Heart muscles

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