Cell Biology and Cellular Transport PDF

Cell biology and Cell organelles: Structure and function Cell membrane cellular transport Composed of:...

Cell biology and Cell organelles: Structure and function Cell membrane cellular transport Composed of: two layers of phospholipids (Lipid bilayer) Nucleus The outer surface of the nucleus consists of a double layered membrane, - nuclear membrane – keeps the Nucleolus Dense region within the nucleus components of ribosomes (RNA and Cholesterol DNA within the nucleus. ribosomal proteins ) are synthesized Eukaryotic cells Proteins The nuclear membrane is- bridged by nuclear permit the Function: passage of certain small proteins and RNA molecules. Protective barrier Any cell that contains a clearly Function Regulate transport0 in & out of cell (selectively permeable) Information center of a cell defined nucleus and membranous Allow cell recognition contains most of the cell’s genetic bound organelles Provide anchoring sites for filaments of cytoskeleton material in the form of long molecules of DNA. Provide a binding site for enzymes Animal, plants, fungi Interlocking surfaces bind cells together (junctions) Contains the cytoplasm (fluid in cell) Prokaryotic cells Any unicellular organisms that Ribosomes Endoplasmic reticulum does not contain a membrane Small structures composed of RNA and certain proteins that are either floating freely in the cytoplasm or are An extensively folded, membranous system surrounding a fluid-filled space. bound nucleus or organelle A portion of the ER connects to the nuclear membrane. attached to the endoplasmic reticulum. Bacteria Function: Some regions of the ER’s outer surface are dotted withOribosomes, called rough ER. Responsible for making specific proteins. Regions without ribosomes are called smooth ER. They assemble amino acids into proteins by connecting Rough ER is involved in the synthesis of proteins. the appropriate amino acids in the correct sequence Smooth ER synthesizes lipids, including some hormones. (enzymes too). Smooth ER is also responsible for packaging the proteins and lipids for delivery to the Golgi apparatus. Golgi apparatus Vesicles Mitochondria A series of interconnected fluid filled spaces Membrane-bound spheres that enclose something within the cell Bean shaped surrounded by membrane, much like a stack of Enclose and transport the products of the ER and Golgi apparatus. 2 membranes –smooth plates Secretory vesicles - contain products destined for export from the cell. outer membrane and inner membrane with numerous folds. Cell’s refining, packaging, and shipping They generally derive from Golgi apparatus membrane. Responsible for providing most of the usable energy – center. Endocytotic vesicles - enclose bacteria and raw materials from the Powerhouse of the cell extracellular environment. Peroxisomes - contain enzymes destroy various toxic wastes produced in the cell, including H2O2 and that has entered from outside like alcohol. Lysosomes - contain powerful digestive enzymes that can digest bacteria and other large objects. Cell structures for support and movement Cytoskeleton Cilia and flagella consists of a loosely hairlike cilia are only 2–10 microns long. Centrioles structured network of fibers tail like Flagella approx. 200 microns long Short, rodlike microtubular structures located near the nucleus. made of protein called Cilia move materials along the surface of a cell with a Involved in cell division and participate in aligning and microtubules (tiny hollow brushing motion – commonly seen on cells that line the dividing the genetic material of the cell tubes) and microfilaments (thin solid fibers). airways. Support the cell In humans, flagella are found only on sperm cells for Forms a framework for the soft plasma membrane movement Also support and anchor the other structures within the cell DIFFUSION Osmosis Diffusion is a PASSIVE process which means no energy is used Diffusion of water across a membrane to make the molecules move, they have a natural KINETIC Moves from HIGH water potential (low solute) to LOW water ENERGY potential (high solute) Simple Diffusion Requires NO energy Types of Transport Proteins Facilitated Diffusion Molecules move from area of HIGH Some Carrier proteins do not extend Channel proteins are embedded in the cell to LOW concentration through the membrane. membrane & have a pore for materials to cross Carrier proteins can change shape to move material They bond and drag molecules through Facilitated diffusion from one side of the membrane to the other the lipid bilayer and release them on the Doesn’t require energy opposite side. Uses transport proteins to move high to low concentration Examples: Glucose or amino acids moving from blood into a cell.  Chemistry of Living The Atom The electrons move in paths called shells or energy levels. things & Biomolecules Atoms have the same number of electrons and protons. Therefore, they are electrically neutral (have no electrical charge). The Atom Atomic number - the characteristic number of protons in the nucleus An atom is the smallest unit of any element that still retains the Atomic mass (or mass number)=total number of neutrons and protons. physical and chemical properties of that element. The center core is called the nucleus. Isotopes The nucleus made of particles - protons and neutrons Atoms with either more or fewer neutrons than the usual number for that element are Protons - positive charge (+1) called isotopes. Neutrons - no electrical charge (0). have the same atomic number as the more common atoms but a different atomic mass. Negatively charged particles - electrons (-1) revolve around the nucleus at different distances from the nucleus. H-bond Covalent bond Ionic bonds A hydrogen bond is a force of attraction A covalent