1. Nervous & Endocrine Systems HUMAN REGULATION

2.  Integration of nervous & endocrine systems Similarities  Secrete chemicals  Major role in homeostasis Differences  Nerve response – more rapid & shorter duration REGULATION

3.  Regulation: All the activities that help to maintain homeostasis in an organism  Impulse: Message carried by the nerve cells  Stimulus (stimuli) – Change in external or internal environment which initiates (starts) an impulse FUNCTIONAL DEFINITIONS

4. TYPES OF RECEPTORS

5.  Receptors – Structures specialized to detect certain stimuli  Effectors: Muscles and glands that respond to the stimulus  Response: Change based on stimulus FUNCTIONAL DEFINITIONS

6. Neurons  Basic cellular unit  Specialized for transmission impulse FUNCTIONAL ORGANIZATION OF THE NERVOUS SYSTEM

7. NEURON

8. ACTUAL NEURONS IN BODY

9. NEURONS

10. THE NEURON Composed of: 1) Dendrites – fibers detect the stimulus & generate impulses toward the cyton 2) Cyton – cell body containing nucleus & most organelles

11. THE NEURON 3) Axon – single long fiber that transmits impulse away from cyton to the terminal branches 4) Terminal branches – ends of axon – synaptic knobs secrete chemicals (neurotransmitters)

12. THE NEURON 5) Synapse – space between adjacent neurons or between neuron & effector 6) Neurotransmitters – chemicals secreted to aid in transmission of impulse across synapse

14. Three types of neurons: 1) Sensory Neurons  From receptors to central nervous system (brain & spinal cord) 2) Interneurons  Inside CNS FUNCTIONAL ORGANIZATION OF NERVOUS SYSTEM

15. 3) Motor Neurons  Transmit from CNS to effectors (muscles and glands) FUNCTIONAL ORGANIZATION OF NERVOUS SYSTEM

16. Nerves – bundles of neurons  Can be sensory, motor, or mixed  Specialized for impulse transmission over long distances FUNCTIONAL ORGANIZATION OF NERVOUS SYSTEM

18. 1) Brain  Large mass of neurons  Protected by skull  Three major divisions: CENTRAL NERVOUS SYSTEM

19. 1a) Cerebrum  Largest part of brain  Voluntary activity, memory, thinking, reasoning CENTRAL NERVOUS SYSTEM

20. 1b) Cerebellum  Coordination of motor activities  Maintaining balance 1c) Medulla  Involuntary activities – breathing, heartbeat, blood pressure, peristalsis  Lowest part of brain  Continuous with the spinal cord CENTRAL NERVOUS SYSTEM

22. 2) Spinal Cord  Lies within, & protected by, vertebrae of spinal column  Coordinates activities between brain & other body structures  Reflex actions CENTRAL NERVOUS SYSTEM

24.  Outside CNS  Nerves extending throughout body  Two parts: 1)Somatic NS – control voluntary muscles PERIPHERAL NERVOUS SYSTEM

25. 2) Autonomic NS – two sets of nerves control involuntary muscles  One set stimulates activity (sympathetic)  Other slows down activity (parasympathetic) PERIPHERAL NERVOUS SYSTEM

27. Peripheral Nervous System Central Nervous System BrainSpinal Cord SomaticAutonomic SympatheticParasympathetic

28.  Cerebral palsy – congenital diseases - motor function disturbance  Meningitis – inflammation of membranes surrounding brain & spinal cord NERVOUS SYSTEM MALFUNCTIONS

29.  Stroke – cerebral hemorrhage (blood clot) in vessels - can result in brain damage  Polio – viral disease of CNS; may result in paralysis; preventable through immunization NERVOUS SYSTEM MALFUNCTIONS

30. Behavior – responses of living things to stimuli Reflex – inborn, involuntary response  Involves a pathway (reflex arc)  Impulse travels from receptor  sensory neuron  spinal cord (interneuron)  motor neuron  effector TYPES OF BEHAVIOR

31. Habit – conditioned behavior acquired by repetition  Repetition establishes pathways for nerve impulse transmission  Permits automatic responses to various stimuli TYPES OF BEHAVIOR

32.  Made up of ductless glands located throughout the body & their hormones  Hormones released directly into the bloodstream - affect various tissues or organs (target tissue)  Hormones coordinate responses to various conditions THE ENDOCRINE SYSTEM

35.  Small region of brain  Produces hormones which influence pituitary gland HYPOTHALAMUS

36.  Base of brain  Secretes: 1) Growth Stimulating Hormone (GSH)  Elongation of bones  Affects metabolic activities for growth PITUITARY GLAND

37. Problems with GSH  Oversecretion in child: Giantism

38.  Oversecretion in adult: Acromegaly (enlarged bones of face, feet, hands)

39.  Undersecretion: Dwarfism

40. 2) Thyroid Stimulating Hormone (TSH)  Tells thyroid to produce thyroxin 3) Follicle Stimulating Hormone (FSH)  Stimulates egg development in ovary & sperm development in testes

41.  In the neck  Produces thyroxin, which contains iodine  Thyroxin regulates metabolic rate – essential for proper development THYROID GLAND

42. Problems with thyroid  Oversecretion: nervous, weight loss  Undersecretion: cretinism (mental retardation, small size)

43.  Deficiency of iodine – goiter (enlarged gland)

46.  Embedded in thyroid gland  Produces & secretes parathormone, which controls calcium metabolism  Necessary for nerve function, blood clotting, proper growth of teeth & bones PARATHYROID GLAND

47. Problems with parathyroid  Undersecretion: nerve disorders, brittle bones, clotting problems

48.  Two – one on top of each kidney  Each has two regions  Outer portion – adrenal cortex  Inner portion – adrenal medulla ADRENAL GLANDS

49.  Secretes two steroid hormones 1)Cortisone – regulates metabolism of organic molecules & promotes conversion of body fat & protein to glucose 2)Aldosterone – promotes reabsorption of sodium & chlorine ions by kidney into bloodstream – affects water balance & maintenance of blood pressure ADRENAL CORTEX

50. Problems with cortisone  Oversecretion – Cushing’s disease (high glucose, excess fat)  Undersecretion – Addison’s disease (low glucose, weight loss)

51.  Secretes adrenaline  Increases blood sugar levels & accelerates heart & breathing rate ADRENAL MEDULLA

52.  Located in pancreas  Secretes insulin & glucagon  Insulin – allows glucose to enter cells from blood – lowers blood sugar levels  Glucagon –stimulates release of sugar into blood – raises blood sugar levels ISLETS OF LANGERHANS

53. Problems with pancreas  Oversecretion of insulin – low blood sugar  Undersecretion – diabetes (high blood sugar)

54.  Male – testes secrete testosterone – influences development of secondary sex characteristics  Female – ovaries secrete several hormones, including estrogen – development of female secondary sex characteristics GONADS

55.  Type of self-regulation  Level of one hormone in blood inhibits (slows) production of another hormone  Keep everything in homeostasis  TSH & thyroxin; insulin & glucagon NEGATIVE FEEDBACK MECHANISM

56. Negative Feedback Mechanism

58. POSITIVE FEEDBACK MECHANISM Positive feedback – one promotes production of the other Ex: snowball rolling down a hill