Anatomy and Physiology: Homeostasis, Hormone Regulation, and Body Cavities - Prof. William, Study notes of Physiology

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CHAPTER ONE–Major Themes of Anatomy and Phys

 What is anatomy: study of the “structure”  What is physiology: study of the “function”  Relationship between the two is very strong  Homeostasis: ability of internal system to remain stable  Homeo: “home”  Stasis: “staying the same”  Examples: o Body temperature: 98.6 deg F or 37 C o Blood pH: 7.35-7.  > 7.45: alkalosis  <7.35: acidosis o Blood glucose: 80-100mg/100mL  Hormone Regulation of blood glucose:  If you eat a heavy meal, blood glucose rises and insulin is secreted by the beta cells of the Islets of Langerhans of the Pancreas…  In the Liver glucoseglycogen  After a period of starvation, glucagon is secreted by the alpha cells of the Islets of Langerhans of the Pancreas…  In Liver glycogenglucose  The Thyroid

 Negative Feedback Mechanism of the Thyroid:  Hypothalamus secretes TRH “Thyrotropin-releasing hormone”  This causes the anterior pituitary’s thyrotropes (cell type) to release TSH “Thyroid stimulating hormone”  The causes the thyroids follicular cells to release TH “thyroid hormone” (T3) which is a metabolic hormone.  Once there is enough TH, the excess amount goes and stops the hypothalamus from releasing TRH and likewise stops the anterior pituitary from releasing TSH.  Hypothyroidism: (usually gain weight)  Can happen if you do not get enough iodine  T3 contains 3 iodine atoms--“triiodothyronine”  If you have a decrease in T3, decrease in metabolic hormones  Because of this, the negative feedback system does not kick in so you have an increase in TSH, which causes a “goiter,” or enlarged thyroid.  Hyperthyroidism: (usually lose weight)  Increase in T3 (metabolic hormones) but decrease in TSH from the anterior pituitary and decrease in TRH from hypothalamus because of the negative feedback system  Positive feedback mechanism of Parturition (delivery of baby):  Posterior Pituitary is the storage site of Oxytocin (OT)  OT is nicknamed the “love hormone” and promotes bonding  OT also responsible for milk ejection or “letdown”  Head of the baby pushes the cervix, causing a wave of nerve impulses to the brain causing the posterior pituitary to release OT.  OT reaches the cells of the uterus causing contraction  The baby pushes more on the cervix, and the positive feedback loop begins.  Picture

 Optic chiasm: where two optic nerves meet  Anterior pituitary: contains many cell types that secrete own hormone  Posterior Pituitary: Storage site for OT and ADH “Anti-diuretic hormone”  The Anatomical Position:  Body Erect  Feet on floor  Hands @ side  Palms facing forward  Hands “supinated” as opposed to pronated  Anatomical Language and terms:  Anterior vs. posterior a.k.a ventral vs. dorsal  Exterior vs. interior a.k.a superficial vs. deep

 Superior vs. inferior  Medial vs. lateral  Ipsilateral vs. contralateral  Ipsi: same side, 2 ears ipsilateral  Epi “above” vs. Hypo “below”  Epidermisdermishypodermis  Proximal vs. distal  Different regions of the abdomen:  4 quadrants:  Right upper quadrant  Left upper quadrant  Right lower quadrant  Left lower quadrant  9 abdominal regions (left to right by rows):  R hypochondriac epigastric L hypochondriac  ---------------------------------------------------subcostal line  R lumbar umbilical L lumbar  ----------------------------------------------------intertubercular line  R iliac hypogastric L iliac Columns separated by midclavicular lines

 Body Planes:  Coronal or frontal plane—runs vertically and divides body into anterior and posterior  Sagital plane: divides body into right and left portions  mid-sagital: runs in midline and gives equal sides  Transverse plane: divides body into superior and inferior portions  Body cavities:  Dorsal cavities:  Cranial that encloses the brain  Vertebral that encloses the spinal cord  All cavities enclosed in membrane: 3 layers that cover brain and spinal cord:  Dura mater—outermost  “Dura”: tough  “mater”: mother  Arachnoid membrane: filled with cerebral spinal fluid  Pia mater—innermost  “pia”: gentle  Ventral Cavities:  Thoracic cavities :  2 pleural cavities enclosing the 2 lungs  Mediastinum: compartment between two lungs including the heart, esophagus, trachea, and thymus  Pericardial cavity enclosing the heart “pericardium”

