Anatomy & Phys 2

• Maintain homeostasis in coordination with the nevous system
• Comunicate between different parts using hormones
• Adjust body to environment changes

• Endocrine
• Paracrine
• Autocrine
• Exocrine

low

• Steroid/ Steroid like
• Non-Steroid

• Sex hormones
• Adrenal cortex hormones
• Lipids containing complex ring structures

• Amines
• Proteins
• Peptides
• Glycoproteins

up or down regulate proteins

binds to cell-surface receptors and activate a second messenger

• controlled by negative feedback
• may be short lived or last for days
• levels maintain or raised by secretion
• secretions are precisely regulated

• located near the thalamus and 3rd ventricle of brain
• recieves information through neural connections and cerebrospinal fluid
• affects specific subpopulation of cells in anterior P.G
• Most prevelent: hormone-releasing

• located at the base of the brain in the sella turcica in sphenoid bone
• connected to the base of hypothalamus by infundibulum

• Anterior Pituitary
• Posterior Pituitary

• Hypothalamic releasing hormones stimulate cells anterior
• pituitary to release hormones
• Nerve impulses from hypothalamus stimulate nerve endings in the posterior pituitary gland to release hormones

• Hypothalamus releases hormone-releasing hormones into capillaries
• Hormone-releasing hormones travel down through the portal vein in the infundibulum
• Hormone-releasing hormones released from capillary bed in anterior pituitary
• Hormone-releasing hormones stimulate or inhibit release of hormones from the anterior pituitary gland into the capillary bed

• Protein
• Stimulates cells to grow and divide more rapidly
• Enhances transport of amino acids across cell membrane
• Increases protein synthesis and rate of utilization of fats
• Decreases rate of utilization of carbohydrates
• Directly stimulates growth of bone tissue
• Indirectly stimulates growth of cartilage using insulin-like growth factor 1

• Protein
• Stimulates milk production in females
• No known function in males
• Excessive levels disrupt sexual function in both sexes

• Secretion inhibited by Prolactin-Release Inhibiting Hormone secreted by hypothalamus
• Secretion may be stimulated by an unknown Prolactin-Releasing Factor

• Glycoprotein
• Controls release of thyroid hormones and size of thyroid gland
• Partial control of release of Thyroid-Stimulating Hormone by Thyrotropin-Releasing Hormone from hypothalamus

• Peptide
• Controls release of hormones from adrenal cortex
• Secretion regulated partially by Corticotropin-Releasing Hormone from hypothalamus
• Stress increases release of Corticotropin-Releasing Hormone and Adrenocorticotropic Hormone

• Glycoproteins
• Females:
• Controls growth and development of follicles
• Stimulates secretion of estrogens by follicular cells
• Males:
• Stimulates production of sperm

• In both sexes
• Secretion of sex hormones
• In females
• Release of eggs from ovaries

Control not well understood; however, hypothalamus releases a Gonadotropin-Releasing Hormone (puberty)

• Consists of nerve fibers and neuroglia, instead of the glandular epithelial cells of the anterior pituitary gland
• Nerve fibers originate in the hypothalamus

• Produced in hypothalamus
• Transported through nerve axons to posterior pituitary gland
• Stored as granules in posterior pituitary gland
• Released to bloodstream from pituitary gland

• Antidiuretic hormone(vasopressin)
• Oxytocin

• Short peptide
• Binds two different receptors
• Causes kidneys to reduce volume of water excreted
• Vasoconstrictor, especially in response to significant blood loss

• Short peptide
• Antidiuretic activity
• Contracts smooth muscles of uterine wall during labor
• Contracts cells near mammary glands and ducts to release milk upon stimulation by suckling
• Stimulate movement of fluids in male reproductive tract during sexual activity

• 2 lateral lobes connected by isthmus and lies just below the larynx
• Removes iodine from the blood
• Consists mostly of thyroglobulin for storage
• Follicular cells secrete hormones
• Extrafollicular cells secrete other hormones

• T3 (triiodothyronine)
• T4 (thyroxine)
• Calcitonin

• Regulate metabolism
• Essential for normal growth and development of nervous system
• Controlled by Thyroid-Stimulating Hormone from the anterior p.g.

• Increase rate of energy release from carbohydrates
• Increase rate of protein synthesis
• Stimulate breakdown and mobilization of lipids
• Control basal metabolic rate

• Produced by nonfollicular cells
• Controls blood calcium and phosphate ion concentration
• Inhibits osteoclast breakdown of bone and release of calcium & phosphate ions
• Stimulates osteoblast activity
• Controlled by concentration of calcium in blood, gastrin and other digestive hormones

• Located on the posterior surface of the thyroid gland
• Typically four parathyroid glands
• Secretes one hormone

• PTH
• (parathyroid hormone or parathormone)

• Closely associated with the kidneys
• Each sit like a cap on each kidney
• Hormones are secreted from two different areas of the gland, the adrenal cortex and the adrenal medulla
• Numerous hormones are secreted by the adrenal glands

• Epinephrine
• Norepinephrine

• Aldosterone
• Cortisol
• Adrenal androgens

• Two types of secrtory tissue
• Known as a dual functioning organ for exocrine gland and endocrine gland

• Alpha cells secrete glucagon
• Beta cells insulin
• Delta cells secrete somatostatin

• Secretes melatonin
• Regulates circadian rhythms

• Secretes thymosins
• Promotes development of certain lymphocytes\
• Important in role of immunity

• Ovaries produce estrogens and progesteroe
• Testes produce testosterone
• Placenta produces estrogens, progesterone, and gonadotropin

