Organization of the Body

Body Composition

• The whole body is composed of organ systems

  • Organ systems are composed of tissues

    • Tissues are composed of cells

      • Cells are composed of organelles

        • Organelles are composed of molecules

          • Molecules are composed of atoms

            • The nucleus of a cell directs all the activities 

Blastocyst

• first two weeks of the developing embryo

  • 5-6 days after fertilization

Cytology

• study of the cell

  • cytologist studies the cell

Fertilization/ zygote

• union of male sperm and female egg

  • results in a zygote

Molecule

• small particle consisting of two or more atoms held tightly together

Oocyte

• female egg cell

Organ/ Organelle

• structure with specific functions in the body system

  • tiny specialized structures in a cell that carry out metabolic tasks

• Examples of organelles:

  • nucleus

  • endoplasmic reticulum

  • Golgi complex or apparatus

  • mitochondria

  • nucleolus

  • ribosomes

  • lysosomes

Vitro

• process of combining sperm and egg in a laboratory dish and placing resulting embryos inside a uterus

Chromatin

• substance composed of DNA that forms chromosomes during cell division

• when cells divide, the chromatin condenses to form 46 chromosomes

• DNA + histone proteins = chromatin

  • DNA that's loosely packaged with proteins

Chromosome

• body in the nucleus that contains DNA and genes

Cytoplasm

• clear, gelatinous substance that forms substance of a cell except for the nucleus

Cytosol

• liquid portion of cell

Deoxyribonucleis acid (DNA)

• the instruction book with all your genetic information

• source of hereditary characteristics found in chromosomes

  • looks like a double helix (2 strands)

Electrolyte

• substance that when dissolved, forms electrically charged particles

Hormone

• chemical messenger that travels through the blood to control or affect another tissue or organ

Membrane

• thin layer of tissue covering a structure or cavity

  • made out of protein and lipids

Metabolism - Anabolism - Catabolism

• Metabolism is the sum of physical and chemical processes

  • it is the constant chemical processes happening in your cells that keep your body functioning.

• Anabolism is the constructive metabolism, buildup from simple substances to complex substances needed in the cell

  • Constructs larger macromolecules (like proteins, nucleic acids, and carbohydrates) out of basic units such as amino acids, nucleotides, and simple sugars.

• Catabolism is the destructive metabolism, breaks down substances to release energy

Nucleolus

• small mass within the nucleus

• a small dense body composed of RNA and protein

• manufactures ribosomes that go from the nuclear membrane into the cytoplasm

Steroid

large family of chemical substances found in drugs, hormones, and body components

Synthesis

process of building a compound from different elements

Endoplasmic Reticulum (smooth & rough)

• The endoplasmic reticulum is a network of folded membranes in a cell that make, process, and move important materials so they can work properly 

  • Smooth ER (has no attached ribosomes)

    • Makes lipids (used to build cell membranes)

    • Makes cholesterol and steroids (steroids include hormones)

    • Detoxifies drugs and alcohol → especially in liver cells, the smooth ER helps break down harmful substances so the body can remove them

  • Rough ER (has ribosomes)

    • Helps make/process proteins 

Nucleus

• largest organelle located between cell membrane and cytoplasm

• directs all cell activities

• nucleus has small openings called pores that molecules pass through

  • each nucleus has 46 molecules of DNA and their associated proteins (chromatin)

• Most cells have one, except RBC have none and liver and muscle cells sometimes contain many 

RNA (ribonucleic acid)

• an essential biological molecule found in all living cells that helps turn genetic instructions into proteins

  • (one strand)

Lysomes

• Lysomes are the garbage disposal units of the cell

  • They digest and dispose worn-out organelles 

  • Digest foreign particles and bacteria 

Mitochondria

• Mitochondria is the powerhouse of the cell

  • They extract energy by breaking down compounds like glucose & fat (catabolism)

  • The energy is then used to do the work of the cell (for example, to make a muscle contract)

