Human organization lecture

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Human organization lecture

  1. 1. Human Organization Module 2 Chapter 4
  2. 2. Levels of Organization molecules → cells→ tissues → organs → organ system
  3. 3. Tissue  A collection of cells of the same type that perform a common function  There are 4 major tissue types in the body: 1. Connective 2. Muscular 3. Nervous 4. Epithelial
  4. 4. Connective Tissue  Binds and supports parts of the body  All have specialized cells, ground substance and protein fibers  There are three main types of connective tissue: A. fibrous , B. supportive and C. fluid
  5. 5. Connective Tissue
  6. 6. Ground Substance  Ground substance is noncellular and ranges from solid to fluid  The ground substance and protein fibers together make up the matrix of the tissue
  7. 7. Fibres  Collagen: white, gives flexibility and strength  Reticular: thin collagen, branched, support network  Elastic: yellow, elastin, very flexible protein, not as strong as collagen
  8. 8. Specialized Connective Tissue Cells  Blood cells  Mast cells  Stem cells  Adipose cells  Fibroblasts
  9. 9. Fibrous Connective Tissue  There are two types: dense or loose, but both contain fibroblast cells with a matrix of collagen and elastic fibers  Loose fibrous tissue is found supporting epithelium and many internal organs  Adipose tissue is a special loose fibrous tissue where fat is stored
  10. 10. Fibrous Connective Tissue Loose Fibrous (areolar tissue) Dense Fibrous 1. Supports epithelium and internal organs Many tightly packed collagen fibres 2.Allows for expansion of organs ie bladder, lungs Tendons (connect muscle to bone) 3.Protective covering for internal organs ie muscle, nerves, blood vessels Ligaments (connects bone to other bones at joints) Adipose tissue special type, enlarged cells to store fat Fat used for energy, insulation and protection under skin, around organs and on surface of heart Matrix for both has collagen and elastin fibres Ground substance is gel-like
  11. 11. Fibrous Connective Tissue
  12. 12. Supportive Connective Tissue  Cartilage:  Cells are in chambers called lacunae  Ground substance (matrix) is solid but flexible  No direct blood supply  3 types are distinguished by types of fibers
  13. 13. Types of Cartilage  Hyaline cartilage – most common type, fine collagen fibers  Location: Nose, ends of long bones and fetal skeleton  Elastic cartilage – more elastic fibers than cartilage fibers, more flexible  Location: Outer ear, epiglottis  Fibrocartilage – strong collagen fibers, withstand tension and pressure  Location: Disks between vertebrae, knee
  14. 14. Supportive Connective Tissue  Bone:  Cells are in chambers called lacunae  Matrix is solid and rigid that is made of collagen and calcium salts  Most rigid connective tissue  Has nerve cells and blood supply  2 types are distinguished by types of fibers
  15. 15. Types of Bone  Compact: Location: Shafts of long bone  Spongy: Location: Ends of long bones  Composition of bone will be studied in more depth with Skeletal System
  16. 16. Fluid Connective Tissue  Blood:  Often not considered connective tissue, but vascular tissue  Made of a fluid matrix called plasma and cellular components that are called formed elements  Formed elements: red and white blood cells and platelets
  17. 17. Blood: Formed Elements  3 formed elements:  Red blood cells: cells that carry oxygen  White blood cells: cells that fight infection  Platelets: pieces of cells that clot blood
  18. 18. Fluid Connective Tissue  Lymph:  Clear, watery, yellowish fluid (lymph) made by lymphatic tissue  White blood cells congregate in this tissue  Absorb excess tissue fluids and transport dissolved solutes and fat molecules  Lymph nodes clean lymph  Help fight infection
  19. 19. Muscle Tissue  Allows for movement in the body  Made of muscle fibers/cells and protein fibers called actin and myosin  There are 3 types of muscle tissue in humans:  A. Skeletal  B. Smooth  C. Cardiac
  20. 20. Muscle Tissue: Skeletal  Appearance: long, cylindrical cells, multiple nuclei, striated fibers (light and dark bands of actin and myosin)  Location: attached to bone for movement  Nature: voluntary movement
  21. 21. Muscle Tissue: Smooth  Appearance: spindle- shaped cell with one nucleus, lack striations  Location: walls of hollow organs (eg. Intestine, bladder, etc) and blood vessels  Nature: involuntary movement
  22. 22. Muscle Tissue: Cardiac  Appearance: branched cells with a single nucleus, striated  Location: heart  Nature: involuntary movement
  23. 23. Nervous Tissue  Allows for communication between cells through sensory input, integration of data and motor output  Made of 2 major cell types: A. Neurons B. Neuroglia
  24. 24. Neurons  Made of dendrites, a cell body and an axon  Dendrites carry information toward the cell body  Axons carry information towards a cell body
  25. 25. Neuroglia  A collection of cells that support and nourish neurons  Outnumber neurons 9:1  Examples are oligodendrocytes, astrocytes and microglia
  26. 26. Epithelial Tissue  A groups of cells that form a tight, continuous network – have a basement membrane  Lines body cavities, covers body surfaces and found in glands  protective covering, secretion, absorption, excretion, filtration  Types: simple, stratified  Basement Membrane:  Thin layer of carbohydrates and proteins used to anchor epithelial tissue to underlying connective tissue
