Practical #3 - Tissues

Question 1

What are the 4 types of Tissues?

Answer 1

• Epithelial
• Connective
• Muscular
• Nervous

Question 2

What are the general characteristics of Epithelial Tissues?

Answer 2

• Arise from sheets of tightly packed cells of several shapes
• Come from all 3 germ layers - ectoderm, endoderm, mesoderm
• Cover the outside of the boyd and cover all internal organs and body cavities. Major tissues of glands
• Anchored to CT by a basement membrane (the extracellular matrix secreted by the epithelial cells
• Functions in protection, secretion, absorption, excretions and sensory reception.
  
  • ​the bladder stretches!
• Some epithelial tissues are ciliated - like in the respiratory tract - ciliated epithelial make a lot of mucus. and then move the mucus
  
  • mucus protects the epithelial bu moistening and waterproofing

Question 3

What are the 3 distinctions of epithelial Tissues?

Answer 3

• Simple Epithelium
  
  • ​they cnosists of one cell layer
• Stratified Epithelium
  
  • ​composed of multiple layers
• Pseudostratified Epithelium
  
  • ​usually one layer, but because of the location of the nuclei, it appears that more than one layer of cells are present

Question 4

Describe Simple Squamos Epithelium

Answer 4

• Single layer of think/flattened cells
• Allow diffusion of gases
• Ex: Capillaries, veins, arteries
  
  • Also called endothelia
• Ex: Skin, mouth cavity, and lungs

Question 5

Describe Simple Cuboidal Epithelium

Answer 5

• single layer of cube-shaped cells
• Carries out secretion and absorption
• Ex: cells lining the kidney tubules and in various glands

Question 6

Describe Simple Columnar Epithelium

Answer 6

• Elongated, column-shaped cells whose nuclei are located near the basement membrane
• Involved in absorption
• Ex: lining the uterus and the difestive tract

Question 7

Describe Stratified Squamos Epithelium

Answer 7

• Composed of many cell layers
• Covers the skin and lines the mouth, throat, vagina, and anal canal
• Keratin - found here and is waterproof

Question 8

Describe Pseudostratified Columnar Epithelium

Answer 8

• Single layer of cells attached to the basement membrane
• Ex: Line trachea and other parts of mammalian respiratory tract

Question 9

Describe Glandular Epithelium

Answer 9

• Cells are specialized to secrete substances
• Ex: Mammary glands, sweat glands, and endocrine glands

Question 10

What are the general characteristics of Connective Tissues?

Answer 10

• joins, supports, and protects other tissues.
• Provides framework for other tissues
• Sparse population of cells - inside extracellular ground substance
  
  • ​single cell or small cluster of cells are surrounded by the matrix
• Matrix is composed of
  
  • ground substances - lots of shit
  • Fibers (collagen)
• Mesodermal origins
• Most of direct blood supply
  *

Question 11

What are the 2 major categories of CT?

Answer 11

• Proper Connective Tissues
  
  • ​generally bind other tissues together, with considerable amount of collagen fibers
• Specialized Connective Tissues
  
  • ​variety of support, storage, transport, and protective functions

Question 12

What are the 2 types of Proper Connective Tissue?

Answer 12

• Areolar - loose CT
• Dense - fibrous CT

Question 13

Describe Areolar CT

Answer 13

• binds epithelial tissues to underlying tissues
• Forms membranes between organs
• composed of spindle shaped cells (fibroblasts) that produce fibers
• Immune cells (macrophages) are present in CT
• These are smaller elastin fibers and larger collagen fibers embedded in a viscous liquid matrix

Question 14

Describe Dense CT

Answer 14

• 2 main kinds:
• Dense Regular CT
  
  • ​found in tendons and ligaments
• Dense Irregular CT
  
  • ​form sapsules around many organs and are found in deep layers of skin. Collagen fibers have a complex arrangement that resists tensile stress
  • Mostly made of strong collagen fibers and relatively few cells

Question 16

What are the 4 types of Specialized CT?

