Anatomy 1 Exam 1

Anatomy

the various structures of the body, and their relationship to one another

Gross anatomy

Cut open and what you can see, structures visible to the naked eye

Microscopic anatomy

structures that are microscopic

cells

Physiology

• how these individual body parts function on a normal level

• What the body part does to keep us alive

• Functional

• Discussed at the cellular level

Principle of Complementarity of Structure and Function

• What a structure can do is dependent on its form

• Physiology depends on anatomy

Structural Organization of the Human Body

1. Chemical level

2. Cellular level

3. Tissue level

4. Organ level

5. Organ system

6. Organismal level

Chemical level

• Atoms combine to form molecules

• We are carbon-based lifeforms

• Vitamins and minerals

Cellular level

• The smallest unit of life

• One individual cell is capable of growing, reproducing and dividing (mitosis), metabolic processes (chemical reactions)

Tissue level

• Aggregations of living cells that carry out a similar function

• Combine into one tissue = more complex function

• Nervous system tissue, muscle, connective, epithelial

Organ level

• Two (or more) tissues operate together to perform a certain function

• Physiologically more complex than tissues

• Aren’t usually isolated, usually attached to other organs

Organ System

• Multiple organs work together to accomplish a purpose

• Digestive system 

• Not all organs in the system are identical in function, they contribute to the same thing

Organismal level

All organ systems working together to keep the organism alive

Necessary life functions

1. Maintaining boundaries

2. Movement

3. Responsiveness

4. Digestion

5. Metabolism

6. Excretion

7. Reproduction

8. Growth

Maintaining boundaries

• At the cellular level, and at the organismal level

• Plasma membrane forms the boundaries of the cell

  • It separates the intracellular fluid from the extracellular fluid 

  • By forming a boundary, it is holding the cell together and ensuring the organelles are staying in the cell

• Skin holds everything in place and prevents drying out 

  • Maintain body water

Movement

• Cooperation of skeletal and muscular systems to coordinate actions

• Responsible for muscle tissue 

• Mobility 

• Skeletal muscle tissue- uses the skeleton to generate movement 

  • Voluntary 

• Cardiac muscle tissue- found only in the heart

• Smooth muscle tissue- found in the walls of hollow organs

  • Digestive

  • Urinary

  • Reproductive

  • Blood vessels

Responsiveness

• Sensing environmental changes and responding to them

• Nervous system is primarily involved with excitability

• Allows you to perceive your external environment and respond to it

• Can be voluntary or involuntary

Digestion

Food is broken down to simple molecules to be absorbed to blood and
delivered to various tissues

Metabolism

• Catabolism, anabolism, and cellular respiration

• Sum of all of the chemical reactions in the body 

Catabolic

• taking large molecule and breaking down into smaller individual pieces

• Protein into amino acids

Anabolic

• taking smaller pieces and combining them to form larger complex molecule/structure

• amino acids into protein

Cellular respiration

ATP production (energy source)

Excretion

• Removal of waste produced during digestive and metabolic functions

• Urinary system

Reproduction

• Cellular level: cells must divide for organism to survive

• Organismal: production of offspring

• Kind of necessary depending on the type

Growth

• Increase in the number of body cells, or increase in size of individual cells themselves

• Building must occur faster than break down in body

• Anabolic reactions have to exceed catabolic reactions

Survival needs

1. Nutrients

2. Oxygen

3. Water

4. Endothermy

5. Atmospheric pressure

Homeostasis

• the maintenance of the internal condition of the body despite a constantly changing external environment

• This maintenance is not a static state

Control of homeostasis

• Mostly regulated by nervous system and endocrine system

• Variable: what organ or function is being controlled or regulated to maintain
  homeostasis

• 3 parts involved in regulation

  • Receptor

  • Control center

  • Effector

Negative feedback mechanisms

• regulatory mechanism that causes the variable to change in a direction that is opposite of the initial change

