Homeostasis and Body Systems Review of Systems Homeostasis, Feedback Systems Endocrinology/Cell communication Nervous System Immune System

R E S P I R A T O R Y

Respiratory Systems of Vertebrates *Lung surface area and moist outer skin p.975 Fig 45.5 Fish: Gill countercurrent exchange; swim bladder for bouyancy Become more efficient: Increased surface area Birds are Most efficient- 2 cycles of inhalation and exhalation to support a one-way flow of air through the lungs. Highly efficient Text-p974-975

Gas Exchange in Animals

CIRCULATORY…

Heart Structure differences in Vertebrates “Double Pump” More efficient O2 distribution; not all separate Advantage: Separation of O2 rich and poor blood- more O2 available to tissues

Mechanical And Chemical DIGESTIVE Mechanical And Chemical

EXCRETORY Nephron Osmoregulation

Nitrogenous Wastes: NH3 Ammonia- highly toxic- directly into water in aquatic species; converted to urea in the liver. Uric Acid- insoluble ‘paste’ Urea- produced in the liver from toxic ammonia(NH3 + CO2) NH3 Text p1016 Fig 47.6

Do Fish Drink? *ABSORB DRINK

Musculo- Skeletal

Anatomy and Physiology SYSTEMS: Endocrine, Nervous, Immune

S Y T E M

HOMEOSTASIS Requirements of Organisms: water – most abundant chemical in body; many functions; required for metabolism & transport of substances nutrients (food) – for energy, structural support, cellular reactions oxygen – for cellular respiration to create energy, which drives metabolism heat – to maintain normal body temperature (~98˚F or 37˚C) – helps to maintain normal reaction rates pressure – normal atmospheric pressure required for proper breathing; normal hydrostatic pressure maintained in blood

Homeostasis Ch. 48 Endocrine Regulation The body has the ability to regulate its internal environment (job of the Nervous and Endocrine systems) dynamic equilibrium Homeostasis involves regulating: Blood levels of vital substances (Oxygen, glucose) Heart rate and blood pressure N-waste and removal Body temperature Rate and depth of breathing etc Regulation is accomplished by Feedback Mechanisms of two types: 1. Negative Feedback “NFM” 2. Positive Feedback “PFM” Positive and Negative Feedback 14.0

Negative Feedback Mechanisms Most F.M. are negative Maintain some physiological function or keep blood chemicals within a safe range Decrease or shut off original stimulus/reduce intensity; return from too high/too low Return stimulus back to a setpoint (proceed in the opposite direction) Ex: Control of Glucose levels, Body temperature

Regulation of Blood Glucose Levels by Negative Feedback 2 3 (beta) 1 1 2 (alpha) 3 Diabetes and Insulin 7.24 Plasmids, Recombinants 4.14

Anti-Diuretic Hormone (ADH)

Hormonal Controls of Ionic Ca++ levels in Blood Stimulate Thyroid (calcitonin): when Ca++ too HIGH (and slows PTH) Stimulate Parathyroid (PTH): when Ca++ too LOW. TARGETS? Bone Kidney Digestion/SI 1 2

Positive Feedback Mechanisms Control episodic (infrequent) events that do not require continuous adjustments Result in enhancing or exaggerating the original stimulus so that the activity (output) is accelerated Accelerates in the same direction until the original stimulus is gone. (the change proceeds in the same direction) Set off a series of events that may be self-perpetuating Ex: Blood-clotting, enhancement of labor contractions during giving birth

Positive feedback loop… enhancing original stimulus *Also released during breast feeding….contraction of smooth muscle, milk glands /uterus

“Classic” endocrine signaling Hormones -transported by the blood (some dissolved in plasma, some bound to proteins) and produce a response only after they reach target cells and bind with specific receptors. Target cells- another endocrine gland or another organ. Hormones are removed from the blood by the liver (inactivates) and by the kidney (secretes).

