Tissues Flashcards
Tissues
- Groups of similar cells that act together to perform specific functions
- Tissues organize themselves into organs
Organs
Groups of two or more tissue types that perform specialized functions
Muscle tissue
- Located in hollow internal organs and tubes and is attached to bones
- This tissue produces movement, posture maintenance, and heat production
Nervous tissue
- Located in the brain, spinal cord, and nerves
- This tissue interprets sensory information and coordinates bodily processes
Interstitial fluid
- Found in extracellular spaces between tissues
- This fluid is primarily water and contains substances such as salts, sugars, fatty acids, amino acids, hormones, and neurotransmitters
- Bathes cells and provides a transport medium for nutrients, gases, and wastes
Layers of embryological tissue: Ectoderm
The outermost layer and gives rise to structures of the nervous system
Layers of embryological tissue: Mesoderm
The middle layer, and it develops into muscles and connective tissues (ex: Fascia, tendons, retinaculum, ligaments, cartilage, and bone)
Layers of embryological tissue: Endoderm
Becomes epithelial tissue lining the body’s cavities, passages, and internal organs
Principal type of tissues: Epithelial tissue
- Lines or covers external and internal body structures
- Lines open body cavities, such as the digestive, respiratory, urinary, and reproductive tracts
- And closed body cavities, such as the dorsal cavity which houses the brain and spinal cord
- Made up of closely packed cells and arranged in one or more layers
- Usually has a high rate of cell division and regenerates quickly
- Functions: Protection, absorption, secretion, excretion, and sensation
Principal type of tissues: Connective tissue
- Connects, supports, transports, and defends
- It forms a supporting framework for organs and glands, and for the body as a whole
- It transports nutrients and wastes, and provides defensive functions such as blood clotting and inflammatory responses
- Most abundant tissue type
- Types: Fibrous, bone, cartilage, and blood
Types of protein fibers
- Elastin, collagen, and a special type of collagen fiber called reticulin
- Collagen is tough and durable, reticulin is delicate, and elastin is flexible and elastic
- Collagen is the most abundant type and makes up approximately 25% of all protein in the body
Fibroblasts
- Precursor cells that produce all types of protein fibers found in connective tissues
- Contribute to wound healing and tissue repair
Fibrous Connective Tissue
- The packing material of the body
- It supports structures, attaches them to each other, fills in spaces between structures, and helps keep them in their proper places
Loose fibrous connective tissue
- The most widely distributes connective tissue types and functions like elastic glue
Adipose tissue
Predominantly fat and serves as storage for surplus food and insulation to conserve body heat, as well as support and protection for certain structures such as the heart, kidneys, and some joints
Reticular tissue
- Provides the supportive framework for bone, bone marrow, lymph nodes, and organs
- It functions as part of the body’s defense system
Dense fibrous connective tissue
- Consists of compact strong bundles of fibers that are glistening white in color
Dense REGULAR fibrous tissue
- Have their fiber bundles arranged in regular parallel rows
- This tissue is elastic, has great tensile strength, and can resist pulling forces in one or two directions
- Ex: Tendons (connect muscle to bone), and ligaments (connect bone to bone)
Dense IRREGULAR fibrous tissue
- Fiber bundles interwoven in irregular patterns and form a strong, thick sheath of connective tissue
- Can resist pulling forces in multiple directions
- Ex: Deep fascial sheaths surrounding muscles, the dermal layer of skin, periosteal sheaths or periosteum surrounding bone, and the outer capsules of organs such as the kidneys and spleen
Bone
- Hardest type of connective tissue
Compact bone
- Forms the hard outer shell of bone
- It contains few spaces and is the strongest form of bone tissue
Spongy bone
Consists of latticework beams
Cartilage
- Strong protective connective tissue capable of withstanding repeated stress
Hyaline cartilage
- Elastic, rubbery, smooth
- Most prevalent type of cartilage and covers the articulating surfaces of bones, connects ribs to the sternum, and if found as supportive tissues in the nose, ears, trachea, and smaller respiratory tubes
Fibrocartilage
- The strongest and most durable type
- Fibrocartilage discs serve as shock absorbers and are found between vertebrae and in the knee
Elastic cartilage
- Softest and most pliable type
- Gives shape to the external nose and ears and is found in internal structures, such as a the larynx
