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What are tissues?
Groups or cellections of cells that perform the same general funtion
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Name the 4 types of tissue
- Epithelial
- Connective
- Muscle
- Nervous
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What is the function of cilia
- Tiny hair like structures near the basement level of simple columnar cells. They help with movement.
- Ex: they line the reproductive tubes to MOVE the egg.
- Non-ciliated - cells that have no cilia
- Line the digestive tract
- -stomach
- -small & large intestine
- movement takes place via partitasis muscles.
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What is the function of microvili
- Specialized simple columnar cells
- Small finger like extensions that increase the suface area for absorbtion (of nutrients) - takes things in.
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What are the four functions of epithesial tissue
- Protection
- Secretion (destination w/in the body/internal)
- Absorption
- Excretion (destination outside the body, waste products)
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Why doesn't epithelial tissue heal well/lacks the ability to repair?
Lacks blood vessels
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What are three (sub)types of epithelial tissues identified by cell layers
- Simple
- Stratified
- Pseudostratified
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What are pseudostratified tissue?
They contain one layer of cells connected at the basement membrane. They appear to have multiple layers (but don't).
- commonly has cilia and goblet cells which secrete
- mucus
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Where are simple squamous cells found?
- Air sacs of lungs
- Capillaries
- Membranes that line the body
- (They're a single layer of flat cells)
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What is the location of eputhelial tissue?
- Covers body surface
- Covers/lines internal organs
- Composes glands
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What are the characteristics of epithesial tissue?
- Continuous cellular sheet
- Lacks blood vessels
- Has basement membrane
- Readily divides
- Tightly packed
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Cancer cells spread into adjacent tissues by:
Secreting substance that disolves basement membrane allowing them to spread into adjacent tissues.
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Simple epithelial tissues are
- one layer
- substances pas through easily
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Striated epithelial tissues are
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What are the three (sub)types of epithelial tissues identified by shape?
- Squamous (flat cells, looks like fried eggs)
- Columnar (tall, culindrical cells)
- Cuboidal (cube shaped cells)
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Simple squamous cells (single layer of flat cells)
- Fragile -easily damaged
- Allow substances (ex: salt) to pass through easily (diffusion & filtration)
- Compse air sacs of lungs (alveoli)
- Capillaries (tiny blood vessels all over the body, that collect and secrete)
- Membranes that line the body
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Simple cuboidal (single layer of cube cells - can change shape as things grow)
Secrets/reabsorbs
- Covers ovaries
- Line kidney tubules
- Line ducts of glands
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Simple columnar (single layer of columnar cells - tall/long)
- Ciliated (line reproductive tubes)
- Non-ciliated (line digestive tract)
- Microvilli (absorbtion)
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Pseudosratified columnar (single layer of cells that appear stratified)
- Ex: Goblet Cells
- Lines the passage of the respiratory system
- Secrets mucus to trap dust
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Statified squamous (many layers of flat cells)
- Compose the outermost layer : Skin (epidermis)
- Deep layers are cube or columnar shaped
- Superficial layers are sqamous (flat) cells
- Cells replicate at the basement membrane
- Older cells are pushed away from the basement membrane
- Older cells accumulate a protein (keratin), they harden and die (dandriff)
- Lines the oral cavaty (mouth - heals heat burns/sharp cuts)
- Lines the anal cavity (acide from stomach)
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Stratified cuboidal (2 or 3 layers of cube cells - more protection than single layer)
- Secrets
- Lines larger ducts and tubules
- -mammary glands
- -sweat glands
- -salvary glands
- -pancreas
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Stratified columnar (several layers of clumnar cells)
- Lines the pharynx (back of the mouth)
- Lines the vas deferens (tube that delivers sperm in men)
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* Transitional epithelium
- Specialized epithelium - changes shape in response to tension
- Lines the urinary bladder (lines organs)
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Glandular epithelium
- -Specialized epithelial cells that produce and secretes substances
- -Exocrine glands
- -Endocrine glands
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Exocrine glands
(stomach = outside/surface)
-secrets products into ducts (tube that delivers products to the surface ex: sweat glands)
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Endocrine glands
- (inner - inside of cheek)
- -secretes products (somethng useful) into tissue or blood (circulatory system)
Ex: hormones start in the brain and work down into the body)
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What is connective tissue?
- Binds structures together (ex: joint capsule)
- Provides support
- Protects
- Fills spaces (fascia - surrounds muscle)
- Stores fat
- Produces blood cells (makes marrow)
- Repairs damaged tissue
- Not tightly packed like epithelial cells
- Cells can divide (replaces damage/rapidly repairs)
- Has various vascularity (blood supply)
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What are the major cell types of connective tissue?
- Fibroblasts
- Macrophage
- Mast Cells
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What is the matrix?
The substance between cells
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Fibroblast cells
- Produces protein fibers (collagen/strong)
- Makes new stuff/proteins
- Elastin
- Reticular fibers
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Collagen
- -Thick threads of protein
- - Flexible
- -Slightly elastic
- -Great strength (VERY STRONG like silly putty - tinsile strength)
- Holds structures together
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Elastin
- Vocal cords, respiratory system air passageways
- -Thinner strand of elastic protein
- -Weaker than collagen
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Reticular fibers
- Ex: Spleen
- Supportive fibers
- Very think collagen fibers
- Supporting networks of tissues
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Macrophage
- Immunity - like the pacman on the body - eats the things that invade the body - trash disposal
- -Begin with white blood cells
- -Are mobile, can move about the body
- -Specialized in phagocytosis (cell eating)
- -Important in protection against infection
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Mast cells
- Large cells located near blood vessels
- Releases heprin (sticky blood thinner) *prevents blood clots (plateletts)
- Releases histamine *promotes inflammation, allergic reactions, swelling
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What are the different types of connective tissue?