Reception Transduction Response animation

Hormones that work through secondary messengers 1. First messenger (ligand) binds a cell surface receptor (membrane protein) 2-3. Creates a series of membrane-bound reactions to activate an effector (G-protein-relay-enzyme) 4. Generates/activates the second messenger molecule- cAMP ) Text p 1035 Fig 48-5 5. Signal Transduction Pathways 9.24

Lipid/Steroid Hormone vs Protein Hormones

Master Gland- secretes hormones that manage the other glands Regulates Ca++ levels in blood Increase metabolic rate; lowers Blood Ca ++ levels Consists mostly of “T” cells; role in immune system Stress; metabolic rate; HR/BP Endocrine AND digestion *Glucose Sex characteristics 1. and Hypothalamus ( Links NS/End.sys) 3. 2. (Whole gland) (four dots) 4. Thymus 5. 6. Islets of Langerhans 7. 8. Chapter 48 p1037-8

Endocrine System Locations

Anterior Lobe of the Pituitary Most use classical endocrine signaling Regulated by the hypothalamus (oxytocin, ADH)

Thyroid Hormone Increases the overall metabolic rate, regulates growth and development as well as the onset of sexual maturity, plays a role in the regulation of calcium. Hormone Cascade Pathway- stimulus to response - Handout

How the Mammalian Kidney Concentrates Urine Reabsorption to blood Filtration Secretion Secretion Glomerular Filtration (180L/24hrs; 99% reabsorbed) Reabsorption (~65%); secretion (local cells) Descending loop: Permeable to H2O, less to NaCl (Concentrates urine) Ascending loop: more permeable to NaCl (reset Concentration Gradient- dilutes urine) Reabsorption; secretion (local cells) Collecting duct- concentrates urine Counterflow of fluid Text p 1022

How the Mammalian Kidney Concentrates Urine Text p 1023

Hormonal Regulation of the Kidney: ADH Thirst (dehydrated; rise in Na+ in blood) Cells of distal tubule and collecting duct become more permeable to water, so more water is reabsorbed back in to the bloodstream.

Chemical Signals - Communication Coordinated by nervous and endocrine systems Chemical Signals: Hormones: Between organs of the body Ductless glands > Blood stream > receptor on target cell (shape specific) *Homeostasis Pheromones: Between Individuals of same species Chemical signal, small amounts, social behavior Local Regulators: *short range; between cells. Diffuses through interstitial fluid and acts on same cell/nearby cells. Other messengers: neurotransmitters, growth factors, nitric oxide gas, histamine, prostaglandin *immune system

Relationships between Nervous & Endocrine systems Structural Many endocrine glands possess nerve tissue; nervous system helps regulate endocrine responses. Chemical Some hormones used as signals in both systems (Example- norepinephrine) Functional Each system can affect the output of the other Endocrine system responds slower than the nervous system, has a wider range of target cells, but has a longer lasting response.

The Nervous System Chapter 40

3 4 2 5 1 7 or 6 8 or 9

Neuron * - * - *

Reflexes: Involuntary responses to sensory information FYI…

Reflex Arc (1): Sensory (PAIN!!) to (2) Afferent neuron (3): Association neuron/spinal cord (4): Efferent neuron to (5) Motor (MOVE!!)

White Matter: Myelinated Grey Matter: Cell bodies/Unmyelinated

Synaptic Cleft - Neurotransmitters

In Note Packet

Action Potential Depolarization: Na+ gates open Na+ Rushes in… Repolarization: Na+ gates close K+ gates open K+ Rushes out Action Potential 5:39 *Neuro-Muscular Action Potential in Packet, p2

*ONE Pump: does 450:300 Sodium OUT:Potassium IN every SECOND ACTIVE TRANSPORT: Na-K Pump THREE Sodium in, TWO Potassium out…. Normal function- (INSIDE of the cell overall NEGATIVE CHARGE at ‘resting potential’….important for Action Potential) **REVIEW….. *ONE Pump: does 450:300 Sodium OUT:Potassium IN every SECOND

The Immune System First Line of Defense: Barriers to pathogens Nonspecific Second Line of Defense: The Inflammatory Response nonspecific Third Line of Defense: Specificity and Diversity TEXT- Chapter 48

Lymphatic System Vessels that transport fluids back to the blood One way system; valves Lymphoid Organs: Nodes Tonsils, Thymus, Spleen Peyer’s patches- Intestines Lymphoid Tissues: (MALT) Mucosa/Walls of lungs & intestines appendix Immune System Cells: WBC “leukocytes” (5-10,00/mm3) Lymphocytes: NK, T, B cells (circulate in lymph and blood) Phagocytes: Neutrophils (50-70%) Macrophages (APC’s) Dendritic cells (APC’s)

A myeloid stem cell matures into a myeloid blast A myeloid stem cell matures into a myeloid blast. The blast can form a red blood cell, platelets, or one of several types of white blood cells. A lymphoid stem cell matures into a lymphoid blast. The blast can form one of several types of white blood cells, such as NK, B or T cells. FYI….

