BIO2217 Basics

9/10-9/24 lectures

Anatomy

study of the physical structure of organisms (humans) and their parts

Physiology

study of the functions and processes of organisms (humans) and their parts and how they work together

Anatomic direction

Anterior (ventral)

Anatomic direction

Posterior (dorsal)

Anatomical direction

Superior (relative)

Anatomical direction

Inferior (relative)

Anatomical direction

Medial (toward the midline)

Anatomical direction

Lateral (away from the midline)

Anatomical direction

Proximal (closer to the trunk)

Anatomical direction

Distal (further from the trunk)

Anatomical direction

Superficial (more external)

Anatomical direction

Deep (more internal)

Standard atomical position requires…

Upright position

Feet flat

Palms rotated anteriorly

Anatomic plane

Sagittal plane (slices vertically, dividing body into left and right)

Anatomic plane

Coronal plane (slices vertically, dividing body into back and front)

Anatomic plane

Transverse plane (slicing horizontally, dividing body into top and bottom)

Midsagittal

Along the midline

Parasagittal

Not along midline

Axial

Head, neck, trunk

Appendicular

Limbs

Cranial cavity

Vertebral cavity

Thoracic cavity

Diaphragm

Abdominal Cavity

Pelvic cavity

Levels of body organization (step by step format)

Chemical level (atom/molecule) > Cellular level (cells) > Tissue level (Epithelial tissue) > Organ level (Small intestine) > Organ system level (Digestive system), Organismal level (Human)

Anatomical varitation

Humans have a wide range of internal morphology and external appearance… anatomy is typically the same but physiology often differs because it relies on factors that often vary between individuals

Physiological variation

Sex, diet, age, activity level, environment, weight, and genetic backgorund

Gradient

Difference in value between one point and another… in A&P context often from lower to higher values/areas (passive)

Matter and energy spontaneously flow down _

Gradients

Homeostasis

State of steady internal conditions

Dynamic equilibrium

Physiological conditions fluctuate around an average value

Set point

Physiological average

Normal range

Range of values around set point that are considered typical and healthy

Homeostatic imbalances can cause…

Illness or death

Humans’ reliance on homeostasis has led to bodies having the ability to detect excessive change, referred to as…

Positive and negative feedback loops

Negative feedback loops

Opposes initial change and reduces stimulus (example: body temperature)

Positive feedback loop

Reinforces initial change and increases stimulus… requires external stimulus to end loop (example: blood clotting)

1.) Sensor: monitors condition, senses change

2.) Control: processes info. from receptor, communicates with effector if needed

3.) Effector: Cell/organ that carries out homeostatic mechanism

This is an example of…

Negative feedback loop

This is an example of…

Negative feedback loop

This is an example of…

Positive feedback loop

Potential energy

stored energy (example: chemical bonds)

Kinetic energy

Energy of motion (muscle contraction)

Potential and kinetic energy are…

Interconvertible (meaning they are easily converted into each other)

Chemical energy

energy stored in molecular bonds

Electrical energy

Generated by movement of charged particles

Mechanical energy

Transferred from one object to another to power movement

One type of energy can be…

converted into the other… Conversions often produce thermal energy

ATP stands for…

Adenosine Triphosphate

Adenosine Triphosphate (ATP) is the…

Primary energy source for cells… the hydrolysis phosphate bond releases energy converting the adenosine triphosphate (ATP) into adenosine diphosphate (ADP)

Adenosine diphosphate (ADP) becomes adenosine triphosphate by…

absorbing energy from food… phosphorylating adenosine diphosphate (ADP) becomes adenosine triphosphate (ATP) by absorbing energy

Bond

Electrical attraction between atoms that holds them together

Molecule

2 or more atoms bonded together

Compound

2 or more elements bonded together

Ionic bonds

transfer of electrons from one atom to another… forms ions… stay near each other due to unequal charge that attracts the other

Ions

Charged particles with unequal numbers of protons and electrons

Ions are attracted to each other…

When they have opposite charges due to transferring electrons to become more stable… strength depends on number of electrons exchanged

Electrolytes

Atoms of opposing charges hold together by ionic bond

Electrolytes do what in water?

Dissociate into ions… these ions conduct electricity which is important for nerve/muscle cell function (ex: NA+, K+, OH-)

Covalent bonds

Bond created that shares electrons between atoms… strength of bond depends on the number of electrons shared

Are ionic or covalent bonds stronger?

Covalent

Electronegativity

How strong protons in the nucleus attract electrons

Non-polar bond

A covalent bond with equivalent electronegativity (meaning that both atoms have the same charge in their nuclei, so electrons are shared equally between them)

Polar bond

A covalent bond with unequal electronegativity… this means that the electrons are not shared evenly between the two atoms because they have different charges in their nuclei…this creates a molecule with slightly negative and slightly positive sides

Polar molecules

Molecules with slightly positive and slightly negative regions

How do polar molecules interact with non-polar and other polar molecules?

