Title: BIOLOGY 2311 ANATOMY AND PHYSIOLOGY PART I LECTURE 1
1Isfahan University of Technology
Advance Physiology (part 5)
By A. Riasi (PhD in Animal Nutrition
Physiology)
2Is there any differences between muscle fiber for
the ATP hydrolysis and synthesis?
3Three types of skeletal muscle fibers 1-
Slow-oxidative (type I) fibers 2- Fast-oxidative
(type IIa) fibers 3- Fast-glycolytic (type IIb,
IId, IIx) fibers
4Fast fibers have higher myosin-ATPase activity
than slow fibers.
Some fiber are better equipped for oxidative
phosphorylation.
5- Oxidative fibers characteristics
- More mitochondria
- More capillaries
- More myoglobin content
Figure 3.25b
6- Fast-glycolytic have following characteristics
- Few mitochondria
- High glycogen content
- Few capillaries
- Low myoglobin and pale
- High myosin-ATase activity
- High intensity of contraction
Figure 3.25b
7Smooth Muscles
Figure 3.25b
8Smooth share some basic properties with skeletal
muscle 1- They are all have a specialized
contractile apparatus. 2- They are all directly
use ATP as energy source for cross-bridge
cycling.
Figure 3.25b
9Some more important of smooth muscle
characteristics
- Smooth muscle cells are spindle-shaped.
- Unlike skeletal muscle cells, a single smooth
muscle cell does not extend the full length of a
muscle. - A group of smooth muscle cells are typically
arranged in sheets. - Lacking sarcomeres, smooth muscle does not have
Z lines as such, but dense bodies containing the
same protein constituent found in Z lines are
present.
Figure 3.25b
10Figure 3.25b
11A smooth muscle cell has three types of filaments
- Thick myosin filaments, which are longer than
those found in skeletal muscle. - Thin actin filaments, which contain tropomyosin
but lack the regulator protein troponin. - Filament of intermediated size.
12Figure 3.25b
13Figure 3.25b
14- The smooth muscle cells are divided to two
groups - Single unit smooth muscle cells
- Multiunit smooth muscle cells
Gap junctions electrically link the muscle fiber
in a single-unit smooth muscle.
Figure 3.25b
15Multiunit smooth muscle exhibits properties
partway between skeletal muscle and a single unit
muscle. Multiunit smooth muscle consist of
multiple discrete units that function
independently of each other and must be
separately stimulated by nerves to contracts.
Figure 3.25b
16Figure 3.25b
17Cardiac Muscles
- Cardiac muscles share structural and functional
characteristics with both skeletal and single
unit smooth muscles.
Figure 3.25b
18Cardiac Muscles
Figure 3.25b
19Cardiac Muscles
Figure 3.25b
20Cardiac Muscles
Figure 3.25b