structure and function test 1

structure determines

function

level 1 of human body organization

chemical level

• (phospholipid molecule, atoms)

level 2 of human body organization

cell membrane

• (squamous epithelial cell)

level 3 of human body organization

tissue level

• (stratified squamous epithelium)

level 4 of human body organization

organ level

• (ex. esophagus, more than 1 tissue)

level 5 of human body organization

organ system level

• 11 systems

• ex. digestive system

group of organs that work together to form a function

organism level

the human body as a whole

tissue

group of similar cells working together for specific function/purpose

tissues are made of

cells

organs are made of different

tissues

how many organ systems are there

11

11 organ systems

circulatory, digestive, reproductive, respiratory, nervous, urinary, lymphatic, muscular, skeletal, integumentary, endocrine

homeostasis

maintenence of a relatively stable internal environment (maintaining baseline)

who coined the term “homeostasis”

walter cannon

variables

things that can change

• ex. blood sugar, blood ph

set-point

ideal target value or reference point that a physiological system aims to maintain to keep the body in stable equilibrium

normal or optimal value for a variable

has a range

sensors

our body has these to alert it when something needs to be regulated

homeostasis is maintained by communication through __ feedback pathways

negative

why does negative feedback return a variable toward set point

its final output directly opposes and reverses the original change

meaning the system counteracts whatever stimulus pushed the variable out of bounds

stimulants

causes a change in variable

receptor

sensors that detect the change in variable

control center

determines the response to the change in the variable. Sends response to the effectors

effectors

target tissue

the tissues/organs that carry out the plan that the control center made to start a physiological response

physiological response

negative or positive feedback

negative feedback

the response acts to negate the change in the variable

tries to get back to set-point

used to maintain homeostasis

positive feedback

makes the change in the variable bigger, and bigger, and bigger

AWAY FROM SETPOINT (not homeostasis)

limited operation in humans

must be self-limiting

examples of negative feedback

sweating to reduce body heat

increasing heart rate and blood pressure to make the oxygen supply=the oxygen demand

positive feedback examples

blood clotting

tumors spreading

childbirth

bacterial infection

running a fever

cell diversity

250 types of cells/human

epithelial cells, fibroblasts, erythrocytes

cells that connect body parts, form linings, or transport gases

skeletal and smooth muscle cells

cells that move organs and body parts

fat cell

cells that store nutrients (lipid)

macrophage

cell that fights disease

sperm

cell of reproduction

nerve cell

cell that gathers info and controls body functions

what determines the function of the cell

the structure/shape

what is the primary component of every membrane

phospholipids

carbohydrates in the cell membrane

glycocalyx (sugar coating on cells) = markers that mark the cell based on what they are aka identifiers

proteins in the cell membrane

help facilitate diffusion of hydrophilic molecules or active transports

hydrophilic

h2o loving

can dissolve in water

will bounce of cell membrane without help

hydrophobic

h2o fearing

loves lipids - lipophilic

can go through membrane

componenets of the cell membrane

phospholipids

carbohydrates (sugars)

proteins

receptor membrane proteins

a receptor that binds to chemical messengers such as hormones sent by other cells

aka receive signaling molecules to help maintain homeostasis

enzyme (membrane protein)

breaks down a chemical messenger and terminates its effect

channel membrane proteins

constantly open and allows solute to pass into and out of the cell

(selective of what they let through)

gated channel membrane protein

a gate that opens and closes to allow solutes through only at certain times

selective of what goes through it

ion channels

channel membrane protein and gated channel protein

transport of hydrophilic substances

transport protein in membrane

allows hydrophilic non ions to pass through the membrane

membrane functions

physical boundary

communication between body organ systems

controls the passive of materials into/out of the cell (is semipermeable)

