Cardiac muscle tissue only exists in the heart and contains specialized cells that allow it to contract and relax in a coordinated way. Cardiac muscle cells are connected through intercalated discs which contain gap junctions that allow electrical signals to pass between cells and coordinate contraction. The heart contains three layers - the epicardium, myocardium, and endocardium - with the myocardium containing the cardiac muscle tissue. Diseases like cardiomyopathy can make it harder for the heart to pump blood by causing the cardiac muscles to enlarge, thicken, or become stiff. Regular exercise can help strengthen the cardiac muscles and reduce the risk of developing cardiomyopathy.

1. Submitted By:
Fatima Adil
Roll Number
18371514-106
Submitted To:
Dr. Syed Zakir Hussain Shah
Topic:
Cardiac Muscles

2. MUSCLE TISSUES
 The human body contains three different kinds of
muscle tissue:
• Skeletal muscle tissue
• smooth muscle tissue
• Cardiac muscle tissue

3. CARDIAC MUSCLE
 Cardiac muscle only exists in the heart.
 Highly organized and contains many types of
cell, including;
• Fibroblasts
• Smooth muscle cells
• Cardiomyocytes

4. What are heart muscles made of?
 Intercalated discs
• Small connections that join cardiac
muscle cells to each other.
 Gap junctions
• Part of the intercalated discs.
• Allows the muscle to contract in a
coordinated way.

5. What are heart muscles made of?
 Desmosomes
• Found within intercalated discs.
• Hold the cardiac muscle fibers together during a contraction.
 Nucleus
• Control center of a cell.
• It contains all of the cell’s genetic material.

6. STRUCTURE
 Appear striated or striped due to myosin and actin filaments.
 Myosin filament connects to two actin filaments forming
sarcomere.
 Cardiac muscle cells contain
• One nucleus, but some have two.
• Mitochondria

7. Pathway of Cardiac Muscle Contraction
 Pacemaker cells initiate the action potential.
 This activates calcium channels in the T-tubules, resulting in
an influx of calcium ions into the cardiomyocyte.
 Calcium binds to troponin-C which moves the troponin
complex away.
 Removal of the troponin complex frees the actin to be
bound by myosin and initiates contraction.

8. Pathway of Cardiac Muscle Contraction
 Myosin head binds to ATP and pulls the actin filaments
toward the center of the sarcomere, contracting the muscle.
 Intracellular calcium is then removed dropping intracellular
calcium concentration.
 troponin complex returns to its inhibiting, ending
contraction.

9. HEART LAYERS
 Heart consist of three layers:
• Epicardium- The outer layer of the heart wall.
• Myocardium- The middle layer.
• Endocardium- The inner layer.

10. Cardiac muscle tissue function
 The heart contains specialized cardiac tissue containing
“pacemaker” cells.
 These contract and expand in response to electrical impulses
from the nervous system.
 Pacemaker cells generate electrical impulses that tell cardiac
muscle cells to contract and relax.
 Pacemaker cell control heart rate
and determine how fast heart
pumps blood.

11. Cardiomyopathy
 Cardiomyopathy is one of the main conditions that can affect
cardiac muscle tissue.
 It’s a disease that makes it harder for your heart to pump
blood.
 TYPES:
 Hypertrophic cardiomyopathy-
• The cardiac muscles enlarge and thicken
 Restrictive cardiomyopathy-
• The ventricles become stiff.

12.  Dilated cardiomyopathy-
• Ventricles become larger & weaker
 Arrhythmogenic right ventricular dysplasia-
• The cardiac muscle tissue of right ventricle is replaced with fatty or
fiber-rich tissue.
• This can lead to arrhythmia, which refers to an abnormal heart rate or
rhythm.

13.  Symptoms of cardiomyopathy:
• Difficulty breathing or shortness of breath
• Fatigue
• Swelling of the legs, ankles, and feet
• Inflammation in the abdomen or neck
• Irregular heartbeat
• Heart murmurs
• Dizziness or lightheadedness

14.  Causes:
• A family history of cardiomyopathy or heart failure
• High blood pressure
• Obesity
• Heavy alcohol consumption
• Use of certain recreational drugs
• Past heart attacks or heart infections

15.  Factors that can increase a person’s risk of
cardiomyopathy include:
• Diabetes
• Thyroid disease
• Coronary heart disease
• Heart attack
• Chronic high blood pressure
• Viral infections that affect the heart muscle
• Valvular disease of the heart
• Heavy alcohol consumption
• A family history of cardiomyopathy

16. How does exercise impact cardiac muscle
tissue?
 Exercise can strengthen your cardiac muscle.
 Exercise can also help reduce risk of developing
cardiomyopathy and make your heart work more efficiently.
 Some examples of aerobic exercises include:
• Running or jogging
• Walking or hiking
• Cycling
• Swimming

17. The bottom line
 Cardiac muscle tissue is one of the three types of muscle in
your body.
 It’s only found in your heart.
 Involved in coordinated contractions that keep your heart
beating.
 To keep your cardiac muscle working efficiently try to get in
some sort of exercise more days of the week than not.

18. THANK YOU