Movement and Movement and skeletal system skeletal system

All organisms move to find food, escape All organisms move to find food, escape from predators, migrate, protect their from predators, migrate, protect their habitat. Plant movement is different than habitat. Plant movement is different than the other organisms because they anchor the other organisms because they anchor to soil with their roots.to soil with their roots.

Skeletal and muscular system help Skeletal and muscular system help movement. movement.

Skeleton gives shape to the organisms. Skeleton gives shape to the organisms. Exoskeleton covers the body of the Exoskeleton covers the body of the

organism(insects, molluscs) Endoskeleton organism(insects, molluscs) Endoskeleton is found inside of the body. (mammal, is found inside of the body. (mammal, birds) birds)

Support and movement in Support and movement in plantsplants

Supportive tissues and turgor pressure give Supportive tissues and turgor pressure give the main support to the body of the plants. the main support to the body of the plants.

Turgor pressure is the pressure against cell Turgor pressure is the pressure against cell wall of the plant cell. If Turgor pressure wall of the plant cell. If Turgor pressure decreases the support will be less. decreases the support will be less.

Supportive tissues (collenchyma-living, and Supportive tissues (collenchyma-living, and sclerenchyma-nonliving) with thickened cell sclerenchyma-nonliving) with thickened cell walls help plant body. walls help plant body.

Also vascular tissues help support. Also vascular tissues help support. Plants move with nastic movements and Plants move with nastic movements and

tropisms as we mentioned before.tropisms as we mentioned before.

Skeletal (Support) system in AnimalsSkeletal (Support) system in Animals In one celled organisms SiO2, CaCO3 fibrils In one celled organisms SiO2, CaCO3 fibrils

help support. They move with cilia, flagella help support. They move with cilia, flagella or by pseudopods.or by pseudopods.

Exoskeleton:Covers the body of the animal. Exoskeleton:Covers the body of the animal. Contains many organic (chitin- a Contains many organic (chitin- a polysaccharide) and inorganic polysaccharide) and inorganic molecules(CaCO3). Muscles are fixed to the molecules(CaCO3). Muscles are fixed to the inner surface of the exoskeleton. Exoskeleton inner surface of the exoskeleton. Exoskeleton prevents growth, so animals with prevents growth, so animals with exoskeleton should break up their skeleton exoskeleton should break up their skeleton and form a new skeleton for and form a new skeleton for growth(molting). Also exoskeleton prevents growth(molting). Also exoskeleton prevents water loss.water loss.

Hydrostatic exoskeleton- Hydrostatic exoskeleton- consists of a volume of fluid enclosed in a body cavity surrounded by muscle.of cnidarians, annelids, and many other soft-bodied invertebrates.

In Endoskeleton muscles are attached to them and with joints endoskeleton helps movement.

Human skeletal systemHuman skeletal system There are 206 bones in the human skeleton. It is less There are 206 bones in the human skeleton. It is less

than the number of bones in the baby. than the number of bones in the baby. The skeleton supports the body. The bones of the lower limbs support the entire body when we are standing, and the pelvic girdle supports the abdominal cavity.

The skeleton protects soft body parts. The bones of the skull protect the brain; the rib cage protects the heart and lungs.

The skeleton produces blood cells. All bones in the fetus have red bone marrow that produces blood cells. In the adult, only certain bones produce blood cells.

The skeleton stores minerals and fat. All bones have a matrix that contains calcium phosphate, a source of calcium ions and phosphate ions in the blood. Fat is stored in yellow bone marrow.

The skeleton, along with the muscles, permits flexible body movement. While articulations (joints) occur between all the bones, we associate body movement in particular with the bones of the limbs.

Compact bone, or dense bone, contains many cylinder-shaped units called osteons. The osteocytes (bone cells) are in tiny chambers called lacunae that occur between concentric layers of matrix called lamellae. The matrix contains collagenous protein fibers and mineral deposits, primarily of calcium and phosphorus salts. In each osteon, the lamellae and lacunae surround a single central canal. Blood vessels and nerves from the periosteum enter the central canal. The osteocytes have extensions that extend into passageways called canaliculi, and thereby the osteocytes are connected to each other and to the central canal.

Spongy bone, or cancellous bone, contains numerous bony bars and plates, called trabeculae. Although lighter than compact bone, spongy bone is still designed for strength. Like braces used for support in buildings, the trabeculae of spongy bone follow lines of stress.