• Most hormones 

• Prevent huge changes in the variable

Positive feedback mechanism

• cause the original change of the variable to be enhanced

• Do not control events that require frequent, small adjustments

• Where you want to cause an extreme change 

• Enhancing the variable

• Blood clotting 

• Labor and delivery

  • Oxytocin keeps increasing

Imbalances in Homeostasis

• Aging leads to homeostatic imbalance

• Control systems become less efficient, making us more susceptible to disease

• Cascade of events caused by positive feedback mechanisms can overpower negative feedback mechanisms

• Leads to disease

Reference point

• Anatomical position

• Right vs left is always viewed in terms of the person being observed (your patient)

• Anatomical position- palms face forward

Directional terms

• helps us explain one body part in relation to the others

• Dorsal (posterior) vs ventral (anterior)

• Lateral vs medial

• Distal vs proximal

• Deep vs superficial

• Superior vs inferior

Sagittal

• Divides body into left and right

• Median/midsagittal plane divides the body exactly in half

Frontal

Divides body into anterior and posterior

Transverse

Divides body in superior and inferior parts

Body cavities

Most organs are found in one of the body cavities

Dorsal body cavity

• Protects organs of the central nervous system (CNS)

• Composed of the cranial cavity and spinal cavity

• Heavily protected by bone

Ventral body cavity

• houses visceral organs

• composed of thoracic cavity and abdominopelvic cavity

Thoracic cavity

Contains heart and lungs

Abdominopelvic cavity

Separated from thoracic cavity by diaphragm

Open cavity

Lead to outside of the body

Closed cavity

Hollow with no opening inside the body; organs

Dorsal

Serous membranes (serosa)

• Double layered membranes

• wrap around most of our internal organs

• Visceral and parietal

Visceral layer

• innermost layer covering the organ

• clings to the outside of the visceral organ

• like wrapping organ with cling wrap

Parietal layer

• outer layer lining the body wall of the cavity

• clings to the walls of the thoracic cavity

Serous fluid

very slippery texture, prevents organs from rubbing against each other, allows gliding

Pericardium

serous membranes surrounding the heart

Pleura

serous membranes surrounding the lungs

Peritoneum

serous membranes surrounding most organs of the abdominopelvic cavity

Mixtures

any substance containing two or more components physically intermixed

Solutions

homogenous mixtures that can exist as a solid, liquid, or gas composed of very small particles that do not settle out

Solvent

the dissolving medium

water is the body’s primary solvent

Solute

dissolved in solvent

percent solution

amount of solute dissolved is expressed as a percentage of the total solution volume

molarity

the number of moles of a substance per liter of solution

Colloids

heterogeneous mixtures composed of large solute particles that do not settle out

can undergo sol-gel transformation

sol-gel transformation

mixture can change from a fluid state to a more solid state, and back again

Suspensions

heterogeneous mixture composed of large solute particles that do settle out

solute particles are so large and heavy that they settle out

for example fluid portion is blood plasma and solute particles are the blood cells

Inorganic compounds

• Not carbon based molecules

• Water

• Salts

• Acids and bases

Water

• makes up most of the total body mass and most of the volume of individual cells

• important in homeostasis

• universal solvent

• high heat capacity

• forms a shield so molecules can move around more easily

• reactive

• protection

Universal solvent

• Transport—>water carries nutrients, respiratory gases, metabolic waste, etcs

• Water can surround some charged structures (ex: large proteins) to prevent
  interactions with other charged particles

High heat capacity

• Can absorb and release large amounts of heat with little change to its own temperature

• Allows body to not change temperature very easily

Protection

Water-based body fluids provide a “cushion” for internal organs

Heat of vaporization is high for water

• Large amount of heat must be absorbed to break bonds & cause evaporation

• Absorbing so much heat that the water evaporates 

• Sweating

Reactive

• water is used in several chemical reactions in the body

• hydrolysis vs dehydration synthesis

Hydrolysis reaction

• add water to a larger compound to break it down into smaller pieces 

  • AB + H2O → AH + BOH

Dehydration reaction

Remove water to form larger molecules

Salts

• dissociate in solution to form electrolytes

• sodium and potassium important for nervous system (produces nerve impulses), iron carries oxygen to red blood cells, calcium good for healthy bones and nerve impulse, zinc important for skin and hair

