Physiology Final Exam

physiology

function of living things
mechanisms of action
homeostasis (foundation)

homeostasis

1. the body's internal environment is relatively constance
2. dynamic constancy drives thousands of reactions in our body
3. two major body systems involved in homeostasis: endocrine and nervous systems

negative feedback loop

feedback that tends to counteract a process

hormone -> stimulates hormone -> hormone stimulates hormone -> hormone inhibits release of hormone

differentiation

process by which cells become specialized to carry out specific functions

results in cellular activity

glycocalyx

labels cells as "self" and "non-self" (belonging to your body)

plasma membrane carbohydrates form it

hyperplasia

stimulated mitotic divisions in cells

increase in number of cells NOT size

like a callus on hand

metaplasia

transformation of one cell type into another

hypertonic solution

cell will shrink

isotonic

no change to cell placed in solution

hypotonic solution

cell would swell and potentially burst

osmosis

movement of wter (solvent) with its concentration gradient toward a higher concentration of solute (permeable membrane)

sequence of facilitated diffusion

1. transporter interacts with molecule
2. transporter changes configuration
3. transporter moves molecule across the membrane
4. transported molecule released from the transporter

primary active transport

requires energy to move molecules AGAINST/UP their concentration gradient

like the Na/K ATPase pump

chemoreceptor

oxygen concentration

mechanoreceptor

skeletal muscle stretch

photoreceptor

light

thermoreceptor

heat and/or cold

unequal distribution of charge of the plasma membrane

result of higher K+ permeability relative to lower Na+ permeability

Na+/K+ ATPase pump

receptors that are located on the plasma membrane can be for

neurotransmitters
water-soluble messengers
proteins

action potentials

membrane permeability causes unqueal charges on either side of the membrane

more permeable to K+ not to Na+

action potentials at synapses vs. neuromuscular junctions

NOT transmitted at a one-to-one basis at synapses but are at neuromuscular junctions

how do action potentials travel

unidirectionally down the axon

summation in action potentials

does NOT make it move more rapidly

threshold potential

point at which there is an explosive increase in Na+ permeability

EPSP results

local hyPOpolarization of the membrane potential

when chemically-gated Na+ channels open

interior of the membrane becomes more POSITIVE

the membrane doesn't always reach threshold, so an action potential is not always generated

microvilli

closely spaced finger-like projections

not required for mucous movement down the respiratory tract

located on most epithelial cells

increase surface area

sequence of neurotransmitter diffusing across a synaptic cleft

1. calcium induces exocytosis of transmitter
2. exocytosis of neurotransmitter
3. diffuse across cleft
4. bind to chemically gated channels
5. channels will now open
6. permeability of postsynaptic membrane altered

central nervous system

90% composed of glial (support) cells
- astrocytes
- oligodendrocytes
- microglia
- ependymal cells

peripheral nervous system glial cells

schwann cells
satellite cells

afferent neurons

transmit signals from receptors TO the CNS

PNS to CNS

efferent pathway

directly sends an impulse to an organ making a response

CNS to PNS

photoreceptors

detect light on the retina

chemoreceptors

detect oxygen concentration and carbon dioxide levels in blood

nocireceptors

pain
tissue damage

mechanical nociceptors

brain notices very quickly

polymodal nociceptors

dull, aching, slow-growing pain

osmoreceptors

detects changes in osmotic pressure

DOES NOT detect liquids

acetylcholinesterase

enzyme that causes rapid hydrolysis of acetylcholine

chews up acetylcholine after it is diffused through synaptic cleft

hypothalamus

NOT RESPIRATION OR CIRCULATORY FUNCTION

temperature control
thirst
urine output
releases CRH

cerebellum

balance
muscle tone
coordination

vestibulocochlear nerve

cranial nerve affective you sense of equilibrium

primary motor cortex

located in the left cerebral hemisphere controls skeletal muscle on the right side of the body

anterior pituitary hormones

prolactin
growth hormone
adrenocorticotripic hormone
lutenizing hormone
follicle-stimulating hormone
thyroid-stimulating hormone

permissiveness of hormones

situation where a hormone can't exert its full effect without the presence of another hormone

-> one hormone needs to be present to allow another hormone to have its full response

pineal gland

releases melatonin to regulate sleep-wake cycle/circadian rhythm

synergistic response

when are response to 2 hormones is greater than the sum of them individually

hormones

don't need carrier proteins
can influence multiple cells or organs
have various secretory patterns
only small amounts required
change how a cell functions

what nerve fivers release acetylcholine

all of the nerve fibers EXCEPT for the postglanglionic nerve of the sympathetic nervous system

what nerve fiber releases epinephrine

postganglionic nerve of the sympathetic nervous system

sympathetic nervous system

NOT always excitatory
part of the afferent division of the peripheral nervous system and a part of the autonomic nervous system
prepares the body for physical exercise

thyroid hormone

increased metabolic rate and heat production
increased activity of sympathetic nervous system

