Anatomy and Physiology - Exam 1

Homeostasis

keeping balance maintaining relative stable internal environment despite changing external enviornment

Negative feedback

Homeostatic

-response counteracts the stimulus shutting off the response loop

Positive feedback

Anti-homeostatic (protective)

-the response reinforces the stimulus sending the parameter farther from the setpoint

Homeostasis failing

-pathologies arise

-mechanisms that return body to homeostasis fail

Biomolecules

-4 classes

-always organic

-synthesized by living organisms

-”currency” of energy and growth

Carbohydrates

C,H, O always 1:2:1

-most abundant biomolecule

Monosaccharide

Basic “building block” unit

ex.) glucose

Disaccharide

2 monosaccharides

ex.) sucrose (table sugar)

Polysaccharide

3 or more monosaccharides

• sugars can serve as cell-surface signaling molecules

ex.) starch, cellulose, glycogen

Glycogen

Primary short term energy storage for cells

-most important energy source

Lipids

Mostly C and H, and some O, N, P

• usually nonpolar (doesn’t dissolve in water)

• triglycerides, phospholipids, eicosanoids, steroids

Triglycerides

-3 fatty acid chain

-1 Glycerol

Long term storage of energy

can be free floating

Saturated “hydrogenated” Triglyceride

animal fats, thicker

no CH=CH double bond

Mono/Poly Unsaturated - Triglycerides

Vegetable fats (oils)

• lower melting points

Trans-fat - Triglycerides

“partially hydrogenated”

• artificially produced

• lower melting point

Phospholipids

Diglyceride + phosphate group (PO4)

Amphipathic

• important for cell membranes

Amphipathic

both hydrophobic and hydrophilic ends

Eicosanoids

modified fatty acids for intercellular communication

• found in cells throughout body; diverse functions; very complex

• can be removed from cell membrane and transfered

• control diveristy of function

ex.) prostaglandins

Steroids

Important in cell membrane and Vitamin D formation

• cholesterol

• Important hormones (testosterone, estrogen)

require carriers in bloodstream (lipoproteins) bc nonpolar

3 6-C rings + 1 5-C ring

Proteins

made of C,H,O, N in amino acids

• diverse cell functions related to structure and shape

• amine + carboxyl groups

• largest chain (100+ AAs)

Oligopeptides

short amino acid chain (<10 AAs)

• smallest

Polypeptides

longer amino acid chain (10-100 AAs)

• medium

Fibrous proteins

structural role

ex.) collagen, acton

Globular proteins

enzyme role

Nucleotides

store and release energy (ADP-ATO)

-important for intracellular communication (cyclic AMP)

Nucleic Acids (nucleotide polymer)

contains genetic code

Nucleotide structure

Base + Sugar + Phosphate

Cell

-multicellularity leads to specialization

-diffusion is limitation

Main Tissue types

-Epithelial

-Nervous

-Muscular

-Connective

Epithelial Tissue

-Apical surface

-attached by basement membrane (basal lamina)

-commonly have microvilli or cilia

-regenerative

Epithelial Cell Shape

Squamous, cuboidal, columnar

Simple Squamous

Exchange Epithelium

-allow movement between cells (weak barriers)

-blood vessels

-alveoli

Simple Cuboidal

-kidneys

-exocrine (glands/ducts)

Simple columnar

Digestive system

oviducts

• transport exchange and secretion

Stratified squamous

Keratonized - skin

Non-keratinized - insides mouth, vagina, vocal chords

Stratified cuboidal

ceratin ducts

Pseudostratified

All cells touching base membrane

-trachea and mucus

Transitional Epithelial

stratified cuboidal - stretchability

-urinary bladder

-umbrella like

Epithelioid Tissue

Lacks a free surface

-associated w endocrine function

Skeletal muscle

long cells - longest in leg

-striated

-multinucleate

-voluntary control (breathing)

Cardiac muscle

uninucleated

-branching

-involuntary control

-gap junctions

Gap junction

pore between cells that allow small substances to pass through freely

• Ca²+ intracellular signaling molecule

Tight junction

restrict paracellular transport but doesn’t impact transcellular

Smooth muscle

uninucleate

• capable of regeneration

• gap junctions

• involuntary control

Where smooth muscle is found

-digestive tract

-urinary tract

-uterus

-blood vessels

Cells (-blast)

creates tissue

Connective tissue funtion

support, anchor, link, other structures together

Cells (-clast)

Destroys tissue

Cells (-cyte)

Mature cells

Dense Regular Connective Tissue

tightly bound

-protein packing

-allow movement of white blood cells

Dense Irregular Connective Tissue

Collagen fibers

-created by fibroblasts

-found in tendons

Loose areolar connective tissue

Spacious

• upper dermis

• allows for diffusion/movement

Avascular

reliant on diffusion; low capacity for repair

Cartilage Characteristics

Avascular

calcification

Reliant on diffusion

Cartilage Composition

Cells: Chondrocytes, Chondroblasts, Fibroblasts

ECM:

1.) Fibers: Collagen

2.) Ground substance: GAGs, Proteoglycans, Glycoproteins

Perichondrium

Growing layer of cartilage

Hyaline Cartilage

growth plates, tracheal rings, surface of joints

• most rigid

Elastic Cartilage

pinna of external ear, larynx

• high amount of elastic fibers

Fibrocartilage

intervertebral disc, pubic symphysis

Adipose Tissue (fat)

Provides protection

Long term energy storage

Hormone production leptin

Chemical work

building molecules

ex.) joining amino acids

Transport work

exchanging ions, molecules across membranes

ex.) electron transport chain

Mechanical work

movement (cilia, flagella, muscle)

Exergonic reactions

release energy - products have less energy than the reactant

• Glycogen → glucose

• ATP →ADP+PO4

Endergonic reactions

Some activation energy in products that have more free energy

• ADP+PO4 →ATP

• Glucose → glycogen

• 
  

Chemical Reaction Rate

Speed with which a reaction occurs; reactants
consumed and products generated

-makes large phisiological difference

Enzymes

metabolic catalysts that increase reaction rate without being
changed themselves

Factors that effect Enzyme activity

-Affinity - enzyme isolation

-Enzyme concentration

-Substrate concentration

-physical conditions

Enzyme concentration

Metabolism

all chemical reactions that occur within an organism

Modulators

factors that affect enzyme activity

• physical - pH, temperature (effect shape)

• chemical - compete with substrate for binding site (eg. penecillin)

Allosteric inhibition

non active site inhibition

Cell membrane structure

Lipids, proteins, and carbohydrates

Cell transporters

Open channels (aquaporin) and Carriers (SGLT)

Cell communication

Receptor (insulin)

Structure of Cell Membrane

Membrane-spanning protein, cytoskeleton, peripheral protein

Muscular Dystropy

How muscle links to the cell membrane

-makes muscle contraction difficult

Simple diffusion

Passive - no energy

movement from high concentration to low concentration

Rules of Diffusion

• related to temperature

• through cell membrane depends on ability to dissolve lipids

• rate across membrane proportional to surface area

Facilitated Diffusion

passive - no energy required

movement from high conc to low conc with help of integral proteins

Active Transport

Requires energy and carrier proteins

movement from ow conc to high conc

Primary Active Transport

ATP directly involved by carrier protein

Secondary Active Transport

ATP not used by carrier protein

Na-K-ATPase

Primary active transporter

pushing sodium OUT

pushing potassium IN

Na-Glucose Transporter

Secondary active transporter

energy of sodium moving in forces glucose to move against gradient