Unit 1 - Levels of Organization

Anatomy

The study of internal and external body structures and relationship between structures

Word description: cutting up

Ana - up

Tome - cutting

Anatomy subdivisions

1. Microanatomy

2. Gross Anatomy

Micro anatomy

The Study of tiny structures of the body - Microscope is required

Ex. Cytology, Histology

word description:

Micro - small

Anatomy - study of structures

Cytology

The study of internal structures of individual cells

Word definition:

Cyto - cell

Logy - study of

Histology

The study of tissues ( Group of cells )

Word definition:

Histo - tissue

Logy - study of

Gross Anatomy

The study of large structures of the body - visible to eye

• Body Cavities

Ex. Bones, heart, stomach

Word description:

Gross - big, large

Anatomy - study of structure

Body Cavities

Spaces ( compartments in the body that hold and protect organs

Ex.

Dorsal body cavity

Abdominal body cavity

Pelvic body cavity

Cranial body cavity

Vertebral body cavity

Ventral body cavity

Lateral view

Side view

Anterior View

Front view

Levels of Organization

How life is structured from simplest to most complex form

1. Chemical Level ( basic level )

2. Cellular Level

3. Tissue Level

4. Organ Level

5. Organ system Level

6. Organism Level

Chemical Level

Includes atoms and molecules

Ex. Hydrogen ( H )

• 18 grams of water contains ( 6.02 × 10E23 ) molecules

Cellular Level

Molecules form organelles which form cells

Cells

Basic unit of structure and function

Cell facts

• All cells contain chemicals

• Different types of cells have different functions

Ex. Erythrocytes - neurons - muscle cells

Tissue Level

A group of structurally similar cells with a common function

4 major types:

• Epithelial

• Connective Tissue

• Muscle

• Nervous

Epithelial Tissue

Covering and Lining Tissue

Functions:

• Covers body surfaces

• Protects body from injury, germs, fluid loss

• Can absorb ( intestine ) filter ( kidneys ) and secrete ( glands )

Connective Tissue

Holds everything together

Function:

• Provide structure, strength, cushioning, transport

Types of connective Tissue

Bone - support and protect

Cartilage - flexible support ( nose, ears )

Blood - transport oxygen, nutrients, waste

Fat - store energy, insulate, cushioning organs

Tendons & Ligaments - Connect muscle to bone and bone to bone

Muscle Tissue

Produce movements by contracting and relaxing

• Made of cells called muscle fibers

• Contain protein - slide to allow movement

• Need energy ATP to work

Types of Muscle Tissue

Skeletal Muscles - attached to bones - voluntary movement

Cardiac Muscle - only in the heart - involuntary movement

Smooth Muscle - Walls of organs - involuntary movement

Nervous Tissue

Control and communicate using signals

Made of 1. Neurons that transmit signals and 2. Supporting cells (Glial Cells )

Function:

Receive: information ( sight, sound, temp )

Process: Brain

Respond: by sending signals to muscles/ glands

Organ Level

Two or more tissues working together for a common function

Ex. Stomach - made of all 4 major tissues - function is digestion

Organ Systems

Several related organs working together towards a common purpose

Ex. Respiratory system ( Trachea, lungs, etc )

Organisms

All systems function together to maintain life

Ex. Humans

Heirarchy