Answer 16

• Bone
• Blood
• Adipose (fat)
• Cartilage

Question 17

Describe Adipose (Fat) Tissues

Answer 17

• stores fat energy
• cushions organs and joints against physical force
• insulation against cold
• found beneath the skin, around the heart and kidney
• Fat cells - are the major type of cell
  
  • large and filled with lipids
  • lipid are storaed in large vacuole - fat droplet
    *

Question 18

Describe Cartilage Tissues

Answer 18

• Provides support and framework for various parts (nose, ear, bones, trachea)
• skeleton of all vertebrate embryos
• Cells - chondrocytes - are presentin small island-like cavities called lacunae
• intercellular material is collagen fibers
• No blood supply - takes a while to heal!

Question 19

Describe Bone Tissues

Answer 19

• Protects vital organs, provides tough endoskeleton
• Main site where blood cells are made (marrow - found in hollow interior of bones)
• Cells - osteocytes - hardened matrix
  
  • consts of mineral salts (Ca and P), collagen fibers
• Strongest CT
• Osteocytes are found in lacunae
• Often arrange din concentric cirles (lamellae) around the Haversian Canals
  
  • ​Haversian Canal contain blood vessels and nerves
• Canaliculi - connect the lacunae and blood and what not
• Osteons - (haversian system) - fundamental unit of bone
  
  • Haversian canal surrounded by mulitple lamellae

Question 20

Describe Blood as CT?

Answer 20

• Transports substances and helps maintain homeostasis
• Matrix = plasma
• Cellular components
  
  • Red blood Cells (erythrocytes)
  • White Blood Cells (leukocytes)
  • Platelets
    
    • ​fragments of cells
• No fibers, except fibrinogen = soluble….forms Fibrin = insoluble and used for clotting
• Globulins and Albumins

Question 21

What are RBCs made of and What is an example of a WBC?

Answer 21

• RBCs
  
  • anucleated in mammals
  • packed with hemoglobin to carry oxygen
  • Biconcave disk
• WBCs
  
  • antibodies
  • Some WBCs perform phagocytosis against dying or worn out cells and agaisnt foreign cells

Question 22

What are the general muscle Tissue characteristics?

Answer 22

• most abundant type of CT in animals
• muscle tissues are contractile that move body parts
• three types
  
  • Skeletal
  • Smooth
  • Cardiac
• Contain parallell bundles of microfilaments
  
  • actin and myosin
• mesodermal origin

Question 23

Describe Skeletal muscles

Answer 23

• Most abundant type of muscle tissue
• Voluntary control
• Attached to bones by tendons
• Voluntary muscles have very prominent striations and each cell is multinucleated
• Skeletal muscle fibers contract immediately when stimulates
  
  • also fatigue most rapidly
• muscle fibers are grouped in bundles which are grouped into muscles
  
  • heavily vascularized

Question 24

Describe the characteristics of Smooth Muscles

Answer 24

• No striations
• uninucleated
• Found in gut, bladder, blood vessels and uterus
• Do not form bundles…but form sheets
• involuntary control
  
  • ​innervated by nerves from autonomic nervous system
  • gap junctions allow ion flow from one cell to the next
  • Can stay contracted longer than skeletal

Question 25

Describe the characteristics of Cardiac Muscle

Answer 25

* Found only in the heart * **involuntary** * ​Rhythmic contractions * Single nucleus is located in the center of each cardiac muscle cell * **intercalated disks -** connect cardiac cells * **​**Help coordinate contraction of adjacdnt cells * Rest between heart beats

Question 26

What are the general nervous tissye characteristics?

Answer 26

* found in the brain, spinal cord, and perpheral nerves * **Nervous Tissues -** sense external and internal stimuli. * send signals to each other and to various body parts such as **effector organs** (glands and muscles) * **ectodermal origin** * **Neurons -** nerve cells - functinoal unit of the nervous system * coordinate, regulate, and integrat body activities * **Synapse -** connection between adjacent nerve cells

Question 27

What are the different types of Nervous Tissue?

Answer 27

* **Neuron -** basic type of cell * uninucleated * Composed of cell body - **axon (soma)** * One or more **dendrites** through which they receive inputs from other cells * **Glial Cells (neuroglial) -** supportive cells in nervous tissues