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York University
Kinesiology & Health Science
KINE 2011
Gillian Wu

Chapter 1 TISSUES 1. Muscle Tissue - skeletal muscle: moves the skeleton - cardiac muscle: pumps blood out of the heart - smooth muscle: encloses and controls movements of contents through hollow tubes and organs, such as the movement of food through the digestive tract 2. Nervous Tissue - Consists of cells specialized for initiating and transmitting electrical impulses - Sometimes over long distances - Signals information from one part of the body to another - Found in the brain, spinal cord and nerves 3. Epithelial Tissue - Consists of cells specialized for exchanging materials between the cell and its environment. - ANY substance that enters of leaves the body must cross an epithelial barrier - 2 general types of structures: epithelial sheets and secretory glands - Join very tightly to form sheets of tissue that cover and line various parts of the body (i.e. outer layer of the skin & lining of the digestive tract) - Epithelial sheets serve as boundaries that separate the body from the external environment and from the contents of cavities that open to the external environment, i.e. the digestive tract lumen - A lumen is a cavity within a hallow organ or tube - Epithelial barriers allow selective transfer of materials 4. Glands - Epithelial tissue derivatives specialized for secreting - Secretion is the release from a cell, in response to appropriate stimulation, of specific products that have been produced by the cell - Formed during embryonic development by pockets of epithelial tissue that dip inward from the surface and develop secretory capabilities - Two categories: exocrine and endocrine - If, during development, the connecting cells between the epithelial surface cells and the secretory gland cells within the depths of the invagination remain intact as a duct between the gland the surface, an exocrine gland is formed. If the connect cells disappear during development and the secretory gland cells are isolated from the surface, an endocrine gland is formed. - Exocrine glands secrete through ducts to the outside of the body (exo means external; crine means secretion). Sweat glands and glands that secrete digestive juices are examples - Endocrine glands lack ducts and release their secretory products known as hormones internally into the blood (endo means internal). For example the pancreas secretes insulin into the blood which transports this hormone. 5. Connective tissue - Relatively few cells dispersed within an abundance of extracellular material - Connective tissue connects, supports, and anchors various body parts - Includes loose connective tissue that attaches epithelial tissue to underlying structures; tendons, which attach skeletal muscles to bones; bone, which gives the body shape, support and protection; and blood, which transports materials from one part of the body to another - Other than blood, cells of connective tissue produce specific structural molecules that they release into the extracellular spaces between the cells. For example, the rubber-band like protein fibre elastin, whose presence facilitates the stretching and recoiling of structures, such as the lungs, which inflate and deflate during breathing. Tissue: to mean the aggression of various cellular and extracellular components that makes up a particular organ (i.e. lung tissue or liver tissue). Body system level are a collection of organs that perform related functions and interact to accomplish a common activity that is essential for survival of the whole body. For example, the digestive system consists of the mouth, salivary glands, pharynx (throat), esophagus, stomach, pancreas, liver, gallbladder, small intestine, and large intestine. - Human body has 11 systems: circulatory, digestive, respiratory, urinary, skeletal, muscular, integumentary, immune, nervous, endocrine and reproductive HOMEOSTATIS - The key is the presence of a watery internal environment with which the body cells are in direct contact and make life-sustaining exchanges. Body Cells - Intracellular fluid (ICF) is the fluid with all body cells - Extracellular fluid (ECF) is the fluid outside the cells; this is the internal environment of the body, the fluid environment in which the cells live. - ECF is made up of two components: plasma (fluid portion of the blood) and interstitial fluid (surrounds and bathes the cell) Body systems – the body cells can live and function only when the extracellular fluid is compatible with their survival; thus, the chemical composition and physical state of this internal environment must be maintained within narrow limits. For example, as cells take up nutrients and oxygen from the internal environment, these essential materials must constantly be replenished. Homeostasis is essential for survival of each cell, and each cell, through its specialized activities, contributes as part of a body system to the maintenance of the internal environment shared by all cells. Cells make up body systems, body systems maintain homeostasis which is essential for survival of all cells. FACTORS HOMEOSTATICALLY REGULATED (See page 10) 1. Concentration of nutrient molecules 2. Concentration of Oxygen and Carbon dioxide 3. Concentration of waste products 4. pH 5. Concentration of water, salt and other electrolytes 6. Volume and pressure 7. Temperature CONTRIBUTIONS OF THE BODY SYSTEMS TO HOMEOSTASIS 1. The circulatory system - Transports materials such as nutrients, oxygen and co2, wastes, electrolytes and hormones from one part of the body to another. - Also helps with thermoregulation by moving heat to the periphery from the core 2. The digestive system - Breaks down dietary food into small nutrient molecules that can be absorbed into the plasma for distribution to the body cells - Transfers water and electrolytes from the external environment into the internal environment - Eliminates undigested food residues to the external environment in the feces 3. The respiratory system - Consists of the lungs and major airways - Receives