1. The Muscular System
Presented by Amritha Somasekar, Sam Boyd, Michael Carbonaro, Max von Blankenburg

2. Introduction:
Your muscles perform all of the motor functions in your body, even pumping blood.

3. Function of the Muscular System:
As a whole, muscular system allows movement in body (ex. standing up, sitting down, pumping blood, etc.)
Most of nervous system impulses → muscle movement
Body cannot function w/o muscular system

4. Specific Functions: Skeletal Muscles
Skeletal muscles cover the skeleton and are attached to the bones, tendons, and ligaments
Fully deal with the voluntary movements
Convert energy from food into ability to move
Stabilize human skeleton, give it posture, and protect internal organs
When we think of using them, nervous system sends impulse telling them to move

5. Specific Function:Cardiac Muscles
Cardiac muscles are found in the heart
Responsible for (1)forcing blood out of heart, (2)makes sure it circulates through body, (3)nutrients come to tissue, and (4) wastes get taken away

6. Specific Function: Smooth Muscles:
Involuntary = we do not have direct control over muscle function
Smooth muscles are the involuntary ones that line internal organs such as blood vessels and the stomach
Ex. Smooth muscles of digestive system contract and allows digestion
Ex. Contractions of the smooth muscles of uterus allow childbirth
Ex. Maintain blood flow in body
Can usually function with nervous stimulation

7. Organization of Muscles:
Although many of the
muscles in the human body are different, they all have the same levels of organization.
On the right is a
pyramid I made showing this

8. Properties of Muscles:
Cells = Muscle Fibers (Appearance)
Tissues = Muscle Tissues (3 Kinds)
Organs = Skeletal Muscle (Instructions)
Organ Systems = Skeletal Muscle System
(Movement/Lift)
Organisms = Human Body (Other Systems)

9. Skeletal Muscle Structure:
The Breakdown
→ skeletal muscles → bundles of muscle fibers → myofibrils → filaments made of actin and myosin → divided into sarcomeres, functional units
striated muscles - muscle tissue that has repeating sarcomeres
sarcomeres separated by z-discs
striations formed by alternating pattern of filaments
thick filaments made up of myosin
thin filaments made of actin

10. How it Works:
Muscle contractions caused by force produced by myosin and actin
filaments
Muscles move when thin filament in fiber slide over thick filament
All the muscles in your body use oxygen and
glucose as a main source of energy. The oxygen allows the glucose to convert to ATP, which is what fuels muscle contractions.
When oxygen is not present, glucose is
converted to lactic acid instead, which is an inefficient fuel source that causes fatigue.
Nerve impulses from brain usually always result in
muscle movement

11. How it Works: Control
Neuromuscular junction -contact point between motor neuron and skeletal muscle cell
Vesicles in the motor neuron release acetycholine, a neurotransmitter, which produces an impulse that causes myosin and actins to work through releasing calcium ions that affect the needed regulatory proteins
this leads to muscle contraction
muscle cell stays contracted until acetycholine stops producing and all other processes stopped

12. How it Works with Other Systems:
Muscles need glucose from the digestive system, but they also need a constant supply of oxygen from the respiratory and circulatory systems.
Signals are sent from the brain through the nervous system, which tell the muscles to contract.
When they contract, they pull on your skeletal system, which allows you to move. Your skeletal systems act as levers that your muscles pull against.

13. Diseases/Disorders that affect Muscles:
-Musculoskeletal Diseases:
Arthritis- painful inflammation and stiffness of the joints.
Fibromyalgia- a chronic disorder characterized by widespread musculoskeletal pain, fatigue, and tenderness in localized area.
-Smooth Muscle Diseases:
Asthma- disorder that causes airways to swell and narrow
Pulmonary Vascular Constrictiuon- pulmonary arteries constrict in the presence of low oxygen levels without high carbon dioxide levels, redirecting blood flow to alveoli with a higher oxygen content
-Cardiac Muscle Diseases/Disorders:
Coranary Artery Disease- plaque buildup in areteries
Hypertrophic Cardiomyopathy - thickening of the walls of the heart

14. 3 Kinds of Muscle Tissues:
Skeletal Muscle (150x)
Smooth Muscle (400x)
Cardiac Muscle (500x)

15. Fun Facts: 600 individual Muscles in our bodys
Skeletal Muscles make up 40% of our body weight
Most of your muscular strength is “turned off” to prevent injury.
The stapedius (ear muscle) is the smallest muscle in your body. The gluteus is largest.

16. Bibliography: http://www.projectsharetexas.org/node/1048
Prentice Hall Biology Book