- Loose connective tissue
- Adipose tissue
- Reticular tissue
- Dense connective tissue
- Elastic connective tissue
- Cartilage
- Bones
- Blood
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Loose connective tissue
- Composed primarily of fibroblasts
- Fascia (raw eggwhites)
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Adipose tissue
- Yellowish
- Fat
- Specialized cells that store fat
- Contine to enlarge to store fat
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Reticular tissue
- Support cells
- Thin collagen fibers
- Support organs: liver, spleen
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Dense connective tissue
- Holds parts together (muscle to bone = tendon)
- Tendons
- Ligaments (bone to bone)
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Elastic connective tissue
- Elastic fibers
- Found in large arteries and liament fo the spinal column and in skin
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Cartilage
- Ridgid connective tissue
- Composed of collagen fibers
- Cartilage cells (chondrocytes or "cartilage site")
- Lack direct bloodflow supply, that is why torn cartilage heals slowly and why chondrocytes do not divide frequently.
- Covered by perchondrium (CT) (around living in), *contains blood supply for cartilage cells
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Where is cartilage located?
At the end of bones, ears, nose, disks...
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Carliage cells
- Chondrocytes
- Live in small houses (lacunae - lake)
- Lack direct blood supply - slow repair time
- Divide slowly
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Name the three types of cartilage
- Hyaline
- Elastic
- Fibrocartilage
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Hyaline Cartilage
- aka Articular Cartilage
- Most absorbant
- Hard white plastic (magic shell ice cream)
- Coveres ends of bones
- Very smooth (reduces friction)
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Elastic Cartilage
- Found in the nose and ears
- Flexible
- Contains many elastic fibers
- External ears
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Fibrocartilage
- Breaks down over time
- Toughest of the three types
- Shock absorber
- Intervertebral discs (spine)
- Menisci in knee (spacers)
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Bones
- Most ridig of the connective tissue (hard)
- Matrix contains calcium and phosphate salts
- Bone cells (osteocystes)
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Bone cells
- aka Osteocytes
- Lay layers of bone matrix around them (lamellae)
- Live in houses (lacunae)
- Form circles around central (haversian) canals (allow communication) *contain blood vessels
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Blood
- Has 3 cell types
- Produced by cells inside the bone (marrow)
- Red blood cells *carry oxygen and carbon dioxiode to cells and waste out of cells
- White blood cells * fight infection
- Platelets *help form clots (sticky cells that prevent flow)
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What are the three types of Muscle Tissue?
- Skeletal muscle
- Smooth muscles
- Cardiac muscle
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Skeltal muscle
- Voluntary control (like the diaphram)
- Look like they have stripes (striated) the stripes are long cells
- Each cell can have many nuclei
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Smooth Muscles
- Lack striations (can contract in various ways)
- Single nucleus
- Involuntary control (stomach grumble) *digestive system (pushes food through paristalsis) *blood vessels *urinary bladder
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Cardiac muscles
- Located in the heart (only)
- Cells are connected by intercalated discs
- Involuntary control (symchronized contractions) lub dub lub dub
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Nervous tissue
- Found in the brain, spinal cord and peripheral nerves
- Specialized for electrical conduction (communication & organization)
- Neurons are basic cells
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Organ
A collection of two or more tissue types performing specialized fuctions
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Integumentary system
- Skin - has all 4 tissue types
- Largest organ in the body by weight
- Skin + acessory structures
- Epthelial membranes (4 types)
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What are the 4 types of epithealial membranes?
- Serous (oily)
- Mucous (snot)
- Synovial (lubricating fluid, jut. juice)
- Cutaneous (skin)
*Note: These are NOT organs
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Serous membrane
- Lines the wall of body cavities that are not exposed to external environment (parietal=wall) *Thoracic cavity *Abdominal cavity * Pelvic cavity
- Covers organs within cavities (viceral)
- Composed of simple squamous cells and a thin layer of connective tissue
- Secrets a thin watery substance (serous fluid) that lubricates the surfaces of the membrane (so there is no friction)
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Mucous membrane
- Lines cavities that open to the external environment *oral cavity *nasal cavity *tubes of the digestive, respiratory, urinary and reproductive system
- Epithesial tissue covers loose connective tissue(protection) *stratified squamous (oral), *psuedostratified columnar (nasal), *simple columnar (small intestine)
- Goblet cells secrete MUCUS (wine glass shaped cells)
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Synovial membrane
- Most freely moveable
- Lines synovial joint cavities
- Fibrous connective tissue overlying loose connective tissue & adepose
- Secretes synovial fluid into the joint space (not serous fluid) *thick & colorless (egg whites), *lubricates ends of bones
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Cutaneous membrane (integumentary system)
- Skin & its tissues (largest organ of the body)
- Fuctions: *Maintain homeostasis, *Protective covering, *Prevents water loss
- Helps regulate body temperature
- Houses sensory receptors (light/deep touch)
- Contains immune system cells
- Suthesizes various chemicals (vitamin D)
- Excretes small amounts of waste products
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Vitamin D
- Synthesized in our skin
- Bone & tooth development
- Dehydrocholesterol (provitamin D) reaches our skin it is exposed to ultraviolet light (sunlight) and is convereted to Vit D.
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Transdermal patch
- Used for motion sickness, chest pain, smoking cessation
- The drug passes from the patch & diffuses in the epidermis & enters the blood vessels in the dermal layer of skin (slower, but more constant).
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