Blood and Endocrine Systems

by Kristen Cojeda and Kyle Almendares

What is the Endocrine System?

-A network of glands that create and release hormones

-Works with circulatory system to send messages

-It is similar to the nervous system in that it is a message

transmitter

-The endocrine system works slowly while the nervous

system is more instantaneous

*Hormone comes from the Greek word “hormon”

which means to set in motion

-There are many structures throughout the body

Types of Hormone Communication

Endocrine

-long range

-affects cells with specific receptors

Autocrine

-cell to cell communication

-such as immune cells communicating

Paracrine

-affects local area

-quickly dissapates

What is a feedback loop?

-There are 2 types of feedback loops: positive and negative

-The most common that occurs within the human body is a negative

feedback loop, which brings things back to equilibrium

-An example of this is thermostatic regulation

-Positive feedback loops often amplify the input, such as clotting:

platelets will bind to the site of injury and release chemicals to

call more platelets to the wound

What are the structures?

Hypothalamus

-located in the brain

-“control center” translator between endocrine and nervous system

-creates ADH(regulates bodily fluid volume) & oxytocin(stimulates

uterus to contract)

*stimulates pituitary

Pituitary

-located below hypothalamus

-nicknamed the “master gland”, it relays any stimulus from the

hypothalamus to the other glands in the body

Pituitary

Pituitary

-located below hypothalamus

-nicknamed the “master gland”, it relays any stimulus from the

hypothalamus to the other glands in the body

secretes:

-ACTH → stimulates adrenal glands

-GH → growth hormone

-ADH → controls kidney water absorption

-oxytocin → child birth/breastmilk production

Thyroid and Parathyroid

Thyroid

-located in neck, surrounds trachea

-regulates metabolism

-creates T3 and T4(both stimulate metabolism)

-releases calcitonin → stimulates osteoclasts

Parathyroid

-4 spots located on back of thyroid

-regulates blood calcium level

-creates PTH → stimulates osteoclasts

Adrenal and GonadsAdrenal

-located on top of/adjacent to kidneys(renal system)

-divided into 2 parts: cortex(outer) and medulla(inner)

-the cortex creates steroids: cortisol(stress hormones) and

aldosterone(regulates blood volume)

-medulla creates catecholamines: adrenaline(fight or flight)

Gonads

-a male’s testes produce testosterone

-a female’s ovaries produce estrogen and progesterone

-stimulates growth of physical features in males and females

Pancreas and Thymus

Pancreas

-located in upper abdomen

-regulates blood sugar

-creates insulin(allows body to use sugar

as energy) and glucagon(causes liver to turn

glycogen into glucose)

Thymus

-located anterior to the heart and posterior to the sternum

-mostly associated with the immune system

-develops T cells

Blood

HUMAN BLOOD CONSISTS 22% SOLIDS & 78% WATER

Components

▪ Plasma- a protein-salt solution in which red & white and platelets are

suspended

▪ Red Blood Cells (erythrocytes)- biconcave; hemoglobin is the protein

which carries oxygen, remove carbon dioxide transporting to lungs to

exhale

▪ White Blood Cells (leukocytes) –protect against disease, bacteria,

viruses & other harmful invaders

▪ Platelets (thrombocytes)- not complete cells; clotting

Location

▪ Spread throughout body in arteries, veins, & capillaries

▪ Origin: Blood cells originate in red bone marrow from

hemocytoblasts, or hematopoietic stem cells

▪ Maturation: hemocytoblasts → myeloid & lymphoid stem cells

which are hematopoietic growth factors

Hematopoeisis

▪ Process of blood formation begins from yolk sac, manufactured in

liver & spleen, & formed in bone marrow

▪ Formation of blood cells and other constituent elements of blood

▪ Complete Blood Cell count

▪ Measurement of size, number, and maturity

▪ Can determine many abnormalities with either production or

destruction of blood cells

▪ Variations from normal #, size or maturity can be used to

indicate infection or disease

Erythropoiesis (making RBCs)

▪ In red bone marrow, hemoblasts give rise to erythroblasts

▪ Erythroblasts divide and give rise to new cells

▪ Nuclei of new cells shrink and are pinched off into thin coverings and cell

membrane

▪ Some young cells contain netlike structure (reticulum) for a day or two

▪ Remainder is the endoplasmic reticulum; cells are called reticulocytes

▪ This exits the bone marrow to enter the blood

▪ Reticulum degenerates and cells are fully mature

Cell Cycle

▪ Average life span of a red blood cell is 120 days

▪ 80-90 days are in a full term infant stage

▪ Red blood cells travel throughout the body appx. 75,000

▪ Low blood oxygen causes the kidneys and liver to release

erythropoietin

▪ Erythropoietin controls the rate of red blood formation

Clotting

Components▪ Platelets

▪ Smooth muscle walls of blood vessel

▪ Collagen fiber

Mechanisms

▪ Extrinsic clotting mechanism- release to biochemical

from broken blood vessels or damaged tissues

▪ Intrinsic clotting mechanism- blood contact with foreign

surfaces in the absence of tissue damage

▪ Platelet plug formation- platelets adhere to each other at

the end of a broken vessel and helps control blood loss

Extrinsic vs intrinsic

extrinsic●activated by external trauma which causes blood to escape●quicker than intrinsic●involves VII

intrinsic●activated by trauma inside vascular system●activated by platelets●slower but more important●involves factor XII,X,IX,VIII

Continued…

▪ Platelet Plug Formation

Blood Typing

▪ Anti-body A = Type A

▪ Anti-body B = Type B

▪ Anti-body A & B = Type AB

▪ Neither A or B = Type O

Sourceshttp://www2.estrellamountain.edu/faculty/farabee/BIOBK/BioBookENDOCR.htmlhttps://www.pinterest.com/piwiman12/endocrine-system/http://blogs.hightechhigh.org/apolloandhomology/page/2/https://www.youtube.com/watch?v=WVrlHH14q3ohttps://www.youtube.com/watch?v=ER49EweKwW8http://www.webmd.com/a-to-z-guides/thyroid-and-parathyroid-glandshttp://www.yourdictionary.com/adrenal-glandhttp://pixshark.com/testes-and-ovaries.htmhttp://studydroid.com/printerFriendlyViewPack.php?packId=83815http://arbl.cvmbs.colostate.edu/hbooks/pathphys/endocrine/basics/control.htmlhttp://www.brookdalehospital.org/patient-services/blood-bank.htmlhttp://en.wikipedia.org/wiki/Blood_type

More Sources