O2 and eliminates CO2 from the external environment - By adjusting the rate of removal of acid-forming CO2, the respiratory system is also important in maintaining the proper pH of the internal environment 4. The urinary system - Removes excess water, salt, acid and other electrolytes from the plasma and eliminates them in the urine, along with waste products other than Co2. - Includes in the kidneys and associated “plumbing” 5. The skeletal system (bones, joints) - Provides support for the soft tissues and organs - Serves as a storage reservoir for calcium (CA2+), an electrolyte whose plasma concentration must be maintained with very narrow limits. - The bone marrow – the soft interior portion of some types of bone – is the ultimate source of all blood cells 6. The muscular system (skeletal muscles) - Skeletal muscles and skeletal system form the basis of movement - Attach via tendons to bones - Muscles contract – bones move and we walk, grab and jump - In a homeostasis perspective, it allows us to move toward food or away from harm - Heat generated is important for temperature regulation - Voluntary control of muscles – range from the fine motor skills required for delicate needlework to the powerful movements involved in weight lifting, are not necessarily directed towards homeostasis 7. The integumentary system (skin, hair, nails) - Serves as an outer protective barrier that prevents internal fluid from being lost from the body and foreign microorganisms from entering - This system is also important in regulating body temperature - Amount of heat lost from the body surface to the external environment can be adjusted by controlling sweat production and by regulating the flow of warm blood through the skin 8. The immune system (white blood cells, lymphoid organs) - Defends against foreign invaders and body cells that have become cancerous - Also paves the way for repairing or replacing injured or worn-out cells 9. The nervous system (brain, spinal cord, nerves) - 1 of 2 major regulatory systems of the body - Controls and coordinates body activities that require swift responses - Very important in detecting and initiating reactions to changes in the external environment - Responsible for higher functions that are not entirely directed toward maintaining homeostasis such as consciousness, memory and creativity 10. The endocrine system - The other major regulatory system (and a communication system) - Unlike the nervous system (body‟s fast communication system), in general the hormone-secreting glands of the endocrine system regulate activities that require duration rather than speed, such as growth - Important in controlling the concentration of nutrients - Adjusts kidney function to control internal environment‟s volume and electrolyte composition 11. The reproductive system - Is not essential for homeostasis and therefore is not essential for survival of the individual - Essential for perpetuating the species HOMEOSTATIC CONTROL SYSTEMS - a functional interconnected network of body components that operate to maintain a given factor in the internal environment relatively constant around an optimal level To maintain homeostasis the control system must be able to: 1. Detect deviations from normal in the internal environmental factor that needs to be held within narrow limits 2. Integrate this information with any other relevant information 3. Make appropriate adjustments in the activity of the body parts responsible for restoring this factor to its desired value Can be grouped into two classes: intrinsic and extrinsic controls Intrinsic (local) controls – built into or are inherent in an organ Extrinsic controls are regulatory mechanisms initiated outside an organ to alter the activity of the organ. This is accomplished by the nervous and endocrine systems, the two major regulatory systems of the body. Most factors in the internal environment are maintained by extrinsic controls. (Read about negative-feedback control page 16) Negative Feedback – a control system‟s output is regulated to resist change so that the controlled variable is kept at a relatively steady set point. That is, a corrective adjustment opposes the original deviation from the normal desired level. For example, a common example of negative feedback is the control of room temperature. It is a controlled variable, a factor that can very but is held within a narrow range by a control system. Positive feedback – output enhances or amplifies a change so that the controlled variable continues to move in the direction of the initial change. Pathophysiology – abnormal functioning of the body (altered physiology) associated with disease. Chapter 2 Cells are the body‟s living building blocks. Just as the body as a whole is highly organized, so too is a cell‟s interior. A cell has 3 major parts: 1. Plasma membrane encloses the cell. 2. Nucleus, which houses the cell‟s genetic material 3. Cytoplasm, which is organized into discrete, highly specialized organelles dispersed throughout a gel-like liquid, the cytosol. The cytosol is pervaded (encompassed) by a protein scaffolding, the cytoskeleton, that serves as the “bone and muscle” of the cell. The plasma membrane, aka cell membrane, is a very thin membranous structure that encloses each cell. The oily barrier separates the cell‟s contents from its surroundings: it keeps the intracellular fluid (ICF) within the cells from mingling with the extracellular fluid (ECF) outside the cells. The plasma membrane is not simply a mechanical barrier to hold in the contents of the cells: it also has the ability to selectively control movement of molecules between the ICF and ECF. The plasma membrane is like the gated walls that enclosed ancient cities. Through this structure, the cell can control the entry of food and other needed supplies and the export of products manufactured within, while at the same time guarding against unwanted traffic into or out of the cell. NUCLEUS Two major parts of the cell‟s interior are the nucleus and the cytoplasm. The nucleus, which is typically the largest single organized cell