VETERINARY PHYSIOLOGY

Major intracellular storage site for Ca in skeletal muscle

Smooth Endoplastic Reticulum

The major site of energy metabolism in a cell is:

mitochondria

Most powerful control of alveolar ventilation in a healthy resting animal

pH of extracellular fluid (tending toward acidemia)

Lipid soluble substrate across cell membrane

Simple diffusion

a process known as a lipid-soluble substrate that moves across cell membranes.

simple diffusion

Facilitated diffusion

Form of co-transport, requires carrier protein to carry substrates

Requires Na+ diffusion

Cotransport of organic substrates (K+) across mammalian cell membranes

Blood is comprised of:

cells (white blood cells, red blood cells, platelets) and plasma

Synthesize blood proteins

Hepatocytes, leukocytes, vascular endothelium

Imparts osmolality to plasma

Albumin

Albumin half-life

19 days

RMP of skeletal m. & nerve cell membranes produced primarily by

Outward diffusion of K+

Equilibrium potential for K+ is a membrane potential produced when there is

No net diffusion of K+

Blocked Na-K pump of excitable cells w/ digitalis results in

Depolarization

More likely to cause blood flow turbulence

High blood viscosity (sickle cell anemia)

Increased excitability of peripheral nerve axons associated with

Increase diameter of nerve axons

Epinephrine increases heart rate by

Increased Ca permeability to nodal cells

Single motor neuron + all muscle fibers innervated

Somatic motor unit

Active enzyme from the kidneys which increases Angiotensin 2 production

Renin

Thyroid hormones alter epinephrine effects by

Increasing number of BETA receptors per cell making it sensitive

Doesn’t require insulin for glucose uptake.

Neurons

Poiseuille's Law: major determinant of volume of blood flow per unit time is

Cross sectional radius of vascular tree

Intraventricular pressure is required to open aortic valves (eject blood)

Afterload to left ventricular contraction.

major determinant of blood viscosity is the

hematocrit

Increased levels of anaerobic metabolites result in

Reactive hyperemia

first heart sound

closing of AV valves

second heart sound

closure of semilunar valves (aortic, pulmonary)

third heart sound

Caused by turbulent blood flow into ventricles (rapid diastolic filling), pathologic in dog & cat

Major beneficial function of surfactant

Decrease surface tension, maintain alveoli integrity

Circulating blood volume primarily regulated by

Plasma protein concentration

Essential for venous return from dependent body parts

Venous valves

Major effect of myelin is to

enhance velocity of action potentials and insulate axons + facilitate flow of impulses

PTH directly activates

kidney conversion to active Vit D (and increases Ca absorption from the gut)

myotatic reflex (stretch reflex) results in

Contraction of homonomous muscles

Second messenger associated with ADH/vasopressin

cAMP

(binding of ADH w/ renal tubular cell membranes activates this)

Intestinal iron absorption results in

Storage in absorptive intestinal cells

Plasma bilirubin solubilized by

Albumin

Ruminant saliva

High bicarbonate and phosphate

H+ are secreted from parietal cells of the stomach by

Hydrogen-potassium exhange pump

Not an exocrine pancreafic secretion

Pepsin (from gastric glandular cells),

Pancreatic secretions

trypsin, chymotrypsin, carboxypeptidase, elastase

Maintain the pool of bile salts (extracted from portal blood)

Enterohepatic circulation

Intestinal absorption of immunoglobulins and drugs in day-old calves occur via

Pinocytosis via specialized enterocytes (esp. during first 6-12 hrs)

Uteroverdin (green pigment assoc w/ fetal membranes of dogs, may be seen during stage 2 labor) derived from

Hemoglobin

Formed in intestinal cells and pass into the lynphocytes

Chylomicron

Basic motor activity of the ruminoreticulum starts with

Rapid biphasic reticular contraction

Elastic recoil (tendency to deflate) of lungs attributable to

Surface tension

Inversely related to elastic recoil

Lung compliance (ability of lung to expand)