• Physical stress
• Psychological stress

• Secrete substances
• Have ducts
• Products delivered directly to the external environment

• Communicate using chemical signals that bind to receptor molecules
• Neurons release neurotransmitters into a synapse affecting postsynaptic cells
• Endocrine glands release hormones into the bloodstream to cell receptors
• Paracrine and autocrine glands release hormones to cell receptors

Neurons

Neutrotransmitter

Receptors on postsynaptic cell

Seconds

Very brief unless neuronal activity continues

Glandular epithelium

Hormone

Receptors on target cell

seconds to hours

May be brief or may last for days even if secretion ceases

• Regulate metabolic processes
• Control rates of certain reactions
• Help transport substances across membranes
• Help regulate water balance, electrolyte balance, and blood pressure
• Are important in reproduction, development, and growth

• Formed from- amino acids
• Ex: Noreprinephrine, epinephrine

• formed from- amino acids
• Ex: ADH, OT, TRH, SS

formed from- protein and carbs

• formed from- cholestrol
• EX: estrogen, testosterone, cortisol

• Are paracrine substances
• Act locally
• Are very potent in small amounts
• Are not stored in cells but synthesized just before release
• Rapidly inactivated
• Regulate cellular responses to hormones
• Can activate or inhibit adenylate cyclase

• Relax smooth muscles of airways & blood vessels
• Contract muscles of uterus
• Stimulate secretion of hormones from the adrenal cortex
• Inhibit secretion of hydrochloric acid from the wall of the stomach
• Promote inflammation of injured tissue
• Influence movement of Na+ and water in the kidneys
• Affect male and female reproductive physiology

• Connective tissue
• Transports vital substances
• Maintains stability of interstitial fluids & homeostasis
• Distributes heat
• Links the internal and external environments

8

5

• “Formed elements”
• Red blood cells (RBCs)
• White blood cells (WBCs)
• Platelets (cell fragments)
• Form mostly in red bone marrow

• Water
• Amino acids
• Proteins
• Carbohydrates
• Lipids
• Vitamins
• Hormones
• Electrolytes
• Cellular wastes

Red marrow from hemocytoblasts or hematopoietic stem cells

• Erythrocytes
• Biconcave discs
• Able to readily squeeze through capillaries
• Lack nuclei and mitochondria

• One-third hemoglobin:
• Oxyhemoglobin (bright red)
• Deoxyhemoglobin (dark red)
• Other two-thirds of volume:
• Membrane
• Water
• Electrolytes
• Enzymes

• 4,600,000 – 6,200,000 in males
• 4,200,000 –5,400,000 in adult females
• 4,500,000 – 5,100,000 in children

• During embryonic development: Yolk sac
• During fetal development:
• Liver
• Spleen
• Later development (Infancy and childhood):
• Red marrow of bones
• Adulthood:
• Red marrow of bones

• Protect against disease
• Hormones stimulate WBC development
• Transported to sites of infection by the blood
• 5 Types of WBCs in circulating blood

• Neutrophils
• Eosinophils
• Basophils
• Lymphocytes
• Monocytes

• Neutrophils
• Eosinophils
• Basophils
• Characteristics:
• Twice the size of RBCs
• Develop in red bone marrow
• Life span of 12 hours

• Lymphocytes
• Monocytes

• Light purple granules in acid-base stain
• Number of lobes increases with age
• First to arrive at infections
• 54% - 62% of leukocytes

• Coarse, deep red granules in acid stain
• Bi-lobed nucleus
• Moderate allergic reactions
• Defend against parasitic worm infestations
• 1% - 3% of leukocytes

• Deep blue granules in basic stain
• Similar to eosinophils in size and shape of nuclei
• Granules can obscure view of nucleus
• Bi-lobed nucleus
• Migrate to damaged tissue
• Release histamine, which promotes inflammation
• Less than 1% of leukocytes

• Largest of all blood cells
• Spherical, kidney-shaped, oval or lobed nuclei
• 3% - 9% of leukocytes
• Life span of several weeks to months

• Slightly larger than RBC
• Large, spherical nucleus surrounded by thin rim of cytoplasm
• May live for years
• T cells and B cells

• WBCs protect against infection
• Leukocytes can squeeze between the cells of a capillary wall and enter the tissue space outside the blood vessel (called diapedesis)
• Cellular Adhesion Molecules help direct leukocytes to site of injury

• May become so engorged with digestive products & bac toxins that they die
• Ingest bac and smaller particles.

• May become so engorged w/ digestive products & bac toxins that they die
• ingest larger particles and have lysosomes that release digestive enzymes that break down organic molecules in digested bacteria.

• Life span of 10 days
• Cell fragments of megakaryocytes
• lack a nucleus
• Roughly half the size of a RBC
• Help repair damaged blood vessels by sticking to broken surfaces

• Straw colored, clear
• 55% of blood volume
• 92% water
• 8 % complex mixture of organic and inorganic biochemicals

• Transports nutrients, gases, and vitamins
• Helps regulate fluid and electrolyte balance
• Maintains pH

• stoppage of bleeding
• Actions that limit or prevent blood loss after injury to a blood vessel include:
• Blood vessel spasm
• Platelet plug formation
• Blood coagulation

• Smooth muscle in blood vessel contracts
• Effect lasts 30 minutes
• By the time the effects of the vasospasm wear off, further blood loss is minimized by:
• Platelet plug formation
• Blood coagulation
• Platelet-induced release of serotonin

• Platelets adhere to rough surface to form a plug
• Shape of platelets changes upon adherence to collagen
• Platelets adhere to each other to form a plug
• Larger vessels may require formation of a blood clot

Most effective hemostatic mechanism