HBS 4.2.1 and 4.2.2
Step 1 of rigor mortis
A motor neuron sends an impulse (action potential) to the muscle fibers at the neuromuscular junction. This is the area where the motor neurons axon and the muscle fibers meet
Which solution produced the greatest percent contraction of the muscles? What does this tell you about the requirements for contraction?
.25% ATP in salt solution
Explain how the structure and the function of one of the muscles of the chest relates to the muscle rules you learned in activity 4.2.1
Rule 1: muscles must have at least 2 attachments and must cross at least 1 joint Serratus anterior origin is on the surface of the 1st to 8th ribs at the side and the insertion is along the entire anterior length of the medial border of the scapula where the ball-socket shoulder joint is located
pectoralis minor example
Shoulder girdle stretch
Explain how the central and peripheral nervous system together allow you to pick up a can of soda?
Signal in brain (CNS) goes to the spinal cord, to an extensor muscle in the PNS to grab the can and flexor muscles to pick it up
When you see the glycerinated muscle fibers shorten, what is actually happening in the muscle cells? Think about what you saw under the microscope
When a muscle contracts the space between the cell s is shortened and they become more closely packed together. Under the microscope we saw the striation getting closer together, becoming more compact
histology of skeletal muscle
a bundle of muscle fibers each with a long multinucleated cell in a parallel formation (multiple nuclei)
moving a part toward the midline
adduction
location of skeletal muscle
attached to bones
movements in all planes, and rotational movement
ball and socket joint movement
ball shaped process of one bone fits into the cup shaped socket of another
ball socket joint structure
types of synovial joints
ball socket, pivot, hinge, saddle, condyloid (ellipsoidal), and planar (plane or gliding)
Tricep brachi medial head
behind
between metacarpals and phalanges
condyloid (ellipsoidal) joint example
an oval shaped structure of one bone fits into a cavity of another bone
condyloid (ellipsoidal) joint structure
back and forth, and circular movements
condyloid (ellipsoidal) movement
lowing a part
depression
orbicularis oculi and transverse abdominis
direction
bending the foot at the ankle toward the shin
dorsiflexion
raising a part
elevation
bending parts at a joint so that the angle between them decreases
flexion
Brachialis (bicep)
front
location of cardiac muscle
heart
function of cardiac muscle
heart contraction
type of cartilage in joints
hyaline cartilage
articulation =
joint
an elastic band of tissue that connects bone to bone and provides stability to the joint
ligaments
Muscle rule #4
muscles that decrease the angle between ventral surfaces of the body are flexors. muscles that increase the angle between ventral surfaces of the body are extensors
axis and atlas (parts of neck)
pivot joint examples
movement is limited around a central axis
pivot joint movement
a clindrical surface of one bone rotates within a ring formed by antoer
pivot joint structure
ankles and wrist
plane (planar or gliding) joint examples
allowing sliding and twisting motion
plane (planar or gliding) joint movement
articulating bones are flat or slightly curved
plane (planar or gliding) joint structure
bending the foot at the ankle toward the sole
plantar flexion
moving a part around an axis
rotation
carpal and metacarpal of the thumb
saddle joint example
allow back and forth, side to side, and some pivotal movements
saddle joint movement
forms between bones whose articulating surfaces that both have concave and convex surfaces
saddle joint structure
trapezium and rhomboid minor
shape
Muscle rule #3
the attachment that moves is known as the insertion (distal) and the attachment that remains stationary is known as the origin (proximal)
histology of cardiac muscle
tightly connected by junctions in a parallel formation ad have a central (single) nucleus
Makes a V at C7 and T1, travels under the clavicle, down the armpit, down the medial side of the humerus, stops before going onto the middle finger, and branche to the ring and little finger
ulnar nerve
pectoralis major clavicular head example
weightlifting
Which type of joint allows for the greatest number of different movements? Explain your reasoning.
Ball and socket because the socket part of the joint doesn't restrict the rotation of the ball part of the joint at all (multiaxial - move in lots of different planes)
What type of joint is the hip joint? What type(s) of movement can this joint carry out?
Ball and socket joint Movements in all planes, and rotational movement
How can an individual improve their range of motion at a particular joint?
Stretching exercises, improve health and exercises
What are the 6 types of joints?
