1. The Musculoskeletal System
Muscle Structure
Lloyd Dean

2. Aims
Identify the 3 different types of muscle tissues and their
characteristics
Describe muscle structure
State the structure of connective tissues
Recall the role of a motor unit

3. White board splash
What are the different types of muscle tissue?
How does each differ?

4. 3 Types Of Muscle
Cardiac or Heart Muscle
Smooth or Involuntary Muscle
Skeletal or Voluntary Muscle

5. Cardiac Muscle
•
Occurs only in the heart
•
Appears striated
•
Involuntary
•
Pace maker
•
3 Layers of Heart Wall
Pericardium (Outer Layer)
Reduce friction & maintain heart shape
Myocardium (Middle Layer)
Largest layer and used in electrical impulse of heart beat
Endocardium (Inner Layer)
Prevent friction between flowing blood and heart muscle

6. The Heart Structure
“Cardium” – Heart
“Peri” – On, around
“Myo” – Muscle
“Endo” – Within, Inward

7. •
The opposing ends of cardiac muscle cells are separated by "intercalated disks."
•
They hold cells together and transmit the force of contraction from cell to cell.
•
Intercellular junctions between the fused membranes of the communication and nerve
impulses to be sent from cell to cell.

8. Cardiac Muscle
Heart needs constant supply of fresh oxygen
The heart has its own arteries and veins to ensure blood
supply continues
Some times this blood is prevented from being delivered
This is known as Myocardial Ischaemia or Angina

9. Smooth Muscle
Involuntary
Unstriated
Helps maintain blood pressure
 Squeezes substances (i.e., food, feces) through organs
Autonomic nervous system – Chemoreceptors and
baroreceptors detect changes and starts smooth muscle
response

10. Muscle Structure and Function
Articulate
Describe each to
your study buddy!

11. Muscle Structure
Muscle fibre
Myofibril
Myofilament

12. Connective Structures
Collagen
Most common. Produced by Fibroblasts. Provides strengths and elasticity.
Found throughout the body and components of tendons and ligaments.
Tendon
Connects muscles to bone. Forms into collagen as it attaches to the bone.
Ligament
Joins a bone to bone. Various ligaments referenced to body position. E.g.
Medial, lateral.
Fascia
Loose connective structure. Imagine a big cobweb that runs through your
whole body! Provides stability for muscles and also helps to transmit forces.

13. Can you spot each connective
structure?

14. Let’s make some
muscle!
You will need:
-Pencils or pens
-Paper
-Blue tak
-Stick tape
Can we beat this
from last year?
What more can
we add?

15. Which statement describes a
motor unit? (1 mark)
A motor neuron that transmits information to the central
nervous system
A sensory neuron that detects muscle movement
A group of muscles working together to create movement
A motor neuron and all of the muscle fibres to which it
connects

16. Motor Units and Recruitment

17. Motor Units and Recruitment
The strength of a muscular contraction will be affected
by:
The frequency of nerve impulses coming into the muscle
cell
The number of motor units activated

18. Exam Questions
You create them based on our aims
Multiple choice, ensure you know the answer!
Put your knowledge to the test here
and here via the PurposeGames related activities