Phys exam 2( good cards)

nervous system

-neurotransmitters released locally in response to nerve impulses

-faster responses, briefer effects, acts on specific target

endocrine system

-hormones-mediator molecule released in 1 part of the body that regulates activity of cells in other parts

-Hormones affect only specific target tissues with specific receptors

-slower responses, effects last longer, broader influence

exocrine glands

-secretory product via a duct, onto surface

-saliva, sweat, intestinal juices

endocrine glands

-secretes hormones into interstitial fluid, diffuse into blood, then travel to target cells that have right receptors

-purpose is body communication and control

-pituitary, thyroid, parathyroid, and adrenal=exclusively endocrine

chemical classes of hormones

-lipid soluble (hydrophobic)-steroids, thyroid and sex hormones; pass through membrane easily

-water soluble (hydrophilic)- made from peptide/protein; ex: growth hormone, insulin; cannot pass through membrane

mechanism of action of lipid-soluble hormones

-diffuses from the blood, through the interstitial fluid, through the plasma membrane into cell

-binds to receptor within cytosol or nucleus

-hormone receptor complex binds to regulatory sites on DNA of target cell genome

-alters gene expression, makes new proteins, changes cell activity

mechanism of action of water soluble hormones

-hormone binds to receptor on target cell surface

-activates G protein

-G protein activates adenylate cyclase

-coverts ATP to cAMP (second messenger that carries message inside cell)

-cAMP activates protein kinases

-activated protein kinases phosphorylate(activate) proteins

-phosphoroylated proteins cause many actions

second messenger systems

-amplification of original small signal (inside cell)

-enzyme cascade-chain reaction (one enzyme activated then another, then another)

-two main systems=cAMP and cGMP/

hypothalamus and pituitary gland

-hypothalamus is major link between nervous and endocrine system

-hypothalamus attached to pituitary gland

-two lobes: anterior and posterior

posterior pituitary

-does not synthesize hormones

-neurosecretory cells in the hypothalamus synthesize and secrete hormones: ADH (antidieuretic) and OT (oxytocin)

-hormones pass down axons and are stored in axon terminals in PP, nerve signal releases them into blood

ADH

-stop urination (retain water)

-stimulates kidney cells to re-absorb more water from the urine; produce more concentrated urine, blood volume increases

-released when dehydration, salty meal, drop in bp (heavy blood loss)

OT

-causes uterine contractions forcing baby head into cervix

-stretch sensitive receptors in cervix send impulse to hypothalamus

-hypo tells pp to release oxytocin into blood

-Oxytocin causes increased uterine contractions →increased stretching → increased release etc

-also acts on mammary glands; stimulates milk ejection

hormones of ant pituitary

-Growth hormone (GH)

-Thyroid stimulating hormone (TSH)

-Adrenocorticotropin Hormone (ACTH)

-Gonadal Hormones (LH and FSH)22

anterior pituitary: portal circulation

-hypopheaseal portal-special network of tiny blood vessels; connects hypo to pituitary gland

-allows quick, undiluted and direct transport of hormones from HT to AP

Hypothalamic Pituitary Axis

-hypothalamus secretes releasing and inhibiting hormones

-transport by hypopheseal portal system to ant pituitary

-stimulates or inhibits the release of Anterior Pituitary hormones

-types of AP hormones: non-tropic=direct action on target organ, tropic=act on a further endocrine gland

Growth Hormone (Non-Tropic Hormones of the AP)

-non tropic=metabolic effects

-GH is released during low blood sugar, stress

-fats: causes lipolysis (breakdown of fat), more fatty acids in blood

-carbs: stims glycogenesis (breaks down glucose), increase in blood glucose

tropic hormones of the AP

-GH: target liver, liver releases insulin like growth factors=help with growth

-TSH: target thyroid gland, thyroid releases T3 and t4= control metabolism

-ACTH:target adrenal gland, adrenal gland releases cortisol=helps with stress response

-FSH: target gonads, gonads release estrogen and testosterone=control sex characteristics

GH pathway

-hypothalamus releases growth hormone releasing hormone (tells AP to release GH) and growth hormone inhibiting hormone (tells AP to stop GH release)

-AP releases GH into blood

-liver releases IGFS which acts on bone, cartilage, and muscle

TSh

-hypo releases Thyrotropin Releasing Hormone signaling AP

-AP releases TSH into blood

-TSh stims thyroid to release thyroid hormones (t3 and t4)

TSh effects

-metabolism:increase basal metabolic rate (body burn more energy even at rest), increase heat production

-cardiovascular: increase heart rate, increase force of heart contraction

-growth: stims GH and IGF secretion=supports growth

-nervous system:crucial role in development of NS

ACTH pathway

CRH --> ACTH --> adrenal cortex --> cortisol --> stress response

cortisol

-glucocortoids-group of steroid hormones including cortisol, corticosterone, and cortisone

-metabolic effects: glucose formation (raises blood sugar), fat breakdown, protein breakdown

-also immunosuppressant, anti inflammatory and allergy effects

stress response

-eustress-positive

-distress-negative

-general adaptation syndrome-body's pattern of response to stress; coordinated by hypo

-fight or flight, resistance reaction

fight or flight

-short lived, initiated by nerve impulses

-Sympathomedullary Response- main system involved. involves sympathetic nervous system + adrenal medulla

-neuronal response: Hypothalamus → Sympathetic NS → Effectors(many)