component, can be seen as a distinct spherical or oval structure, usually located near the centre of the cell - It is surrounded by a double-layered membrane, the nuclear envelope, which separates the nucleus from the cytoplasm. - The nuclear envelope is pierced by many nuclear pores which allow necessary traffic to move between the nucleus and the cytoplasm - Nucleus houses the cells genetic material, deoxyribonucleic acid (DNA) which has 2 important functions: 1. Directing protein synthesis 2. Serving as a genetic “blueprint” during cell replication 3 types of ribonucleic acid (RNA) play a role in cell protein synthesis. First, DNA‟s genetic code for a particular protein is transcribed into a messenger RNA molecule, which exits the nucleus through the nuclear pores (portholes). Within the cytoplasm, messenger RNA delivers the coded message to the ribosomes, which “read” messenger RNA‟s code and translate it. Ribosomal RNA is an essential component of ribosomes Finally, transfer RNA transfers the appropriate amino acids within the cytoplasm to their designated site in the protein under construction CYTOPLASM - The portion of the cell‟s interior not occupied by the nucleus - Contains a number of distinct, highly organized, membrane-enclosed structures-the organelles dispersed within the ytosol, which is a complex, gel- like liquid. - Nearly half of the total cell volume is occupied by organelles - Nearly all cells contain 6 main types of organelles – the endoplastic reticulum, Golgi complex, lysosomes, peroxisomes, mitochondria, and vaults. - Organelles are like intracellular “specialty shops” CYTOSOL Remainder of the cytoplasm not occupied by organelles consists of the cytosol (“cell liquid”) - The cytosol is made up of a semiliquid, gel-like mass laced with an elaborate protein network known as the cytoskeleton - Cytoskeletal network gives the cell its shape, provides for its internal organization and regulates its various movements - ICF comprises all the fluid contained within the plasma membrane including the cytosol ENDOPLASTIC RETICULUM - Endoplastic reticulum (ER) is an elaborate fluid-filled membranous system distributed extensively throughout the cytosol. - Protein and lipid-assembly line - Smooth ER is meshwork of tiny interconnected tubules, the rough ER projects outward from the smooth ER as stacks of relatively flattened sacs. ROUGH ER - small, dark protein-assemblers (workbenches) called ribosomes, which give the rough ER its granular (rough) appearance - Ribosomes bind to the ER once protein synthesis (assembly begins) - Works with the Golgi Complex to assemble new proteins and get them to their proper destinations; synthesizes and releases a variety of new proteins - Rough ER is most abundant in cells specialized for protein secretion (i.e. cells that secrete digestive enzymes) or in cells that require extensive membrane synthesis (i.e. rapidly growing cells, such as immature egg cells) - When the rough ER synthesizes a protein it cannot pass through the ER membrane and is permanently separated from the cytosol BUT it can do so through the action of the smooth endoplasmic reticulum (the “transporter”). These proteins serve one of two purposes: 1. some proteins are destined for export to the cell‟s exterior as secretory products, such as protein hormones or enzymes (all enzymes are proteins) 2. other proteins are transported to sites within the cell for use in constructing new cellular membrane (either new plasma membrane or new organelle membrane) or other protein components of organelles Smooth ER - Lacks ribosomes so it is “smooth” - No ribosomes = no protein synthesis - Abundant in cells that specialize in lipid metabolism – cells that secrete lipid- derived steroid hormones (i.e. liver) - In the liver, smooth ER contains enzymes to detoxify harmful substances produced within the body by metabolism or substances that enter the body from the outside like drugs - Muscle cells have an elaborate, but modified smooth ER known as the sarcoplasmic reticulum, which stores calcium. Calcium plays an important role in attachment of the myosin head to the actin which facilitates muscle contraction and movement - Rather sparse and serves primarily as a central packaging and discharge site (central shipping) for molecules to be transported from the ER - Newly synthesized proteins and lipids pass from the rough ER to gather in the smooth ER. Portions of the smooth ER then “bud off” on the surface, forming transport vesicles that contain the new molecules enclosed in a spherical capsule of membrane derived from the smooth ER membrane. - Smooth ER is like a seaport where ocean-going ships (vesicles) are sent off to another destination (the Golgi complex) after being loaded with their cargo (protein, lipids) The Golgi complex is closely associated with the endoplasmic reticulum. Each Golgi complex consists of a stack of flattened, slightly curved, membrane-enclosed sacs, or cisternae. The flattened sacs are thin in the middle but have dilated or bulging edges. Transport Vesicles 1. The raw materials are processed into finished products. Within the Golgi complex, the “raw” proteins from the ER are modified into their final form, for example, by having sugar attached to them during glycosylation (a process that links saccharides to produce glycans, either free or attached to proteins and lipids). The biochemical pathways that the proteins undergo during their passage through the Golgi complex are elaborate, precisely programmed, and specific for each final product. 2. The finished products are sorted and directed to their final destinations. The Golgi complex is responsible for sorting and segregating different types of products according to their function and destination, namely products (1) to be secreted to the cell‟s exterior (2) to be used for construction of new plasma membrane, or (3) to be incorporated into other organelles, especially lysosomes. (READ PROCESS pg. 26-29) Secretory Vesicles - Docking marker (like an address on an envelope) - Each vesicle ca
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