Human Skeletal & Muscle Human Skeletal & Muscle SystemsSystems

Structures, Functions, and Structures, Functions, and ExamplesExamples

Body OrientationBody Orientation

Ventral--front of the bodyVentral--front of the bodyDorsal--back of bodyDorsal--back of bodyLateral--side of bodyLateral--side of bodyMedial--middle of bodyMedial--middle of bodyCranial--head regionCranial--head regionCaudal--feet regionCaudal--feet regionProximal--toward the trunkProximal--toward the trunkDistal--away from the trunkDistal--away from the trunk

Major Body CavitiesMajor Body Cavities

DorsalDorsal– Cranial (skull)Cranial (skull)– SpinalSpinal

VentralVentral– AbdominalAbdominal– PelvicPelvic– Thoracic (chest)Thoracic (chest)

Skeletal System—FunctionsSkeletal System—Functions

Support-framework for the bodySupport-framework for the body

Movement-site for muscle attachmentMovement-site for muscle attachment

Protection-cover brain, spinal cord, lungs, Protection-cover brain, spinal cord, lungs, etc.etc.

Mineral & lipid (type of fat) storage-yellow Mineral & lipid (type of fat) storage-yellow marrow contains Ca (calcium), P marrow contains Ca (calcium), P (phosphorous), and lipids(phosphorous), and lipids

Hemopoiesis-red marrow makes blood Hemopoiesis-red marrow makes blood cells (red, white, macrophages, platelets, cells (red, white, macrophages, platelets, etc.)etc.)

Bone FormationBone Formation

Very controlled process of converting Very controlled process of converting embryonic connective tissue into bone.embryonic connective tissue into bone.

Process is called ossification.Process is called ossification.

Process of ossification occurs throughout life Process of ossification occurs throughout life however, it is more rapid in younger years.however, it is more rapid in younger years.

Process of bone formation can be altered with Process of bone formation can be altered with destructive life styles.destructive life styles.

Process of bone formation is under control of Process of bone formation is under control of many vitamins and hormones.many vitamins and hormones.

Skeletal System-Specific BonesSkeletal System-Specific Bones

Skull—headSkull—head

Shoulder—scapula, clavicleShoulder—scapula, clavicle

Arm—humerus, radius, ulna, metacarpals, Arm—humerus, radius, ulna, metacarpals, phallangesphallanges

Chest—ribs, sternum, xiphoid processChest—ribs, sternum, xiphoid process

Spine—cervical, thoracic, lumbar, sacral, Spine—cervical, thoracic, lumbar, sacral, coccyxcoccyx

Hips—pelvisHips—pelvis

Skeletal System-Specific BonesSkeletal System-Specific Bones

Leg—femur, tibia, fibula, metatarsals, Leg—femur, tibia, fibula, metatarsals, phallangesphallanges

Other Components of Other Components of Skeletal SystemSkeletal System

Cartilage—firm flexible connective tissue Cartilage—firm flexible connective tissue that comprises the infant skeletal system; that comprises the infant skeletal system; gradually gets replaced by bone; adult gradually gets replaced by bone; adult cartilage examples include nose and top of cartilage examples include nose and top of ear.ear.

Ligament—tough, flexible, and fibrous Ligament—tough, flexible, and fibrous connective tissue linking bone to bone.connective tissue linking bone to bone.

Muscle TypesMuscle TypesSkeletal muscle—moves bones directly Skeletal muscle—moves bones directly or indirectly; voluntarily controlled; or indirectly; voluntarily controlled; bandedbandedCardiac muscle—pumps blood through Cardiac muscle—pumps blood through body; involuntarily controlled; bandedbody; involuntarily controlled; bandedSmooth muscle—moves materials Smooth muscle—moves materials through structures; involuntarily through structures; involuntarily controlled; not banded; examples controlled; not banded; examples where smooth muscle is found include where smooth muscle is found include arteries, intestines, stomach, and arteries, intestines, stomach, and esophagusesophagus

How Muscle FunctionsHow Muscle Functions

Nerves control the muscle tissueNerves control the muscle tissue

Requires the use of ATP and calcium Requires the use of ATP and calcium for energyfor energy

Uses two types of filaments (Actin and Uses two types of filaments (Actin and Myosin) for contraction and relaxationMyosin) for contraction and relaxation

Needs aerobic conditions to functionNeeds aerobic conditions to function

Excess muscle use leads to anaerobic Excess muscle use leads to anaerobic conditions resulting in crampingconditions resulting in cramping

Muscle Shape and ArchitectureMuscle Shape and Architecture

FlatFlat

Pennate (leaf-like)Pennate (leaf-like)

FusiformFusiform

QuadrateQuadrate

Circular or SphincteralCircular or Sphincteral

Skeletal Muscles of Skeletal Muscles of Arm MovementArm Movement

Biceps—bends arm at elbow proximally to Biceps—bends arm at elbow proximally to cranial areacranial area

Triceps—bends arm at elbow distally from Triceps—bends arm at elbow distally from cranial areacranial area

Deltoid—moves arm at shoulder (clavicle Deltoid—moves arm at shoulder (clavicle and scapula)and scapula)

Pectoralis major—moves arms forwardPectoralis major—moves arms forward

Trapezius—moves arms backwardTrapezius—moves arms backward

Cardiac MuscleCardiac Muscle

Strongly regulated by nerve bundles to Strongly regulated by nerve bundles to control rhythm of heart beatcontrol rhythm of heart beatIrregular heart beats can be regulated by a Irregular heart beats can be regulated by a pacemakerpacemakerSudden stoppage of the normal heartbeat Sudden stoppage of the normal heartbeat can sometimes be restarted by electric can sometimes be restarted by electric shock (defibrillator)shock (defibrillator)Electrocardiogram is the measure of the Electrocardiogram is the measure of the electrical impulses in the heartelectrical impulses in the heart

Smooth MuscleSmooth Muscle

Involuntary muscle controls variety of Involuntary muscle controls variety of tissues or organstissues or organs

Digestive tract has number of examples of Digestive tract has number of examples of smooth muscle (stomach, intestines, smooth muscle (stomach, intestines, esophagusesophagus

Smooth muscle of arteries act to pump Smooth muscle of arteries act to pump blood throughout the bodyblood throughout the body

End of Skeletal and End of Skeletal and Muscle SystemsMuscle Systems