A&P 1.13 Flashcards Preview

Anatomy & Physiology I > A&P 1.13 > Flashcards

Flashcards in A&P 1.13 Deck (30)
1

Deltoids

general

3 branches - anterior, middle and posterior
Named for shape

2

anterior deltoid

A, O, I

O - lateral 1/3 of clavicle

A- all fibers: abduct the shoulder joint
Anterior: flex the humerus, medially rotate the shoulder joint, horizontally adduct the shoulder joint

I- deltoid tuberosity

3

middle deltoid

A, O, I

O - acromion

I- deltoid tuberosity

A- all fibers: abduct the shoulder joint

4

Posterior deltoid

A, O, I

O - spine of the scapula
I - deltoid tuberosity

A - all fibers: abduct the shoulder joint

Posterior: extend the humerus, laterally rotate the shoulder joint, horizontally abduct the shoulder joint

5

Deltoids

Summary
A, O, I


3 branches - anterior, middle and posterior
Named for shape

O- lateral 1/3 of clavicle (anterior), acromion (middle), and spine of the scapula (posterior)

I- deltoid tuberosity

A- all fibers: abduct the shoulder joint
Anterior: flex the shoulder joint, medially rotate the shoulder joint, horizontally adduct the shoulder joint
Posterior: extend the shoulder joint, laterally rotate the shoulder joint, horizontally abduct the shoulder joint

6

Antagonists

Defined

Perform opposite actions

7

Muscle belly contraction

2 types

Tetanus
muscle tone

8

tetanus

normal skeletal muscle contractions
smooth, sustained contractions resulting from coordinated contractions of different motor units within a muscle

9

muscle tone

a tonic contraction
it is continual, partial and low level
normally exhibited by individuals while awake in order to keep upright (posture)

10

Motor unit

Defined

A motor neuron and the fibers it innervates
It is the functional unit
Variable number of branches

Few fibers - more precise

More fibers - less precise

11

Neuromuscular junction

Defined

Synapse

end of axon near the surface of a muscle fiber at its motor end plate region

12

All or nothing principle

Defined

Action potentials

Similar to dominos, when a neuron reaches its threshold (enough excitation) the first domino is pushed and the entire row topples (as action potential occurs). There is no stopping once it starts

Pushing on the first domino produces an "all or nothing event". All fall or none. Action potentials can travel long distances with out dying out thus can communicate over long or short distances.

13

Action potential

More info

Can travel long distances without dying out (neurons can be extremely long)

Different neurons have different thresholds for generation of an action potential but the threshold for each individual neuron remains constant

14

Types of contractions

Isotonic

Isometric

15

Isotonic Contraction

define & 2 types

MOVEMENT: a load is moved
Means the same as "dynamic tension"

Iso- equal Tonic - tension

The tone or tension within a muscle remains the same as the length of the muscle changes

concentric & eccentric

16

Concentric isotonic contraction

Movement results in shortening of the muscle as when you pick up a book. Our muscle of the day action is an example of this.

17

Eccentric isotonic contraction

Movement results in lengthening of the muscle being contracted, when you lower the book you have picked up.

18

Isometric contractions

NO movement
Means same length as "static tension" . Muscle length remains the same while the muscle tension increases. Muscles tighten to resist a force, but they do not produce movement.

19

Atrophy

Defined

Wasting away or decrease in size of a part, due to failure, poor nutrition, or lack of use

20

Contracture

Defined

Common result from spinal cord injury, starts as spasticity, which can become permanent.

Chronically tight muscle fibers eventually atrophy and are replaced by thick tough CT

21

Hypertrophy

Defined

Increase of cell size without cellular division/reproduction

Increase in the diameter of muscle cells resulting from very forceful, repetitive muscle activity and an increase in myofibriils, sarcoplasmic reticulum, and mitochondria.

22

Hyperplasia

Defined

An abnormal increase in the number of cells in a tissue or organ (cancer)

Due to increase in frequency of cell division

23

Cramps

Defined

Painful short-lived acute contraction. Often occur when a muscle organ is inflamed. (Charlie horse)

24

Spasms

Defined

Considered low-grade, long lasting contractions

25

Contractures

Defined

More stuff

Common result from spinal cord injury (nerve damage) starts as spasticity, which may become permanent (motor axons tighten) chronically tight muscle fibers eventually atrophy, to be replaced by thick, connective tissue.

26

wraps around the organelles

T-tubes

27

Is the cell membrane

Sarcolema

28

Covers the organ

Epimysium

29

Covers the tissue

perimysium

30

covers the cell

Endomysium