In infants, red bone marrow, a specialized tissue that produces blood cells, is found in the cavities of most bones. In adults, red blood cell formation, called hematopoiesis, occurs in the spongy bone of the skull, ribs, sternum (breastbone), and vertebrae, and in the ends of the long bones.

Bone is made up of solidified extracellular matrix Bone is made up of solidified extracellular matrix (osein)which contains protein, Ca, P, MgP, (osein)which contains protein, Ca, P, MgP, CaCO3,CaFl. CaCO3,CaFl.

Bones are classified according to their shapes: Bones are classified according to their shapes: Long: arm, legLong: arm, leg Short: ankleShort: ankle Flat: skull, Flat: skull, Irregular –vertebrae.Irregular –vertebrae.

The skeleton is divided The skeleton is divided into the axial skeleton into the axial skeleton and the appendicular and the appendicular skeleton. The tissues of skeleton. The tissues of the axial and the axial and appendicular skeletons appendicular skeletons are bone (both compact are bone (both compact and spongy), cartilage and spongy), cartilage (hyaline, fibrocartilage, (hyaline, fibrocartilage, and elastic cartilage), and elastic cartilage), and dense connective and dense connective tissue, a type of fibrous tissue, a type of fibrous connective tissue. connective tissue.

Joints: Bones are held together by Joints: Bones are held together by joints. They are classified according joints. They are classified according to their ability to move. to their ability to move.

Synovial joints: They can freely move Synovial joints: They can freely move . They have joint cavity which is . They have joint cavity which is filled with synovial fluid and covered filled with synovial fluid and covered with synovial membrane. Knee joint with synovial membrane. Knee joint

Cartilaginous joints: Slightly Cartilaginous joints: Slightly moveable joints in vertebrae, ribs moveable joints in vertebrae, ribs and pubic symphysis. They contain and pubic symphysis. They contain fibrous cartilage.fibrous cartilage.

Fibrous joints: Immoveable joints in Fibrous joints: Immoveable joints in skull. skull.

MUSCULAR SYSTEMMUSCULAR SYSTEM All invertebrates contain smooth muscle All invertebrates contain smooth muscle

except arthropoda. except arthropoda. Arthropoda has skeletal(striated) muscle. Arthropoda has skeletal(striated) muscle.

Skeletal muscleSkeletal muscle Cardiac muscleCardiac muscle Smooth muscleSmooth muscle

Multinucleated at the Multinucleated at the peripheryperiphery

Long fibersLong fibers

Voluntary-striatedVoluntary-striated

Fast contractionFast contraction

Rapid fatigueRapid fatigue

1 or 2 nuclei at the 1 or 2 nuclei at the center center

Striated but Striated but involuntary involuntary

Contain branches in Contain branches in fibersfibers

Intercalated discs Intercalated discs between cells.between cells.

Never get tiredNever get tired

1 nucleus at the 1 nucleus at the centercenter

Not striatedNot striated

InvoluntaryInvoluntary

Spindle shapedSpindle shaped

Slow contractionSlow contraction

Human muscular system, Human muscular system, structure of the muscle and structure of the muscle and

contractioncontractionSmooth muscles are stimulated by Smooth muscles are stimulated by autonomous nervous sytem. They contract autonomous nervous sytem. They contract with the help of the Ca ions and with the help of the Ca ions and hormones. hormones.

Skeletal muscles contract with the Skeletal muscles contract with the information from brain and spinal cord. information from brain and spinal cord. The junction between neuron axon ending The junction between neuron axon ending with muscle is named as neuromuscular with muscle is named as neuromuscular junction. One neuron can extend to many junction. One neuron can extend to many muscle fibers. muscle fibers.

Muscles can contract with the stimulation Muscles can contract with the stimulation of motor neurons. To start the of motor neurons. To start the contraction, the stimulus should be at a contraction, the stimulus should be at a certain level. All or none law. certain level. All or none law.

