Muscles Flashcards
1
Q
What do muscles do?
A
- Only thing is contract (get shorter)
- Function is movement
- Produce heat to maintain body temperature
2
Q
Cardiac Muscle Tissue
A
- Deeply Striated - indicates strength
- Can be deepened/strengthened by exercise
- Strongest muscle!!
- Never fatigues
Why? - after a contraction, the cardiac muscle cell will completely rest before the next contraction - No nucleus in red blood cells
- Branched structure
- Involuntary control
- Found only in heart
- One nucleus per cell
- Individual cells are fused together, to function as one big unit, allowing electrical impulses to travel through all of the cells without additional nerves
- The initial impulse that causes contraction does NOT begin in the brain !!
- Nodal tissue in the heart produces the electrical impulse needed for contraction
3
Q
Skeletal Muscle Tissue
A
- Striated - indicates strength
- Can be deepened/strengthened by exercise
- Cylindrical
- Multi nucleated !
- Attached to bones
- Voluntary control – you think about it to move body parts
- Quick to fatigue / Slow to recover
4
Q
Smooth Muscle Tissue
A
- NO Striations – Weaker than cardiac and skeletal but NOT Weak
- Found lining the organs (hollow internal organs)
1. Digestive system
2. Reproductive system
3. Circulatory system – walls of the veins and arteries - Shape: spindle shape – thinner at ends than at the center
- Move materials through hollow internal organs
- Form sheets
- One nucleus per cell
- Involuntary – you do not control blood flowing through veins or food going through digestive system etc
- Contracts slowly
- Slow to fatigue / Quick to recover
5
Q
What do all muscles contain?
A
- Muscles Tissues
- Connective Tissue
- Nervous Tissue
- Blood Vessels (brings in oxygen, nutrients / removes waste products)
6
Q
Functions of Skeletal Muscle
A
- Supports the body – allows you to maintain your posture
- Some skeletal muscle is always contracting, allowing people to stand up straight without thinking about it
- Movement of bones
- Maintains body temperature – produces heat
- Protects internal organs
- Stabilizes joints – synovial joints!!
- Moves blood in veins (heart moves blood in arteries)
- Veins usually found deep inside the skeletal muscle tissue
- When muscle contracts, it puts pressure on outside of the brain which forces the blood back to the heart
- Moves blood in lymphatic vessels
7
Q
What is the structure of skeletal muscle from largest to smallest?
A
Muscle, Muscle Bundle, Muscle Fiber, Myofibrils
8
Q
Muscle
A
Covered by connective tissue (called fascia) which gets thicker at the ends to form tendons
9
Q
Muscle Bundle
A
Bundles of fibers enclosed in connective tissue
10
Q
Muscle Fiber
A
Groups of myofibrils
11
Q
Myofibrils !!!!!!
A
- Functional unit of a muscle – where contraction starts then it moves up the list
- Can only contract !!
- Proteins → actin and myosin
- Actin and myosin proteins slide past one another causing the myofibril to shorten/contract
- Needs ATP to slide past one another
- Electrical impulse from the brain initiates this process
- Removing the electrical impulse allows the muscle to relax
12
Q
Muscle Contraction
A
- Contraction of numerous myofibrils
- Requires electrical stimulation from nervous tissue
- Requires calcium – from bones/bloodstream
- Requires ATP to force actin to slide past myosin
13
Q
Myoglobin
A
Stores oxygen in muscle tissue (similar to hemoglobin)
14
Q
Glycogen
A
Provides glucose for ATP production
15
Q
Creatine Phosphate
A
aids in regeneration of ATP (fast recovery)