Ball and socket joint , condyloid (ellipsoidal) joint, plane (planar or gliding) joint, hinge joint, and pivot joint, saddle joint
Describe how the structural makeup of a muscle contributes to the muscles ability to do its job.
Branching allows the cells to communicate with cells around them (allowing the cells on the heart to beat in rhythm); Some cells must have more than one nucleus to increase the amount of DNA and increase the synthesis of proteins; Muscles have a lot of mitochondira because it allows a lot of ATP to be used
Your friend tried to convince you that the only reason to drink milk and to make sure you get enough calcium is so you can build strong bones. Can you off him/her another reason?
Calcium is also a main component in the contraction of our muscles which helps us move
What can low the rick of injury to the carpal tunnel?
Changing angle of typing, taking breaks, stretch, use brace
Step 6 of rigor mortis
During rigor mortis, the membrane of muscle cell will become more permeable to calcium ions, which causes an influx of these ions into the cell. With death, there is little to no ATP produced, so as the calcium ions bind with troponin and allow myosin and actin to bind, there will be no ATP to detach the myosin and actin. This results in constant contraction, which makes the muscles seem stiff
Given the placement of the radial nerve, what type of muscles does this nerve most likely stimulate?
Extensor because it's on the dorsal side and muscles can only pull and shorten
Look at where the ulnar nerve runs in the arm. What type of forearm muscle does this nerve stimulate? Explain.
Flexor because on ventral surface and muscles can only pull and shorten
Step 5 of rigor mortis
Relaxation will occur when stimulation of the nerve stops. Calcium is pumped back into the sacroplasmic reticulum and stops the binding between actin and myosin. This can also occur due to the lack of ATP
Step 3 of rigor mortis
The calcium then floods into the muscle cell and binds with troponin, which moves the trypomysin (the protein that block myosin) and allows actin and myosin to bind. The actin and myosin cross bridge uses ATP as an energy source to disconnect. ATP hydrolyze and turn into ADP and P
Why did we observe the elbow joint of a cow? Why is a cow elbow different structurally from your elbow?
The connecting bones are the same - ulna, radius, and humerus. The difference in the bones is that in a cow the ulna and radius become fused whereas in a human they are two distinct bones with a space in between
What does it mean when we say a muscle contract involuntarily? Describe one body function that is linked to an involuntary muscle contraction
The contraction of the muscle doesn't occur whenever we consciouly desire them to move. How the esophagus gets food to the stomach, heart, digestion, breathing (still down when sleeping), blinking
How do bones, muscles, and joints work together to move the body?
The muscles pull on bones to make them move and joints enable their flexibility
Explain how it is the actin and myosin in the sarcomere never actually shorten and yet the muscle as a whole does
The myosin and actin in the sarcomere pull the muscle fibers together, so the fibers themselves shorten, but the myosin and actin slide past each other. Lots of sarcomeres in muscle cells all slide, allowing the muscle to shorten
Think about the way in which organ systems work together to kick your leg or swing your arm. Besides the skeletal and the muscular system, what other systems are involved in moving the human machine?
The nervous system is involved in moving the human machine because in order to move, neurons must transmit signals between different parts of the body.
Take a look at the temporalis, one of the face muscles you built in unit 1. Using what you have learned about muscles and their attachments, describe the origin and the insertion of this muscle. How is this structure linked to the function?
The origin of the temporalis is the temporal fossa on the temporal bone of the skull. The insertion is the coronoid process of the mandible. With the origin pulling the insertion, the function of this muscle is to retract (move back) and elevate the mandible during the chewing motion
How is the location of the nuclear nerve lined to the pain you feel when you hit your funny bone? Why is this nerve so vulnerable?
