205 exam 1 (cells, tissue, bones)

Four key functions of the cell membrane are:

1. physical isolation

2. regulation of exchange in cell environment

3. communication between cell and environment

4. structural support

describe physical isolation

• integral proteins are the key

• channels

• proteins bind to change shape of channels

• keep ECF out and ICF in

describe regulation of exchange in the cell environment

• channels (ion channels, water channels)

describe communication between the cell and its environment

communication through integral proteins and immune system

alerts system about foreign cells and disease

describe structural support

shape is maintained by membrane, integral proteins, and internal & external fluctuations

What are the main structures of the cell membrane?

phospholipids, integral proteins, and cholesterol (lipid rafts)

what are phospholipids?

phosphate head and two lipid tails

PO4 likes water, hydrophilic

two lipid tails hate water, hydrophobic

the PO4 heads face the ECF and the tails are facing the ICF

what are integral proteins and how are they imbedded?

Imbedded three ways:

• transmembrane

• facing outside

• facing inside

They can move across the membrane when needed (moved by the cholesterol lipid raft)

they can be lipid-anchored

hat is cholesterol and why is it needed?

It is all within the ICF

Form lipid rafts to move integral proteins throughout the cell membrane tor

What is the fluid mosaic model?

phospholipids arranged w/ their polar (hydrophilic heads) face protein layer and non-polar (hydrophobic tails) face each other

what are modified proteins?

modifications can be made with molecules such as glycolipds

How do proteins interact

covalent bonds

Specific functions of phospholipids

structural stability, cell recognition, and barrier formation

specific functions of integral proteins

transport of substances across cell membrane

provision of binding site

formation of cell:cell junctions by contact adhesions

provision of enzymes

cell recognition

specific functions of cholesterol

barrier formation and lipid rafts

integral proteins: active vs passive transport

active: requires energy, uses ATP

passive: no energy spent, no ATP

integral proteins: passive transport (what does it transport and how? water channels vs ion channels vs glucose?)

diffusion: moves to lower concentration (down gradient)

osmosis

Transports nutrients, water, and ions

no net gain & no net loss (ie. 5 molecules go in, 5 must come out)

• 
  

Water channels:

• uses aquaporins

Ion channels:

• moves Na+, K+, or both (dual ion transport)

Glucose moved with facilitated transport (glucose transport receptor, GTR)

Integral proteins: provision of binding sites

Becomes a receptor (only a portion, not the entire protein, exclusive)

Ie. hormones binding to receptor

or dual ion channel that binds with ATP and turns it into ADP to change shape to bind to many things

Integral proteins: cell:cell junction

Two types: non-permissive and permissive

Non-permissive: integral proteins form a zipper-like binding of cells w/ strong covalent bonds

Permissive: integral proteins still join the cells, but there is a gap for hormones or ions to pass from one cell to the other

Integral proteins: provision of enzymes

portion of the integral protein is enzymatic

(*all enzymes are proteins, but not all proteins are enzymes!)

Integral proteins: immunosurvalence

tests for self vs non-self

• checks w/ short, weak covalent bonds

• then signals to terminate non-self

Diffusion (& describe simple vs facilitated)

Passive bc DOWN gradient (from high to low conc.)

distribution of a substance in a solvent such that it gets equally concentrated

Simple: DOWN conc. gradient (no help, ions, gas, & alcohol)

Facilitated: DOWN a conc. gradient but requires a CARRIER system (transmembrane protein) (help, ie. glucose transport receptor)

5 main points of osmosis

(integral proteins: transport)

• Passive transport

• water moves (substances are “stuck”)

• across the membrane

• via aquaporins

• from low to high solute/particles concentration (dilutes high conc.)

What is ATP?

Adenosine triphosphate

What is the normal concentration of NaCl (saline) in the body?

0.9%

Isotonic solution

iso means “same”

Equal conc. of solute in the ICF and ECF

water moves equally between the ECF and ICF so there is no net gain and no net loss

Hypotonic solution

Higher conc. of solute in ICF, so water from the ECF rushes in to make the conc. equal again

Cells will swell and can lyse

Hypertonic solution

Higher conc. of solute in the ECF than the ICF

Water rushes out of the cell into the ECF

cells with shrivel (crenation)

What tissues does active transport happen in?

excitable cells: muscle cells and neurons

3 types of stimuli for excitable cells

• chemical (ie. smell)

• physical (ie. touch)

• electrical (ie. changes)

When excited, channels open

At rest, channels closed

breakage of ATP term

hydrolysis

(becomes adenosine diphosphate, then monophosphate)

Describe & draw how the Na+, K+, and dual ion channels work in cell membranes (& polarizations, depolarization)

More Na+ on outside & more K+ on inside, + outside & - inside

1. Stimulus

2. Na+ travels through Na+ ion channel

3. Inside of membrane depolarizes (excited)

4. Na+ diffuses and K+ leaves through the K+ ion channel in response, repolarization occurs (relaxation)

These are all PASSIVE traspnsport, no ATP used bc the particle are going from high to low concentration

Then, Na+ & K+ can travel through the dual ion channel transmembrane integral protein pump

1. 3 Na+ ions bind in the native state

2. pump cleaves a PO4 from an ATP (phosphorylation) and changes shape to expel 3 Na+ ions into the ECF

3. Two K+ bind as PO4 is still attached

4. Dephosphorylation occurs and pump returns to native state & expels 2 K+ ions into the ICF

Repeat

Specifically describe the dual ion channel

Integral protein

Depolarization = ?

