What does the Epithelial characteristic Cellularity mean?
Composed almost entirerly of cells bound closely together by interconnection known as cell junctions.
What does the Epithelial characteristic Polarity mean?
- Refers to the presence of structural and functional differences between the exsposed and attached surfaces.
What does the Epithelial characteristic Attachement mean?
Base of epithelium is bound to a thin basal lamina(basement membrane)
What does the Epithelial characteristic Avascularity mean?
- Avascular(lack of blood vessels)
- Must obtain nutrients by diffusion or absorbtion across either the exsposed or attached epithelial structure.
What does the Epitheial characteristic Regeneration mean?
Damage or lost cells replaced through division of stem cells in epithelial structure
What are the functions of the Epithelial tissues?
- Secretion(gland cells)
This secures the epithelial in place and prevents it from tearing?
Between the epithilial and the connective tissue is a thin extracellular layer called what? What are its components?pg.83
- Basement membrane
- Basal lamina
- Reticular lamina
What is the function of the basement membrane?
physical support, anchoring to connective tissue, and barrier to regulate movement of large molecules between epithelium and connective tissue
What are the types of Intercellular Junctions and what is there purpose?
- Tight junctions
- Gap junctions
- Adhering junction
- These allow cells to function as a tissue
What is a tight junction and its function?
- Lipid portions of the 2 cell membranes are tightly bound together by interlocking membrane proteins.
- Prevent passage of H2O and solutes between cells
What is a gap junction and its function?Refer to Quiz question?
- Has a pore and connexon that ions diffuse through
- Used for intercommunication between cells
What is a Desmosomes and its function?
They connect cell membrane to cell membrane.
What are the Classification of epithilia by number of cell layers?
- Simple epithelium- thin, one layer of cells cover the basal lamina
- Stratified epithelium
- Pseudostratified epithelium
Where would Simple epithelium be located in the human body?
- a. Fragile, located only in protected areas inside the body
- b. Line internal compartments and passageways, ventral body cavities, heart chambers, blood vessels
- c. Small intestines
- d. lungs
Where would Stratified epithelium be located in the human body?
- a. Located where mechanical stresses are severe, for defence
- b. Surfaces of skin, lining of the mouth, esophagus, and anus
Where would Pseudostratified epithelium be located in the human body?
a. Nuclei distributed at different levels between apical and basal surfaces
What are the Classifications by Cell shape?
- 1. Squamous
- 2. Cuboidal:
- 3. Columnar
- 4. Transitional
Where would Simple Squamous be located?
- Most delicate.
- 2. Located in protected regions where absorption of diffusion takes place
- 3. Alveoli, lining of ventral cavities, lining of heart and blood vessels
- 4. Mesothelium(inside cavities)- line ventral body cavities, pleura, peritoneum, and pericardium
- 5. Endothelium(Inside blood vessels and heart cavity)- line the inner surface of the heart and all blood vessels
What are the functions Simple cuboidal and there locations?
- Absorption and secretion.
- Thyroid gland folicals
- Kidney tubules
What are the functions Nonciliated Simple Columnar Epithelia Cells and there locations?
- Absoption and secretion;secretion of mucin through goblet cells
- Lining of most of the digestive track
What are the functions ciliated Simple Columnar Epithelia Cells and there locations?
- Secretion of mucin and movement of mucus along aplical surface of epithilium by action of cilia
- Lining of uterine tubes and larger bronchioles
What are the functions Non Keratinized Stratified Squamous Epithelia Cells and there locations?
- Protection of underlying tissues, alive at the top surafce
- Surfaces of skin, mouth, pharynx, anus, vagina
What are the functions Keratinized Stratified Squamous Epithelia Cells and there locations?
- Protection of underlying tissues,dead at top surface
- Epidermis of skin
- The importance of the top layer being dead is that bacteria can not live in a hostile enviorment
What is Keratin?
A fiberous protien
What are the function Stratified Cuboidal Epithelia Cells and there locations?
- Protection and secretion
- Large ducts, exocrine glands, some pats of the male urethra(glandeir ducts)
What are the functions Stratified Columnar Epithelia Cells and there locations?
- Protection and secretion
- Rare;Regions of male urethra
What are the functions Pseudostratified nonciliated columnar Epithelia Cells and there locations
Small intestine of the GI track
What are the functions Pseudostratified ciliated columnar Epithelia Cells and there locations?
- Offers protection pushes out things.
- Possesses cilia (nasal cavity, trachea, bronchi)
What are the functions Transitional Epithelia Cells and there locations?
- 1. Tolerates repeated cycles of stretching
- 2. Urinary bladder
What is the purpose of Endocrine glands?
- Secretions called hormones (regulate or coordinate the activities or various tissues, organs, and organ systems)
- Thyroid gland, Pituitary gland
What is the purpose of Exocrine glands?
- release secretions into passageways called ducts that open onto an epithelial surface.
- 1. Goblet cell: respiratory tract lined with pseudostratified ciliated columnar epithelium which contains goblet cells-mucus Fig.4.3
- 2. Acini- secretory portion
What are the Exocrine gland secretion methods?
How does the Merocrine gland work and what are some its locations?
- salivary glands(Location)
- Product is released from secretory vesicles by exocytosis
- Mucus- mucin mixes with water, effective lubricant, protective barrier, and sticky trap for foreign particles and microorganisms
How does the Apocrine gland work and what are some its locations?Quiz question?
- Mammary gland(location)
- Involves the loss of cytoplasm as well as the secretory product
How does the Holocrine gland work and what are some its locations?Refer to pg.94
- Hair follicle(location)
- Entire cell becomes packed with secretory products and then bursts, releasing the secretion but killing the cell
What are the three main components of connective tissues?
