LIFE 103 Unit 4
Circulation in simple organsims
Diffusion
Circulation in larger organism
More complex systems of folded tissue
Gastrovascular cavity
Digest and transport substances
Cnidaria GVC
2 cells enclose GVC
jellies= more complex GVC
flatworms GVC
large surface area to volume ratio
Components of circulatory system
Circulatory fluid: blood/ hemolymph
tube: vessels
muscular pump: heart
Open circulatory systems
Insects, arthropods, molluscs
blood bathes organs
blood and interstitial fluid mixed
Closed circulatory system
Blood confined in vessels and distinct from interstitial fluid
more efficient transport in large organisms
Blood plasma
92% water
nutrients
wastes
hormones
ions and trace minerals
proteins
Blood proteins
Albumin, a and b globulins, fibrinogen
Erythrocytes
red blood cells
mature cells no nuclei in mammals
Hematrocrit
Percentage of blood volume
occupied by red blood cells
Hemoglobin
Vertebrates
binds to O2 for transport
Hemoglobin structure
4 polypeptide chains (2 alpha, 2 beta)
1 heme+central atom for O2 bonding
Hemoglobin bonding to O2
Oxyhemoglobin
releases O2 as it passes through capillary
deoxyhemoglobin (retains some O2)
Factors effecting hemoglobin oxygen affinity
pH and temperature
drop in pH lowers the affinity of hemoglobin for O2
shifts dissociation
O2 unbinds
Leukocytes
white blood cells
1% of blood cells
big
nuecleated
can leave capillaries and into tissue
Granular leukocytes
Neutrophils, eosinophils, basophils
Agranular leukocytes
Lymphocytes and monocytes
blood cell development
from pluripotent stem cells in marrow
2 types: lymphoid and myeloid
Lymphoid
lyphocytes
myeloid
all other blood cells other than lymphocytes
Hematopoiesis
Blood cell formation
Erythropoiesis
Production of red blood cells stimulated by erythropoietin
Branches of arteries
Arterioles
Branches of viens
Venules
capillary/capillary beds
chemical exchange between blood and interstitial fluid
thin walls to slow the flow of absorption
endothelium for gas exchange
Single circulation
2 chambered heart
blood passes through 2 capillary beds before returning to heart bony and cartilaginous fish
Double circulation
Oxygenated and deoxygenated blood separate
amphibians, reptiles, and mammals
Artery and vein composition
Endothelium, smooth muscles, and connective tissue
Drives blood flow back to heart
Vein muscle action
Diastole
Low pressure
relaxation of hear
Systole
High pressure
contraction
Fick's law
Rate of diffusion increases when surface area and pressure difference increase
when distance decreases
Fick's equation variables
R= rate of diffusion
D= diffusion constant
A= area
(delta)p= pressure difference
d=distance of diffusion
Lamellae
thin membranous plates
project into water flow
water flows past lamellae in one direction only
countercurrent
blood flows opposite direction of water movement
maximize oxygenation of blood
increase (delta)p
gills
most efficient respiratory organ
amphibians respiration
cutaneous respiration
positive pressure
terrestrial arthropod respiration
Trachea and tracheoles
mammal respiration
negative pressure
birds
multiple air sacs improve efficiency
air moves in a single direction over lung surfaces
tracheoles
direct contact with cells
spiracles
opening in the exoskeleton
can be opened or closed by valves
positive pressure
air is forced into the lungs
exhalation is completed by elastic response of lungs
negative pressure
diaphragm contracts and intercostal muscles expand chest
mammal lungs
alveoli and surrounding capillaries
larynx>epiglottis>trachea>bronchi>bronchioles
partial pressure
% of gas in dry air at sea level
gas exchange driven by difference in partial pressure
Deoxygenated blood partial pressure
40 mm Hg
Oxygenated blood partial pressure
100 mm Hg
alveoli partial pressure
105 mm Hg
Visceral plueural membrane
Covers lungs
Parietal plueral membrane
Line thoracic cavity
Pleural cavity
Between parietal and visceral pleural
fluid filled
Respiratory pigments
Proteins that transport oxygen
increase amount of oxygen that blood can carry
Hemocyanin
Respiratory pigment that uses copper as its oxygen-binding component
hemolymph of arthropods and many molluscs
blueish
CO2 movement
via plasma, hemoglobin, or bicarbonate
20% moved by hemoglobin
diffuse into blood
Sensory receptors
Detect stimuli
Motor effectors
Respond to stimuli
Nervous system links
Motor and sensory via neurons and support cells
CNS
brain and spinal process information
PNS
all tissue outside CNW
sensory and motor neurons
relays information to body
somatic and autonomic
Somatic
voluntary
skeletal muscles
Autonomic
Involuntary
smooth, cardiac, and glands
sympathetic and parasympathetic
Vertebrate neuron types
sensory
motor
