Muscular System

Did you know? 40% of our body weight is muscle There are over 30 facial muscles The meat you eat are the organisms muscles Which the biggest muscle? The heart is a muscle

Skeletal Muscle Fibers Muscles of the Body Made up of: ________ muscle tissue _________ tissue ________ Vessels ___________ Skeletal Connective Blood Skeletal Muscle Fibers

Skeletal Muscle Fibers Are grouped in bundles called _________ __________ are bundled together by __________ tissue to create a __________. Fasicle Fasicles Connective muscle

Muscle Fibers (Muscles) Contain many _________ which have two filaments 1. 2. myofibrils Actin Myosin

Something to Ponder Muscle fibers have many nuclei. Which other organelle would be the most abundant in muscle fibers? Why?

Actin _______ filament Thin Looks like ______________ A string of pearls

Myosin Thick ________ filament Looks like it has _____________ Oval heads

BRAINPOP!!! Flex Voluntary Skeletal Muscle Contract Tendon Involuntary Striated Cramp

The Pec Pop of Love https://www.youtube.com/watch?v=KHysl3kYOB4

Which muscle is being used?

Which muscle is being used?

Which muscle is being used?

Muscle Review Game http://www.purposegames.com/game/forensic-bio-major-muscles-game

Muscle Fatigue Videos https://www.youtube.com/watch?v=PzSnVyf_dkU https://www.youtube.com/watch?v=_QPSYfzOQ84

Voluntary vs Involuntary Conscious control You move them Involuntary Unconscious control Move on their own

Sarcomere The ________ between _____ lines _________ when muscles move distance Z Contract What is a Z line? Point of attachment for myofibrils

Muscle Contraction

How do muscles contract? ________ heads bend inward and pull __________ It’s like _______________ This shortens the ______________ Does this require ATP (energy)? Myosin actin Climbing a rope sarcomere https://www.youtube.com/watch?v=Ct8AbZn_A8A

Muscle Fatigue Occurs when there is a ___________ in the ability for muscles to ___________ Short term vs long term fatigue Why does this happen? Not enough O2 reduction contract Short term (lifting heavy weights) Long term (running a marathon)

Muscles Move in Pairs Muscles move in ____________ pairs opposite While one _________ the other __________ Flexor- __________ Extensor- __________ opposite contracts relaxes shortens lengthens

Muscle Movement Activity Which muscles work in pairs to perform the following exercises? #1: Bicep Curl Flexor: Extensor: #2: Skull Crusher #3: Leg Extension Flexor: Extensor: #4: Wall Squat

Tendons vs Ligaments Tendons Ligaments Attach muscle to bone Attach bone to bone

How does this effect movement?

How does this effect movement?

Livor Mortis Blood __________ in body parts closest to the ___________ Skin appears ____________ Onset __________ after death Last about __________ accumulates ground Blue-purple 30 minutes 12 hours

What effects Livor Mortis? Affected by things that __________ blood flow E.X Tight clothing, Pressure from objects Helps determine if _____________ impede the body has been moved

Estimating Time of Death Rigor Mortis The stiffening of ________ after death Muscles remain ________ because ____________ accumulates muscles contracted calcium

Continued Starts __________ after death Begins to reverse around _________ 2 hours 15 hours

What can you tell me about this victim?

Example #1 Is this livor mortis or rigor mortis? Explain the pattern on the body?

Example #2 Which muscles are effected by rigor mortis? How long has she been dead?

Example #3 Explain the markings on the pig http://www.vet.uga.edu/ivcvm/courses/VPAT5200/02_injury/postmortem/postmortem.htm

Example #4 Where does lividity appear?