BIO 202: Unit One Exam

hypothalamus

part of the diencephalon and starting point of the endocrine system

• puppet master that controls the pituitary gland

hypophysis

another name for the pituitary gland

adenohypophysis

another name for the anterior pituitary gland 

• pinched off the pharynx snd is the same tissue as the tonsils

neurohypophysis

another name for the posterior pituitary gland

• grows out from part of the brain

oxytocin

hormone produced by the hypothalamus but stored and released by the posterior pituitary gland 

• triggers uterine contractions during childbirth 

antidiuretic hormone

hormone made by the hypothalamus but stored and released by the posterior pituitary gland 

• retains water to maintain blood pressure 

follicle stimulating hormone

stimulates development of follicle and sustentacular cells

luteinizing hormone

triggers ovulation and stimulates interstitial cells to make sperm

adrenocorticotropic hormone

stimulates the adrenal cortex to secrete hormones

thyroid stimulating hormone

stimulates the thyroid gland to secrete hormones

prolactin

promotes milk production

growth hormone

stimulates cell division and protein synthesis

hypothalamo-hypophyseal portal system

means by which hormones travel from the hypothalamus to the anterior pituitary gland

• consists of blood capillaries that connect to each other and don’t send blood back to heart

negative feedback loop

increased target organ hormone levels inhibit release of more tropic hormones

• ex: thyrotropin releasing hormone from hypothalamus triggers anterior pituitary to release thyroid stimulating hormone so thyroid can make hormones until hypothalamus inhibits TRH

hyperglycemic hormones

raise blood glucose concentration

• glucagon: tells liver to break glycogen to glucose to avoid major blood glucose drops

hypoglycemic hormones

lower blood glucose

• insulin: tells body cells to use glucose

skin

secretes calcitriol/vitamin D to absorb calcium

kidneys

secretes calcitriol, erythropoietin for RBC production, and renin to maintain blood pressure

heart

secretes atrial natriuretic peptide to lower blood pressure

humoral hormone regulation

hormones released through response of blood levels so gland itself regulates blood levels

• parathyroid gland releasing parathyroid hormone when blood calcium levels are low

neural hormone regulation

hormones released through neural communication so nervous system is telling gland to release hormone

• pre-ganglionic SNS fiber stimulating adrenal medulla to secrete catecholamines

hormonal hormone regulation

hormones released through axis and negative feedback loops

• hypothalamus secreting hormones that stimulate other endocrine glands to secrete hormones 

steroid hormones

derived from cholesterol 

• includes estradiol and testosterone 

peptide and glycoprotein hormones

protein hormones that are made exactly like proteins and act like proteins

• includes insulin and angiotensin II

monoamine hormones

derived from amino acids

• includes epinephrine and thyroxine

receptors

protein or glycoprotein molecules on the plasma membrane, in cytoplasm, or in nucleus

• act like switches that turn on metabolic pathways when hormones bind to them

hydrophilic hormones

easily travel and free float in the bloodstream

• bind to cell surface receptors and activate second messenger systems and CANNOT enter the cell

• includes peptide hormones

hydrophobic hormones

usually bound to some carrier/transport protein and can directly bind to receptors in the nucleus

• includes steroid hormones

metabolic clearance rate

rate of hormone removal from blood

half life

time required to clear 50% of hormone from blood

up-regulation

target cell makes more receptors to get a stronger response

down-regulation

receptors are removed to get more of a diminished response

synergistic effect

effect in which multiple hormones act together for a greater effect

• ex: growth hormone and insulin growth factor working together to stimulate development

permissive effect

effect in which one hormone enhances the target organ’s response to a second later hormone

• ex: hormone causing up-regulation

antagonistic effect

effect in which one hormone opposed the action of another hormone

• ex: insulin lowering blood glucose levels while glucagon raises blood glucose levels

general adaption syndrome

consistent way the body reacts to stress which typically involved elevated levels of epinephrine and cortisol