There is only skin and fat over this space with no bones or muscles to protect it causing blows to your humerus to be quite painful compared to other less sensitive areas of the body
What can put a worker at risk of carpal tunnel syndrome
anything computer (ie: student, teacher)
pectoralis major sternal head example
arm westling
the smooth, white tissue that covers the ends of bones where they come together to form joint
articular cartilage
hips and shoulder
ball and socket joint movement
loops around the carpal
carpal tunnel
a soft, gel-like padding between bones that protects joints and facilitates movement
cartilage
histology of smooth muscle
cells stick together to form gap junctions, they are spindle shaped and have the central (single) nucleus
moving a part so that its end follows a circular path
circumduction
Using your knowledge of tissues, what type of tissue makes up the three layers of member you encountered in you muscle?
connective
muscle tissue in which the contractile (contraction) fibrils in the cells area aligned in parallel bundles, so that their different regions form stripes visible in a microscope
striated muscle
Freely moveable joint that, combined with oily fluid filled cavity, separates the bones that allow us to swing our arms or jump up and down
synovial joints
a band of tissue that connects muscle to bone
tendons
elbows and knees
hinge joint examples
permits back and forth movements
hinge joint movement
convex surface of one bone fits into the concave surface of another
hinge joint structure
excess extension of the parts at a joint beyond anatomical position
hyperextension
After a few years, your goniomoter breaks. How else can a clever HBS student measure range of motion?
protractor
abduction v
v adduction
rotation v
v circumduction
plantar flexion v
v dorsiflexion
depression v
v elevation
flexion v
v extension
You overhear two women at the gym talking about their extensor muscles of the forearms. Based on what you know about the movement at joints, how would you describe the movement of these muscles?
Muscles in the forearm that extend and control movement of the fingers (muscles pull, not push)
Muscle rule #1
Muscles must have at least 2 attachments and must cross at least 1 jiont
serratus anterior ex
Push ups
process of sarcomeres sliding past each other
the sliding filament mechanism of muscle contraction
How do ions and electrical charges play a role in communication with the muscle?
ACH travels across neuromuscular junction, binds to sarcolemma (cell membrane of muscle cells), tells potassium channels to open, then open sodium channels, sending action potential through the tubules and releasing calcium
Step 4 of rigor mortis
ATP is then re-synthesized to allow actin and myosin to continue this process, allowing movement of the muscle. The myosin and actin will continue to bind and rebind
Think about the action of the muscle you have built. Describe at least two exercises that will strengthen the muscles of the chest. Make sure to not the specific muscles that are targeted to each exercise.
Abdominal: sit ups Pectoralis minor: shoulder girdle stretch
Summarize the science behind rigor mortis. Why is this state a temporary condition?
After death, calcium will be released and flow into muscle cells allowing action and myosin to continue contracting. ATP will no longer be produced due to the lack of brain activity so the actin and myosin won't be able to break a part and continuously contraction will occur, making the muscles stiff. It is a temporary state because the body will eventually begin to decay which will cause all body actions to stop.
What does it mean to have a dislocated shoulder?
It means the entire ball in the shoulder joint (ball and socket joint) is out of the socket.
When you are cold, your muscles begin to contract involuntarily and cause you to shiver. Why do you think this occurs? How does the contraction of muscles help the body maintain homeostasis?
It produces heat because muscles generate a lot of heat
What factors influence range of motion of a joint?
Joint structure (double jointed - loose joint; type of joint; genetics - how its formed), ligaments (tighter), tendons (tighter), muscles, skin, tissues injury, fact (or adipose) tissue, body temperature, activity level, age, and sex all influence an individual's range of motion about a joint
Using what you know about rigor mortis and about energy, what do you think happens inside your muscle when you get a muscle cramp? Why is this not a permanent condition?
Lack of oxygen, can't make ATP: stop what doing and breathe deeper Run out of ATP: break glycogen or burn fat if no glucose to make ATP Run our of potassium, sodium, or calcium ions Dehydration: can re-synthesize ATP
Your mom comes back from the doctor and says she has pulled her tibialis anterior. She knows you are taking HBS and asks you to tell her about her injury. Based on what you have learned, what can you deduce about this muscle and her injury?
Located around the front of her tibia bone
Did your muscle samples eventually relax and return to the length they were before contraction? Thinking back to the muscles rules and how you know muscles works, why does this make sense?
Muscle rule number 2 is that muscles always pull and get shorter. This means that the muscles didn't return to the former length because there would need to be an opposing bone or tendon pulling it in the other direction in order for it to become long and ready to pull again.
How do multiple human body systems work together to cause muscle contraction and movement of the body?