 Lined with serosa membrane (double layered membrane)  Outer layer (lining the cavity): parietal In between two layers serous fluid  Inner layer (covering the organ): visceral  EXAMPLES:  Parietal pericardium: outer layer of serosa membrane lining the heart cavity  Visceral pleura: inner layer of serosa membrane covering the lung  Abdominopelvic cavity : “peritoneum”  Encloses all viscera of abdomen/pelvic region  Also lined with double layer serosa membrane with serous fluid in between  Mesentery: part of the peritoneum attaching intestines to body wall (has many blood vessels and nerves)  Lesser omentum: attaches stomach to the liver  Greater omentum: covers small intestines like an apron –is unattached at its inferior border  Mesocolon: anchors colon to posterior wall  EXAMPLES:  Parietal peritoneum: outer layer of serosa membrane lining the peritoneal cavity  Visceral peritoneum: inner layer covering the organ  Retroperitoneal organs: posterior to the peritoneum—covered by peritoneum only on the side facing the peritoneal cavity  Organ include:  Kidneys, aorta, inferior vena cava, adrenal glands, ureters, and most of the pancreas  Levels of organization of the human body:

 #1–Atoms: The “Big Four” include:  Carbon—found in all organic molecules or “carbon molecules”  Hydrogen  Oxygen  Nitrogen—found in all proteins and nucleic acids (DNA and RNA)  Others include calcium for bones, potassium, sodium, chlorine, iron for hemoglobin of blood, iodine for thyroid hormone synthesis  #2–Molecules: Four types of organic molecules  Carbohydrates  Lipids  Proteins  Nucleic acids (DNA “deoxyribonucleic acid”, RNA “ribonucleic acid”)  #3-organelles:  nucleus, endoplasmic reticulum, golgi body, mitochondria, etc.  #4-cells:  At least 300 types of cells  Cytology: study of cells  #5-tissue: Four main types of tissues:  Muscle tissue  Epithelial tissue: covers body surface and lines body cavities that open to the exterior  Nervous tissue

 Connective tissue: blood, adipose, cartilage, bone  #6-organs  #7-organ systems  Integumentary system  Digestive system  Respiratory system  Muscular system  Circulatory (cardiovascular) system  Urinary system  Skeletal  Lymphatic (immune) system  Endocrine  Reproductive  Vitamin D as an example of interdependency bwn organ systems:  Sunlight and heat active keratinocytes (cell type of epidermis) to help turn cholesterol into vitamin D  In the liver, vitamin D3 is converted into calcidiol  In the kidneys, calcidiol is converted into calcitriol  Calcitriol is the most active form of vitamin D  Circulates in the blood to reach the small intestine  In the small intestine, helps enhance the absorption of calcium  Calcium then gets incorporated into osseous (bone) tissue

CHAPTER TWO – The Chemistry of Life

 Four main types of organic molecules:  Carbohydrates—made up of monosaccharides (simple sugars)  Proteins—made up of amino acids  Lipids—mostly made up of fatty acids and glycerol (3C molecule)  Nucleic acids—nucleotides  Carbohydrates:  Monosaccharides: simplest carbohydrates  Pentoses—5 carbon sugar  Ribose (C 5 H 10 O 5 )^ Deoxyribose (C 5 H 10 O 4 )  Hexoses—6 carbon sugar—all have formula C 6 H 12 O 6 (isomers)

 Glucose^ Fructose^ Galactose  Disaccharides: composed of two monosaccharides  All synthesized by dehydration (condensation) or the removal of water  Glycosidic bond—very strong covalent bond that joins sugars together  Sucrose = glucose + fructose  Humans cannot synthesize sucrose!! (Can break it down)  Lactose = glucose + Galactose  Milk sugar (C 12 H 22 O 11 )  Maltose = Glucose + glucose  Polysaccharides—many glucose units condensed together  Glycogen—  energy storage polysaccharide made^ primarily^ in the liver (read back to hormone regulation of glucose)  Long,^ branched^ system of glucose units  Only polysaccharide that animals can make

