1. Module 4 Responding to the environment
2.4.8 Three types of muscle

2. Learning Objectives Success Criteria
To understand the three types of muscle
Identify 3 types of muscle and where they are found
(Grade E - D)
Outline the structural differences between each type of muscle
(Grade C –B)
Explain the structural differences according to function between all 3 muscle types
(Grade B – A) 2

3. Starter
Complete exam question

4. Starter - PA
Q4 june 2010

5. Strength of contraction
Depending on e.g. how hard you want to grasp something
Brain controls this
Many motor neurones controls a single muscle
Each branches to a neuromuscular junction causing contraction of a group of muscles (motor unit)
More muscles = greater force (gradation of response)
Read section – Investigating contraction in isolated muscles page 233 – Draw figure 4

6. Impulses, twitches, summation and tetanus
a) Shows individual action potentials causing individual contractions or twitches. The period in between contractions is the refractory period. Increase in stimulus can cause increase in contraction.
b) Shows repeated impulses – leading to enhanced contraction. This is called summation
c) Shows a series of quick impulses leading to a state of maximum contraction called tetanus. The muscle would eventually fatigue.

7. FACTS Your Body has over 600 muscles
Muscle contracts to move bones and body parts
Muscle makes up approx half your body weight
Three different types of Muscle

8. Control Mechanisms The Nervous System Autonomic Nervous System
Heart (cardiac)
Involuntary (Smooth)
Central nervous System
Voluntary (Skeletal/striated)

9. Heart/Cardiac Muscle Built in Pacemaker – Sino-atrial node
Heartbeat is involuntary
Influenced by many factors – Such as?
Sympathetic innervation speeds up heart rate, Parasympathetic slows it down
Myogenic
Intercalated discs – cell membranes fused together resulting in gap junctions allowing rapid ion passage
Contracts powerfully, without fatigue

10. Involuntary (Smooth) Muscle
Autonomic nervous control
Spindle shaped muscle fibres
Slow contraction, tires very slowly
Found in visceral organs
(Hollow organs)
Name three locations where you would find smooth muscle?
Organs, arteries, iris, intestine

11. Voluntary (skeletal) Muscle
Attached to the skeleton
Provides movement and stability
Striated in appearance
Many nuclei in each fibre
Many mitochondria
Contracts quickly and powerfully, tires quickly

12. Voluntary (skeletal) Muscle
is attached to
bones by
tendons
REMEMBER
Ligaments -Bone to Bone
Tendons – Muscle to Bone

13. Structure of Voluntary (Skeletal) Muscle
Made up of thousands of fibres
Inside these fibres – Myofibrils
Within these Myofibrils muscle contraction takes place

14. 3 Muscle types
Get into groups of 3 and each one research a muscle type and feedback
Complete table

15. Activity You should now be able to complete the following table
Muscle Type
Muscle Structure
Primary Function of the muscle
Control Mechanism
Location

16. Muscle Type
Muscle Structure
Primary Function of the muscle
Control Mechanism
Location
Heart
Striated and Smooth
Pumping of heart
Hearts automatic nervous system and the ANS
In the heart
Involuntary
Smooth
Vital organs
Autonomic nervous system (unconsciously)
Blood vessels and Visceral organs
Skeletal
Striated
Movement of the body
CNS (consciously)
Attached to bones

17. Plenary
Q2 Jan 2011

19. Learning Objectives Success Criteria
To understand the three types of muscle
Identify 3 types of muscle and where they are found
(Grade E - D)
Outline the structural differences between each type of muscle
(Grade C –B)
Explain the structural differences according to function between all 3 muscle types
(Grade B – A) 19