Unit 18 (Ch. 14) Support & Movement
Whats another word for movement? 200 Whats another word for movement? Locomotion Which two systems work together to allow support & movement? Muscular & skeletal system Joints of the Skeletal System Interactive Table More Joints of the Skeletal System Interactive Table Muscle & Connective Tissue Animation How do skeletal & muscular systems show unity within diversity? Many organisms have either internal or external skeletons which carry out similar functions (protection & support) How does form follow function? The structure of bones primarily hollow tubes allows for strength without adding too much weight muscle structures allow them to contract & relax causing movement Which two systems work together to allow support & movement? The Role of the Skeleton
What are the 3 main functions of the skeletal system? support the body protect organs aid in movement provides attachment site for muscles Protection (skull, ribs, breast bone, vertebrae) of organs support (thigh bones = femur) Locomotion/movement (attachment for muscles) ALSO: Make blood cells (in bone marrow) & store calcium (give bones strength) Bone Living or Not? Is bone living?
Yes, even though its hard & made of minerals, bone IS a LIVING tissue that grows. Think about it are you the same height as you were when you were a baby? a young child? last year? 3 types of bone cells Osteoblasts cells that form new bone through ossification replacement of cartilage or membrane by bone take calcium from blood Osteocytes -- are mature osteoblasts found in most formed bone tissue Osteoclasts break down bone Ossification = replacement of cartilage w/ bone by activity of osteoblasts & addition of minerals such as calcium compounds (taken from blood) Occurs in most bonesNot completed until ~25 years old Some cartilage remains at ends to provide smooth joint surfaces Tissues of the Skeletal System
What types of tissue make up the skeletal system? cartilage bone compact (solid) bone spongy bone membrane (periosteum) marrow ligaments Cartilage What is cartilage? Where is cartilage found?
A tough, flexible tissue that doesnt store calcium, so it is less dense than bone. Where is cartilage found? mostly at the ends of bone Why? acts as a cushion for joints Where is cartilage found? at the ends of bones in adult (to provide for smooth joint surface), as rings around the trachea to prevent collapse, most of the skeleton in the vertebrate fetus & a number of parts of juvenile skeleton, Density = mass/volume(higher density = more mass per unit volume, so more compact) Bone Structure What types of tissues are found in bone?
Interactive Bone Diagram What types of tissues are found in bone? compact (solid) bone hard part of bone very strong b/c stores calcium usually found along outer edges spongy bone has many empty spaces usually found near end of bones membrane (periosteum) covers bone contains nerves & blood vessels marrow soft center in bone makes blood cells Periosteum tough outer membrane, supplies nerves and blood vessels to Haversian canal, contains cells needed for growth & repair, point of attachment for muscle 2 types of bone tissue compact bone shafts of long bones, hard & compact, made of alternating layers of collagen (protein) & minerals & contains many tiny channels called Haversian canals which carry blood vessels & nerves that supply osteocytes in the bone tissue, marrowin central hollows of many bones (red marrow in flat bones & ends of long bones produces red blood cells, some white blood cells, & platelets, & yellow marrow in hollow interior of long bones stores fat), marrow also functions in formation of bone cells spongy bone ends of long bones, under a layer of compact bone, composed of a system of cavities & intersecting plates Ligaments What are ligaments?
connective tissue: holds bones to other bones What holds bones to other bones? connective tissue called ligaments (made of collagen & some elastic fibers) Muscles also play a role Joints What is a joint? What allows joints to move smoothly?
where bones come together What allows joints to move smoothly? cartilage covering the end of the bones fluid-filled bags between cartilage & bone Ends of bones covered with cartilageprovide smooth joint surfacesFluid-filled bags between cartilage & bone (= bursa) Why? Cushion to prevent bones from rubbing against each other types Types of Joints fixed movable ball & socket hinge pivot gliding
gliding joint types fixed movable ball & socket hinge pivot gliding Ends of bones covered with cartilageprovide smooth joint surfacesFluid-filled bags between cartilage & bone (= bursa) Why? Most are movable What holds them together?Muscles & connective tissue called ligaments (made of collagen & some elastic fibers Classification of Joints Animation Fixed Joints Are not connected by ligaments. Do they move?
What is an example? skull Examples individual bones of skull mobility? Fixed joints in the skull create flexibility during birth b/c not fused yet (soft spots),in adults fused together (not connected by ligaments), connected by fibrous connective tissue Also known as immovable joints or sutures Types of Movable Joints
1. ball & socket In which direction(s) does it move? rotate, front-back, side-side most mobility of all joints What are examples? hip, shoulder Examples shoulder (end of humerus = rounded knob, shoulder/scapula = depression) & hip (end of femur = rounded knob, pelvis = depression) most mobility How can it move? Rotate, move frontback, move side-side Types of Movable Joints
2. hinge In which direction(s) does it move? open-closed (only in 1 direction) like a door What are examples? elbow, knee Examples Elbow, knee, fingers, toes Limited mobilityWhich directions?movement in only 1 direction (like a door opened or closed) Types of Movable Joints
3. pivot In which direction(s) does it move? twists/rotates like a door knob What are examples? skull w/ neck vertebrae, lower arm Examples where skull connects to vertebrae/spine, where ulna & radius (lower arm) connect near elbow limited mobility Which directions? The end of one bone rotates (pivots) on another Types of Movable Joints
4. gliding In which direction(s) does it move? slides back-forth, side-side What are examples? vertebrae (back), wrist, ankle Examples vertebrae, wrist, ankle limited mobility Which directions? back and forth motion, side to side The Muscular System What is the muscular system?