Depolarization excitation

Polarization = ?

Polarization = relaxation

Repolarization & RMP

The initial gain in Na+ in the ICF makes the RMP less negative, repolarization makes it negative again with a loss of K+

The K+ leaves in response to the Na+ arriving into the ICF

Na+-K+ ATPase Pump

Identify this cell:cell junction

Gap junctions (communicating junctions)

AKA cell adhesion molecules (CAMs)

Permissive

Direct cell:cell communication (ex: smooth & cardiac muscle)

Identify this cell:cell junction

Tight junctions (occluding junctions)(“buttons”)

Non-permissive

Blocks movement between cells (ie. Epithelial cells)

Identify this cell:cell junction

Desmosome (a cell:cell anchoring junction)

Holds cells together & to ECM

Non-permissive

(Ie. Skin cells) (ex: protein ares heat labile, so when friction melts proteins on the skin, fluid fills the space & forms a blister. The desmosomes are what dissolve when blisters are formed)

What is in the cytoplasm?

Cytosol (ICF) (liquid component)

Organelles

• mitochondria (powerhouse, ATP)(excitable cells hv a lot)

• endoplasmic reticulum (rough & smooth)

• ribosomes (site of protein synthesis)

• lysosomes (holds enzymes, acids, H2O, etc. & kills & breaks down, aggressive)

Cytoskeleton (filaments/microtubules)

Describe plasma & its role & ratio to cells

55% plasma & 45% cell

Forms bodily fluids

(ECF derived from plasma)

Mitochondria

Excitable cells hv the most (muscle & neurons)

Endoplasmic reticulum (specify rough vs smooth)

Rough: ribosomes on surface

• in immune cells (bc they make a lot of proteins)

Smooth: no ribosomes, site for lipid synthesis

• (ie. Steroidal glandular cells, muscle cells bc sarcoplasmic reticulum is the storehouse of Ca+ in muscles)

Lysosomes

Vesicles that contain powerful enzymes

Ie. White blood cell macrophage and osteoclasts

Four basic types of tissue

Epithelial (most abundant)

Connective

Muscle (excitable)

Nervous/neural (neurons excitable)

Epithelial classification by layers: simple

One layer

Epithelial classification by layers: stratified

Many layers

Epithelial classification by shape: squamous

Flat

Epithelial classification by shape: Cuboidal

Square

Epithelial classification by shape: columnar

Tall

Identify this tissue

Simple squamous epithelial (simplest)

Function: Allows passage of materials by diffusion where protection is not important, flat for gaseous exchange

Found in parts of kidney, alveolar cells (lung air sacs), lining of heart, blood vessels, and lymphatic vessels

What is the simple squamous cell in capillaries called?

Endothelial cell epithelial

Identify this tissue

Simple cuboidal epithelial

Function: secretion & absorption

Found in kidney tubules, ducts, & small glands

Identify this tissue

Simple columnar epithelial

Function: absorption; secretion of mucus, enzymes, etc

Non-ciliated: in digestive tract, gallbladder

Ciliated: bronchi, uterine tubes, and parts of uterus

Identify this tissue

Pseudostratified epithelial

“Falsely” stratified, single layer

Varied height in cells due to nucleus changing position is why it appears stratified

Functions: secretion of mucus, entraps pathogens before it enters the body

Found in sperm ducts and parts of trachea and upper respiratory tract

The goblet cells hv a lumen, provides thin layer of sticky mucous to trap foreign particles, then macrophages destroy them with lysosomes

Identify this tissue

Stratified squamous epithelial

Function: text underlying tissues in areas subjected to abrasions

Nonkeratinized type is found in moist linings of the esophagus mouth and vagina

Keratinized variety forms, the epidermidis of the skin, which is a dry membrane (impervious)

Identify this tissue

Stratified cuboidal epithelial

Function: protection

Found in large ducts of sweat, glands, mammary glands, and salivary glands

If they’re in a duct: it is the stratified cuboidal cells of the exocrine gland

If they are n a cluster (and directly putting their hormone into the blood supply): they are endocrine stratified cuboidal cells

Identify this tissue

Stratified columnar epithelial, RARE

Function: protection, secretion, conveys urine and semen

Found in male urethra

Variation in height is just due to the inner cells having less space to stretch out

identify this tissue

Transitional epithelial

Function: stretches and expels urine in the kidney pelvis (compresses when a lot of urine is present)

Found in the kidney, ureters, and part of urethra

Connective tissue (what does it do, what are the two categories, and what are the specific examples?)