 Cellulose—  Energy storage polysaccharide of plants  Straight chain^ of glucose units  Proteins:  Amino acids are the structural unit  All proteins made because of gene expression (central dogma)  DNA(genes)----------------->RNA-------------------->Proteins  Genetic makeup=genotype; proteins make up phenotype (physical traits)  Examples of amino acids:  Glysine “Gly” (simplest a.a) Cysteine “Cys”

 Phenylalanine “Phe” Tyrosine “Tyr”  Phenylalanine:  We cannot synthesize phenylalanine making it one of the essential amino acids (meaning we must get it from diet)  Deficiency of phenylalanine hydroxydase because of a genetic disorder (meaning you got a bad gene from BOTH parents) results in accumulation of phenylalanine which is converted into phenyl ketonesthese attack neurons of the CNS causing disorder called PKU “phenylketonuria”  Babies tested at 1 day of age for PKU (prick ear for blood and test to see if ANY phenyl ketones present)  PKU baby has to be put on a very restricted diet that is almost completely free of phenylalanine and must stay like this for life ( no banana, milk, diet drinks)  BE ABLE TO SKETCH DIPEPTIDE BOND:  Gly-tyr depeptide

 Structures of proteins:  Primary structure:  Amino acid sequence  Secondary structure: structures held together by very weak hydrogen bonds that are easily broken and reformed  1. Alpha helix  2. Beta-pleated sheets  Keratin= hair protein rich in alpha helixes and beta-pleated sheets (weak hydrogen bonds allow for straight/curly hair)  Tertiary structure:

 Stabilized by^ covalent bonds:  Ie: disulfide bonds or “bridges”; only formed by two cysteine; contribute to stabilization of the protein  Formed by dehydrogenation  Example of protein rich in disulfide bridges:  Lysozyme: enzyme protein formed in lacrimal secretion- “tears” and in saliva  Function: breaks down peptidoglycan (bacteria cell wall)  Defense mechanism  Quaternary structure:  A single protein consists of more than one polypeptide chain  Hemoglobin (transports oxygen):  Consists of 4 polypeptide chains; 2 alpha helixes, 2 beta sheets

 Sickle cell anemia caused when mutation on #6 a.a on beta chain glutamate (glu)------> valine (val)  Cell is pointed, fragile, sticky  Because fragile, causes hemolysis which leads to hypoxemia (less than normal 0 2 level in blood) which in turn causes more sickling  Because sticky, causes agglutination (clumping) and clogs small blood vessels  Lipids:  Structural unit for most is fatty acids (carboxyl group + long chain of Carbons and hydrogens  Saturated fatty acids=animal fat  Pack easily with each other and are solid at room temperature  Unsaturated fatty acids=plant oils

 Double bond between two carbons in chain creates a “kink”  Fluid at room temperature because don’t pack well b/c kinks  Trans-fatty acids=  Packed together and solid at room temperature  Double bond becomes TRANS due to partial dehydrogenation  Stay forever in your blood vessels because resistant to degradation in circulation  Contribute to cardiovascular disease  Increases shelf life of products  Monoglyceride:  Glycerol (3 carbon alcohol)

 Glycerol connected to fatty acid by dehydration:  Fats with no fatty acids in structure:  Cholesterol: 3 six sided rings and 1 five sided ring

 Things made from cholesterol  Vitamin D  Steroid hormones (testosterone, progesterone)  Nucleic Acids: DNA, RNA  Structural unit called nucleotides  each nucleotide made of 3 components:  nitrogen base  purine (adenine, guanine)  pyrimidine (cytosine, uracil, thymine)  sugar  ribose, deoxyribose (look back in notes for picture)  phosphate group  attached to carbon 5 of sugar  label with P circled **nucleoside: no phosphate group, just nitrogen base + sugar