Vertebrate Anatomy & Physiology: Organisation & Cell

Study Notes

The body can be broken down into levels: atomic, molecular, cellular, tissue, organ, organ system, and organism
Each level builds upon the previous one to form a hierarchical structure

Cells are the building blocks of all living things
Cells are specialized for particular functions, such as taking up nutrients, creating energy, and providing structure
The function of the cell determines its shape and structure, and which organelles are predominant

Cells are made up of:
- Cell (plasma) membrane: semipermeable membrane that allows some molecules to pass through
- Nucleus: "control center" of the cell that contains genetic material (DNA)
- Cytoplasm: substance of the cell that contains organelles
The nucleus has three regions:
- Nuclear membrane: similar to the plasma membrane
- Nucleolus: site of ribosome production
- Chromatin: composed of DNA and protein, condenses to form chromosomes during cell division

Mitochondria: "powerhouse" of the cell, produces energy for the cell through cellular respiration
Ribosomes: sites of protein synthesis, found free in the cytoplasm or attached to the rough endoplasmic reticulum
Endoplasmic Reticulum (ER): series of folded membranes, has two types: rough ER (studded with ribosomes) and smooth ER (manufactures lipids, phospholipids, and hormones)
Golgi Apparatus: receives proteins from the ER, modifies and packages them in vesicles, and sends them to where they are needed
Lysosomes: type of vesicle that contains digestive enzymes that break down materials within the cell
Cytoplasmic Inclusions: vesicles, vacuoles, and lipid droplets in the cytoplasm that function in storage and transport

There are four main types of tissues: epithelial, connective, muscle, and nervous
Each tissue type has specific functions and characteristics

Skeletal and Muscular Systems: provide form and support to the body, enable movement
Lymphatic System: returns fluid in the tissues to the circulation, complementary to the circulation
Respiratory System: involved in gas exchange, includes upper respiratory tract, lungs, muscles, and is protected by ribs
Digestive System: breaks down food into small particles to be absorbed and used by the body
Nervous System: controls, regulates, and communicates with different systems in the body
Endocrine System: regulates growth, reproduction, energy, stress, metabolism, etc. through hormones
Cardiovascular System: transports nutrients and oxygen to body tissues and removes waste products
Urinary System: eliminates waste products and clears toxins from the blood, maintains water homeostasis and electrolyte concentrations
Reproductive System: produces sex hormones, involved in sexual reproduction