Types of Tissues Flashcards
Tissue def
a group of cells with the same morphology (shape) and function.
There are 4 types of tissue:
Epithelial tissue (epithelium), muscle tissue, connective tissue and nervous tissue.
Epithelial tissue def
Lining outside surfaces (skin), and the inside of hollow organs, is the inner-most lining.
3 types of epithelial cells:
squamous, cuboidal, columnar
Simple squamous epithelium def+examples
- one layer of squamous cell, forming alveoli and capillaries. This arrangement allows relatively free passage of molecules between the cells.
Simple cuboidal epithelium def+examples
- one layer of cuboidal cells. Found in places like the kidneys, where a high level of absorption and secretion is needed.
Simple columnar epithelium def+examples
simple layer of columnar cells, found in places like the small intestine, offering protection and absorption.
Stratified squamous epithelium-
def+examples
Multiple layers of squamous cells. Found in the skin (epidermis) and places under mechanical pressure, like the pharynx.
Stratified cuboidal epithelium def+examples
multiple layers of cuboidal cells. Found in many exocrine glands like salivary, pancreas, sebaceous- secretional glands.
Stratified columnar epithelium def+examples
multiple layers of columnar cells. Found in the eye and urethra- places where high protection is needed.
Pseudo-stratified columnar epithelium- def+examples
One layer of columnar cells that appear to be stratified because the nuclei are a different heights. This tissue when ciliated can be found in the trachea. Helps to clean the air from pollutants by trapping them.
Transitional epithelium- def+examples
A mixture of epithelial cells that’s found in the urinary bladder, allowing it to expand and protecting the underlying tissue from the urine.
Keratinized stratified squamous epithelium-
The cells have a keratin layer, and the exterior cell layer is dead. The cells contain no nucleus or cytoplasm, making them tough and resistant (like in human skin).
*Keratin - protein fiber helps make intermediate filaments.
Non-keratinized stratified squamous epithelium-
Doesn’t have a keratin layer, making it moist, like in the esophagus lining and in the pharynx.
Smooth Muscle Tissue cell Shape
Spindle shape
Cardiac muscle cell Shape
Branched shape
With intercalated discs, providing synchronised contractions.
Skeletal muscle cell Shape
Cylindrical shape.
Long, thin muscle fibres
how many nuclei (nucleus ) in smooth muscle, cardiac and skeletal muscle cells
smooth- one
cardiac- 1/2
skeletal- multinucleated
where can smooth muscle be found
Walls of certain internal organs and blood vessels
where can cardiac muscle be found
Heart walls
where can skeletal muscle be found
Attached to bones; providing movement to the body
which muscle tissues are striated
cardiac and skeletal- have myosin and actin fibers
type of contraction for each muscle tissue
smooth-Smooth, continuous contractions
cardiac+ skeletal-Strong, forceful contractions
what nervous sys. controls smooth muscles
Non-voluntary.
Controlled by ANS- autonomic nervous system
what nervous sys. controls cardiac muscles
Non-voluntary.
Controlled by ANS- autonomic nervous system
what nervous sys. controls skeletal muscles
Voluntary.
Controlled by SNS- somatic nervous system
Connective Tissue:
def
Different types of cells and molecules which are scattered in the body. Connective tissue connects and separates different tissues and organs. It is the most abundant tissue in the body.
Collagen def
very strong protein fibre produced by cells known as fibroblasts.
Dense connective tissue def + examples
Highest concentration of collagen, forming ligaments that connect bone to bone, and tendons connecting muscle to bone. In both cases, dense connective tissue can withstand and resist high pressure.
Loose connective tissue def + examples
Lower concentration of collagen fibers, holding organs together but allowing some flexibility. For example, the dermis under the epidermis.
Reticular connective tissue def + examples
Reticular- net like shape. Forming the skeleton of some organs, like the liver.
