Integrated Organ Physiology Exam 1

integumentary system

barrier, rentention, excretion, temperature regulation

nervous system

receive input, process, drive output, internal/external, autonomic (sympathetic/parasympathetic), somatic

musculoskeletal system

structure, movement, protection, hematopoiesis, storage

circulatory system

transport, exchange, delivery/removal, temperature, solute balance

respiratory system

breathing, gas exchange, vocalization, chemical sensation, temperature

urinary system

filtration, excretion, storage, solute levels, volume controls

digestive system

ingestion, motility, digestion, absorption, defecation

immune system

protection (bacteria, viruses, parasites, xenobiotics)

endocrine system

regulation, metabolism, growth/development, tissue function

reproductive system

production, maintenance, delivery, development

law of mass balance

what goes in must equal what comes out

control systems chain

input signal -> integrating center -> output signal -> response

reflex control (long distance or short distance)

long distance pathway

Response loop

stimulus → sensor → input signal → integrating center →output → signal → target → response

what does feedforward control do?

anticipates change

hydrostatic pressure

pressure that is exerted by a fluid at a given equilibrium at a given point within the fluid, due to force of gravity, → heart must pump blood up against fluid in the upper body

arterial baroreceptor reflex

arterial pressure increases

baroreceptor firing rate increases

vasoconstrictor region decreases

vessel diameter increases

resistance decreases

positive feedback loop (top gun example)

reduced cerebral blood flow

increased vagal tone

vasodilation (vagus nerve slows the heart rate adn widens blood vessels)

worsened hypoxia

unconsciousness

hypothalamus contains 2 control centers

feeding center, satiety center

glucostatic theory

glucose uptake causes the satiety center to send inhibitory signals to the hunger center and this suppresses the appetite

lipostatic theory

body fat content is maintained

when energy balance is positive, fat increases

leptin release

leptin feeds back to brain to decrease energy storage

what has more calories per gram? (fat/protein/CHO)

fat

factors that effect basal metabolic rate

age, sex, lean body mass, hormones, genetics, activity level, thermic effect of eating

fasted state

energy used, catabolism

fed state (absorptive)

energy absorbed and stored, ingested molecules (used in energy, used in synthesis, stored), anabolism

3 things that ingested biomolecules can do

energy to do mechanical work

synthesis for growth an maintenance

storage as glycogen or fat

alpha cells (pancreas)

glucagon

beta cells (pancreas)

insulin

d cells (pancreas, GI tract, hypothalamus)

somatostatin

adrenal medulla

epinephrine

adrenal cortex

cortisol

ileum

GLP-1

adipocytes

leptin

glycogenesis

process of synthesizing glycogen

glycogenolysis

process of breaking down glycogen to release glucose

gluconeogenesis

process of synthesizing glucose

glycolysis

process of utilizing glucose metabolically

fed state

insulin dominates (glucose oxidation, glycogen synthesis, fat synthesis, fat synthesis, protein synthesis)

fasted state

glucagon dominates (glycogenolysis, gluconeogenesis, ketogenesis)

pharmacologic properties of insulin

protein metabolism (transport amino acids into cells, protein synthesis, and positive nitrogen balance)

isoenzymes

catalyze same reaction, but under different conditions, diagnostic enzymes

enzymes (function)

lower the activation energy of reactions, speed up the rate of chemical reactions (catalysts, reactants are called substrates)

aquaporins

special protein channels in cellular membrane that facilitate water movement across membrane in response to a solute concentration gradient

osmolarity

expresses number of particles (osmol/L) (more important in physiology bc it will take into account dissociation of the molecules in a solution)

tonicity

takes into account both relative solute concentrations and the cell membrane’s permeability to those solutes

isotonic

equal, no change

hypertonic

higher osmolarity (more particles)

hypotonic

lower osmolarity (fewer particles)

types of gated ion channels

mechanical, chemical, voltage-gated, ligand-gated

facilitated diffusion

uses carrier proteins, no energy input, down concentration gradient, conformational change

active transport

uses carrier proteins, energy input, against concentration gradient, competition and saturation

maltose

competitive inhibitor that binds to the GLUT transporter but is not itself carried across the membrane

