Homeostasis and the Organization of the Animal Body Homeostasis Tendency of living things to try to maintain there structure and regulate their internal membrane Body temperature goes up humans sweat to lower it Body temp goes down body shivers to heat you up Example of negative feedback regulation change in one direction is counteracted by a response in the opposite direction Positive feedback regulation ex Having a baby o Pushing on cervics o Hypothalamus can tell posterior pituitary gland to release oxytocin o When muscles receive the hormones they contract Hypothalamus o Oxytocin is given off by the pituitary gland Positive feedback All about sensors and effectors Initial change in one direction sets off a series of events that intensifies a change in that same direction Organization of the animal body Four tissue types 1 Epithelial 2 Connective 3 Muscle 4 Nervous Tissues composed of cells Outermost layer of skin eventually dies At maturity cells are dead skin Dead cells slough off the human body Replaced by the cell division that is taking place Cells Tissues Organs Organ Systems Tissues cells and or non cellular Epithelial Tissue Cells form continuous sheets called membranes cover body and line all body cavities Forms barrier Squamous short squished epithelial cells Columnar long epithelial cells Connective Tissue Surrounded by large quantities of extracellular substances between the living cells which are secreted from the cells of connective tissue Cartilage Skin dermis o Found underneath skin Fat cells adipose Blood cells Tendons and ligaments Bone Lymph stream Muscle Tissue Tissue specialized for contraction Cells that contain actin and myosin Both form muscle fibers alone entire length of a muscle Muscle fibers slide to contract Nerve Tissue Specialized to generate and conduct electrical signals Made of neurons allow for movement o Nerve Cells Reflex response senses pain and loops back to brain to pull hand away from hot plate Organs Formed from two or more tissue types Different organs have different proportion of tissue types Ex Skin 1 Epidermis specialized epithelial tissue 2 Dermis connective tissue 3 Nerve tissue 4 Muscle tissue get notes from missed class Why does blood look red Red blood cells are red Why Hemoglobin which consist of 4 subunits 2 alpha and 2 beta Blood 1 Plasma Major component of blood water or plasma a Proteins and hormones b Nutrients o Also including dissolved gases in plasma CO2 o Sodium chloride etc o Regulate concentration of ion c Gases d Ions e Wastes 1 Cells Major cell components of blood a Red blood cells o No nuclei o They comprise 99 of all blood cells o 1 mL of blood has over 5 billion RBCs o Red color because hemoglobin o Pick up by the blood stream and eventually released by blood stream RBC only last 90 days Have concave shape Hemoglobin Sickle cell anemia individuals produce a hemoglobin protein that clump together to the point that it grossly changes the shape into a sickle shape cell that s why people have a hard time moving oxygen to their cells o Consists of 2 alpha and 2 beta subunits total of 4 subunits and at these sites that individual oxygen bind to produce the ability to move oxygen from our lungs to our body o Found millions per red blood cells o Protein made of polypeptide chains o Oxygen moves into the blood stream from plasma to RBCs o Hemoglobin which has oxygen bonded to it what we called oxygenated blood cells o Oxygen moves by diffusion into cells into mitochondria o Breathe in to bring oxygen to every cells in our body o Exhale to remove CO2 caused by the oxygen RBC regulatory ve feedback Picture from class Oxygen deficiency stimulates erythropoietin epo production by kidneys stimulates red blood cell production in bone marrow causes restored oxygen level inhibits erythropoietin production by kidneys Erythropoietin floods bone marrow cells turn on certain genes to eventually become RBC Negative feedback regulation Low oxygen increases RBC production Study process b White blood cells o Fight infections Types differ in size shape WBC attack bacteria c Platelets Cell fragments o Platelets help form blood clots Blood Clotting 1 Platelets form a plug 2 Thrombin produced from pro 3 Fibrinogen Fibrin 4 More platelets stick 5 Platelets contract Thrombin is active form prothrombin produces thrombin which recognizes the substrate producing a fibrinogen Example Paper cut capillaries are cut lead to bleeding lead to thrombin which recognizes substrate etc Clot forming in wrong part of body can be deadly Blood vessels Heart arteries arterioles capillaries venules veins heart Name of artery that carries away from heart Capillaries site of exchange for entire body to every single cell 1 Arteries and arterioles o carry blood away from the heart o think walls o Artery consist of three different tissues which means they are organs Organ within a organ system 2 Capillaries o Where the exchange of wastes nutrients gases and hormones between blood and body cells occur o Thin tubes with walls only one cell thick so that dissolved material can diffuse in and out o So narrow that RBCs must pass through them in single file Histamines bind to wall of capillaries making them larger allowing more to flow through Moving by diffusion from high to low concentration 3 Venules and Veins o Provide low pressure pathways for blood back to the heart o Walls are much thinner Compressing blood cells contracting muscles manipulates 1 Help move blood up 2 Increase overall blood pressure Heart disease is caused when plaque builds up in the coronary artery blocking blood flow and oxygen to the heart Heart disease High cholesterol is heart disease What is it Who gets it What causes it How do you prevent it How is it treated o Some drugs decrease plaque build up o Drugs that lower Chloestrol What percentage of deaths in USA o Heart disease is more common when youre older o In foreign countries humans usually die earlier in life before they could encounter heart disease o Number one cause of death around country infectious bacteria etc What is a heart attack Respiratory System 2 or more tissue type In a stroke cells located in die Cyanide goes into respiratory system then transported throughout body Cellular respiration 1 Done by mitochondria 2 Requires oxygen 3 Generates carbon dioxide as a waste 4 ATP energy generated during this process Respiratory system Body has to have a way to move oxygen in and carbon dioxide out 1 Requires large moist surface
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