- 1. Specialized cells
- 2. protein fibers
- 3. Ground substances
What are some of the functions of the connective tissues?
- 1. Structural framework
- 2. Transporting fluids
- 3. Protecting
- 4. Supporting
- 5. Storing energy
- 6. Defending the body
What is connective tissue proper?Redu this answer listen to recording jan 24
- Contain a variable mixture os both connective tissue cell types.
- Resident cells
- Wandering cells
What are the Resident cell types?
- Fibroblasts cells
- Adipocytes cells
- Fixed machrophages cells
- Mesenchymal cells(stem cells)
What are the different Wandering cells?
- Mast cells(leukocytes)
- Plasma cells(leukocytes)
- Free macrophages(leukocytes)
What do fibroblast do?
- The only cell that is always presents
- Produce fibers and ground substances
What do Macrophages(free and Fixed do)?
- Scattered through out the matrix, engulf pathogens or damaged cells that enter the tissue
- Fixed-sends out chemicals that stimulates immune system when it encounters forien materials
- free-mitigate through tissues and engulf and destroy any bacteria
- a. Contain a single, enormous lipid droplet
- b. Nucleus, organelles, and cytoplasm squeezed to one side
- Single cells that are present in many connective tissues.
- a. Respond to local injury by dividing into daughter cells (fibroblasts, macrophages, or other connective tissues
Mast cells(wandering cells, leukocytes, white blood cells)?
1. Mast cells- small, mobile connective tissues that are common near blood vessels a. Cytoplasm filled with granules containing histamines and heparin
Plasma cells(wandering cells, leukocytes, white blood cells)?
- Synthesize antibodies
- Found in the intestinal walls, spleen, and lymph nodes
Free Macrophages(wandering cells, leukocytes, white blood cells)?
Formed from monocytes, wander and engulf and destroy any bacteria, damaged cells, etc
What are the Fibers of the connective tissue?
- Collagen fibers
- Reticular fibers
- Elastic fibers
- fibroblasts form all three by secreting protein subunits that interact in the matrix
- long, straight, and unbranched, white fibers
- a. Wound together like rope, strong and flexible (tendons)
- b. 25% of body’s protein, withstand forces in one direction
- a. Thinner than collagen fibers, branching, interwoven framework that is tough and flexible
- b. Resist forces from many directions
- c. Stroma- interwoven network stabilizes the positions of the functional cells (parenchymal), stabilizes the positions of organs, blood vessels, nerves, despite position and gravity
- Contain the protein elastin, branched and wavy, yellow fibers
- a. Interconnecting vertebrae
What are the types of Connective Tissues?
- Loose Connective Tissue(fewer fibers, more ground substance).
- Dense Connective Tissue(More fibers,less ground substance).
What are the types of Loose Connective Tissue?
- Packing material of the body, fill spaces between organs, cushion and stabilize specialized cells in many organs, and support epithelia
What are the types of Dense Connective Tissue?
- Collagen fibers are parallel to each other, packed tightly and aligned with the forces applied to the tissue
Areolar(Loose connective tissue)?
- Surrounds nerves, blood vessels.
- a. Open framework
- b. Viscous ground substance accounts for most of its volume and absorbs shock
- c. Elastic fibers make it resilient, can distort after damage
- d. Form the padding between skin and muscle, pinch test or muscle contacts does not change shape
- e. Vascular, common injection site
Adipose(Loose connective tissue)?
- Fat capsule around Kidney, pericardial and abdominopelvic cavities.
- a. Provides padding, absorbs shock, acts as an insulator to slow down heat loss, and is fillers around structures b. White fat- pale, yellow white color c. Brown fat- highly vascularized and individual adipocytes contain numerous mitochondria d. Lipid breakdown, energy absorbed by the blood to increase temperature e. Losing weight, cells shrink but are not killed f. Mesenchymal cells are ones that increase production of fat cells
Reticular(Loose connective tissue)?
Spleen and liver, reticular fibers create a complex 3-dimensional stroma, which supports the parenchyma (functional cell)
Regular(Dense connective tissue)?Makes up tendons and ligements
- collagen fibers are parallel to each other, packed tightly and aligned with the forces applied to the tissue Table 4.10
- a. Tendon-attach skeletal muscle to bone
- b. Ligaments-connect 1 bone to another or stabilize the position of internal organs
- c. Aponeurosis: tendinous sheet that attaches a broad, flat muscle to another muscle or to several bones of the skeleton
- d. Stabilizes the positions of tendons and ligaments
- e. Associated with muscles of lower back and abdomen and with tendons and ligaments of the palms of the hand or soles of the feet
Irregular(Dense connective tissue)?
- Gives skin its strength Table4.10
- a. Form an interwoven meshwork in no consistent pattern
- b. Gives skin its strength in many directions
- c. Capsules: surrounds internal organs such as a liver, kidney, spleen, and encloses cavities of the joints
Elastic(Dense connective tissue)?
Stabilize vertebrae of spine
What are the Supporting Connective tissues?
- Cartilage(semi solid matrix)
- Bone(solid matrix)
What cells make up Cartilage?
Chondrocytes- cartilage cells, only cells in the cartilage matrix, occupy small chambers called lacunae.
What cells make up bone?
Osteocytes- bone cells
What are the types of cartilage?
- Hyaline cartilage Connections between ribs, sternum, elbow, and knee
- Elastic cartilage External flap of the ear, epiglottis, auditory tube, and small cartilages in the larynx
- Fibrocartilage between spinal vertebrae, between pubic bones of the pubis
What are the types of bone?