perception

conscious awareness of sensation

actin

THIN

myosin

THICK

myosin and actin binding stimulation

stimulated by direct or indirect presence of calcium in all three muscle types

neuromuscular junctions

one-to-one transmission of action potentials
always excitatory

synapses

not always one-to-one
can have INSPs and ENSPs
between two neurons

skeletal muscle contraction

1. impulse is going to reach the axons synaptic knob
2. release acetulcholine via exocytosis
3. acetylcholine binds to receptors on sarcomere
4. causes sodium channels to open and sodium to flow in
5. action potential will develop in the muscle cell

what determines muscle tension

number of motor units
tension developed by each fiber
the frequency of stimulation
NOT the percentage of fibers present in a single motor unit that are contracting

sequence of electrical flow through the heart

1. SA node
2. AV node
3. AV bundle
4. Purkinje fibers

end systolic volume

the greater the filling, the stronger the contraction and the smaller the end systolic volume (frank starling law of the heart)

end diastolic volume

the longer the period of diastole, the greater the end of diastolic volume

the greater the venous return, the greater the end diastolic volume

rate of blood flow decreased by

increase in viscosity
increase in the length of a blood vessel
decrease in blood pressure

rate of blood flow increased by

decrease in viscosity
decrease in length of blood vessel
increase in blood pressure

capillaries

velocity of blood flow is inversely proportional to cross-sectional area
pre-capillary sphincters regulate blood flow into the capillary beds

capillaries have the most/highest cross-sectional area

greatest volume of blood in the body at rest is in the

veins

diastole

during diastole blood is entering into all chambers of the heart
blood flow in coronary arteries of the heart is greatest during diastole

systole

contraction

mean arterial pressure

(systolic + 2(diastolic))/3 = mmHg

EKG sequence

1. atrial depolarization (P wave)
2. ventricular depolarization (QRS)
3. time ventricles are contracting and emptying
4. ventricular repolarization (T wave)
5. time ventricles are relaxing and filling

inflammatory response

increase blood flow, fluid accumulation, pain...
NOT a release of interfereons by macrophages

clotting

prostacyclin is released by the normal endothelium nextto the platelet plug to avoid spreading of the coagulin

prostacyclin does NOT make them sticky

plasmin

used to break down blood clots

albumin

maintains blood osmotic pressure and prevents edema

thrombocytes (platelets)

release chemicals to stimulate vasocontriction: ADP and thromboxane A2

passive immunity

injective someone with antibodies

antibody-mediated immunity cells

T cells (but not just this!)
ALSO
B cells (that differentiate into) plasma cells

inspiration

inhalation takes place when pressure inside the alveoli of the lungs is less than atmospheric air pressure

changes in volume create differences in pressure - inspiration occurs when volume increases

expiration

brought on by the recoil of the inhalation/inspiration muscles
elastic tissues stretched during inhalation recoil
thoracic cavity volume decreases

intracellular compartment

40% LARGER PORTION

extracellular compartment

20%

plasma and interstitial fluid

what causes the percentage of hemoglobing saturation to decrease (Hb gives up oxygen to tissues)

elevated CO2
hydrogen
temperature

medulla

brain region that provides neural output to repiratory muscles

plasma clearance

volume of plasma that is completely cleared of the substance/minute -> by the kidneys

sequence of filtrate flow through the nephron

bowman's capsule
PCT
descending loop
ascending loop
DCT
collecting duct

tubular secretion

transferring from blood to tubule

pitch

determined by frequency of sound waves

functions of the GI tract

transfer nutrients, water, and electrolytes from external environment to internal environment

motility, digestion, absorption, secretion, elimination

colon

reduces volume of chyme (primary function)
colonic bacteria digest cellulose

peristalsis

moving ring-like contractions
occurs in areas of tract where smooth muscle is present
propulsion of ingesta forward

segmentation

mixing of ingesta with digestive secretions
takes place in stomach and small intestine
promotes digestion and facilitates absorption

swallowing reflex

1. tongue presses bolus against the hard palate
2. tongue propels the bolus to the pharynx
3. swallowing center temporarily inhibits the respiratory center
4. elevation of uvula prevents food from entering the nasal passageways
5. position of the tongue prevents food from returning to the oral cavity
6. vocal cords prevent food from entering the trachea
7. epiglottis folds over the closed glottis
8. contraction of the pharyngeal muscles pushes the bolus through opend pharyngoesophageal sphincter into the esophagus
9. peristalsis propels material down the length of the esophagus

enteric nervous system

composed of the intrisic nerve plexi, neurotransmitters

intrinsic nerve plexi

contains afferent neurons that monitor changes in the digestive system
efferent neurons that innervate smooth muscle, endocrine cells, and exocrine cells
interneurons that receive inputs and send outputs

acetylcholine

promotes smooth muscle contraction

nitric oxide, vasoactive intestinal peptide

promotes smooth muscle relaxation

acid reflux

when material flows backward through the lower esophageal sphincter

where are proteins digested

in the stomach

protein digestion enzyme

pepsin (pepsinogen + HCL)