Finals | Muscular System Flashcards
Functions of the muscular system
- Producing body movements/ motions
- Stabilizing body positions (ex. standing/ sitting)
- Storing and moving of substances within the body
- Generating heat (Thermogenesis)
Used to maintain temperature within the body
Thermogenesis
Signs and symptons of fever which is a mechanism of body to increase heat
Shivering
Properties of a muscular tissue
- Electrical excitability
- Contractility
- Extensibility
- Elasticity
Ability to respond to certain stimuli by producing electrical signals such as action potential/ impulses
Electrical excitability
Electrical signals
Action potentials/ impulses
Action potentials in muscles
muscle action potentials
Action potentials in nerve cells
nerve action potentials
Two main types of stimuli trigger action potentials for muscle cells
- Electrical signals
- Chemical Stimuli
Arises from muscular tissue itself
Electrical signals
Example of an electrical signal
Pacemaker
Send low-energy electrical impulses to control the rate and rhythm of the heartbeat
Pacemaker
What area of the heartbeat does the pacemaker control?
rate and rhythm
Neurotransmitters released by neurons, hormones distributed by the blood, or even changes in pH
Chemical stimuli
What falls under chemical stimuli?
- Neurotransmitters released by neurons
- Hormones distributed by the blood
- Changes in pH
When skeletal muscle contracts it generates tension while pulling on its attachment points
Contractility
Motion of flexion
Contractility
When this contracts, it generates tension while pulling on its attachment points
Skeletal muscle
Muscle develops tension but does not shorten
Muscle contractions
Another word for tension
Force of contraction
Ability to stretch within limits, without being damaged
Extensibility
The (1) within the muscle, limits the range of extensibility and keeps it within the contractile range of the (2)
- connective tissue
- muscle cells
Ability of the muscular tissue to return to its original length and shape after contraction or extension
Elsticity
Lines the body wall and limbs and supports and surrounds muscles and other organs of the body
Fascia
Functions of the fascia
- Lines body walls and limbs
- Support and surround muscles and other organs
3 layers of connective tissue
- Epimysium
- Perimysium
- Endomysium
Used to surround and protect muscular tissues
Connective tissue
Insulating layer that will reduce heat loss
Triglyceride
Protects the muscle from physical trauma
Triglyceride
Outer later of connective tissue tthat encircle the entire muscle
Epimysium
Surrounds groups of 10-100 or more muscle fiber separating them into bundles called fascicles
Perimysium
The perimysium surrounds groups of (1) or more muscle fibers separating them into (2) called (3)
- 10-100
- bundles
- fascicles
Penetrates the interior of each fascicle and separates individual fiber from one another
Endomysium
Orientation of the coverings/linings of the connective tissue from outer to inner
Triglyceride
Fascia
Epimysium
Perimysium
Endomysium
Define tendons
Muscle-to-bone attachment
Example of tendons
Achilles tendon (calcaneal): gastrocnemius muscle (calf)- calcaneus (heel bone)
Connective tissue extend as broad, flat sheet
Aponeurosis
Example of aponeurosis
Epicranial aponeurosis
Where is epicranial aponeurosis found?
Between the frontal and occipital bellies of the occipitofrontalis muscle
Muscle that moves the eyebrow
Frontal belly
Diameter and length of a skeletal muscle fiber
Diameter: 10 to 100 μm
Length: 10 cm (4 in), some are 30 cm (12 in)
Fusion of a hundred or more small mesodermal cells
Myoblasts
When does a myoblast arises?
During embryonic development
Myoblast:
- Fusion of hundred or more small (1)
- Once fusion is done, muscle fiber loses its ability to undergo (2)
- Thus, number of (3) is set is set before you are born
- mesodermal cells
- cell division
- skeletal muscle fibers
Outer covering of muscle fiber
Plasma membrane