Transcript Regulation
Regulation: Chemical and Nervous So Far… • • • • • Nutrition Transport-Blood and Immunity Respiration Excretion Support and Locomotion How do we coordinate all these activities? How do we maintain Homeostasis? • Regulation – Chemical • Hormones and Glands of Endocrine System • Slow-Snail Mail (travel via blood long distance) • Long-lasting effects and hormones can remain active in blood from minutes to days – Nervous • Neurons and Neurotransmitters of Nervous System • Fast-E-mail (travel through wires 100m/s) • Short-lived effects Endocrine System • Glands – Organs that secrete chemicals – Glands of the Endocrine System are Ductless Gland • Secretion goes right into blood stream • Blood brings it to target Blood Vessels Other types of Glands • Exocrine Glands – Secretions delivered to target through ducts Gland that is Endocrine and Exocrine: Pancreas Makes Digestive Enzymes And Hormones Hormones • • • • Secreted by Endocrine Glands Chemicals Travel via blood to target Regulate processes at target How do Hormones act on target? • One Messenger Model: – Hormone crosses target cell membrane – Binds cytoplasmic receptor protein – Hormone-Receptor Complex interacts with DNA – Effect produced – Ex. Steroids (Lipid-like) Steroid Model How do Hormones act on target? • 2 Messenger Model: – Hormone binds receptor on membrane – Binding activates a second chemical in cytoplasm (ex. cAMP, cGMP, Calcium) – 2nd Chemical leads to cell response – Protein Hormones 2nd Messenger Model The Glands 1. Pituitary Gland • • • • In Head “Master Gland” Two Sections (Anterior and Posterior) Regulated by the Hypothalamus (Part of Brain) Pituitary Gland Releasing Factors Makes & Secretes Hormone Stores & Secretes Neuropeptides of Hypothalamus Hormones of Anterior Pituitary Hormone TSH ACTH GH FSH LH Prolactin Target Response Thyroid Adrenals Many cells Ovary Ovary Mammary Glands Thyroxin Release Hormone Release Bone Growth Follicle Growth egg release Milk Production Hormones of Posterior Pituitary Neuropeptide Target Oxytocin Uterus Vasopressin (ADH) Kidney Response Contractions More H20 Reabsorption The Glands 2. Thyroid Gland – In neck Hormones of Thyroid • Thyroxine (T3,T4) – Has iodine – Regulates protein, carb and fat metabolism – Regulates cellular respiration • Calcitonin – Regulates blood calcium levels – Lowers blood calcium levels The Glands 3. Parathyroid Glands – Four glands embedded in thyroid gland Hormone of Parathyroid Gland • Parathormone – Regulates Calcium and Phosphate metabolism – Increases blood calcium levels by taking Calcium out of bone The Glands 4. The Adrenal Glands – On surface of kidneys – Has two layers (inner medulla and outer cortex) Hormones of Adrenal Medulla • Epinephrine (Adrenalin) and “Fight or Flight Response” – Nervous System regulation – Increase: Heartbeat, blood pressure, respiration, clotting rate, glucose levels • Norepinephrine – Released in response to low blood pressure, causes for an increase. Hormones of Adrenal Cortex Corticosteroids: • Cortisol (Glucocorticoid) – Affects carb, protein and fat metabolism • Aldosterone (Mineraolcorticoid) – Affects Sodium and Potassium levels at kidney level The Glands 5. Pancreas – Islets of Langerhan cells: • Alpha cells= secrete the hormone Glucagon • Beta cells=secrete the hormone Insulin Hormones of Pancreas • Glucagon – raises blood glucose levels • (Glycogen to glucose) • Insulin – Lowers blood glucose levels • (Glucose to Glycogen) The Glands 6. Gonads: • Ovaries – Located in female abdominal cavity • Testes – Located in male scrotum Hormones of Ovaries • Estrogen – Stimulates female reproductive system – Female secondary sexual characteristics – Regulates menstrual cycle • Progesterone – Regulates menstrual cycle Hormones of Testes • Testosterone (an Androgen) – Stimulates male reproductive system development – Male secondary sexual characteristics The Glands 7. Thymus • In upper chest • More important in early years than adulthood Hormones of Thymus • Thymosin – Stimulate T cell development The Glands 8. Pineal Gland – At base of brain Hormone of the Pineal Gland • Melatonin – Involved in daily rhythms and biological clock – Much still unknown Digestive System Hormones • Gastrin from Stomach • Secretin, CCK, GIP from Small Intestine “Local Hormones” • Prostaglandins – Don’t travel far from production site (unlike other hormones) – Wide range of functions Problems • Diabetes: – Excess glucose in blood – Low Insulin (Hyposecretion) or too much glucagon (Hypersecretion) – Type 1= don’t make insulin (autoimmune against beta cells) – Type 2= Diet related sugar management problem, liver doesn’t respond to insulin) – Gestational= Pregnancy related • Hypoglycemia – Too low blood glucose – Too high insulin or too low glucagon Problems • Giantism – In kids – Normal proportions – Too much GH • Acromegaly – In adults – Too much GH – Large body parts • Dwarfism – In kids – Small but proportional body – Low GH Problems • Hyperthyroidism – Too much thyroxine – Hyper, eye bulging , may include Goiter condition Problems • Cushing’s Disease – Hypersecretion of Aldosterone and Cortisol – Fat deposits – High blood glucose • Addison’s Disease – Low amount of aldosterone and cortisol – Glucose metabolism problems – Sluggish, weak, weight loss – Increased skin pigmentation Problems Problems • Hypothyroidism – In infant: becomes dwarf with disproportionate body and mental retardation (cretinism) – In adult: sluggish, heavy person How are hormone levels normally regulated? Homeostatic Feedback Regulation 1) Baby Suckling nerves signal Hypothalamus to release Oxytocin Breast Milk 2) Temp. drop nerves signal Hypothalamus to release TSH-releasing factor TSH release from Pituitary Thyroid Gland release Thyroxin 3) Hot nerves signal Hypothalamus to release ADH kidney releases less urine Negative Homeostatic Feedback • Too much Thyroid hormones in blood • Shut down anterior pituitary and hypothalamus related to Thyroid hormones Nervous Regulation • Like E-mail • Fast but short-lived response Basic Unit of Nervous Regulation • Neuron (They don’t divide!) Parts of Neuron • Dendrite – Branched – Short – Receives signals – Sends signals towards axon Parts of Neurons • Cell Body (Cyton) – Contains organelles of neuron – Does metabolic activities Parts of Neuron • Axon – Long – Single fiber 1cm to 1 meter in length – Carries electrical signals towards terminal branches – Can be wrapped with 2 types of glial cells • Schwann Cells that may produce Myelin (Fatty insulating material) on axons, PNS • Oligodendrocytes, CNS – Myelination progresses as we grow into adult Spots of exposed axon between Schwann Cells=Nodes of Ranvier Parts of Neuron • Terminal Branches – Sends electrical signals towards synaptic knobs (terminal knobs) Parts of Neuron • Synaptic Knobs – Electrical signal causes release of neurotransmitter (chemical) from vesicles •Neurotransmitters cross Synapse (Space) •Bind to receptors on dendrites of other neurons or receptors on muscles Types of Neurons • Sensory – Send messages from receptors to brain and spinal cord • Receptors: ex. Eye, Ear, Skin • Interneurons (associative neurons) – Relays messages from one neuron to another – Usually short • Motor Neuron – Send messages from brain and spinal cord to Effectors • Effectors: ex. Muscles and Glands Neurons vs. Nerves • Nerves=bundles of neurons The Message=Impulse • A neuron at rest: – Outside neuron positively charged – Inside neuron negatively charged (-70mV) – Membrane is “Polarized” Cell at Rest Negative Chlorine also outside What starts an Impulse? • Stimulus – Ex. Light, heat, sound, pain An impulse will lead to a “Response” What happens during an impulse? • Wave of depolarization and repolarization along neuron=Action Potential How do we get the depolarization? Action Potential At Rest (Polarized) Need to reach “Threshold” to open enough Na gates to start impulse (All or none Response) Na Gates Open-Positive Na rushes in, Positive K stays in (Depolarization), More positive entering than leaving Na gates close, K gates open, more positive leaving than coming in (Repolarization) Undershoot Resting Potential, Very negative inside, REFRACTORY PERIOD-Unresponsive Wave travels along membrane Gates are voltage regulated Na rushing through one gate will move towards the right and open downstream gates What regulates the speed of the wave? • Size of neuron • Myelin presence A large myelinated