The Endocrine System Chemical Communication Main Function: It releases hormones (chemical messengers) into the blood to signal other cells (target cells) to behave in certain ways. It is a slow but widespread form of communication.

The Endocrine System Consists of: Endocrine glands- Release hormones into the bloodstream. Hormones- are chemicals released in one part of the body that travel through the bloodstream and affect the activities of cells in other parts of the body.

Interaction of Glands The hypothalamus is located in the brain releases hormones from the pituitary gland. important link between the endocrine and nervous systems.

Interaction of Glands The brain and glands work together to maintain homeostasis through a process called negative and positive feedback mechanisms.

Endocrine System Pituitary Gland Add hypothalmus

Pituitary Gland Robert Wadlow Function: It secretes nine hormones that control all other endocrine glands. -produces human growth hormone - Disorders: Too much growth hormone can result in a condition called gigantism. Robert Wadlow

Endocrine System Thyroid Gland Pituitary Gland Parathyroid Gland

Thyroid Gland Hormone: Thyroxin Function: helps regulate the body’s metabolism. Disorders: Hyperthyroidism-too much thyroxin; fast metabolism Hypothyroidism- too little thyroxin; slow metabolism Goiter-lack of iodine in diet, no thyroxin secretion, enlargement of thyroid gland

Endocrine System Thyroid Gland Pituitary Gland Parathyroid Gland Adrenal Glands

Adrenal Gland Functions: -The adrenal glands release Adrenaline in the body that helps prepare for and deal with stress. -Fight or Flight

Endocrine System Thyroid Gland Pituitary Gland Parathyroid Gland Ovaries Adrenal Glands

Ovaries Functions: Pair of reproductive organs found in women that produce eggs. Also secrete estrogen and progesterone, which control ovulation and menstruation.

Endocrine System Pineal Gland Thyroid Gland Pituitary Gland Parathyroid Gland Ovaries Thymus Adrenal Glands Testes

Testes Functions: Pair of reproductive glands that produces sperm. Also secrete Testosterone to give the body its masculine characteristics.

Endocrine System Pineal Gland Thyroid Gland Pituitary Gland Pancreas Parathyroid Gland Ovaries Thymus Adrenal Glands Testes

Pancreas [Islets of Langerhans] Insulin: Reduces levels of glucose in the blood conversion of glucose to glycogen promoting glucose absorption and use by body cells Glucagon: Increases levels of glucose in the blood causes liver to convert glycogen to glucose

Negative Feedback Is a type of self-regulation associated with endocrine regulation Functions like a thermostat. Only activated when there is a need. Shuts off once that need has been met. Way to maintain balance, trying to maintain 55 mph Homeostasis

Glucose                                                                                                                                                                                                            Glucose

Glycogen If there is too much glucose in the blood, insulin converts some of it to glycogen Insulin Glucose in the blood

Glycogen If there is not enough glucose in the blood, glucagon converts some glycogen into glucose. Glucagon Glucose in the blood

Glucose levels rise after a meal. Insulin is produced and glucose levels fall to normal again. Glucose Concentration Normal Time Meal eaten

Failure of Homeostasis: [Islets of Langerhans] Diabetes: Islets of Langerhans don’t make enough insulin Glucose in blood can’t be stored as glycogen Blood levels of glucose INCREASE

Insulin The glucose in the blood increases. Glycogen The glucose in the blood increases. But there is no insulin to convert it into glycogen. Glucose concentration rises to dangerous levels. Insulin Glucose in the blood

Meal eaten Glucose levels rise after a meal. Diabetic Concentration Diabetic Insulin is not produced so glucose levels stay high Time Meal eaten

Positive Feedback Enhances an existing response Hormones involved in Child birth Way to maintain balance, trying to maintain 55 mph

Interaction of Glands The feedback the brain gets is from the information it collects as the hypothalamus monitors the bloodstream. Using this information, the brain knows what hormones to start and stop releasing.

Regents Practice #1 Which substances play an important role in communication between cells in a multicellular organism by acting as (1) fats (3) minerals (2) antibiotics (4) hormones chemical messengers?

Regents Practice #2 The maintenance of in the body is most directly related to (1) cellular communication (2) cycling of energy (3) aging of the organism (4) recombination of chromosomes homeostasis

Regents Practice #3 Which process is most directly responsible for maintaining internal stability in an organism when its environment is constantly changing? (1) digestion (3) reproduction (2) feedback (4) evolution

The Nervous System Electrical Communication

Main Function: The Nervous System This communication system controls and coordinates functions throughout the body and responds to internal and external stimuli. Our nervous system allows us to feel pain.