Polar molecules repel non-polar molecules and attract other polar molecules

Plasma membrane

Flexible outer surface of a cell

Cytoplasm

Intracellular fluid containing organelles

Nucleus

DNA containing organelle… control center of cell… typically largest organelle in the cell

Label numbers 1-3

1.) Nucleus

2.) Cytoplasm

3.) Intercellular fluid

Plasma membrane

Barrier separating intracellular fluid (ICF) and extracellular fluid (ECF)… selectively permeable… made up of phospholipid bilayer

Phospholipid bilayer

Phosphate group + 2 fatty acid chains… head was hydrophilic and tails were hydrophobic… make up phospholipid bilayer to keep intracellular and extracellular fluid separate

Passive transport

Substances crossing phospholipid bilayer without the use of energy… substances diffuse until equilibrium is reached… examples: simple diffusion, facilitated diffusion, osmosis

Active transport

Substances need energy to pass through phospholipid bilayer… substances moving against concentration gradient require energy… there is primary or secondary active transport…

Simple diffusion

Non-polar, lipid-soluble (hydrophobic) substances diffuse directly through the phospholipid bilayer (ex: oxygen, carbon dioxide, steroid hormones)

Facilitated diffusion

requires involvement of protein channels or carrier proteins in plasma membrane (ex: glucose, amino acids, ions)

Protein channels

inside the plasma membrane… helps specific solutes get through… typically for an individual solute… always passive transport…

Carrier proteins

in plasma membrane… considered passive facilitated diffusion…

Carrier proteins:

1.) Uniporter:

2.) Symporter:

3.) Antiporter:

1.) carries a single solute

2.) carries 2 solute in the same direction

3.) Exchanges 2 solutes (one in each direction)

Osmosis

movement of water across the plasma membrane… moves along osmotic gradients (more water to less water/ less solute to more solute)… primarily through aquaporins… this occurs until solute concentration equalize… results in volume changes to both sides

Active transport

Uses energy to move a molecule against its concentration gradient… maintains/enhances the concentration gradients… important for nerve and muscle function

Phagocytosis

Active transport (needs ATP) for substances into the cell… cell surrounds substance to be engulfed… receptors bind to microorganisms/solid particles… engulfed substance digested internally… important mechanism for immune system

Tissue

Discrete population of related cells + extracellular matrix… different types: epithelial, connective, muscular, nervous

Epithelial tissue

Sheets of cells covering body surfaces, lining cavities and organs… Attaches to underlying connective tissue (basement membrane)… avascular, which means that it is nourished by diffusion from underlying connective tissue… since it relies on closeness to connective tissue, it limits the thickness

Glands

Specialized epithelial tissue

Connective tissue

Connect and anchor structures of the body… composed of cells (adipocytes, chondrocytes, etc), protein fibers (collagen for tensile strength, elastic for stretch and recoil, and reticular for support), and ground substance (ECF, proteins, carbohydrates) which cushions and supports tissue and maintains cells

Extracellular matix

Made up of the protein fibers and ground substance of connective tissue

Different types of connective tissue

Connective tissue proper (loose and dense), fluid connective tissue (blood and lymph), and supporting connective tissue (cartilage and bone)

Muscle tissue

Contractile cells, produce movement, highly vascular (lots of blood flow/nourishment)… different types: skeletal, cardiac, smooth

Nervous tissue

~10% neurons (which conduct electrical signals), ~90% neuroglia (which support neuronal functions)… ex: brain, spinal cord, nerves

Tissue regeneration

Replacement of damaged tissue with tissue of the same type (retains original function)… different tissues have different regeneration capacities… high capacity=epithelial tissue, bone, connective tissue… low capacity=cardiac muscle, nervous tissue… some injuries may fibrose instead (replacement of original tissue with connective tissue, where it becomes scar tissue instead and loses its original function)… collagen fibers support tissue repair, so larger injuries are more likely to scar

Fibrose

The process of damaged tissues becoming scar tissue… more likely for larger injuries for multiple reasons: the extracellular matrix is destroyed in larger injuries (making organized functional tissue regeneration difficult or impossible), in larger injuries the body prioritizes rapid repair (to prevent infection, fluid loss, and structural failure) so fibroblasts quickly proliferate and deposit dense disorganized collagen fibers to bridge the defect faster than functional tissue can proliferate… even tissues with high regeneration capacity (ex:epithelial tissue) cannot bridge massive gaps before collagenous connective tissue fills the space… since collagen connective tissue restores strength but lacks specialized functions, the replaces tissue becomes a permanent scar… scar tissue blocks contraction, nerve transmission, substance transport, and adhere to neighboring strucutres

Influences on tissue regenerative capacity… 5 answers

1.) extent of injury

2.) mitotic capactiy of cell population

3.) nutrition (ex: intake of protein, vitamin c, etc)

4.) blood supply (delivery of immune support and oxygen/nutrient supply to cells)

5.) age of the individual

Skin

Also referred to as cutaneous membrane… epithelial tissue + connective tissue… largest organ in the body

Epidermis

Keratinized stratified squamous epithelium… avascular (lacking blood cells or poor blood supply)… regenerates every 35-35 days

Cells that make up the epidermis

Keratinocytes (produce keratin (which provides skin with durability) and produce vitamin D precursor), melanocytes (produce melanin), Dendritic cells (immune protection), and tactile cells (sensory reception)

Keratinocytes

Cell of epidermis that produces keratin (which provides skin with durability) and produce vitamin D precursor

Melanocytes

Cell of epidermis that produces melanin