neuron impulse speed= 100 meters/sec Why so fast? • Saltatory Conduction: Skipping is faster than walking! What happens when impulse reaches the knobs? • Signal must cross Synapse! • Change electrical signal to a chemical signal • Neurotransmitter • Diffuse across synapse • Bind receptor on next dendrite-cause the generation of action potential • Enzymes breakdown transmitters Neurotransmitters • • • • Acetylcholine Norepinephrine Serotonin Glutamic Acid (MSG in foods) Strength of Stimulus? • Relate to frequency of action potentials • Different neurons have different thresholds Why can’t we smell through our ears? How is a response produced? • Neuromuscular Junctions • Neurons end with Motor End Plates • Neurotransmitters like acetylcholine bind to muscle cells • Muscle contracts Drugs and Poisons Interfere with Neuromuscular Junctions • Nerve Gas • Curare • Botulin toxin • Insecticides Interfere with synaptic transmission • Uppers and Downers • Caffeine Nervous Regulation in Protists • No Neurons • No Nervous System • Can respond to stimuli like chemicals, light, obstacles • They have “irritability”=Whole organism response to stimuli Nervous Regulation in Hydra • Neurons • No Brain • 2 way transmission along neuron, not 1 way • Nerve net • Whole body responses to stimuli Nervous Regulation in Worm • Has Central Nervous System – “Brain”-fused ganglia – 2 Nerve cords • Has Peripheral Nervous System – Branching sensory, motor and associative nerves off of CNS • One way transmission Two, ventral nerve cords Periodically there are bulges of cell called ganglia that relay info Peripheral nerves branch off of nerve cord Nervous Regulation in Grasshopper • Central and Peripheral Nervous System • Sensory Receptors like antennae, eyes, tympana • Brain • 2 ventral nerve cords that have ganglia Nervous Regulation in Humans • Central Nervous System – Brain – Dorsal Spinal nerve cord • Peripheral Nervous System – Nerves to and from receptors and effectors Brain • Protected by cranium • You might not realize it, but your brain is a code-cracking machine. • For emaxlpe, it deson't mttaer in waht oredr the ltteers in a wrod aepapr, the olny iprmoatnt tihng is taht the frist and lsat ltteer are in the rghit pcale. The rset can be a toatl mses and you can sitll raed it wouthit pobelrm. • S1M1L4RLY, Y0UR M1ND 15 R34D1NG 7H15 4U70M471C4LLY W17H0U7 3V3N 7H1NK1NG 4B0U7 17 Brain • Covered by Meninges Membranes • Bathed in Cerebrospinal Fluid Parts of Brain • • • • • • Cerebrum Cerebellum Medulla Oblongata Thalamus Hypothalamus Pons Parts of Brain • Cerebrum – Largest part – Divided down the middle into the right and left cerebral hemispheres • Rt Art/Music • Lt Math/Analytical – The nerves that cross the hemispheres are the “corpus callosum” Brain • Cerebrum – Outer Gray Matter ( Cerebral Cortex) • motor neuron cytons and interneurons • Many unmyelinated cells • Processing area of brain • Sensory, motor and associative functions – Speech, thought, hearing, vision, voluntary body movements, memory, smell • Many folds=increase surface area – Inner White Matter region • Mostly region of myelinated axons • Communication of data between sides of cortex • Communication from cortex region and rest of body • Crossed “wires”:Lt side of brain controls Rt side of body and vise versa Compartmentalization Memory Stored in Hippocampus Region Tiered circuits of impulses • Momentary – Lasts minutes • Short-term – Lasts several hours • Long-term – Lasts years – Stored in Cortex Why do casinos stay open all night and have no clocks? Naps boost memory (J. Sleep Research) • As much as a 6 min. nap improves recall – Brain extracts the gist of learned info – Brain files info and combines info with previously learned info – Brain adds meaning to info learned Brain • Cerebellum – Outside has gray matter – Inside has white matter – Coordinates movements Brain • Medulla Oblongata – Lowest brain part – Outside is white matter – Inside is gray – Controls involuntary activities Brain • Thalamus – Relay center – pain • Hypothalamus – Controls body temperature, blood pressure, sleep, emotions – Regulates pituitary gland • Pons – Relay center Brain Waves EEG Behaviors • Reflex – No thought – Response is