Acids & Base

• also form electrolytes

• charged particles

• influence pH

• Must maintain an optimal blood pH 

• If too high or too low, the chemical reactions slow down, speed up, or stop entirely, can cause severe disruptions in nervous system functionings (overstimulated or lethargic)

Organic compounds

• All organic molecules found in the body contain carbon

• Carbon is electroneutral- neither gains or loses electrons

• Can form molecules of various shapes (long chains, rings, etc.) that all have
  specific functions in the body

Macromolecules

proteins, triglycerides, carbohydrates

polymers that are made up of several smaller, identical subunits called monomers

Carbohydrates

• Sugars and starches

• Monomer: monosaccharide

• Galactose = milk products

• Fructose = fruits 

• Glucose* = ATP

Major function of carbohydrates

ATP production, breaks down glucose very quickly'

Cell-cell interactions, Can recognize if the cell belongs here or not, can tell how many cells are around them 

Lipids

Triglycerides, phospholipids, and steroids

Triglycerides

• Monomers: fatty acids and glycerol

Saturated triglycerides

Molecules packed closely together

solid in nature, meat, butter

Unsaturated triglycerides

• molecules more spread out

• longer bonds in between the bonds/monomers, more fluid and liquid in nature, more plant-based, olive and avocado oil, nut oil

Trans fats

• Oil fats

• More hydrogen added to the bonds

• The worst for health

Omega-3 fatty acids

• Oil fat found in cold-water fish

Lipids major functions

Protection, insulation, fast and easily accessible energy storage

Phospholipids

• Modified triglycerides with 2 fatty acid chains and a phosphate group

• Major functions: used to build cell membranes (phospholipid bilayer)

Steroids

• Most important steroid for life: cholesterol

• Major functions: structural component of cell membranes & is “base” used by body to form other steroid

Proteins

• Monomers: amino acids

• Structure determines function

•  Sequence is highly specific

Fibrous proteins

• Form long strands that can link together to form long, stable structures

• Function(s): provide mechanical support & tensile strength, some contractile ability

Globular proteins

• compact, spherical in shape

• chemically active

• functions: transport molecules, immune defenses, regulation of growth and development

Tensile strength

can pull on the body part due to collagen holding it together

Enzymes

• Biological catalysts

• Function: catalysts lower the activation energy of chemical reactions

• Varying degrees of specificity

• Importance: without, most reactions in the body would either not occur or would occur too slowly to sustain life

ATP

• the energy transferring molecule of any body cell

• Importance: without, many chemical reactions & cell transport stops, muscle tissue cannot contractdeath occurs

ATP has a triphosphate tail that has high bond energy

When a phosphate tail is transferred to another molecule, that molecule temporarily has more energy to do work

Words involved with cells

• Any word starting with prefix “cyto”

• Any word ending with suffix “-cyte”

Loss of cellular function is always going to lead to

some loss of homeostasis

Plasma membrane

outermost boundary, selectively permeable

Cytoplasm

intracellular fluid

Mostly water, but also contains salts and organic molecules

holds all the organelles and some proteins

Nucleus

controls cellular activities

contains the DNA, regulates cellular division, what proteins the cell produces, etc

cell types without a nucleus

red blood cells

Fluid Mosaic Model

• describes the general structure of the plasma membrane

• membranes consist of a phospholipid bilayer with proteins randomly dispersed in it

• bilayer is exceptionally thin (fluid)

• proteins (mosaic)

Importance of plasma membrane

• separates the intracellular fluid (ICF) from the extracellular fluid (ECF)

• Without the plasma membrane, the organelles will not be held together and a cell would completely lose its function

• Determines what goes in and out of cell

Phospholipids

• forms basic structure of membrane

Cholesterol

• provides structure to the membrane and causes membrane to lose fluidity to prevent membrane from becoming too flimsy

• Aren’t easily damaged

Proteins

Constitute most of the specialized membrane functions