Chapter 4: tissues - membranes Flashcards
Sheets of pliable tissue that cover or line a part of the body
Membranes
Epithelial Membranes
Majority of membranes
Have an epithelial layer and an underlying connective tissue layer
Include mucous membranes, serous membranes, and the cutaneous membrane (skin)
Synovial Membranes
Second type of membrane, no epithelial layer
lines joints and contains connective tissue
Membranes
Mucous Membranes
Serous Membranes
Cutaneous Membrane
Mucous Membrane (mucosa)
Lines a body cavity that opens direclty to the exterior
- lining layer of epithelium with underlying connective tissue layer
- contains goblet cells for mucous
- tight junctions as barrier of protection
Mucous membrane connective tissue layer?
Areolar CT
(Mature, CT Proper)
Called the Lamina Propria
Serous Membrane
lines a body cavity that does not open directly to the outside
covers organs within cavity
Areolar connective tissue covered by mesothelium (simple squamous epithelium)
Parietal layer - attached to and lining cavity wall
Visceral layer - covers adn adheres to the orgrans
Mesothelium secretes serous fluid
Cutaneous Membrane
skin
epidermis is superficial portion - keratanized stratified squamous epithelium
dermis is deeper portion - dense irregular connective tissue and areolar connective tissue
Synovial Membrane
line the cavisities of freely moveable joints
lack epithelium
discontinuous layer of synoviocytes and a layer of connective tissue
synoviocytes secrete synovial fluid
synovial fluid lubricates and nourishes cartilage in moveable joint, contains macrophages that remove debris and microbes from the joint
Muscular tissue
consists of elongated cells called muscle fibres or myocytes that use ATP for energy to generate force
myocytes
muscle fibres (cells)
Function of muscular tissue
movement, posture, generate heat
3 classifications of muscular tissue
- skeletal
- cardiac
- smooth
Skeletal Muscle Tissue
COmponsed of long, cylindrical striated fibres (alternating light and dark bands within fibres)
vary inlegnth
muscle fibre is roughly cylindrical, multinucleated with nuclei at the periphery
Voluntary muscle
Usually attached to bones by tendons
help with motion,posture, heat and protection
CArdiac Muscle Tissue
branched, striated fibres with usually one centrally located nucleus (sometimes 2)
attached end to end by intercalated discs (transverse thickenings of plasma membrane) that have desmosomes and gap junctions
Gap junction - route for electrical signals
desmosomes - strength
Involuntary
Smooth muscle tissue
Nonstriated fibres that are a small spindle shaped cell - thickest in the middle, tapered at each end
single central nucleus
gap junctions connect them usually (in small intestine for example)
usually involuntary
no gap junction - fibres then contract individually (iris of eye)
walls of hollow organs, iris, blood vessels, airways to lungs, stomach, bladder, uterus
Function is motion (move things through things)
Nervous tissue
Two types of cells
- neurons
- neuroglia
Neurons
nerve cells; sensitive to stimuli
Convert stimuli into electrical signals called “nerve action potentials” (nerve impulses) and conduct them to other neurons, muscle tissue or glands
Three basic parts of a neuron
- cell body
- axons
- dendrites
Neuron cell body
contains the nucleus and other organelles
Neuron Dendrite
tapering, highly branched and usually short cell processes
major recieving portion of a neuron
Neuron Axon
Single thin sylindrical process that may be very long
sends output by conducting nerve impulses toward another neuron or tissue
Neuroglia
D o not generate or conduct nerve impulses
Excitable Cells
Muscle fibres and neurons are considered excitable cells because they exhibit electrical excitability
electrical excitability
the ability to respond to certain stimuli by producing electrical signals