interneurons
Sensory neuron
afferent neurons carry impulses to CNS
Motor neurons
efferent neurons carry impulses from CNS to effectors (muscles and glands)
Interneurons
Association neurons provide more complex reflexes and learning/memory
Neuroglia
Cells that support and protect neurons
White matter
Myelinated axons
Grey matter
Dendrites and cell body
Negative pole
Cytoplasmic side (inside cell)
Positive Pole
Extracellular side (outside)
Resting cell potential
-70mV
(-40--90)
Sodium Potassium Pump
2 K+ in for every 3 Na+ out
Ion leakage channel
Allow more K+ to diffuse out than Na+ to diffuse in
Equilibrium potential
Balance between diffusional force and electrical force
Action potential
depolarization reaches the threshold potential (-55 mV)
Depolarization
bring a neuron closer to the threshold
activation
makes inside of cell more positive
Hyperpolarization
Move the neuron further from the threshold
inactivation
makes inside more negative
Cause of polarization (de and hypre)
caused by voltage-gated K+ and Na+ channels
Phases of action potential
rising, falling, and undershoot
Action potential interaction
separate
non-additive
do not interfere with each other
intensity determined by frequency, not amplitude
Producing agent potential
reverses voltage (depolarization)
Depolarization steps
Na+ flows in making inside more positive
next region depolarizes while previous region hyper polarizes snd returns to threshold membrane potential
Signal direction
away from cell body
Increasing speed of signal
Larger axon
more myelin
Larger axon diameter
Less resistance to current
found primarily in invertebrates
More Myelin
acti`on potential is only produced at the nodes of Ranvier
Impulse jumps from node to node
saltatory conduction
Salltatory conduction
The jumping of action potentials from node to node of myelinated axons
faster
Synapse
intercellular junctions with the other neurons, with muscle cells, or with endocrine or exocrine cells
Presynaptic cells
Sends signal
Post synaptic cell
cell receiving the signal
electrical synapse
Electrical current flows directly from one cell to another via a gap junction
rare in vertebrates
chemical synapse cell structure
synaptic cleft between the two cells end of presynaptic cell contains synaptic vesicles packed with neurotransmitters
Synaptic cleft
Gap between presynaptic and post synaptic cells
Chemical synapse steps
Action potentional triggers influx of Ca2+
synaptic vesicles fuse with cell membrane
Neurotransmitter is released by exocytosis and diffuse to other side of cleft to fuse to gated receptor protein
produce graded potential in postsynaptic cell membrane
neurotransmitters stopped when cell uses up enzymes
Acetylcholine
Connects neuron to muscle fiber
binds to receptors in post synaptic membrane
opens gated channels
produces excitatory postsynaptic potential
stimulates muscle contraction
Achetylocholinestrerase
Enzyme that inactivates acetylcholine at synapse
relaxes muscle
Glutamate
Excitatory neutransmitter in vertebrate CNS
amino acid
Glycine and GABA
Inhibitory postsynaptic potential (IPSP)
produces hyper-polarization back to threshold
opens ligand channels for Cl-
main acid
Epinephrine/noepinephrine
(bigoenic amine)
fight or flight response
adrenaline
Dopamine
(biogenic amine)
Control movement in nervous system
paracrine messengar
vasodilator
Serotonin
(biogenic amine)
sleep
Substance p
(neuropeptides)
released by sensory neurons from painful stimuli
Pain intensity
depends on enkephalins and endorphines
nitric oxide
(neuropeptides)
Arginine gas
smooth muscle relaxant
2 ways to reach thershold voltage
spatial summation
temporal summation
Spatial summation
Many different dendrites produce ESPSs
Temporal summation
Single dendrite produces ESPSs
Excitatory postsynaptic potential (ESPS)
When sodium channels open in response to stimulus
Hormones
Chem signals
slow long response
regulatory
Exagenous chemicals
endocrine disruptors
Hormone path
Chemical binds to receptor protein in or on cell
local regulator
effect close cells via diffusion
blood pressure, nervous function, reproduction
paracrine and autocrine
Paracrine
Act on close cells
Autocrine
Act upon itself
Synaptic communication
cell to cell
Neuroendocrine
Neurotransmitters act as hormone in blood
Pheromones
Chemical signals that communication information to other organisms
Hormone classes
Polypeptides
amines
steroids
polypeptides
Proteins
peptides
Amines
Animo acid derivatives
steroids
lipids
Lipophilic hormones
Move through cell membrane
love lipid tails
Hydrophilic hormones
Can't pass through membrane
Solubility of hormones determines
if the receptor is on the inside or outside of membrane
Lipihilic travel