Stages of contractionStages of contraction Stimulation of the muscle and start Stimulation of the muscle and start

of contraction –latent periodof contraction –latent period Contraction-Contraction- Relaxation- muscle relaxes and Relaxation- muscle relaxes and

waits for new stimulus.waits for new stimulus. http://www.http://www.brookscolebrookscole.com/.com/chemistrychemistry_d/_d/

templatestemplates//studentstudent__resourcesresources//sharedshared__resourcesresources

//animationsanimations//musclesmuscles//musclesmuscles.html.html

The plasma membrane of a muscle fiber is called the sarcolemma; the cytoplasm is the sarcoplasm; and the endoplasmic reticulum is the sarcoplasmic reticulum.

The sarcolemma forms T (transverse) tubules that penetrate into the cell so that they come into contact—but do not fuse—with expanded portions of the sarcoplasmic reticulum.

The expanded portions of the sarcoplasmic reticulum are calcium storage sites.

The sarcoplasm contains millions of myofibrils. Contractile portions of muscles.

Myofibrils and Sarcomeres Myofibrils are cylindrical in shape and run the length

of the muscle fiber. The striations of skeletal muscle fibers are formed by the placement of myofilaments within units of myofibrils called sarcomeres. A sarcomere extends between two dark lines called the Z lines. A sarcomere contains two types of protein myofilaments. The thick filaments are made up of a protein called myosin, and the thin filaments are made up of a protein called actin. Other proteins are also present. The I band is light colored because it contains only actin filaments attached to a Z line. The dark regions of the A band contain overlapping actin and myosin filaments, and its H zone has only myosin filaments.

The sarcoplasm also contains glycogen, which provides stored energy for muscle contraction, and the red pigment myoglobin, which binds oxygen until it is needed for muscle contraction.

Contraction mechanismContraction mechanism The muscle fiber contracts as the

sarcomeres within the myofibrils shorten. When a sarcomere shortens, the actin (thin)

filaments slide on the myosin (thick) filaments and approach one another.

The movement of actin filaments in relation to myosin filaments is called the sliding filament theory of muscle contraction

http://highered.mcgraw-hill.com/sites/0072324813/student_view0/chapter12/elearning_connection.html

http://harveyproject.science.wayne.edu/development/muscle/juncti~1.htm

In the sarcomere, dark band (A) contains myosin and actin In the sarcomere, dark band (A) contains myosin and actin myofibrils. Light band contains (I) contains thin actin myofibrils. Light band contains (I) contains thin actin myofilaments. myofilaments.

When a sarcomere shortens, the actin (thin) filaments slide on the myosin (thick) filaments and approach one another. This causes the I band to shorten and the H zone to almost or completely disappear.

, the sarcomere shortens even though the filaments themselves remain the same length.

Myosin filaments break down ATP and have crossbridges that pull the actin filaments toward the center of the sarcomere.

1.1. Axon endings of a neuron contains a special Axon endings of a neuron contains a special neurotransmitter called acetylcholine. neurotransmitter called acetylcholine.

2.2. When stimulus reaches the axon end, the When stimulus reaches the axon end, the neurotransmitter is released to the synaptic cleft. neurotransmitter is released to the synaptic cleft.

3.3. Acetylcholine binds to receptors on muscle sarcolemma Acetylcholine binds to receptors on muscle sarcolemma and forms a impulse in muscle fiber.and forms a impulse in muscle fiber.

4. Impulse travels down T tubules in sarcolemma, and calcium is released from the sarcoplasmic reticulum.

5.5. Ca binds actin and on the actin myosin binding sites are Ca binds actin and on the actin myosin binding sites are free to bind with myosin. Myosin heads with ATP bind free to bind with myosin. Myosin heads with ATP bind with actin myofilaments. Actin slides over the myosin by with actin myofilaments. Actin slides over the myosin by dephosphorylation of ATP. Sarcomere shortens. dephosphorylation of ATP. Sarcomere shortens.

6.6. Dark band (A band) stays at same length but Light band Dark band (A band) stays at same length but Light band (I ) and H band shortens.(I ) and H band shortens.

7.7. During relaxation, myosin detaches from the actin by During relaxation, myosin detaches from the actin by ATP binding. And Ca ions are collected in Sarcoplasmic ATP binding. And Ca ions are collected in Sarcoplasmic reticulum. reticulum.

Muscle and bone relationMuscle and bone relation

Muscles are attached to bones by tendons. Muscles are attached to bones by tendons. Antagonistic muscle pairs work opposite one

another to bring about movement in opposite directions. For example, the biceps brachii and the triceps brachii are antagonists; one flexes the forearm, and the other extends the forearm