-endocrine supplement: Hypothalamus → SNS → adrenal medulla → releases epinephrine (E) and norepinephrine (NE)

resistance reaction

-slower, longer

-Stress → Hypothalamus (CRH) → AP (ACTH) → Adrenal Cortex (Cortisol) → Body adapts to prolonged stress

hormonal control of calcium

-not controlled by hypothalamic-pituitary axis

-thyroid gland releases calcitonin (lowers blood calcium)

-parathyroid gland releases parathyroid hormone (raises blood calcium)

sensory/afferent division of nervous system

-transmits info from periphery to CNS; contains receptors

-somatic-receives sensory info from skin, joints, skeletal muscle etc;

-visceral -receives sensory info from viscera (internal organs)

motor/efferent

-transmits info from CNS to rest of body; sends motor info to effectors

-somatic-"voluntary" NS; innervates skeletal muscles

-autonomic-"involuntary." innervates cardiac and smooth muscle, glands

autonomic motor pathways

sympathetic: fight or flight

parasympathetic-rest/digest

sympathetic NS

-pupils dilate

-heart rate and force of contraction increase

-blood vessels that supply kin, kidneys and go tract vaconstrict

-airways open up (bronchodilator)

-liver has increased glycogenesis (break down glycogen)

-digestive system slows down

-adrenal medulla releases NE and E=makes effects stronger and last longer

parasympathetic NS

-conserve and restore body energy

-increase digestive and urinary function

-decrease body functions that support physical activity

physiological effects of NS

-dual innervation-most organs get signals from both parts of NS

-autonomic tone- balance between symp and para activity

-regulated by hypothalamus

PNS

-uses ACH as chemical messenger

-cholinergic fibers-nerves that use ACH

-at ganglion (connection btwn nerves) receptor reacts to ACH and nicotine (nicotinic receptors)

-at effectors/organs receptor reacts to ACH and muscarine (muscarinic receptors)

SNS

-neurotransmitter at ganglion=ACH

-neuotransmitter at effector=NE

-adrenergic fibers=nerves that release NE

-receptors at ganglion bind to ACH but also nicotine (nicotinic receptor)

-receptors at effector bind to NE (alpha and beta receptors)

beta receptors

-agonists-stimulate beta receptors, found mainly in bronchi, opens airways (bromchodilation)= helps treat asthma

-blockers-found mainly in heart, blocks NE from binding and causing effects, slows heart rate and force of contraction, treat high bp

blood functions

-transportation (gases, nutrients, hormones, waste)

-regulation (ph, body temp, osmotic pressure)

-regulation (body temp, ph, osmotic pressure)

-protection (clotting, white blood cells, proteins)

blood: liquid connective tissue

-formed elements: red blood cells (erythrocytes), white blood cells (leukocytes), platelets (thrombocytes)

-blood plasma: liquid part, 90% water and 10% other solutes (albumins, clotting factors, antibodies, globulins electrolytes, nutrients, enzymes, hormones, gases waste products)

-

red blood cells/erythrocytes

-contain oxygen carrying protein hemogoblin

-biconcave disc-increases surface area

-strong, flexible plasma membrane

-lack nucleus and mitochondria

blood groups and blood types

-surface of rbcs contain genetically determined assortment of antigens (agglutinogens)

-blood group determined by presence or absence of different antigens

-at least 24 blood groups and 100+ antigens identified

-most important blood group systems are ABO and Rh systems

antibodies and antigens

-antigens-proteins that trigger immune response

-antibodies-proteins of immune response to fight invaders

-antigen-antibody (Ag-Ab) reactions protect us from pathogens; however bad for mismatched blood bc if you receive blood with antigens your body doesn't have, antibodies will attack it

ABO classification

-A blood-carry A antigen and anti-b antibodies

-B blood- carry B antigen (A antibodies)

-AB blood-carry both A and B antigens (no antibodies)

-O blood-carry no antigen (both anti- A and B antibodies)

transfusion compatibility

-donor and recipient must be compatible

-if blood types mix the immune system will attack the foreign rbcs; can cause kidney damage

RH blood group

-protein found on outside of rbc (d antigen)

-either have it (RH pos) or not (RH neg)

-important in blood transfusions and pregnancy

-If Rh⁻ blood is exposed to Rh⁺ blood, the Rh⁻ person's immune system can make anti-Rh antibodies that attack Rh⁺ cells

white blood cells/leukocytes

-have nuclei

-do not contain hemogoblin

-granular (visible granules in cytoplasm); neutrophils, eosinophils, basophils

-agranular; lymphocytes and monocytes

functions of white blood cells

-immune responses

-non specific immune responses: neutrophils (first responders to infection), monocytes (differentiate into macrophages; also fixed macrophages, phagocytosis (cell eating)

-specific immune responses: B cells make antibodies to attack certain invaders, T cells destroy infected or abnormal cells directly

-allergic responses: basophils release histamine

platelets/thrombocytes

-disc shaped with many vesicles (contain clot forming chemicals) but no nucleus

-life span 5-9 days; replaced by new ones made in bone marrow

-essential for hemostasis-prevents blood loss

-hemostasis: blood vessel is damaged, platelets stick to the broken area and to each other, forming a temporary plug to stop bleeding; then if injury is larger, the body activates a clotting process that forms a strong, stable blood clot that seals wound until vessel heals

platelet plug formation

-platelet adhesion-platelet sticks to exposed area of damaged blood vessel

-secretion of inflammatory mediators-platelets release chemical signals which attract more platelets and trigger inflammation

-platelet aggregation-platelets clumps to form plug

blood clotting/coagulation steps

-platelet plug

-bigger damage=clot formed

-formation of fibrin strands-during clotting, fibrinogen is converted to fibrin; fibrin strands weave through platelet plug sealing wound until healing is complete