Tissues 2 Flashcards
Which muscle tissue is striated?
Skeletal and Cardiac
What determines if muscle tissue is striated or non striated?
Whether the Actin and Myesin are ordered in a highly arranged manner or not.
Explain the structure of skeletal muscle?
Multinucleated, Many long myoblasts in bundles with no cell-cell junctions. Muscle fibres (myoblasts) surrounded by basal lamina
What is the function of skeletal muscle?
Moves joints with strong and rapid contractions, controlling voluntary movements.
How does Skeletal Muscle regenerate?
Cannot divide itself but basal lamina contains satellite cells which replicate and regenerate damaged muscle. Also undergoes hypertrophy.
What is hypertrophy?
A cell laying down new protein to enlarge itself.
Which proteins make up all muscle tissue?
Actin and Myesin
Cardiac muscle function
Found in the heart, controlling involuntary movement,
Cardiac muscle structure
- Less highly ordered than Skeletal, still striated.
- Mononucleated cells
- Intercalated discs to hold cells together when heart contracts.
- Gap junctions
How does cardiac muscle regenerate?
No satellite cells so die when damaged. Also undergo hypertrophy.
Smooth muscle function
Surrounds vessels and ducts, under the basal lamina. It controls involuntary movements. Contracts to push contents through.
Smooth muscle structure
- Actin and myosin arranged.
- Fusiform shape.
- gap-gap junctions.
Smooth muscle regeneration
Can divide itself. Also undergoes hypertrophy
What are the three shapes neutrons come in and which is the most common
Bipolar, pseudounipolar, multipolar. multipolar
2 examples of exocrine glands
Sweat and Salivary
What are the three mechanisms of exocrine secretion?
merocrine, apocrine, holocrine
What are myoepithelial cells?
Muscle cells found in the epithelium to help contract vessels and ducts
What do we look at to classify exocrine cells? (3)
no. of cells, shape, type of secretion
How many cells makes up an exocrine gland?
Can be unicellular (goblet cells) or multicellular (salivary)
What shapes can exocrine glands come in?
Simple or Compound. Acinar, tubular or tubuloacinar (compound)
What are the 2 types of secretion by exocrine glands?
Mucous secreting and Serous secreting
How do exocrine glands work?
Attached to a lumen and secretes content directly into lumen
How do endocrine glands work? + example
Not attached to lumen. Secrete content directly into surrounding blood vessels. E.g. pituitary gland
Explain mucous secretion with e.g.
secretes substance rich in proteoglycans. has flattened nuclei and a pale appearance on microscope. e.g. trachea
Explain serous secretion
Secretes watery substance filled with enzymes, and circular nuclei. protein rich. Dark staining
What’s merocrine secretion?
Vesicles fuse with gland and release content.
What’s apocrine secretion?
Half the cell is pinched off and secreted
What’s holocrine secretion?
Mature cell dies and is fully secreted