w1 Tissues

• collagen fibres gives strength
• elastic fibres allow tissue to stretch and return to its original shape
• cats have lots of elastic fibres on their scruff allowing it to be pulled back
• macrophages engulf foreign particles
• interstitial fluid flows between tissue and bathes cells
• what are the 4 classifications of tissue

  muscle

  nervous

  epithelial

  connective
• muscle tissue is contractile and contains the protein fibres actin and myosin
• what are the 3 muscle tissues

  cardiac

  skeletal

  smooth
• how would you describe cardiac muscle tissue

  stripey, with many gaps
• how would you describe skeletal muscle tissue

  stripey, no gaps
• how would you describe smooth muscle tissue

  not stripey
• nervous tissue controls and coordinates body activity
• what is nervous tissue made up of

  nerve cells
• what are nerve cells

  made of many neurones held together by connective tissue, which can transmit electrical impulse
• 1. receives stimuli detected by receptor cells and reacts with response
  2. impulse is sent to CNS
  3. CNS processes information and relays via motor neurone to the effectors
• epithelial tissue covers the outside of body and lines body cavities and organs
• in epithelial tissues, cells are packed close together with little intercellular space
• in epithelial cells, the bottom layer of cells sits on basement membrane of connective tissue
• what are the functions of epithelial cells 


  protection of skin

  absorption (especially in the digestive tract)

  secretion of sweat and salivary glands
• what does thickness of epithelial tissue depend on

  the protection required
• where do we see examples of keratinisation in dogs 


  older dogs who have arthritis often lay down on the same points every day. This causes hard spots (kalasis) to form usually on hips, elbows, legs
• give classification system of arrangement of cells

  simple (one layer)

  stratified (multiple layers)
• give classification of shape of cells

  squamos

  cuboidal

  columnar
• what do the stratified squamos tissues do that is important

  shed, often found in oesophagus
• what do columnar tissues contain and where can these be found

  hairs called cilia, found in fallopian tubes and are used to push sperm and egg
• what is transitional epithelium

  many layers of epithelial cells which can expand and contract
• what is glandular tissue

  modified epithelial tissue, where epithelial secretion increases, cells cluster and sink below the surface causing sink and producing glands
• what are the 2 types of glands

  exocrine and endocrine
• what is exocrine gland 


  connection to epithelial surface and secrete fluid via ducts
• what does classification of exocrine glands depend on

  the secretory opening and structure ducts
• what are endocrine gland

  no connection to the surface, no secretion fluid but releases hormones via blood
• give 3 simple exocrine glands and where there found

  tubular- in wall of stomach and small intestine

  saccular- in skin

  coiled- sweat glands e.g. in foot pad
• give 2 compound glands and where their found

  compound alveolar glands- salivary glands

  compound tubular glands- duodenum gland
• give an example of a mixed gland and what it produces

  pancreas

  exocrine produces enzymes via duodenum

  endocrine produces insulin
• connective tissue is most abundant and cells are widely spread.
• what does connective tissue consist of

  viscous solution with cells and fibres embedded within it
• in CT what does the proportion of matrix depend on

  the type of connective tissue
• give the functions of connective tissue

  bind to other tissues

  acts as a transport system carrying nutrients to tissues and carrying waste products away

  stores energy reserves as adipose tissue

  forms sheath around organs to separate

  attaches skin to underlying tissue
• what are the 5 categories of connective tissue

  loose connective tissue, dense connective tissue, cartilage, bone, blood
• loose connective tissue (areolar tissue) found beneath the skin connecting organs. Its made of many cells in loose network of collagen and elastic fibres, and needs a constant blood and nerve supply