01a Cells and Tissues
|Simple Squamous Epithelium||Endothelium diffuses oxygen into blood of the lung vessels. Filtrates oxygen in blood of glomerular capsule of kidney. Mesothelium's function is secretion which happens in the serous membranes e.g pericardial, pleural, and peritoneal cavities.|
|Simple Cuboidal Epithelium||Carries out active transport, facilitated diffusion, or secretion. They are found in mitochondria and kidneys. Form the secretory portions of glands e.g Thyroid and ducts of glands e.g pancreas. And they line the ovaries and kidney tubules.|
|Stratified Squamous Epithelium||Keratinized can be used in protection (covers areas of high abrasion, UV rays, water loss); found in skin and non-keratinized can be found in the upper digestive tract (mouth, esophagus) has mucous which keeps cells moist. Both types form the first line of defense against microbes.|
|Psuedostratified Columnar Epithelium|| Nuclei at different levels. |
Ciliated. Have goblet cells which secrete mucus, location trachea, most of upper respiratory tract, cilia beat to move mucous.
Non-ciliated- no goblet no mucous, Absorption and protection in the epididymis, lines larger ducts of glands and male urethra.
|Stratified Columnar Epithelium||It is only found in large excretory glands e.g. the mammary gland ducts, the larynx, and a portion of the male urethra. It functions in secretion, protection, and some absorption.|
|Transitional Epithelium||Appear cuboidal when not stretched, but squamous when stretched; found in the urinary organs|
|Stratified Cuboidal||Lines ducts of mammary, salivary and sweat glands. Protection, limited secretion and absorption.|
|Simple Columnar Epithelium Ciliated||Ciliated- Have goblet cells, secrete mucus, cilia beat to move mucus respiratory tract to be swallowed or coughed up. Cilia also beat to move oocytes through fallopian tubes from ovaries to uterus.|
|Simple Columnar Epithelium Non-ciliated|| Have goblet cells and produce mucus. Line |
gastrointestinal tract, in stomach the mucus
protects stomach acid from dissolving stomach
walls. Also fund in urinary tract, ducts of
glands and gall bladder.
Have microvilli which increase
surface area for absorption.
|Mesenchymal Connective Tissue|| Embryonic|
Gives rise to all other connective tissues.
Irregularly shaped mesenchymal cells in a semifluid ground substance with delicate reticular fibres.
Under skin and along bones of embryo
Some in adult tissue, especially along blood vessels
|Mesothelium||Function is secretion which happens in the serous membranes e.g pericardial, pleural, and peritoneal cavities.|
|Endothelium||Diffuses oxygen into blood of the lung vessels. Filtrates oxygen in blood of glomerular capsule of kidney.|
|Aerolar Connective Tissue||Few fibres of reticular, collagen and elastic.|
Several kinds of cells; fibroblasts, macrophages, plasma cells, adipocytes, mast cells and white blood) embedded in semifluid ground substance (hyaluronic acid, chrondroitin sulfate, dermatan sulfate and ketatan sulfate).
Called 'Packing Material' because its in nearly every body structure- subcutaneous layer deep to skin, around blood vessels, nerves and organs.
Strength, elasticity and support.
|Adipose Connective Tissue||Adipocytes, derived from fibroblasts, these store |
triglycerides as a central droplet.
Wherever areolar tissue is present so is this.
Found under skin- Reduces heat loss of skin.
Energy reserve- Yellow bone marrow.
Supports and protects- on heart, kidneys, padding
around joints and behind eyeball in eye socket.
|Reticular Connective Tissue|| Fine interlacing network of reticular fibres and reticular cells.|
Forms stroma (supporting framework) of organs such as the liver.
Binds smooth muscle tissue.
Filters and remove worn out blood cells in the lymph nodes and spleen.
|Dense Regular Connective Tissue|| Shiny white extracellular matrix made of mainly collagen fibres in regularly arranged bundles with fibroblasts in rows in between bundles.|
Forms Tendon and Bones.
Provides strong attachment between various structures as tissue withstands tension along axis of fibres.
|Dense Irregular Connective Tissue||Collagen fibres irregularly arranged in bundles with a few fibroblasts.|
Provides tensile strength in many directions.
Found in sheets as fasciae (tissue beneath skin and around muscles and other organs), deeper region of dermis of skin, fibrous pericardium of heart, periosteum of bone, perchiondrium of cartilage, membrane capsules around other organs- kidneys, liver, lymph nodes. Also in
|Dense Elastic Connective Tissue|| Predominantly elastic fibres with fibroblasts between fibres.|
Unstained tissue is yellowish.
