Muscle tissue Flashcards
Types of muscle cells
- Skeletal
2.Cardiac
3.Smooth
Smooth muscles
Found in viscera
Involuntary
Autonomic and homornal control
Cardiac muscle
Striated (less)
Structural and functional characteristics of skeletal and smooth
Skeletal muscle
-elongated
-multi-nucleated
-damaged nerve supply could lead to atrophy
Skeletal muscle covering
- Endomysium: DELICATE tissue occupying space
- Perimysium: surrounding loose collagen
- Epimysium: surrounding dense collagen
View of skeletal muscle tissue
-Nucleus at the edge
-Striated
What do muscle stem cells resemble myoblast to
Satellite cells
How to tell if muscle regeneration regeneration has occured?
The nucleus shifts to the centre from the edge
What is a sacormere?
Basic contractile unit of muscle fibre
Two types of myofilaments
- Thick-M lines-Myosin
- Thin-Z lines-Actin
Sliding filament mechanism
Myosin has ATP molecules which force it to bind to actin to form
-crossbridge (linkage between thick and thin filaments)
SARCOMERE SHORTENS
Smooth muscle tissue
-CONTRACTILITY (occurs without innervation)
-Single nucleated
-Centrally located nucleus
-Small
-Fibres in irregular fascicle (because they are not striated)
Cardiac muscle tissue
-Intermediate characteristics
-Central nucleus and ends of fibres split into smaller branches (CARDIAC MYOCYTES)
-INTERCALATED DISCS
What do intercalated discs do?
-Anchor
-Rapid spread of stimuli
-Mark cell boundaries
Health diseases
- Hypertrophy: increase in size of individual cell due to synthesis of more contractile proteins
- Hyperplasia: increase in number of smooth muscle cells
