Organization of the Human Body

Chap 46

Cell specialization• Zygote

– Forms three germ layers• Ectoderm; outher layer, skin & nervous system• Mesoderm: middle layer, muscles, bones and

connective tissue• Endoderm: Inner layer, organs

Germ Layers

Cell specialization• Tissue types

– Connective: binds and supports other structures (bones, elastins)

• Function: gives strength to softer tissues• Origin: mesoderm

Connective Tissue

Cell specialization (cont)– Muscle

• Function: movement• Origin: mesoderm

Muscle tissue

Cell specialization (cont)– Nerve

• Function: communication, coordination, information

• Origin: ectoderm• Types of nervous transmission

– Afferent: sensory– Efferent: motor

Nerve Tissue

Afferent vs Efferent nerves

Afferent

Efferent

Tissues make organs

Organs make up Organ systems

Organ systems (cont)

Skeletal System

– Endoskeleton• Advantages

• Flexible• No molting• Greatest support with

least weight• Disadvantages

• less protection than exo-

• Depend on nervous system for protection

– Skeleton Functions• Support• Muscle attachment• Protection: organs and CNS• Store minerals• Marrow storage

– Bone development• Long bones

– Develop from cartilage: Ossification– Remove minerals from blood

» Calcium phosphate ions» Calcium carbonate ions

– Continues throughout childhood

Long bones

Long bone Developement

– Bone development (cont)• Flat bones: cranium, sternum, jaw

– Develop from membrane layers– Sutures: joints in bones– Bones not fused in baby: allows brain to grow

Flatbones

Bone Structure

– Diaphysis: shaft of bone– Epiphysis: ends of long bones– Epiphyseal line: growth line/plate– Haversian system

– Haversian canal: channels through bones

– Functions: delivers blood to bone, nutrients, osteocytes

– Marrow– Red

– Found: flat bones, epiphyseal portion of long bones

– Function: RBC, WBC (erythrocytes, leucocytes)

– Yellow– Found: central cavity of

long bones (diaphysis)– Function: fat storage (in

emergency may produce RBC’s

Bone Structure

Buffalo Humerus- Identify the parts of the long bone

Joints– Types

– Hinge: elbow– Ball and socket: hip– Angular: wrist– Gliding: vertebrae– Pivotal: Atlas and Axis

– Top 2 vertebrae that allow head rotation

– Attachment– Bone to bone:

ligaments– Muscle to bone:

tendons

Ligaments and Tendons

Muscle systems– Muscle tissue

• Made of cells that are able to shorten

Muscle fibers

– Fibers are single cells– Energy provided by ATP (lots

of mitochondria)– Bundle of fibers is a motor unit

Muscle structure- made of may fibers

Muscle contraction videos

• http://www.youtube.com/watch?v=CepeYFvqmk4

• http://www.youtube.com/watch?v=NRzJjx3ANuE

Three Muscle types

(get notes from descriptions of pictures)

Identify these Muscle types

Flexors vs Extensors– Flexor- pulls bone toward

each other (flex)

– Extensors- pulls bones away from each other (extend)

– Work in opposites- each flexor has and extensor to control the range of motion

Heart Contractions– Sinoatrial node

(pacemaker): in right atrium, impulse start here and causes contraction

– Atrioventricular node: Causes ventricle contraction

– Atria contract, then ventricles, moves right to left

Heart contractions

Electrocardiograms (EKG/ECG)

Figure 8.15B, C