Allows organs to stretch and then return to original shape such as the lung tissue (recoil after exhaling) and elastic arteries (recoil between heartbeats).
|Hyaline Cartilage Connective Tissue||Weakest type of cartilage.|
Contains a resilient gel as ground substance and appears in the body as bluish-white, shiny substance.
Fine collagen fibres are not visible.
Provides smooth surfaces for movement of joints like at the end of long bones.
Flexibility and support- anterior ends of ribs, nose, larynx, trachea, bronchi and fetal skeleton.
|Fibrocartilage Connective Tissue||Chondrocytes scattered among clearly visible thick |
bundles of collagen fibres within extracellular matrix.
Support and joining structures together such as where the hip bones join anteriorly, intervertebral discs, menisci of knee, portions of tendons insert into cartilage.
Strength and rigidity make it the strongest type of
|Elastic Cartilage Connective Tissue|| Chondrocytes in threadlike network of elastic fibres within extracellular matrix.|
Maintains shape of certain structures, provides strength and elastcitiy.
Located on lid on top of larynx (epiglottis)
and part of external ear (auricle) and auditory tubes (Eustachian).
|Compact Bone Connective Tissue|| Consists of osteons (haversian system) that contain lamellae, lacunae, osteocytes, canaliculi, and central canal (haversian canal).|
Makes up various parts of the body.
Support and protection.
Serves as levers that act with muscle tissue to enable movement.
|Spongy Bone Connective Tissue|| Consists of thin columns called trabeculae; |
spaces between are filled with red bone marrow.
Storage, houses blood forming tissue.
|Liquid Blood Connective Tissue|| Blood plasma and formed elements; erythrocytes, leukocytes, and thrombocytes.|
Located withing blood vessels; ateries, veins, capillaries, venules and chambers of heart.
|Osseous Tissue||Bone Tissue, composed of four types of cells.|
|Lamellae|| Concentric rings of mineral salts |
for hardness. Calcium phosphate and calcium hydroxide this forms hydroxyapatite, which combines with collagen for tensile strength.
|Lacunae||small spaces between lamellae that contain mature bone cells (osteocytes)|
|Canaliculi||minute canals containing extracelluar fluid and minute osteocytic processes that radiate from lacunae and provide routes for oxygen, nutrients and waste.|
|Central Canal|| Known as Haversian canal.|
Contains blood vessels and nerves.
|Marfan Syndrome|| Hereditary defect in elastic fibres.|
-Mutation on chromosome 15-fibrillin.
-Tall, long limbed, chest deformity.
-May have weakened heart valves and arterial walls which may be life threatening.
-1 in 20,000 live births.
-Abraham Lincoln may have had this syndrome.
|Ground Substance||Composed of water, proteins, and poylsaccharides (sugars). GAG's can trap water to become more jelly like.|
|Endocrine Glands||glands of the endocrine system that release hormones into the bloodstream|
|Exocrine Glands||release their secretions through ducts or tubes onto a body surface or into a cavity. ex. sweat, salivary or tear glands|
|Osteoclasts||formed from monocytes, break down bone matrix by resorption.|
|Osteogenic||The embryonic type of bone cell. Later develops into an osteoblast|
|Osteoblasts||bone forming cells that lay down the bone matrix|
|Osteocytes||mature bone cells derived from trapped osteoblasts, involved in transport of nutrients and waste|
|Sugars found in Ground Substance|| Glycosaminoglycans- chondroitin sulfate, dermatan sulfate and keratin sulfate which bond covalently to core proteins.|
GAG hyaluronic acid doesn't bond to core proteins.
|Tight Junctions||Strands of transmembrane proteins- Occludin. Electrically tight, stop ions from entering, near the apical surface of cells.|
|Adherens Junctions||Strands of transmembrane glycoprotein- Cadherin link to Microfillament- Actin. Hold cells together strongly, reinforces Tight, also near the surface.|
|Desmosome||Strands of transmembrane glycoprotein- Cadherin link to Intermediate filament- Keratin. Contain Plaque.|
|Hemidesmosome||Intermediate filament- Keratin, Strands of transmembrane glycoprotein- Integrin bond to Basement Membrane|
|Gap Junctions||Connexons composed of connexins allow a channel for proteins to pass across, communicating junctions.|