Carbohydrate

Organic food compounds that include sugars, starch, glycogen, and cellulose

Centriole

A paired organelle lying in the cytoplasm near the nucleus

Epithelium

Tissue that covers surfaces or lines cavities

Excrete

To pass waste products of metabolism out of the body

Histology

Structure and function of cells, tissues, and organs

Lysosome

Enzyme that digests foreign material and workout cell components

Secrete

to produce a chemical substance in a cell and release it from the cell

Protien

Class of food substances based on amino acids

Osteoblasts & bone matrix

• bone building cells

• make and deposit bone matrix that become bone

  • bone matrix is the material that makes up the bone around the cell

    • Chocolate chips = bone cells

    • Cookie dough = bone matrix

Osteocytes & Osteoclasts

• Osteocytes are former osteoblasts that maintain bone matrix by living inside the finished material 

• Osteoclasts dissolve bone matrix to release calcium and phosphate into blood when the chemicals are needed elsewhere

Cartilage

• Cartilage (connective tissue) has a flexible rubbery matrix

  • Cushions joints and bones so they don't rub on eachother 

  • Provides support - gives shape to things like shape of ear, tip of nose, and your larynx

  • Absorbs shock when you run/jump/walk

    • Chondroblasts deposit the cartilage matrix

    • Chondrocytes maintain matrix

    • Fibers give cartilage strength and flexibility 

Ligaments & Tendons

• Ligaments are bands of fibrous connective tissues that help connect bone to bone

  • Cells called fibroblasts form a jellylike, closely packed matrix and collagen fibers (these fibers help ligaments resist being stretched/torn)

  • Blood supply is poor so do not heal well without surgery 

• Tendons are thick, strong ligaments that attach muscle to bone

Joint Capsules and Synovial Fluid

• Joint capsules are a thin, collagenous fibrous connective tissue envelope that surrounds and seals the joint

  • Inner surface of joint capsules are lined with a synovial membrane that secretes synovial fluid - a slippery lubricant in the joint cavity that helps make joint movement friction free and distributes nutrients to the cartilage on the joint surfaces of bone

Collagen

• Major protein of connective tissue, cartilage, and bone

  • fibroblast is the cell that forms collagen fibers

Integumentary System

• Skin, hair, nails, sweat glands, sebaceous glands

  • Protects tissues, regulates body temperature, supports sensory receptors

Skeletal System

• Bones, ligaments, cartilages, tendons

  • Provides framework, protects soft tissues, provides attachment to muscles, produces blood cells, stores inorganic salts

Muscular System

• Muscles

  • Causes movements, maintain posture, produce body heat

Nervous System

• Brain, spinal cord, nerves, sense organs

  • Detect changes, receive/interpret sensory info, stimulate muscles and glands

Endocrine System

• Glands that secrete hormones: pituitary, thyroid, parathyroid, adrenal, pancreas, ovaries, testes, pineal, thymus

  • Releases hormones into the blood to control & coordinate vital body processes

  • Controls metabolic activities of organs and structures

Cardiovascular system

• heart, blood vessels

  • move blood and transport substances throughout the body

Lymphatic system

• Lymph vessels and nodes, thymus, spleen

  • Returns tissue fluid to blood, carries certain absorbed food molecules, defends body against infection

Digestive system

• Mouth, tongue, teeth, salivary glands, pharynx, esophagus, stomach, liver, gallbladder, pancreas, small & large intestines

  • Receive, break down, and absorb food, eliminate unabsorbed materia

Respiratory system

• Nasal cavity, pharynx, larynx, trachea, bronchi, lungs

  • Control intake & output of air, exchange gases between air and blood

Urinary system

• Kidneys, ureters, urinary bladder, urethra

  • Removes waste from blood, maintain water & electrolyte balance, store and transport urine

Reproductive system (male)

• Scrotum, testes, epididymides, vas deferens, seminal vesicles, prostate, bulbourethral glands, urethra, penis

  • sperm cells, transfer sperm into female reproductive tract, secrete male hormones

Reproductive system (female)

• Ovaries, uterine, (fallopian) tubes, uterus, vagina, vulv

  • Produce & maintain egg cells, receive sperm cells, support embryo development, function in process of birth, secrete female hormone