Practical #3 - Tissues Flashcards
What are the 4 types of Tissues?
- Epithelial
- Connective
- Muscular
- Nervous
What are the general characteristics of Epithelial Tissues?
- 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
What are the 3 distinctions of epithelial Tissues?
-
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
Describe Simple Squamos Epithelium
- Single layer of think/flattened cells
- Allow diffusion of gases
- Ex: Capillaries, veins, arteries
- Also called endothelia
- Ex: Skin, mouth cavity, and lungs
Describe Simple Cuboidal Epithelium
- single layer of cube-shaped cells
- Carries out secretion and absorption
- Ex: cells lining the kidney tubules and in various glands
Describe Simple Columnar Epithelium
- Elongated, column-shaped cells whose nuclei are located near the basement membrane
- Involved in absorption
- Ex: lining the uterus and the difestive tract
Describe Stratified Squamos Epithelium
- Composed of many cell layers
- Covers the skin and lines the mouth, throat, vagina, and anal canal
- Keratin - found here and is waterproof
Describe Pseudostratified Columnar Epithelium
- Single layer of cells attached to the basement membrane
- Ex: Line trachea and other parts of mammalian respiratory tract
Describe Glandular Epithelium
- Cells are specialized to secrete substances
- Ex: Mammary glands, sweat glands, and endocrine glands
What are the general characteristics of Connective Tissues?
- 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
*
What are the 2 major categories of CT?
-
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
What are the 2 types of Proper Connective Tissue?
- Areolar - loose CT
- Dense - fibrous CT
Describe Areolar CT
- 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
Describe Dense CT
- 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
What are the 4 types of Specialized CT?
- Bone
- Blood
- Adipose (fat)
- Cartilage
Describe Adipose (Fat) Tissues
- 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
*
Describe Cartilage Tissues
- 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!
Describe Bone Tissues
- 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
Describe Blood as CT?
- 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
What are RBCs made of and What is an example of a WBC?
- 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
What are the general muscle Tissue characteristics?
- 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
Describe Skeletal muscles
- 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
Describe the characteristics of Smooth Muscles
- 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
Describe the characteristics of Cardiac Muscle
- 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
What are the general nervous tissye characteristics?
- 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
What are the different types of Nervous Tissue?
-
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