1 - Levels of organisation

Levels of organisation

1. Chemical/molecular

2. Cellular

3. Tissue

4. Organ

5. Organ system

6. Organism

(1) Chemical level

1. Atoms e.g hydrogen

2. Molecules e.g water

Chemical level (Larger Molecules)

1. Carbohydrates

2. Lipids

3. Proteins

4. Nucleic acids

5. High energy compounds

Cell

(2) Cellular level

Cells = smallest unit of life e.g. bacteria

Cellular differentiation = higher life forms contain cells specialised for different functions e.g sperm

(3) Tissue level

1. Cells + extracellular material/fluids

2. Tissues

3. Organs

4. Organ system

1. Epithelia

2. Connective

3. Muscle

4. Neural

Epithelia

1. Flat

2. Cover exposed surfaces

3. Line internal passageways/chambers

4. Produce glandular secretion

Connective tissues

1. 3D

2. Store substances

3. Structural support

4. Store energy

Muscle tissues

1. Contracts to produce active movement

Neural tissue

1. Conducts electrical impulses

2. Carries/transmits info

(4) Organ level

a discrete collection of 2 or more tissues cooperatively performing a function

(5) Organ system

1. Integumentary

2. Skeletal

3. Muscular

4. Nervous

5. Endocrine

6. Cardiovascular

7. Lymphatic

8. Respiratory

9. Digestive

10. Urinary

11. Reproductive

Integumentary

1. Protection

2. Thermoregulation

3. Sensation

Skeletal

support, protection

Muscular

movement

Nervous

communication

Endocrine

hormones to communicate

Cardiovascular

transportation

Lymphatic

1. Deal with pathogens

2. Immune response

Respiratory

ventilation

Digestive

digestion of nutrients

Urinary

excrete waste

Reproductive

1. Reproduce

2. Fetus

Anatomical landmarks (front)

Anatomical landmarks (back)

Anatomical position

Directional terms - anterior

1. Superior - head

2. Inferior - feet

3. Lateral - side

4. Medial - mid line

5. Proximal - nearest to trunk

6. Distal - furthest from trunk

7. Proximal

8. Distal

Directional terms (lateral)

1. cranial - head

2. caudal - tail

3. dorsal/posterior - back

4. ventral/anterior - front

frontal plane

split forward + back

sagittal plane

left + right

transverse plane

split top + bottom half

dorsal cavity

contains brain and spinal cord

ventral cavity

contains thoracic, abdominal, pelvic organs

Thoracic + Abdominalpelvic cavity

Homeostasis

the maintenance of a constant internal environment

1. Negative feedback - opposes variation from normal

2. Positive feedback - exaggerates variation

Negative feedback

thermoregulation

Positive feedback

blood clotting