FYI…

Recognizing Self vs Non-self cells Body’s cells must have: “Self-markers” a collection of molecules called MHC (Major Histocompatibility complex- a protein complex) Imbedded in the cell membrane No two complexes are alike* …A biochemical ‘fingerprint’ 2 classes of MHC molecules: Class I on all nucleated cells Class II on macrophages and B cells MHC + Antigen = Antigen Presenting Cell (APC) Impaired System?

First, Second and Third Lines of Defense *Skin,*Mucous Membranes/cilia *Stomach acids *Histamine *WBC’s PhagocytesNK cells *Interferons *Fever Nonspecific Mechanisms: Responds to all invaders; 1st (external) & 2nd (internal) Specific: responds to specific invader; “True immune system” Works simultaneously with 2nd line of defense Phagocytes- APC’s, Lymphocytes- “The STARS of the IS”: B cells and T cells

Second line of defense: Inside *Chart in Note Packet PATHOGEN INVADES SPECIFIC (ADAPTIVE) “third line of defense” NONSPECIFIC (INNATE) Second line of defense: Inside ‘B’ ‘T’ WBC’s: Neutrophils (70%) ~20 pathogens/die Monocytes- Dendritic; Macrophages ~100 pathogens/die NK cells Basophils- Allergy Eosinophils- Parasite 2.19 Chemical Mediators- ’Reinforcements’- Phagocytosis; Inflammation Cytokines: interleukins (‘between’ WBC’s), interferons (antiviral) Complement: 20 different; chemotaxis, cell lysis Pyrogens: Body Temperature (fever) NK cells 3.02

Inflammatory Response Dilates vessels, Increase blood flow, more permeable- leads to swelling *If there is a severe infection (systemic)- Stimulates Bone marrow - release more WBC’s Fever- Pyrogens released by WBC’s

The Third Line of Defense *Antibodies immobilize pathogens until phagocytes and “complement” chemicals destroy them *Cells already infected. T cells bind to and destroy infected cells/cancer cells

Antigen-Antibody Binding site

Third Line of Defense: Specificity and Diversity Antigen Pathogen Macrophage “APC” (MHC + antigen = APC) T Helper: “Th” B cell T Cytotoxic “Tc” Active “effector” vs Memory 1 macrophage 2 3 4 5 6 8 7

“Call 911” Cytotoxic T cell .17

Central Role of Helper T-cells Interleukin-1 and 2 and other cytokines activate Th cells, B cells, and Tc cells (In Note Packet) T cells produced in the bone marrow; mature in the thymus gland. Helper T (Th or CD4*) Cytotoxic C (Tc or CD8)

AIDS HIV Lifecycle 4.52 Aids and the Plague 7.26

Clonal Selection of B cells Produced and mature in the bone marrow Once activated by the matching antigen, differentiates into plasma or memory cells One plasma cell can produce > 1 mill. antibody/hr Proliferation to form a clone Secreted into circulation

The Immune Response: Third Line of Defense: B Cells (Humoral) Antibody Production

1st and 2nd Lines of Defense Phagocytes, NK cells w/ perforin, Complement APOPTOSIS (Cell Death) vs LYSIS (Cell Bursting)

Induced/Adaptive Immunity Takes 7-14 days; long lasting protection Immediate, short term protection You get sick > make AB’s, memory cells Ex- Chicken pox, measles Flu, shingles vaccine, infant vaccines Fetus gets AB’s from mother infant through placenta, breast milk -Injection of Gamma globulin after exposure to dangerous disease (viral hepatitis) -Antitoxin after being bitten by poisonous snake