, in the brain.

38. Changes in brain chemistry can cause illness.
Different neurotransmitters relate to different functions.
synapse
Normal
receptor
neurotransmitter
some stimulate impulses
some prevent impulses

39. Abnormal levels of neurotransmitter can cause illness.
schizophrenia
depression
Normal
Schizophrenic
Depressed

40. Drugs alter brain chemistry.
Addiction is the physiological need for a substance.
Tolerance occurs when more drug is needed to produce an effect.
Drugs might cause desensitization or sensitization.
desensitization: more neurotransmitter leads to fewer receptors
sensitization: less neurotransmitter leads to more receptors.
When the amount of neurotransmitter becomes abnormal, the adjacent neuron adapts.

41. Stimulants cause more action potentials
may increase neurotransmitter in synapse
may decrease removal of neurotransmitter in synapse
cocaine
neurotransmitter
synapse

42. Depressants cause fewer action potentials.
may produce neurotransmitter that prevent impulses
may slow release of neurotransmitter that generates impulses

43. KEY CONCEPT The endocrine system produces hormones that affect growth, development, and homeostasis.

44. Hormones influence a cell’s activities by entering the cell or binding to its membrane.
Glands are organs of the endocrine system.

45. Hormones are chemical signals that influence cell’s activities.
produced by glands
travel through the circulatory system
affects cells with matching receptors
target cell
hormone
bloodstream
receptor
not a target cell

46. There are steroid hormones and nonsteroid hormones.
Steroid hormones enter the cell.
Nonsteroid hormones do not enter the cell.
Steroid hormone
Non-steroid hormone
Steroid hormone diffuses through the cell membrane
Steroid hormone binds to a receptor within the cell.
The hormone and receptor enter the nucleus and bind to DNA
Steroid hormone causes DNA to make proteins.
Nonsteroid hormone binds to receptor on the cell membrane.
Receptor stimulates a second messenger with in the cell.
Second messenger starts a series of chemical reactions in the cytoplasm.
Second messenger reactions activate enzymes.
receptor
receptor
second messenger
nucleus
Chemical reactions
DNA
activated enzymes
proteins

47. Endocrine glands secrete hormones that act throughout the body.
There are many glands located throughout the body.
HYPOTHALAMUS
PITUITARY
THYROID
THYMUS
ADRENAL GLANDS
PANCREAS
FEMALE GONADS :OVARIES
MALE GONADS : TESTES
Hormones travel through the bloodstream to cells with matching receptors.

48. The hypothalamus interacts with the nervous and endocrine systems.
The hypothalamus is a gland found in the brain.
a structure of both the nervous and endocrine systems
produces releasing hormones, sent to pituitary gland
The pituitary gland is found below the hypothalamus in the brain.
controls growth and water levels in blood
produces releasing hormones sent throughout the body

49. Releasing hormones stimulate other glands to produce hormones.
allow glands to communicate with one another
are used in temperature regulation

50. Hormonal imbalances can cause severe illness.
Abnormal hormone levels affect homeostasis.
Hormonal imbalances might be treated with surgery or medicine.
Steroids, a pituitary tumor, or some prescription drugs can make the pituitary overactive and indirectly cause problems.