Nervous - action potential Muscular - muscle fibers contract Skeletal - bone moves Digestive - ATP Respiratory - need oxygen to break down food in the mitochondria
Step 2 of rigor mortis
Next, the sarcoplasmic reticulum, which is a type of smooth ER that regulates the calcium ion concentration in the cytoplasm of striated muscle cells, is stimulated to release calcium into the muscle cell
Explain how you know which attachment of muscle is in the origin and which attachment is the insertion
Origin - the muscle that stays stationary (more proximal) Insertion - the muscle that moves (more distal)
Explain how the muscles pectoralis major and serratus anterior show 2 different ways to which muscles are named
Pectoralis major is a method naming muscles based on size. This muscle is very large, hence "major" Serratus anterior is a method naming muscles based on shape, serratus meaning teeth of saw, but also location, anterior meaning front of the body
How does your range of motion compare to the range of motion of other groups. Why are differences most likely to occur?
People have a difference range of flexibility, tissues (thick arms), past injuries, diseases
How are tendons and ligaments similar in both structure and function? How are they different in both structure and function?
They are similar because they are both white fibrous tissue that work to improve and control motion. They are different because a tendon is tougher and thicker. Tendons also attach muscles to bones, pulling the bone when the muscle contracts, enabling movement. Ligaments attach bone to bone. They are more elastic and help hold structures together and keep them stable
What would happen to a person's ability to use their arm if the radial nerve were damaged? What about the wrist?
They might have difficulty extending the arm at the elbow, or they may have trouble extending their wrist or fingers
moving a part away from the midline
abduction
any muscle that pulls a body part away from the midline
abductors
flexor carpi ulnaris and extensor digitorum longus
actions
Are the muscles of pectoralis major adductors of abductors
adductor because it pull the arms into the midline
any muscle that pulls a body part toward the midline
adductors
Explain to your client why you need multiple exercises to effectively build and tone the muscles of the chest
each exercise uses and builds a specific muscle
straightening parts at the joint so that the angle between them increases
extension
location of smooth muscle
lines blood vessels and hollow organs, such as the stomach,, intestine, and bladder
frontalis and temporalis
location
travels between the radius and ulna, and ends at the tip of the middle finger
median nerve
function of smooth muscle
movement of blood through vessels, food through digestive system
function of skeletal muscle
movement, heat, posture
Muscle rule #6
muscle striations point to the attachments and show the direction of pull
muscles whose action is normally controlled by an individual's will
muscle under voluntary control
Muscle rule #2
muscles always "pull" and get shorter (not push and get longer)
Muscle rule #5
muscles work in opposing pairs
__________ is thick filament and _________ is thin filament
myosin; acting
biceps brachii and triceps brachii
number or origins
sternocleidomastoid and brachioradialis
origin and insertion
A W shape branch of nerve connects to a V on C4 and C5 and a straight on C6, travels under the clavicle, down the armpit, down the dorsal side of the humerus, moves to the front to pass through the antecubital region (where they draw your blood), runs down the medial side of the radius 1/4 of the way, then on the dorsal side, then it branches into each digit on the back of the palm (it also branches from the humerus to the tricep medial heads)
radial nerve
different ways in which muscles can be named
shape, size, location, direction, actions, origin and insertion, number of origins
external intercostal ex
sighing
pectoralis major abdominal example
sit ups
gluteus maximus and gluteus minimus
size
muscle(s) that are voluntary
skeletal
describe the structural differences in three 3 types of muscle tissues
skeletal - striated; multinuclear (more than one nucleus) Smooth - not striated, thin Cardiac - striated; branched (can see distinct lines) under microscope, intercalated discs (at top and bottom of branches that help reinforce the weak branches)
muscle(s) that have striations
skeletal and cardiac
Types of muscles
skeletal, smooth, cardiac
muscle(s) that don't have striations
smooth
muscle(s) that aren't voluntary
smooth and cardiac
What happens at the junction between a nerve and a muskle to initiate muscle contraction?
the electrical signal travels down a motor neuron toward a muscle cell. The signal is transferred to the sarcoplasmic reticulum. Once the signal reaches the SR, calcium is released, which starts the process of muscle contraction.
Describe how problems at the carpal tunnel can lead to pain and discomfort
the median nerve which controls sensation and movement in the thumb and first three fingers, runs through this passageway along with tendons to the fingers and thumb. When it's pinched or compressed, the result is numbness, tingling, weakness, or pain in the head