inborn – Unlearned – Protection or survival-related Behaviors • Instinct – Inborn – Unlearned – Sequence of reflexes with each one triggering the next reflex Behaviors • Conditioned Reflex – Learned behavior together with a reflex Behaviors • Conditioned Response – Associate one stimulus with another Child will associate fear with mice Behaviors • Habit – Behavior requiring no thought – Performed quickly – Not inborn – Desire, Repetition and Satisfaction Behaviors • Imprinting – Behavior patterns developed soon after birth – learned from what ever it thinks to be its parent Spinal Cord • Extends from medulla down through the vertebral column Spinal Cord • Protected by vertebral column Spinal Cord • • • • • Covered by the menenges and CSF Outer White Matter Inner Gray Matter Connects Peripheral Nerve with Brain Controls Reflexes Simple Reflex Arc Peripheral Nervous System • Nerves not of brain and spinal cord – 31 pairs of spinal nerves – 12 pairs of cranial nerves serving eyes, ears, nose, mouth… Two Divisions of Peripheral Nervous System 1. Somatic Nervous System 2. Autonomic Nervous System Somatic Nervous System • Sensory and Motor Neurons dealing with activities that are voluntary (ex. Pick up a book) Autonomic Nervous System • Nerves that facilitate events that are not under voluntary control (ex. Gland contraction) Two Divisions of Autonomic System 1. Parasympathetic Nervous System 2. Sympathetic Nervous System Parasympathetic System Causes impulses for: – Slow heartbeat – Increase peristalsis of digestion – Dilate blood vessels – Constrict urinary bladder – Constrict bronchi – Pupil constricted Sympathetic Nervous System Causes impulses for: – Speed up heart rate – Slow digestion peristalsis – Constricts blood vessels – Relax bladder – Widen bronchi – Dilate pupils • • • • • • • • • • • • • • • • • • • Problems Multiple Sclerosis Schizophrenia Dyslexia Autism ADHD Paralysis Bipolar Syndrome Alzheimer's Disease Cerebral Palsy Parkinson's Disease Headaches Muscular Dystrophy Encephalitis, Meningitis Stroke / "Brain Attack" Epilepsy and Seizures Brain Tumors Polio Addiction/Anxiety/Depression Pinched nerves Headaches Receptor Organs • • • • • Eye Ear Tongue Nose Skin Eye Eye Sclera • Outer layer • White of eye • Provide shape and protection Cornea • • • • • • Front of sclera Bulges outward Thin Transparent Light enters Provides focus Choroid Coat • Beneath Sclera layer • Blood Vessels • Stops reflection inside eye Iris • Front of Choroid coat • Colored • Controls amount of light entering eye like camera shutter • Muscle controlled • Autonomic control Pupil • Hole at center of iris • Light enters Lens • Behind iris • Focuses light on retina • Muscles change shape of lens Retina • • • • Inner layer Image screening Light receptors No receptors where optic nerve exits eye=“blind spot” Retina • Vision: – Rod cells=black and white, low light vision – Cone cells (Red, Green, Blue)=color vision – Cells have Retinal Pigment (Need Vit. A) – Send info out through optic nerve Cavities of Eye • Fluid-filled – Aqueous Humor • Between cornea and lens – Vitreous humor • Jelly • Provides shape • Behind lens Ear • Outer Ear – Pinna • Funnel sound – Auditory Canal • wax Ear • Middle Ear – – – – – Tympanic membrane Hammer Anvil Stirrup Oval Window Membrane – Eustachian Tube Ear • Inner Ear – Cochlea • hearing – Semicircular canals • Balance – Auditory Nerve Skin • • • • Touch receptors Pressure Receptors Pain Receptors Temperature Receptors Tongue • Taste Receptor – “Taste bud” – Substance needs to be in solution to taste – Much of flavor comes from smell Tongue • Tastes and receptor localization (old view) • Evidence shows taste receptors detect all flavors • More sugar binding, more impulses to brain Old Model! • Olfactory cells • Adaptation Nose Problems • Eye – Farsightedness=Can’t see near (Hyperopia) • Eyeball too short Problems • Eye – Nearsightedness=Can’t see far (Myopia) – Eyeball too long Problems • Eye – Astigmatism=Misshaped cornea • Focus problem Problems • Glaucoma – Increased eye pressure – Damage to optic nerve Glaucoma Vision Problems • Cataracts – Lens turns cloudy Cataract Vision Problem • Colorblindness – Problem with cones Stare at center dot for 20sec