Volume of air inhaled with each breath (8-10 ml/kg BW)

Tidal volume

Negative pressure in pleural cavity

At all times during eupnea

Major part of airway resistance attributable to the

Larynx

Physiologic dead space

portion of the tracheobronchial tree that does not participate in gas exchange

alveolar dead space

space occupied by nonfunctional alveoli; can be due to collapse or obstruction

Physiologic dead space equal to

Alveolar dead space

Ovulation in cats

induced by copulation (matimg stimulates LH releasek

Receptors for FSH (for stimulation of E2 secretion) is located on the

Granulosa cells

T/F. Oxytocin is synthesized by the pituitary gland

False. Synthesized by hypothalamus but stored in posterior pituitary gland

Effect of increasing CO2 content of blood on the affinity of hemoglobin for O2 known as

Bohr Effect

Hemoglobin has 250x more affinity to ___ vs. oxygen

Carbon monoxide

Serves as a carrier for hemoglobin

Haptoglobin (plasma protein)

Integrity of gastric mucosal barrier to HCl dependent on

Prostaglandins

Life span of granulocytes

12 hrs (6 hrs half life)

Lysine vasopressin

Pig

Released by sweat glands, lowers BP and produces vasodilation for heat loss

Bradykinin

active form of vitamin D

1,25-dihydroxycholecalciferol (CALCITRIOL)

enhances intestinal absorption of calcium

Vitamin D

Increases calcium level in extracellular fluid

Parathyroid Hormone

Stimulated by PTH to make active vit D for Ca absorption

Kidneys

Too much PTH & kidney disease

Secondary hyperparathyroidism

Enhanced Na resorption & K secretion

Aldosterone

Best indicator for GFR

Creatinine clearance

Protein reabsorbed from the glomerular filtrate in what tubule

Proximal convoluted tubule via pinocytosis

Acidic urine in a state of metabilic acidosis

Paradoxic aciduria

Most common mechanism for acidification of urine

Resorption of sodium bicarbonate

Major source of blood urea

Liver (from hydrolysis of arginine to urea & ornithine)

Chronic vomiting results in hypochloremia and

Hypokalemia

Most water from the ingesta is absorbed in the horse's

cecum

Vessel which normally carries blood with high levels of CO2

Vena Cava

Increases angle between two bones

Extensor

Oxygen & CO2 are transferred between inspired air and blood in the lung by the process of

Diffusion

Initiates conscious body movements

Cerebrum

Instant death if this part of CNS is damaged

Brainstem (w/ control centers for many basic body functions)

Rotary motion of head stimulated by

Semicircular canal

Organ of Corti for transductionof aufitory signals is located in

Scala media of cochlea

Stimulates spermatogenesis in males

FSH

DNA serves as template for mRNA formation

Transcription

Na-K-ATPase pump electrogenic because

its action produces a net movement of positive charge out of cells (3 Na+ out, 2 K+ in)

integral proteins

penetrate the hydrophobic interior of the lipid bilayer (ex. ion channels)

Promoter region of gene

where RNA polymerase can bind and begin transcription

Involves an increase in the rate of muscle contraction

Frequency summation (wave summation)

Occurs as more motor units of a muscle are activated

Multiple fiber summation

Cover active sites on actin, preventing actin-myosin binding

Tropomyosin

T/F. Brief period of hyperpolarization in nerve action potential is a result of voltage gated K+ channels remaining open during & after repolarization

True

Acetycholine receptor

Ligand gated ion channel

Second active transport: movement of a molecule against a gradient & linked to?

Movement of Na+ into the cell

Site of lipid and steroid synthesis

Smooth ER

Last site involved in synthesis of secretory vesicles and lysosomes from the ER

Golgi Complex

Derived from conjugation of 2 tyrosine molecules

Thyroid hormone

T/F. Circulating cortisol levels follows an episodic secretion with a diurnal rhythm

True

Drug: selective necrosis of adrenal zona fasciculata/reticularis in dogs, may be used for hyperadrenocorticism

Dopamine (mitotane)