maintains gradient

physical boundary

between a cell and its neighbors, other structure

cells are separated by cell membrane

communication between body organ systems

actually occurs at the cellular level

requires signaling molecules/stimuli, acting on receptors in cell membranes

homeostasis at the cellular level (different signal by different molecules

controls passage of materials into/out of the cell

hydrophobic substance cross membranes freely with no help

hydrophilic substances; need help (ion channels or transport proteins) to cross through the lipid bilayer

endocrine signaling

hormone leaves cell into the bloodstream (circulatory system) and then a receptor from a bone cell receives the signal to cause a physiological response

paracrine signaling = neighbors

neighboring cells

one releases a signal than the other cell has a receptor that receives the signal to cause a physiological response

cell to cell communication requires

a membrane

gradient

a difference between side A of the membrane and Side b

or difference outside and inside of cell

high to low (in membrane transport)

down/with gradient

low to high (in membrane transport)

against gradient

passive transport

does not require ATP

moves down gradient

high concentration to low concentration

active transport

requires atp

transport against gradient

low concentration to high concentration

types of passive transport

simple diffusion

facilitated diffusion

osmosis

simple diffusion

hydrophobic molecules

rate dependent on

• Concentration Gradient: A larger difference in concentration across the membrane results in a faster rate of diffusion.

• Temperature: Higher temperatures increase molecular motion, which speeds up diffusion.

• Membrane Thickness: Thinner membranes allow substances to cross more quickly

down gradient

an increase in surface area

speeds up rate of diffusion

facilitated diffusion

hydrophilic molecules

• carrier mediated

• through ion channels

• transport proteins

no atp but requires help

down gradient

osmosis

the diffusion of water based on solute gradient (think water follows salt)

active transport types

(hydrophilic molecules)

• exocytosis/endocytosis

• Na+/K+ pump

smaller molecules diffuse

faster

bigger gradient = _ diffusion

faster/quicker

thicker membrane, diffusion

decreases

ICF contains what amount of TBW

2/3 TBW

cells 25 L

ECF contains how much of TBW

1/3

80% in ECF in interstitial (tissue) fluid: 12 L

20% in ECF in plasma: 3 L

osmolarity

the ratio between solute and water

if the concentration gradient is equal on both sides

no net movement of water

where water is housed

compartments

plasma osmolarity

285-295 mOsm/L

isotonic

when osmolarity is equal and there is no net movement

hypertonic

when there is a higher concentration of solute, and a higher osmolarity than water

water moves into this type of solution

bigger number of osmolarity =

more concentrated/solute

hypotonic solutions

have more water compared to solute

less concentrated/more dilute

lower osmolarity

water moves OUT of this type of solution

what is the most abundant ion in ECF

Na+

most abundant ion in ICF

K+

Na+/k+ pump

uses 1 atp each

For every single molecule of ATP used, the pump moves three sodium ions (Na⁺) out of the cell and two potassium ions (K⁺) into the cell

ECF Na+ concentration

145

ICF na+ concentration

12

ECF k+ concentration

4

ICF K+ concentration

150

na+ moves _ the cell

into the cell into the ICF

K+ moves _ the cell

out of the cell into the ECF

what is the largest organ in your body

skin

skin is what percent of body weight

16%

the average adult has nearly how many square feet of skin that contains over how many miles of blood vessels

21 square feet

11 miles

a single square inch of skin has about how many sweat glands

300

the thickest and thinnest skin is found where

thickest = bottom of feet

thinnest = eyelids

functions of the skin

thermoregulation (sweat/blood vessels)

melanin production

barrier to water

barrier to infection ( keratin, acid mantle, defensins, dendritic cells)

synthesis of vitamin D3

general senses ( touch, pressure, pain, temp)

blood vessels when hot and when cold

dilate when hot

close when cold

what type of tissue is epidermis

epithelial tissue

what type of tissue is the dermis

connective tissue

epidermis

no blood vessels

contains nerves

the majority of cells in the epidermis are special epithelial cells called

keratinocytes

most superficial layer of epidermis

stratum corneum

dead keratin layer