Consists of: brain, spinal cord, nerves and sense organs The Nervous System Consists of: brain, spinal cord, nerves and sense organs Sense Organs: Eyes, Skin, Ears, Nose & Tongue

The Nerve A nerve is an organ containing a bundle of nerve cells called neurons. Neurons carry electrical messages called impulses throughout the body. Picture shows hundreds of severed neuron axons

Impulse in a Neuron TYPICAL MOTOR NEURON dendrite muscle tissue Axon synapse cell body cell body

Parts of a Neuron Cell body: contains nucleus & most of the cytoplasm Dendrites: projections that bring impulses into the neuron to the cell body. Axon: long projection that carries impulses away from cell body Terminal Branch: transmit impulses to other neurons. 1 3 2 travels dendrite towards axon 4

Sensory Neuron Interneuron Motor Neuron Types of Neurons Interneuron Synapse Synapse Motor Neuron Interneuron Synapse Muscle Contracts Motor Neuron Sensory Neuron

Where can the largest cells in the world be found? Sensory Neuron carry impulses from sense organs to spinal cord & brain Fun Fact: Where can the largest cells in the world be found? The giraffe’s sensory and motor neurons! Some must bring impulses from the bottom of their legs to their spinal cord several meters away!!

Interneuron processes impulses in brain and spinal cord - connect sensory and motor neurons

Motor Neurons carry impulses from the brain & spinal cord to muscles & glands Axon End Axons branching out to muscle fibers

Types of Neurons Sensory Neurons Carry impulses from sense receptors towards brain and spinal cord B SR Motor Neurons Carry impulses from brain and spinal cord to muscles and glands What are receptors/effectors? Sensory organs: eyes, ears, nose, skin, tongue Effectors: muscles, glands---whatever needs to do an action for response B M/G Interneurons Carry impulses within the brain and spinal cord

Synapse (gap) Neurotransmitters Because neurons never touch, chemical signalers called neurotransmitters must travel through the space called synapse between two neurons. Neurotransmitters (pink spheres) The message is transferred when RECEPTORS receive neurotrans-mitters. Synapse (gap)

Communication with Neurons Nerves work together with muscles for movement. An impulse begins when one neuron is stimulated by another neuron or by the sense organs. The impulse travels down the axons of Sensory neurons to the brain cells called Interneurons. The brain will then send an impulse through motor neurons to the necessary muscle or organs, telling it to contract.

Regents Practice The arrows in Figure X show— A. Movement of a stimulus in a cyton B. Transport of oxygen in a nerve C. Transfer of an impulse from one neuron to another neuron D. Response of an effector to a stimulus Figure X What is this diagram showing? Movement of message along nerves Correct answer: C

Reflexes protect the body before the brain knows what is going on. A reflex is an involuntary response that is processed in the spinal cord not the brain. Reflexes protect the body before the brain knows what is going on. Reflex Arc

Reflex Arc Reflex Arc S P I N Path reflex impulse travels A L O R D Path reflex impulse travels Sense Receptor Sensory Neuron U-turn neuron in spine: interneuron Motor Neuron Muscle/Gland

Human Nervous System Central Nervous System Peripheral Nervous System [CNS] [PNS] Brain & Spinal Cord Nerves branching from the brain and spinal cord

Central Nervous System Consists of: Brain and Spinal Cord brain Spinal Cord Cerebellum Cerebrum Medulla Oblongata

Cerebrum Cerebellum Medulla Oblongata (Brain Stem) Spinal Cord Central Nervous System Cerebrum Cerebellum Medulla Oblongata (Brain Stem) Spinal Cord Voluntary or conscious activities of the body-learning, judgment Coordinates and balances the actions of the muscles Controls involuntary actions like blood pressure, heart rate, breathing, and swallowing The main communications link between the brain and the rest of the body

Consists of: Sensory division and Motor division Peripheral Nervous System Consists of: Sensory division and Motor division -includes all sensory neurons, motor neurons, and sense organs

Subdivisions of PNS Somatic Nervous System: voluntary control responsible for conscious body movement Autonomic Nervous System: no voluntary control serve internal organs involved with: heart rate blood flow breathing movements digestive system gland secretions

Sympathetic: “fight or flight” speed up body functions Autonomic Nervous System: Sympathetic: “fight or flight” speed up body functions Parasympathetic: slow down body functions Sympathetic: speed up heart/breathing, liver:glycogen to glucose, adrenaline released Para: calms body, decrease heart/breathing, enhance digestion

Concept Map The Nervous System is divided into Central nervous system Peripheral nervous system Sensory nerves Motor nerves which consists of that make up Autonomic nervous system Somatic nervous system which is divided into Sympathetic nervous system Parasympathetic nervous system

Regents Practice The peripheral nervous system consists of the A. neurons located in the brain and spinal cord B. nerves that extend from the brain and spinal cord C. interneurons of the central nervous system D. portions of the brain known as the medulla and cerebellum What makes up the peripheral nervous system? Nerves attached to brain and spinal column Correct answer: B

Regents Practice

Nervous vs. Endocrine System Similarities: both involved with maintaining homeostasis both secrete chemicals Endocrine System: hormones Nervous System: neurotransmitter Differences: NS response is much faster than ES response ES response lasts longer than NS response Nerve impulse transmitted by neuron, hormones transported by the blood