Lecture 2 Flashcards
What are tissues?
Group of cells with a common origin. Can be liquid, solid, etc - blood, fat.
4 Types of Tissue
- Epithelial Tissue - (skin) body surfaces, body cavities, etc
- Connective Tissue - closely related, bone, blood vessels found within connective tissues
- Muscular Tissue - makes up muscle cells
- Nervous Tissue - sends nerve impulses
Epithelial Tissue
1. Cell arrangement
With many cells tightly packed together and little to no extracellular matrix (fewer cells/volume)
Cells have a free surface lateral, basal surface
Connective Tissue
1. Cell arrangement
With a few scattered cells surrounded by large amounts of extracellular matrix
Epithelial Tissue Organization (Look at diagram)
The epithelium is the outermost level with apical surface, with lateral surfaces in between.
The next level is the basement membrane, which includes the basal lamina and the reticular lamina.
Lastly the bottom layer contains the connective tissue which includes the nerves and blood vessels within.
What are the 5 Cell Junctions?
- Gap Junction
- Tight Junction
- Hemidesmosome
- Desmosome
- Adhering Junction
(Not unique to epithelial tissue; some muscle and nerve cells also have junctions)
What is a Gap Junction?
Forms pores, allow small molecules thru to communicate. (Look at diagram in presentation)
What is a Tight Junction?
Network of proteins that fuse together. Creates a permeability barrier that doesn’t let much through.
What is a Hemidesmosome?
Cell attaches to basement membrane called interproteins. Very small stud-like structures found in keratinocytes of the epidermis of skin that attach to the extracellular matrix.
What is a Desmosome?
Intermediate filaments (thicker). Have plaque but spots, not like adhering junctions. Adhesive intercellular junctions that mechanically integrate adjacent cells by coupling adhesive interactions mediated by desmosomal cadherins to the intermediate filament cytoskeletal network.
What is Adhering Junction?
Forma bonds with other membranes. The microfilaments provide structural integrity. The adhesion belt (plaque dense layer of proteins). Which if someone had cancer they’d lose this. Connect bundles of actin filaments from cell to cell.
What are two types of Epithelial Tissue?
- Surface (major tissue in glands, and covers all internal and external surfaces of your body)
- Glandular (lines certain internal organs)
3 Cell Shapes (Arrangement of layers)
- Simple (Cover lungs)
- Pseudostratified (1 layer, nuclei can be arranged in different levels but is an illusion)
- Stratified (2 or more layers)
3 Cell Shapes
- Squamous (flat cells on surface)
- Cuboidal (cube-shaped)
- Columnar (tall and skinny)
You have a lining of peritoneum that has one layer, and flat cells. This would be a?
This would be a Simple Squamous Epithelium.
You have a view of the kidney tubules, the tubules have 1 layer with cube-like shape. This would be a?
This would be a Simple Cuboidal Epithelium.
You have a view of the lining of jejunum of small intestine, the tubules have 1 layer with tall and skinny shape. This would be a?
This would be a Nonciliated Simple Columnar Epithelium.
What do Microvilli do?
Increase surface area and exchange cells.
You have a view of ciliated epithelium in the uterine tube. They have one layer, and a skinny tall shape. What is this?
Ciliated Simple Columnar Epithelium.
You have a view of nonciliated 1 layer arrangement, skinny and tall. The nuclei can be arranged in different levels but it’s an illusion.
Nonciliated Pseudostratified Columnar Epithelium.
You have a view of ciliated 1 layer arrangement, skinny and tall. The nuclei can be arranged in different levels but it’s an illusion.
Ciliated Pseudostratified Columnar Epithelium.
You have a view of the epithelium of epidermis. This have 2 or more layers, and has flat cells on the surface.
Stratified Squamous Epithelium.