Elastic connective tissue def + examples
Collagen fibers are mixed with elastin fibers to provide elasticity of some organs. For example: lungs and large blood vessels (aorta).
Adipose tissue is Made of cells called….
adipocytes
Adipose tissue Functions include
Insulation, thermal insulation, cushioning, protection and energy storage
(in the form of TAG).
BAT- Brown Adipose tissue/
brown fat
Smaller size
Many TAG droplets
Many mitochondria
(gives reddish brown color)
Rich blood supply
High adrenaline recpetors
Found mostly in babies and in subclavian area in adults
WAT-White Adipose tissue/
white fat
Larger cell
One large droplet of TAG
Fewer mitochondria
Lower blood supply
Lower adrenaline receptors
Found mostly in children and adults
adipose tissue is a type of…. tissue
connective
Cartilage connective tissue def
A smooth flexible connective tissue composed of cells known as chondrocytes. the chondrocytes sit in the Lacuna and secrete proteoglycans - proteins rich in sugars and collagen fibers.
Cartilage is a non-regenerating tissue - it doesn’t have a blood supply, so nutrients pass by diffusion.
Cartilage is A smooth flexible connective tissue composed of cells known as ……. the ……….sit in the …………and secrete …………..- proteins rich in sugars and collagen fibers.
Cartilage is A smooth flexible connective tissue composed of cells known as chondrocytes. the chondrocytes sit in the Lacuna and secrete proteoglycans - proteins rich in sugars and collagen fibers.
Types of cartilage
Elastic cartilage- found in ears
Hyaline cartilage- found in joints
Fibrocartilage- found in spine
Blood connective tissue def
Blood is A specialized connective tissue composed of blood cells, proteins, electrolytes and fluid.
blood composition
55% plasma
4% White Blood Cells- Leukocytes
Platelets- Thrombocytes
41% Red Blood Cells- Erythrocytes
plasma composition
90% water, 10% dissolved material:
Gasses- O2, CO2
Salts
Electrolytes- Na+, Cl-, Zn, Mg2+, Ca 2+, K+, HCO3-
Nutrients- glucose (only source of nutrition for RBC)
Hormones- Insulin
Vitamins- Folic, B9
Proteins- LDL, HDL, Ig (Immunoglobulin), Albumin (oncotic pressure)
Red blood cells don’t have a …..
nucleus
Red blood cells have a ….. shape
biconcave
Red blood cells have a ……-day lifespan.
120
Hemoglobin def/structure
4 polypeptide chains with a Hemi group, made of 4 pyrrole rings with Fe2+ (turns into Fe3+ after hemoglobin is oxidised).
Bone Connective Tissue def
Bone is a rigid connective tissue that is constantly and continuously being built and broken down- it is a dynamic process.
Bones form the endoskeleton that provides stability, protection, movement and support.
the functional unit of bones is
Osteons
Osteons
cylindrical shaped structures surrounded by collagen fibers, and consist of a central
harvasion canal that contains blood vessels and nerve supply.
There are ….. bones in an adult
206
Types of bone cells:
Osteocytes- cells inside the bone
Osteoblasts- cells that build bone by secreting a matrix (proteoglycans, collagen fibers, Ca2+)
Osteoclast- breaks down bone
Neuron/nerve cell def
Transmits electrochemical signals. the basic structure unit of the nervous system.
Neuron structure
Soma/body- contains organelles
Dendrites- branched structures that receive and transmit information to the body.
Axon- a nerve fibre transmitting an electric signal.
Axon terminal- contains neurotransmitters.
Synapse- space between neurons that allows message transmission.
Glial cells/ support cells-
Glial cells provide support and nourishment to the neurons. They don’t produce an electrical impulse. Glial cells also produce myelin, a phospholipid material that surrounds the axons, providing electrical insulation.
what cells provide myelin in the CNS- central nervous system
Oligodendrocytes
Schwann cells provide myelin in the …
PNS- peripheral nervous system.
