BIOL225L Tissues Flashcards
What does epithelial tissue do?
Covers surfaces and lines cavities; lacks own blood supply
What are the types of epithelial tissue?
Simple, stratified
What are the types of simple epithelial tissue?
Simple squamous, simple cuboidal, simple columnar
What are the types of stratified epithelial tissue?
Stratified squamous
What does connective tissue do?
Provides structural and metabolic support
What are the types of connective tissue?
Connective tissue proper, supporting connective tissue, fluid connective tissue
What are the types of connective tissue proper?
Loose connective tissue
What are the types of loose connective tissue?
Areolar, adipose
What are the types of supporting connective tissue?
Bone, hyaline cartilage
What are the types of fluid connective tissue?
Human blood, amphibian blood
What type of cells is muscle tissue composed of?
Contractile cells
What are the types of muscle tissue?
Smooth muscle, skeletal muscle, cardiac muscle
What is the structure of skeletal muscle?
Striated
What is the structure of cardiac muscle?
Striated with intercalated discs
What is neural tissue?
Reception of stimuli and conduction of nerve impulses
What are the types of neural tissue?
Neurons
What is simple squamous epithelium?
Single layer of flattened cells; designed for diffusion by maximizing surface area and minimizing distance
Where is simple squamous epithelium found?
Capillaries, alveoli of lungs
Write out Fick’s Law and know how to manipulate it.
Q = DA (c1-c2)
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L
What is simple cuboidal epithelium?
- Single layer of cube-like cells, often secretory
- cells need more space because they require organelles
Where is simple cuboidal epithelium found?
Lining ducts and tubules of mucus glands, kidney nephrons
What is the basement membrane?
- made of proteins; often seen as a thin, dark line around cells
- anchors cells and separates epithelium from the underlying connective tissue
What is simple columnar epithelium ?
Single layer of rectangular cells designed for absorption and secretion
Where is simple columnar epithelium found?
Small intestine lining, stomach lining
What are goblet cells?
- Found between cells that make up the simple columnar epithelium
- secrete mucin which dissolves in water to form mucus to protect the free surface of the tension
What is stratified squamous epithelium?
Multiple layers of cells that are in areas with abrasion
How do the cells in stratified squamous epithelium get their shape?
- basal layer of cells (cuboidal in shape) undergo division and replace cells that are lost
- as these cells get pushed to the surface by other cells producing beneath them, they become squamous
- outer layer of cells may become keratinized
What is keratin?
A protein that replaces cytoplasm and cells become keratinized (hardens), making them resistant to abrasion and water diffusion
When might the outer layer of cells in the epithelium become keratinized?
When the epithelium is exposed to highly abrasive and dry conditions (ex. Skin)
When might the epithelium NOT become keratinized?
When the epithelium is more protected (ex. Esophagus)
What is areolar connective tissue?
- Anchors skin, blood vessels, nerves and binds muscles together
- includes fibroblasts and extracellular matrix
What are fibroblasts?
Cells that make up the extracellular matrix
What is the extracellular matrix composed of?
Fibers and ground substance that is clear and jelly-like
What are collagen fibers?
- broad, ribbon-like, lighter in color than thin elastic fibers
- provide strength to the tissue
What are elastic fibers?
- thin, darker than collagen
- provide elasticity to tissue
What is adipose tissue?
- Designed to store lipids
- cushions and insulates the body
- the nucleus is pushed to one side of the cell
What is hyaline cartilage composed of?
- composed of chondrocytes which secrete the extracellular matrix
What is the extracellular matrix composed of in connective tissue?
Closely packed collagen fibers and a firm gel-like ground substance
Where can hyaline cartilage be found?
Nose, trachea, articulating bone surfaces
What are lacunae?
The cavities occupied by cells
- chondrocytes in terms of hyaline cartilage
What is an osteon?
Compact bone that runs the length bones
What are canaliculi?
Tiny canals that carry oxygen and nutrients to and waste from osteocytes
What are osteoblasts?
Cells that form bone tissue
What is an osteocyte?
A bone cell that forms when an osteoblast becomes trapped and embedded in its own extracellular matrix
What does the central/haversian canal in bone contain?
Blood vessels, nerves
What are lamellae?
Rings in each osteon
What is the difference between compact bone and spongy bone?
Spongy bone does not have osteons
Are white blood cells or red blood cells larger in size?
White blood cells (leukocytes)
What is the function of mammalian erythrocytes?
carry oxygen oxygen to body cells
What types of animals have erythrocytes that lack nuclei?
Mammalian, birds
What animal type have erythrocytes that have nuclei?
Amphibians
What is a neutrophil?
- A leukocyte that phagocytizes pathogens
What is the structure of neutrophils?
- bilobed nucleus
- granular cytoplasm
What is the function of monocyte?
- can transform into a macrophage (big eater) when it leaves the circulatory system
- as a macrophage, it can phagocytize pathogens
What is the structure of monocytes?
- large in size
- bilobed nucleus
What is the function of lymphocytes?
Involved with immune response
What is the structure of lymphocytes?
- large nucleus
- same size as an erythrocyte
What is the function of basophils?
Release histamine
What is histamine?
A chemical that causes capillaries to become leaky, allowing neutrophils and monocytes to squeeze out more easily to phagocytize pathogens
What is the structure of basophils?
- bilobed nucleus
- dark purple-stained granules that contain histamine
- more grainy appearance relative to a neutrophil (darker graininess)
What is the function of an eosinophil?
Phagocytize or release cytotoxic enzymes from granules onto parasites coated with antibodies
What is the structure of eosinophils?
- bilobed nucleus
- red-stained granules
What is the structure of smooth muscle?
Long, spindle-shaped cells with a centrally located nucleus
Where is smooth muscle found?
Blood vessels, digestive tracts, uterus
Is smooth muscle controlled voluntarily or involuntarily?
Involuntarily
What is the structure of skeletal muscle?
- striations that are perpendicular to the long axis of the muscle fiber
- multinucleate fibers
Is skeletal muscle under voluntary or involuntary control?
Voluntary
What is the structure of cardiac muscle?
- striations perpendicular to the long axis of the muscle fiber
- intercalated discs
- branched
What are intercalated discs?
- Structures in cardiac muscle that connect one muscle fiber to another, allowing ions to flow from one cell to the next
- permit simultaneous contraction of cardiac muscle fibers
Is cardiac muscle controlled voluntarily or involuntarily?
Involuntarily
What is neural tissue mainly composed of?
Neurons, neuroglial cells
What is a motor unit?
A neuron and its associated muscle fibers
What are chromatophores?
Cells that contain pigment that gives color to an organism, in this case a frog
What type of tissue makes up the epidermis in frog skin?
Stratified squamous epithelium
What structures make up the dermis of frog skin?
Chromatophores and a gland with a duct to the skin surface
What is the name for the simple squamous epithelium that lines blood and lymphatic vessels?
Simple squamous endothelium
How does the structure of an artery compare to that of a vein?
- arteries have thicker walls
- usually retain this circular cross-sectional shape when being viewed on a tissue slide under a microscope
What type of tissue makes up the mucosa of the small intestine?
Simple columnar epithelium
What type of tissue makes up the submucosa of the small intestine?
Moderately dense connective tissue
What type of muscle makes up the muscle layers of the small intestine?
Smooth muscle
What type of tissue makes up the serosa of the small intestine?
Areolar connective tissue covered by the mesothelium
What is the mesothelium?
Simple squamous epithelium that lines body cavities and covers internal organs
List the layers of tissues found in the small intestine in order from deepest to most superficial.
Mucosa —> submucosa —> muscle layers —> serosa