Connects other tissues

Gives form and strength to organs

Two types: Loose and dense

• cartilage

• Bone

• Blood

Extracellular matrix (ECM)

Matrix is being produced by the cells, and it is gooey and proteinaceous

It then becomes the environment in which the cell lives, communicates, etc.

It plays a large role in the skeletal system

Determines what kind of cartilage it will be

Mesenchymal (stem) cells

Identify this tissue

Hyaline cartilage (connective)

Function: supports and reinforces, cushioning

Found in costal cartilage, nose, trachea, larynx, embryonic skeletons, ends of long bones (plays a role in long bone synthesis)

Identify this tissue

Fibrocartilage (connective)

Function: tensile strength that absorbs compressive shock

Found in intervertebral discs, pubic symphysis, discs of knee join

Identify this tissue

Elastic cartilage (connective)

Function: maintains the shape of a structure while allowing great flexibility

Found in the external ear (pinna)

Identify this tissue

Compact bone (connective)

Rigid outer layer of bone, has central blood vessel

Most mineralized and inorganic, 80% CaPO4

Function: supports and protects; provides levers for muscles to act on, stores calcium and other minerals, marrow in the bone is the site for blood/hematopoiesis

Identify this tissue

Blood (connective)

Function: transports respiratory gases, nutrients, water, and other substances

Found in blood vessels

mature RBC hv no nuclei, only immature ones do

Muscle tissue traits and types

Contractile

Excitable- they conduct signals

Actin and myosin

Types:

• Skeletal

• Cardiac

• Smooth

Identify this tissue

Skeletal muscle (connective)

Function: voluntary movement

Found in muscles attached to bones or skin

Identify this tissue

Cardiac muscle (connective)

Function: contracts to propel blood, involuntary

Found in the walls of heart

Identify this tissue

smooth muscle (connective)

Function: propels substances or objects along internal passageways; involuntary

Found in that walls of organs

Identify the tissue and cells

Neuron and glial cells (nervous tissue)

Neurons send signals

• excitable

• Electrical

• Chemical

Glial cells (aka neuroglia) support neurons (more abundant)

Function of skeletal system

What is compact bone

Hard layer covers most bones, forms shaft of long bones

What is cancellous bone

Spongy bone

Spicules arranged in a porous network, has small open spaces filled with marrow

What is medullary cavity

Space surrounded by cortex of a long bone filled with red or yellow marrow

What is the epiphysis

Ends of the bone

What is the diaphysis

Shaft of the bone which surrounds the medullary cavity

What is articulate cartilage

Hyaline, cartilage in joints (glassy and smooth for movement)

Cushions ends of bones and allows smooth movement

What is epiphyseal plate

Areas made of cartilage allowing for growth of the bone; lengthens

Chondroblasts live in here, lengthen bone

What is periosteum and endosteum

Fibrous membrane covering compact bone and cancellous bone/medullary

Peri: outside, lining the compact bone

Endo: inside, lining the cancellous bone

What does the periosteum contain?

Mesenchymal (stem) cells and osteoblasts (immature)

For repair, ie. broken bone

What are mesenchymal cells and what do they create?

Label this long bone

Label

Label (mainly osteon)

Long bones

Levers, aid in support, locomotion, pretension

Ie. femur

Short bones

Gliding/sliding movements, absorb shock

Ie. carpals

Flat bones

Protect vital organs

Ie. skull

Irregular bones

Protection, support, muscular attachment

Ie. Vertebrae

Sesamoid bones

Reduce friction, increase leverage, change direction of pull

Ie. patella & digital joints

Name the parts of the axial and appendicular skeleton

Axial:

• skull

• Vert. column

• Sternum

• Ribs

Appendicular:

• thoracic limb (forelimb)/pectoral

• Pelvic limbs (hind limb)

• Shoulder

• Pelvis

Anatomy label

What bone cell is this and what does it do?

Osteogenic cell (Mesenchymal cell aka bone stem cell)

produce osteoblasts

What bone cell is this and what does it do?

Osteoblast: immature bone cell that secretes the organic part of matrix (osteoid)

What is osteoid?

Bone matrix on which Ca++ is deposited on from the blood

(Blood to bone, bone to blood is Ca++ flow)

What bone cell is this and what does it do?

Osteocyte: mature bone cell that maintains the bone matrix

What bone cell is this and what does it do?

Osteoclast: multinucleate cell that secretes acids and enzymes to dissolve bone matrix

Has lysosomes that break down CaPO4 to make Ca++ available in the blood (shoots the lamellae in the compact bone with the lysosomes)(lamellae are the inorganic, CaPO4 containing part of the bone)

What is osteon?

Concentric circle, telescopic tube running the compact bone

and the atypical osteon running through the cancellous bone that does not hv a blood vessel running through it (blood supply on outside)