Anatomy Unit 3 - Muscular and Nervous Systems

Omg it feels like we justttt haddd a tessttt, anywhooo, l o c k ! i n ! 9/30-10/14

What are the functions of the muscular system?

Movement, heat generation, protection, and posture

What are the types of muscle

1. Skeletal muscle

2. smooth muscle

3. cardiac muscle

What is the muscle organ?

The muscle belly, the largest unit of the muscle, basically just the muscle

What is the muscle fascicle?

Bundles of muscle fibers that make up the muscle belly. Run from end to end of muscle belly.

Muscle fibers

The muscle cell unit, make up muscle fascicles. Made of myofibrils

What are myofibrils?

They make up the muscle fibers

What are sarcomeres

The contracting units of the muscle

What is the sarcoplasmic reticulum?

A specialized organelle that wraps around sarcomeres. It…

• Stores Calcium ions

• Surrounds myofibrils

What are the steps to a muscle contraction?

1. An electrical charge

2. Sarcoplasmic reticulum releases calcium ions

3. A bunch of chemical reactions take place :/

4. Myosin and actin fivers move along each other

Where are the myosin fibers?

branching out from the m line, they’re thicker, have grabby thingies

Where are the actin filaments?

branching out from the z line, they’re thinner

Energy is needed for…

Both Contraction and Relaxation

What is rigor mortis?

Body stiffening after death. All the sarcoplasmic reticulum release all their Ca+ ions, so reactions occur and all the muscles contract.

Timeline of rigor mortis:

1. It starts 2-3 hours after death because all the Ca+ ions are released

2. It ends after 12-18 hours, the body is very rigid at this point b/c of all the ions

3. It fades after 2 days because the cells start to disintegrate, so u can move the body easily now.

Hypertrophy

• More stress on the muscles, so there are more myofibrils (muscles grow in size.)

• This is caused by exercise (demand)

Atrophy

• Less stress on the muscles, so there are less myofibrils (muscles lose their size.)

• This is caused by laziness, so muscles are lost for efficiency’s sake

What are the two muscle fiber types

• Red/dark/slow

• White/light/fast

Where are red muscle fibers found?

Your trunk and legs

Where are white muscle fibers found?

Your eyes and hands

Properties of red muscle fibers

• best for endurance

• have more adipose (fat) for longer energy storage

• have more capillaries to provide oxygen

• have myoglobin for oxygen storage

Properties of white muscle fibers

• best for quick strength

• have a lot of glycogen (glucose storage for shorter, quick energy storage)

What is an origin

the stationary attachment point for a muscle

What is an insertion

the moving attachment point for a muscle

What is an antagonist muscle

Muscles that work against one another (eg- biceps and triceps)

What is a muscle action? har har harr.

what it does duuuuuuhhh boioioi why did even a queshtoun

What is a synergist muscle?

Muscles that work together (eg- brachialis and biceps brachii)

How is the strength of a muscle determined?

It’s cross-sectional area

What happens in an injury

Damage is done to the muscle tissue

What is a sprain

when a ligament is torn

what is a strain/pull/tear

when a tendon or muscle is torn

What is a parallel muscle type

A muscle with muscle fibers that run parallel from end to end

what is a pennate muscle type

several muscle bellies pull on a tendon for more strength

what is a circular/sphincter/orbicularis muscle type?

A circular area of muscle, for openings

Masseter action

elevate the mandible (molars)

Masseter origin and insertion

Origin- Zygomatic arch

Insertion- Angle of the mandible

Temporalis action

elevate the mandible (front teeth)

Temporalis origin and insertion

Origin- Lateral skull

Insertion- Coronoid process of the mandible

Lateral Pterygoid action

Depress the mandible, lateral mandibular movement

Medial pterygoid action

elevates the mandible, lateral movement of the mandible

Genioglossus aciton

depress and protract (stick out) tongue

Genioglossus origin and insertion

Origin- The genio region of the mandible (below the mental)

Insertion- Tongue

Hyoglossus action

depress and retract the tongue

Hyoglossus origin and insertion

Origin- Hyoid bone

Insertion- Tongue

Palatoglossus action

elevate tongue

Palatoglossus origin and insertion

Origin- Hard palate bonde

Insertion- tongue

Styloglossus action

Retract the tongue and elevate the lateral sides to make a hawt dawwwggg (yermmmy)