• occurs in three stages

stage of alarm reaction

individual experiences stressful event

stage of resistance

stress causes cortisol to begin “glucose sparing effect” so brain gets priority on available glucose and not secondary systems

stage of exhaustion

stress causes body to tap into fat reserves, proteins, and muscle for energy 

• body is susceptible to illness, fatigue, and weakness

paracrine secretions

not true endocrine secretions but are local communication signals and chemical messengers that diffuse short distances to stimulate nearby cells

• histamine, nitric oxide, and eicosanoids

type I diabetes

autoantibodies attack and destroy pancreatic beta cells that produce insulin 

• always treated with insulin

type II diabetes

failure of target cells to response to insulin

• treated with weight loss and exercise

blood

only fluid connective tissue in the body

• made up plasma + formed elements

hematocrit

percentage of red blood cells in total blood volume

• about 45%

plasma

sticky fluid that is about 90% water with over 100 dissolved solutes like nutrients, gases, hormones, proteins, and ions

• most abundant solute is plasma proteins

albumin

most abundant and makes up about 60% of plasma proteins

• function as carrier of other molecules and contribute to plasma osmotic pressure

erythrocytes

most abundant and well adapted red blood cells

• shape helps increase surface area for gas exchange

• lacks nucleus and organelles

hemoglobin

globin + 4 heme groups

• each heme group has one Fe atom that can bind one O atom

erythropoiesis

formation of red blood cells

• begins with hemocytoblast stem cell

reticulocytes

not fully matures erythrocytes that make it into circulation 

• help indicate rate of erythropoiesis and how quickly someone is making RBCs

neutrophils

granulocytes, most numerous WBCs that kill bacteria and microbes

• respiratory burst: synthesize potent oxidizing substances

• form spears that pierce membrane

eosinophils

granulocytes, play role in allergies and asthma

• release enzymes on large parasitic worms to digest their surface

basophils

granulocytes, least numerous WBCs

• make histamine and are most similar to mast cells

lymphocytes

agranulocyte, second most numerous WBC

• T lymphocytes: act against virus-infected and tumor cells 

• B lymphocytes: give rise to plasma cells that produce antibodies 

monocytes

agranulocytes, largest

• differentiate into macrophages 

platelets

fragments of larger cells (megakaryocytes) that contain chemicals involved in clotting by forming temporary platelet plug

• kepts inactive by NO and prostacyclin to not stick to everything

vascular spasm

first step in hemostasis in which blood vessel gets damaged so smooth muscle contracts to vasoconstrict and prevent further blood loss

platelet plug formation

second step in hemostasis in which blood vessel injury exposes fibers that platelets can adhere to 

• platelets release chemicals to cause other platelet so stick to form platelet plug 

coagulation

third step in hemostasis in which fibrin forms mesh that traps RBCs and platelet to form clot 

• phase I: clotting factors activate and intrinsic and extrinsic pathways meet  

• phase II: thrombus clot forms

• phase III: fibrinogen turns into fibrin

clot retraction

process in which contraction causes actin and myosin in platelets to pull fibrin strands together to squeeze serum from clot and draw ruptured vessels together

fibrinolysis

process in which clots are removed after repair is complete within 2 days

• plasminogen → plasmin which is a fibrin-digesting enzyme

disseminated intravascular coagulation

involved both widespread clotting and severe bleeding

• occurs in septicemia, incompatible blood transfusion, or pregnancy complications

contractile cells

responsible for contraction and make up bulk of the heart

pacemaker cells

non contractile cells that can spontaneously depolarize to initiate heart depolarization without nervous system stimulation

junctional rhythm

SA node is nonfunctional so AV node takes over and paces heart at 40-60 beats/min

• P waves are absent on EKG

second degree heart block

AV node fails to conduct some SA node impulses

• more P waves than QRS complexes are shown on EKG

cardiac cycle

blood flow through the heart during one complete heartbeat 

end diastolic volume

max volume at the end of diastole (before contraction)

end systolic volume

minimum volume at the end of systole (after contraction)