  27. 27. Simple Epithelia  Number of cell layers:  Simple: one layer of cells  Stratified: more than one layer of cells  Pseudostratified: appears to have layers but only has one layer  Shape of cell:  Cuboidal: cube-shaped  Columnar: column-shaped  Squamous: flattened
  28. 28. Glands  epithelial tissue that secrete substances are termed glandular epithelial.  may be single cells (sweat and mucous glands) or multiple (endocrine glands eg.pancreas)
  29. 29. Cell Junctions  Epithelial cells cover the surface of organs and line body cavities.  Depending on their location, their function at that site dictates the manner in which they are connected to each other and to nerves and muscles.
  30. 30. Cell Junctions  If the epithelial layer must be impermeable, proteins will join each cell forming a tight junction. This occurs in stomach, intestines and kidneys.  Tissue that is exposed to mechanical stress is joined by adhesion junctions. Proteins again join the epithelial cell, but allow some stretching of the cells by creating a small space between the cell membranes. These junctions are found in skin.
  31. 31. Cell Junctions  If some communication must occur throughout a tissue, the junction must allow for some ions and molecules to pass from one cell to another.  The gap junction makes up part of the cardiac muscle, allowing electrical impulses to coordinate one heart beat.
  32. 32. Cell Junctions
  33. 33. The integumentary system  Includes the skin and accessory organs such as hair, nails and glands  The skin has two main regions called the epidermis and the dermis  Under the skin there is a subcutaneous layer between the dermis and internal structures where fat is stored  Is important for maintaining homeostasis
  34. 34. Function 1. Protects the body from physical trauma, invasion by pathogens and water loss 2. Helps regulate body temperature 3. Allows us to be aware of our surroundings through sensory receptors 4. Synthesizes chemicals such as melanin and vitamin D
  35. 35. Skin Layers
  36. 36. Epidermis  The thin, outermost layer of the skin  Made of epithelial tissue  Cells in the uppermost cells are dead and become filled with keratin thus acting as a waterproof barrier
  37. 37. Epidermis continued  new cells constantly being produced at innermost layer by stem cells  Langerhans cells are a type of white blood cell that help fight pathogens  Melanocytes produce melanin that lend to skin color and protection for UV light  Some cells convert cholesterol to vitamin D
  38. 38. Dermis  The thick, inner layer of the skin  Made of dense fibrous connective tissue  Contains elastic and collagen fibers  Contains blood vessels, many sensory receptors and glands
  39. 39. Dermis  sebaceous (oil) glands secrete sebum. The oil moves to epidermis layer to act as protectant, lubricant and waterproof  sweat glands for body temperature control and also anti-bacterial
  40. 40. Subcutaneous Layer  Located below the dermis, this layer is the site of “subcutaneous” injections. It is made up of adipose and loose connective tissue.  The subcutaneous layer is NOT part of the skin. Its function is protection and an energy source.
  41. 41. Accessory Organs  originate in the epidermal layer  Includes nails, hair and glands  Nails  nail roots begin in epithelial layer  cuticle protects root  lunula (half-moon) is thick cell layer  nail made up of keratin (protein)
  42. 42. Accessory Organs  Hair  follicles start as bulb in dermis and grow to outside epidermis  colour dictated by melanin (and iron and sulfur content in the pigment)  muscles cause hair to become erect  Sweat Glands  present in all regions of skin  begins in dermis  opens to epidermis or hair follicle  help to control body temperature
  43. 43. Moving from tissue to organs and organ systems  An organ is 2 or more tissue types working towards a particular function  An organ system is a combination of organs that work together to carry out a particular function
  44. 44. Body Cavities
  45. 45. Membranes  Mucous membranes – lining of the digestive, respiratory, urinary and reproductive systems  Serous membranes – line lungs, heart, abdominal cavity and cover the internal organs; named after their location • Pleura: lungs • Peritoneum: abdominal cavity and organs • Pericardium: heart  Synovial membrane – lines the cavities of freely movable joints  Meninges – cover the brain and spinal cord
  46. 46. Homeostasis Maintaining relative constancy within an environment.  Warm blooded animals maintain a constant internal environment by communication between organ systems  If constancy is not maintained, illness results  The endocrine and nervous system play a major role in maintaining homeostasis  Regulation is monitored and controlled by feedback mechanisms
  47. 47. Negative Feedback  The primary mechanism for maintaining homeostasis  Has two components: • sensor • control center  The output of the system dampens the original stimulus
  48. 48. Negative Feedback  Eg. maintaining body temperature
  49. 49. Positive Feedback  A mechanism for increasing the change of the internal environment in one direction  An example is the secretion of oxytocin during birth to continually increase uterine contractions  Can be harmful such as when a fever is too high and continues to rise
  50. 50.  Explain how the following are examples of negative feedback: body temperature regulation glucose regulation
  51. 51.  Explain how the following are examples of positive feedback: nursing childbirth

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