Diffuse through membranes must bind to transport proteins to move through blood
Hydrophilic travel
receptors on outside of target cell or use transport protein to pass through membrane
secreted by exocytosis
transported in blood
Water soluble path
hormone bind to receptor
triggers signal transduction path
cytoplasm responds
enzyme activates/gene changes
lipid path
Changes gene expression
enter targe cells and bind to protein receptors in cytoplasm/nucleus
Vitamin D
formed in skin
moved to liver
converted to physiological active form
Vitamin D function
Calcium and phosphate in the blood
Cell proliferation and apoptosis
Neuromuscular function
Adrenal medulla
Epinephrine and noepinephrine
Adrenal cortex
secretes glucocorticoids and aldosterone
Hormone regulated by _____ feedback
negative
Pancreas
clusters of endocrine
cells: pancreatic islets
glucagon and insulin (antagonistic)
Alpha cells in pancreas
Produce glucagon
Beta cells in pancreas
Produce insulin
Insulin
Reduce glucose by
produce uptake of glucose
slow breakdown of glycogen
promote fat storage
Type 1 diabetes
Autoimmune-damage to beta cells
insulin dependent
Type 2 diabetes
Non-insulin dependent
insulin deficiency/reduced response of target cells due to change in insulin receptors
Antidiuretic hormone (ADH)
reabsorption of water by kidneys
Insect hormones
Influence molting and metamorphosis
Brain hormone
Spurs production of ecdysone to shed
Corpora allata
Produces juvenile hormone
low levels spur metamorphosis
Renal medulla
epinephrine
Renal cortex
Norepinephrine
Mediation of fight or flight
Triggers the release of glucose and fatty acids into the blood
increase oxygen deliver to body cells
direct blood toward heart, brain, and skeletal muscles, and way from skin, digestive system, and kindeys
triggered by hypothalamus
Extracellular digestion
Digestion that takes place outside the cell
all eumetoazoa
Intracellular digestion
Digest in vacuoles
endocytosis: cells engulf food
non eumetazoa
4 classes of nutrients
essential amino acid
essential fatty acid
vitamins
minerals
amino acid
20 in humans
1/2 synthesizable
fatty acids
mostly synthesizable
only unsaturated fatty acids are essential
rare deficiencies
Vitamins
organic
trace amounts needed
13 essentials
fatty vs water soluble
toxicity of water soluble vitamins
peed out
toxicity of fat soluble vitamins
stored in fat and liver
toxic effects
minerals
inorganic
needed in small amounts
Digestion
breaking down food into absorpable molecules
chemical digestion
enzymatic hydrolysis/spitting of molecules with water
absorption
uptake of nutrients by body cells small intestine
Elimination
passage of undigested material out of the digestive system
rectum/anus
oral path
mechanical processing
salivary glands lubricate and expose to amylase to breakdown glucose
tongue shapes bolus
throat/pharynx join esophagus and trachea
peristalsis
muscle contraction that keep food moving along
sphincters
valves that regulate movement of material between compartments
stomach
gastric juice converts food into acid chyme
stores food
gastric juice
hydrochloric acid and pepsin
digest protein
mucus protect stomach lining
parietal cell
secretes hydrochloric acid and chloride
chief cells
secrete inactive pepsinogen
combines with HCl in stomach to activate into pepsin
pancreas (GI)
produces proteases trypsin and chymotrypsin
Trupsin and chymotrypsin
protein-digesting enzymes that are activated after entering the duodenum
bile
made in the liver
stored in gall bladder
aids in digestion/absorption of fats in stomach
small intestine
longest section of alimentary canal
digestion and absorption
longer in herbivores
epithelium, smooth, and connective tissues
Cecum
fermentation of plant material
appendix
Carbs digestied in
oral cavity and lumen/ epithelium of small intestine
proteins digested in
stomach and lumen/epithelium of small intestine
fat digested in
lumen of small intestine
Innate immunity
all animals
no previous exposure: born with it
few receptors detect many microbes
Adaptive/Acquired immunity
Only vertebrates
many receptors for specific pathogen
Innate immunity INvertebrates
exoskeleton
hemocytes
antimicrobrial peptides
Hemocytes
produce antimicrobial peptide
production that break down membranes
Antimicrobial peptides
Recognition proteins bind to molecules on cell walls of fungi/bacteria
activates the toll protein on immune response cells
signal transduction causes the synthesis of antimicrobial proteins
Vertebrates innate immunity
Barrier defenses
phagocytosis
antimicrobial peptides
inflammatory response and natural killer cells
barrier defense in vertebrates
skin: blocks many pathogens
mucus: traps pathogens
saliva/tears: lysozome