• lowered with greater contractility 

stroke volume

amount of blood pumped out of ventricles with every contraction/beat

• equals EDV - ESV

cardiac output

volume of blood pumped by each ventricle in one minute

• equals SV x HR

• normal value is about 5.25 L/min

cardiac reserve

difference between resting and maximum cardiac output

preload, contractility, and afterload

three factors that regulate stroke volume

preload

amount of blood in the ventricles before contraction

• equals EDV

• influenced heavily by venous return

venous return

amount of blood returning to heart

• slow HR and exercise increase it

contractility

contractile strength at given muscle length 

• increased by positive inotropic agents

• decreased by negative inotropic agents

afterload

pressure that ventricles must overcome in order to eject blood

• equals ESV

• increased by hypertension

continuous capillaries

least permeable but most common

• have most intact, solid walls with pericytes

• allow nutrients to diffuse through simple squamous epithelium due to intercellular clefts

fenestrated capillaries

have large fenestrations (pores) that increase permeability

• occur in areas of active filtration like in the kidneys and areas of absorption like in small intestine

• also have intracellular clefts

sinusoid capillaries

most permeable but rare

• occur in liver, bone marrow, spleen, and adrenal medulla

• have incomplete basement membranes and large intracellular clefts that allow large molecules and cells to move through

60%

veins have relative proportion of ___ of blood volume throughout the cardiovascular system

blood flow

volume of blood flowing through vessel, organ, or entire circulation in a given period

• measured in mL/min

• equivalent to cardiac output

blood pressure

force per unit area exerted on wall of blood vessel by blood 

• expressed in mmHg

peripheral resistance

opposition to flow or amount of friction that blood encounters with vessel walls which is dependent on three sources

• blood viscosity

• blood vessel length

• blood vessel diameter

resistance

in terms of blood vessel length, greater distance and farther from the heart, the more ____

true

true or false: closest to the heart, blood pressure is the highest and exhibits the greatest difference while the biggest drop off begins at the arterioles 

pulse pressure

difference between systolic and diastolic pressure

• ex: 120/80 → 40 mmHg

mean arterial pressure

pressure that propels blood to tissues

• equals diastolic pressure + 1/3 (pulse pressure)

muscular pump, respiratory pump, and sympathetic venocontraction 

factors that aid in venous return

muscular pump

contraction of skeletal muscles which help squeeze blood back to heart, valves help

respiratory pump

pressure changes during breathing move blood towards heart by squeezing abdominal veins

sympathetic venoconstriction

under sympathetic control, smooth muscle contracts to push blood to heart 

750

no matter whats happening with the body, brain blood volume should NOT change and remain ___ mL/min

hydrostatic pressure

capillary movement on the arterial side

• pressure from the heart during ventricular systole which pushes fluid out to surrounding tissues

• 35 mmHg

colloid osmotic pressure

capillary movement on the venous side

• solutes encourage and pull fluid into the capillary

• 26 mmHg

lymphatic vessels

pull in extra fluid that the veins cannot fully pull in

• more fluid is pushed out than pulled back in

myogenic controls

intrinsic mechanism to regulate blood flow in which smooth muscles respond to stretch and blood vessels change diameter in response to pressure

metabolic controls 

intrinsic mechanism to regulate blood flow in which active tissues cause blood vessels in these tissues to open and deliver blood to tissues that need it

• influenced by low oxygen, high carbon dioxide, low pH, and high potassium

extrinsic neural controls of blood flow

• decreased sympathetic tone → vasodilation

• increased sympathetic tone → vasoconstriction

extrinsic hormonal controls of blood flow

• atrial natriuretic peptide → vasodilation

• angiotensin II, antidiuretic hormone, epinephrine, and norepinephrine → vasoconstriction