charge of ICF vs ECF

ICF has net negative charge, ECF has a net positive charge

GPCR

large membrane-spanning proteins, cytoplasmic tail linked to G protein — 3-part transducer molecule, when activated, they open ion channels in the membrane and alter enzyme activity on the cytoplasmic side of the membrane

adenylyl cyclase-cAMP

second messenger for many protein hormones

GPCR-Adenylyl cyclase signal transduction and amplification

signal molecule binds to GPCR, which activates the G protein, G protein turns on adenylyl cyclase, an amplifier enzyme, adenylyl cyclase converts ATP into cyclic AMP, cAMP activates protein kinase A, protein kinase A phosphorylates other proteins, leading ultimately to a cellular response

most rapid signal pathways change ion flow through channels

found mostly in nerve and muscle, ligand binding to a receptor-channel protein changes permeability to an ion, rapid flow of an ion in or out of the cell brings about a rapid response from the cell

phagocytosis

vesicles created by the cytoskeleton and engulfs particle

endocytosis

membrane surface indents and forms vesicles, active process that can be nonselective (pinocytosis) or highly selective, receptor-mediated endocytosis uses coated pits, membrane recycling

exocytosis

cellular secretion

central nervous system (organization)

brain and spinal cord

peripheral nervous system (organization)

sensory (afferent), efferent neurons

efferent neurons

somatic motor neurons, autonomic nervous systems (sympathetic + parasymptathetic)

types of functional neurons

sensory, efferent, interneurons

types of structural neurons

multipolar, bipolar, pseudounipolar, and anaxonic

pseudounipolar neuron

have a single process called axon, during development, the dentrite fused with the anxon, sensory neuron

bipolar neuron

have 2 relatively equal fibers extending off the central cell body, sensory neuron

anaxonic neuron

CNS neuron, have no apparent axon, interneuron

multipolar neuron

CNS interneuron, highly branched but lack long extensions

efferent neuron

typical mulitpolar efferent euson has 5-7 dendrites, each branching 4-6 times, single long axon may branch several tiimes and end at enlarged axon terminals

slow axonal transport

moves soluble material by axoplasmic (cytoplasmic) flow at 0.2-2.5 mm/day

fast axonal transport

moves organelles at rates of up to 400mm/day

forward/anterograde transport

from cell body to axon terminal

backward/retrograde transport

from axon terminal to cell body

ganglia

collections of neuronal cell bodies in the PNS

nuclei

collections of neuronal cell bodies in CNS

PNS glial cells

schwann cells, satellite cells

CNS glial cells

oligodendrocytes, astrocytes, microglia, ependymal cells

schwann cells

form myelin sheaths

satellite cells

form supportive capsules around a ganglion

oligodendrocytes

form myelin sheath

astrocytes

take up and release chemicals, feed neurons, water K+ balance, and part of blood-brain barrier

microglia

provide immune defense

ependymal cells

form the lining of ventricles and are a source of stem cells

demyelinating diseases

multiple sclerosis, guillain-barre syndrome

chemical synapses

use chemical signals that cross synaptic clefts, uni-directional signal, target cell must have a matching receptor

electrical synapses

pass electric signals through gap junctions, signal can be bidirectional, synchronizes the activity of a network of cells

neurotransmitters and neuromodulators

paracrine signals that act as short distances (neurocrines)

neurotransmitters

fast acting at synapses

neuromodulators

slow acing synaptic and non-synaptic sites

autocrine signals

can act on the neurons that release them

neurohormones

act over long distances, secreted into the blood and distributed throughout the body

neurocrine receptors

ionotropic receptors, metabotropic receptors

ionotropic receptors

ligand-gated ion channels, mediate rapid responses, alter ion flow across membranes

metabotropic receptors

G protein-coupled receptors (GPCRs), mediate slower responses, some open or close ion channels

agonist and antagonist molecules

mimic or inhibit activity by binding to receptors

acetylcholine (ACh)

synthesized from choline an acetyl CoA

cholinergenic receptors

nicotinic, muscarinic

nicotonic receptor

skeletal muscle, autonomic division of PNS, and CNS, monovalent cation channels (Na+ and K+)

muscarinic receptor

CNS and autonomic parasympathetic division of the PNS, GPCR