Styloglossus origin and insertion

Origin- Styloid process of the temporal bone

Insertion- Tongue

Medial Rectus action

Moves eye medically

Medial rectus orig and insert

Origin- posterior orbit

Insertion- medial eye

Lateral rectus action

Moves eye laterally

Lateral rectus origin and insertion

Origin- posterior orbit

Insertion- lateral eye

Superior Rectus action

Moves the eye superiorly

Superior rectus origin and insertion

Origin- posterior orbit

Insertion- superior eye

Inferior Rectus action

Move eye inferiorly

Inferior rectus origin and insertion

Origin- posterior orbit

Insertion- inferior eye

Superior oblique action

Move eye inferiorly and laterally

Superior oblique origin and insertion

Origin- posterior orbit

Insertion- posterior lateral eye

Inferior oblique action

Move eye superiorly and laterally

Inferior oblique origin and insertion

Origin- medial orbit

Insertion- posterior lateral eye

Diaphragm action

Move the central tendon inferiorly, this increases volume and decreases pressure in lungs to rush air in to breathe

Diaphragm orig insert

Origin- costal margin

Insertion- central tendon of the diaphragm

Deltoid action

Abduct, flex, and extend the arm (not actually a part of the rotator cuff)

Deltoid origin and insertion

Origin- spine of the scapula and clavicle

Insertion- deltoid tuberosity on the humerus

Supraspinatus action (rotator cuff)

Arm abduction

Supraspinatus origin and insertion

Origin- Supraspinous fossa

Insertion- greater tubercle of the humerus

Infraspinatus action (rotator cuff)

Lateral arm rotation

Infraspinatus origin and insertion

Origin- Infraspinous fossa

Insertion- greater tubercle of the humerus

Teres minor action (rotator cuff)

Lateral arm rotation and arm adduction

Teres minor origin and insertion

Origin- lateral border of the scapula

Insertion- greater tubercle of the humerus

Subscapularis action (rotator cuff)

Medial arm rotation

Subscapularis origin and insertion

Origin- Subscapular fossa

Insertion- lesser tubercle of the humerus

What do the rotator cuff muscles do?

Their tendons actually hold the humerus in the AC joint

What is the labrum

the cartilage cuff in the shoulder joint

Flexor retinaculum

Holds the digit tendons except the palmaris longus

Carpal tunnel

the area the tendons to the digits go through, under flexor retinaculum:

• When digits constantly move, tendons fray and rub, swelling begins and pressure is put on the median nerve

Flexor digitorum superficialis action

Flexes the middle phalanx of each digit

Flexor digitorum superficialis origin and insertion

Origin- humeroulnar and radial head

Insertion- middle phalanx of digits 2-5

Flexor digitorum profundus action

Flexes distal phalanges for digits 2-5

Flexor digitorum profundus origin and insertion (deep)

Origin- proximal ulna

Insertion- distal phalanges digits 2-5

Lumbrical action

Flexes the proximal phalanges of digits 2-5

Lumbrical origin and insertion

Origin- flexor digitorum profundus tendons

Insertion- proximal phalanges of digits 2-5

Extensor digitorum action

Extends digits 2-5

Extensor digitorum origin and insertion

Origin- lateral epicondyle

Insertion- both middle and distal phalanges of digits 2-5

Interossei (between the digits) action

Abduction and adduction of digits 2-5

Why is it easier to move digits 2 & 5 than 3 & 4?

• digit 2 has the indicies muscles

• Digit 5 has the digiti minimi

• Digits 3 & 4 don’t have their own muscles

Pronator Quadratus action

Pronation

Pronator quadratus origin and insertion

Origin- distal ulna

Insertion- distal radius

Pronator Teres action

Pronation

Pronator Teres origin and insertion

Origin- medial epicondyle of humerus

Insertion- Coronoid process of ulna

Supinator action

Supination

Supinator origin and insertion

Origin- lateral epicondyle

Insertion- proximal radius

What is the function of the nervous system?

To transmit ELECTRICAL signals

What are the 2 divisions of the nervous system?

• central nervous system (CNS)

• Peripheral nervous system (PNS)

What is the CNS

• made up of the brain and spinal cord (reflexes)

• It’s where processing takes place

• It is isolated from the rest of the body by layers of tissue called meninges

What is the PNS

• Made of the nerves throughout the body (peripheral)

• Incoming and outgoing electrical signals

• Not isolated from the body

• Have myelinated axons for more speeeeed!!!

What are neurons

The cells that actually send the electrical signals throughout the body

Neuron cell body

Is the living part of the neuron, has the ER, mitochondria, and other organelles etc.

Dendrites

Connect to cell body and take in incoming electrical signals

Axon

Long part that conducts the nerve impulse towards the synaptic terminals

Axon hillock

Between the axon and cell body, where the electrical signal is generated, packed with mitochondria