all muscles inthe body What is the function of the muscular system? movement What is a muscle? tissue that can change shape & length >600 muscles human body made of long, excitable cells capable of contraction attached to skeleton contract pull on skeleton results in movement 3 Human Muscles Types What are the 3 different muscle types in humans?
skeletal (a.k.a. striated) smooth cardiac Each has a different structure, pattern, job, & location in the body. Skeletal muscles (striated) voluntary,moves bones, long multinucleate cells fibers Smooth muscles involuntary, lines digestive and respiratory tracts and blood vessels, tapered distinct cells Cardiac muscle involuntary, only in heart, striated and branched 3 Human Muscles Types 1. skeletal (striated)
What do the cells look like? long fibers dark & light stripes (striations) Where are they typically found? most of the body attached to skeleton What is their function? move bones of the skeleton by contracting in opposing pairs Are their movements voluntary or involuntary? voluntary Appearance of cells?long multinucleate striated/striped cells fibers Where typically found?Legs/arms Function Used for locomotion?Yes moves bones (locomotion) Use for peristalsis?no Involved in reflex arc?Yes Voluntary or involuntary?Voluntary Contracts quickly or slowly?quickly Stays contracted for a long or short period?short 3 Human Muscles Types 2. smooth What do the cells look like?
tapered (thin ends, thick center) no stripes (no striations) Where are they typically found? digestive tract, respiratory tract, blood vessels, other organs What is their function? regulate activity of organs or vessels Are their movements voluntary or involuntary? involuntary Appearance of cells?tapered distinct cells each w/ nucleus Where typically found?lines digestive tract, respiratory tract, & blood vessels NOT connected to bone Function Used for locomotion?no Use for peristalsis?Yes Regulate activity of organs or diameter or vessels Involved in reflex arc?yes Voluntary or involuntary?involuntary Contracts quickly or slowly?slowly Stays contracted for a long or short period?long 3 Human Muscles Types 3. cardiac What do the cells look like?
long fibers that branch & weave together dark & light stripes (striations) Where are they typically found? ONLY in heart What is their function? contracts rhythmically pump blood out of heart Are their movements voluntary or involuntary? involuntary Appearance of cells?Striated & branched Where typically found?Only in heart NOT connected to bone Functioncontracts rhythmically to force blood out of heart chambers into arteries Used for locomotion?no Use for peristalsis?no Involved in reflex arc?no Voluntary or involuntary?involuntary Contracts quickly or slowly?quick Stays contracted for a long or short period?short Voluntary or involuntary? Muscle Types in the Body
Striated (skeletal) Cardiac Smooth Appearance of cells? Striped (striated) Striped (striated) & branched Tapered (thin ends, thick center); no stripes (not striated) Where typically found? Attached to skeleton (ex. legs/ arms) heart digestive system, respiratory system, blood vessels Function? movement pump blood fromheart to arteries peristalsis, regulate activity of organs or diameter or vessels Voluntary or involuntary? voluntary involuntary Muscle Types in the Body Tendons What are tendons? connective tissue: holds muscles to bones
must be attached to bones at 2 points at opposite ends of the muscle What holds muscles to bones? connective tissue called tendons Attachment to 2 sites is necessary for movement (during contraction one end of the muscle the bone to which it is attached do not move = point of origin) (other end of the muscle & the bone to which it is attached move when the muscle contracts = point of insertion) The Achilles tendon is the thickest and strongest tendon in the human body How Muscles Work How do muscles work? by contracting or relaxing
muscle fibers cannot lengthen So, skeletal muscles must work in opposing pairs. flexors extensors Muscle fibers are made of fibrils which are made of protein filaments called actin (thin) & myosin (thick) Sliding Filament Hypothesis muscle receives nerve impulse actin & myosin slide over one another muscle contracts when muscle relaxes actin & myosin go back to original positions Skeletal Muscles Work in Pairs
What does a flexor do when it contracts? bends the joint Examples of flexors? biceps, hamstring (back of thigh) Animation of Muscles Working in Pairs Muscles Contracting in Pairs flexor extensor What does each do? flexor causes flexing/decrease of angle (bending) at a joint ex. biceps, hamstring extensor causes the extension/increase of angle (straightening) of a joint ex. triceps, quadriceps Flexors & extensors are also important for support of body b/c both muscles of pair are always slightly contracted (muscle tone), keeps muscles ready for quick contractions. Skeletal Muscles Work in Pairs
What does an extensor do when it contracts? straightens the joint Examples of extensors? triceps, quadriceps (front of thigh) Animation of Muscles Working in Pairs Muscles Contracting in Pairs flexor extensor What does each do? flexor causes flexing/decrease of angle (bending) at a joint ex. biceps, hamstring extensor causes the extension/increase of angle (straightening) of a joint ex. triceps, quadriceps Flexors & extensors are also important for support of body b/c both muscles of pair are always slightly contracted (muscle tone), keeps muscles ready for quick contractions.