Tissues Flashcards
EPITHELIAL TISSUE
• Closely packed cells in one or several layers
• Has basement membrane anchoring tissue to underlying connective tissue
→ an extracellular structure of protein fibers
• High capacity of renewal by cell division
• Nerve supply but no blood vessels → connective tissue exchange nutrients and wastes
SIMPLE SQUAMOUS EPITHELIUM
• 1 layer of cells
• Flat and thin cells → rapid passage through them
• Lines inner surface of blood vessels and alveolar sacs, and lines body cavities
STRATIFIED SQUAMOUS EPITHELIUM
• Several layers of cells
• Flat and thin cells forming thick layer
• Gives skin protective structure
SIMPLE CUBOIDAL EPITHELIUM
• Single layer of cube shaped cells
• Cells carry out active transport, diffusion, or secretion
• Located in glands and their ducts, the brain, bronchioles, and surfaces of the ovaries
SIMPLE COLUMNAR EPITHELIUM
• Single layer but 2 types: cilitated and noncilitated
• Noncilitated: has microvilli and helps with secretion and absorption → lines uterus, stomach, and intestines
• Cilitated: has cillia and help move different things → found in upper respiratory tracts and in central canal
GLANDULAR EPITHELIUM
• Forms glands
• Specialized to secrete substances
CONNECTIVE TISSUE
• Binds, supports, and strengthen other tissues and protects internal organs
• Main site of immune responses and a source of stored energy reservior
• Consists of ground substance = hyaluronic acid + water; fibers, and cells
LOOSE CONNECTIVE TISSUE
• Fibers loosely arranged between the cells
• Areolar tissue*: consists of collagen, elastic and reticular fibers synthesized by fibroblasts; holds organs in place giving strength, elasticity, and support
• Adipose tissue: consists of adipocytes which are cells storing fat; found in deepest layer of skin, around the heart and the kidneys; and it reduces heat loss through skin, serves as energy reserve, supports and protects organs
DENSE CONNECTIVE TISSUE
• More and thicker fibers packed closer together
• Supports and protects organs; and are active in healing process of a wound
• Connects muscles to bones as tendons or ligaments
• 2 types: regular and irregular
CARTILAGE
• Dense network of fibers
• Has chondroblasts maturing into chondrocytes
BONE TISSUE
• Contains 3 cells spread in extracellular matrix: osteoblasts, osteocytes, and osteoclasts and osteogenic stem cells
• Osteogenic → osteoblasts produce collagen → osteocytes, main bone cells and store calcium
• Osteoclasts are related to white blood cells and repair, develop, and maintain bone
• 2 types of tissue: compact and spongy (lighter)
• Found in skeleton
LIQUID CONNECTIVE TISSUE (blood)
• Consists mainly of water, but also nutrients, waste, enzymes, hormones, respiratory gases, and ions
• 3 cell types: erythrocytes = red blood cells transporting O2 and CO2; thrombocytes = white blood cells participating in immune system; leucocytes = platelets involved in blood clotting
• Found in blood vessels in the whole body
MUSCULAR TISSUE
Consists of muscle fibers and have contractile myofilaments → actin and myosin
SMOOTH MUSCLE TISSUE
• Structure: long and spindle shaped cell with a nucleus in the middle
• Function: regulates size of organs, forces fluid through tubes, and make goose bumps on skin
• Location: in iris, walls of blood vessels, and along stomach and intestines
CARDIAC MUSCLE TISSUE
• Structure: straited, long and branched with 1-2 nuclei in the middle
• Function: preforms coordinated contractions of the heart
• Location: the heart
SKELETAL MUSLE TISSUE
• ** Structure:** long (up to 50 cm) and can contain hundreds of nudei
• Function: responsible for voluntary movements and reflexes of body parts
• Location: attached to bones for skeletal movements
NERVOUS TISSUE
Two different groups: neurons (nerve cells) and neuroglial cells
ASTROCYTES
• Glial cell in CNS
• Protects, supports, and helps metabolism of the neurons
• Isolates synapses and maintains the chemical environment as well as regulating synaptic activity
MICROGLIAL
• Neurogia in the CNS
• Protect neurons by becoming phagocytic
• Phagocytize microbes and other foreign substances
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OLIGODENDROCYTE
• Neuroglida in the CNS
• Supports and insulates axons by producing myelin
• Maintains myelin sheaths around several adjacent axons
EPENDYMAL CELL
• Neuroglida in the CNS
• Line the central canal and cavities in the brain
• Produce cerebrospinal fluid
SCHWANN CELL
• Neuroglida in PNS
• Produce myelin sheath around a single axon → wrap their membrane around the axon
ENDOCRINE GLANDS
• Secretes hormones
• Secretion goes to extracellular fluid and diffuses into the blood
EXOCRINE GLANDS
• Secretes substances through ducts onto surface of the body
• Example: *sweat, tears, saliva, milk, and digestive juices
HYALINE CARTILAGE
• Cover ends of bones forming joints
• Provides flexibility making it possible to preform pressured and strong movements
• Example: connecting costae to sternum making ribcage able to extend when breathing
ELASTIC CARTILAGE
• Contains elastic fibers
• Strong and flexible
• Found in ears and epiglottis
FIBROCARTILAGE
• Contains thick bundles of collagen
• Offers support and joins structures together
• Found in between vertebrae as discs, and in knee and elbow joint
NEURON-Structure
• Dentrites - recieve signals/impulses and send them further through the cell
• Cell body - with organellis and 1 nucleus
• Axon - leads impulses from cell body
Terminals - at the end of axon; synapse on another neuron, muscle cell, or gland cells → sending signals further
• Myelin sheath - speed up impulses by creating spaces between sheaths, node of Ranvier, where impulses can jump between; small neurons or neurons that don’t have to send fast impulses may not have myelin
NEURON - Function
• Communication between different body parts - signals are sent all the time
• Communication between the body and it’s environment - senses detect changes in environment → adjustments if needed