bond is a chemical bond that A chemical bond formed when atoms lose between a hydrogen (H) atom which is involves the sharing of electron pairs or gain electrons is called an ionic bond. bound to a more electronegative atom or between atoms. the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion. group, Organic and Inorganic Compounds PH Organic compounds are compounds that contain both carbon and hydrogen. The classes of organic compounds found in living things are: A pH above 7 indicates that the solution is basic. Carbohydrates The lower the pH number, the stronger the acid solution is. The higher the pH, the more strongly basic is the solution. Proteins Lipids Carbohydrates Carbohydrates are the main source of energy Nucleic acids for cell activities. Inorganic compounds: Compounds that do not contain both carbon and hydrogen. starch and sugar Carbohydrates are made up of the elements Proteins - carbon, oxygen, and hydrogen. Proteins also play an Important role in cell repair and growth. Proteins form important cell products such as enzymes, hormones, antibodies, and hemoglobin. The simplest carbohydrates are called monosaccharides Proteins are made up of- carbon, hydrogen, oxygen, and nitrogen. Like glucose Proteins are composed of simpler units (building blocks) called amino acids. There are twenty amino acids found in living things. When two simple sugars combine, they form a disaccharide or double sugar. Two amino acids bonded together form a dipeptide. Like maltose Many amino acids bonded together form polypeptides. Long chains of monosaccharides (sugar Primary structure - represented by its amino acid sequence. In writing, each amino acid is indicated by a molecules) bonded together form polysaccharides. three- letter code. glycogen, starch (energy storage) and cellulose Secondary structure - describes how the chain of amino acids is oriented in space. (structural support). Tertiary structure - refers to how the protein twists and folds to form a 3D shape. The protein’s 3D structure Lipids depends in part on its sequence of amino acids Lipids are a source of stored energy in living organisms. Lipids include triglycerides, phospholipids and steroids. Quaternary structure - refers to how many polypeptide chains make up the protein and Triglycerides – neutral fats- composed of a molecule of glycerol and three fatty how they associate with each other. acids. Saturated fats have a full complement of two hydrogen atoms for each carbon in their tails. Nucleic Acids In saturated fats, the tails are fairly straight, allowing them to pack closely Nucleic acids are very large molecules made up of carbon, oxygen, nitrogen - together- generally solid at room temperature, the unsaturated is not straight and have fewer than two hydrogen atoms on one or more of the carbon atoms and phosphorus. - Phospholipid The simplest unit or building block of nucleic acids is the nucleotide. They have a molecule of glycerol as the backbone, but they have only two fatty acid Nucleotides are composed of Steroids - relatively insoluble in water. a sugar molecule, a nitrogen base, and a phosphate group. Steroids consist of a backbone of three 6-membered carbon rings and one 5- DNA and RNA are two kinds of nucleic acids. membered carbon ring to which any number of different groups may be DNA makes up genes and is involved in heredity. RNA is involved in the making of attached. proteins.  Genetics and Genetics is the study of genes and their transmission from one generation to the next. Inheritance is something received from an ancestor or another person. In terms of genetics, each of us inherits one complete set of genes from our inheritance mother and one set from our father. Chromosomes Chromosome Size Chromosomes are partially composed of DNA. The size of chromosomes varies depending upon the stages of cell division. Genes are DNA sequences that contain instructions for building proteins. Interphase: longest & thinnest Humans have 23pairs of chromosomes (22 pairs of autosomes + a pair of sex chromosomes). Prophase: progressive decrease in length and increase in thickness Autosomal gene is located on the 22 autosomes. Anaphase: chromosomes are smallest. Sex linked gene is located on X & Y chromosome. Metaphase: easily observed, very thick, quite short and well spread A composite display of all the chromosomes of an organism is called a karyotype. in the cell. Dominant vs. Recessive Gene A dominant allele is expressed even if it is paired with a recessive allele. A gene is a segment of DNA that carries the code for making one or more proteins. A recessive allele is only visible when paired with another recessive allele. Humans have about 30000 different genes on 23 pairs of chromosomes. two alleles of the same gene is to assign them uppercase (such as A) and lowercase Locus - copy of the same gene at the same location on chromosome letters Alleles - Each person has two identical or nearly identical copies, For example Dominant alleles are not always common in a population. called alleles (alternative versions of genes), which are located at the Polydactyly, or the presence of extra digits, is an uncommon A.A Homozygous dominant same locus on two homologous chromosomes. One allele was inherited from each parent. A.a a.a E Heterozygous dominant Homozygous recessive phenotype in both humans and cats caused by a dominant allele. Differences between alleles are the result of rare mutations over millions of years of evolution. Codominance A.A Homozygous and Heterozygous T Codominance: Both gene products are equally expressed. If an individual possesses two identical alleles of a particular gene, the person is said to be homozygous for that gene. Eg: Blood type (3 alleles- A,B and O) , Sickle cell anemia A.a = A person who has two different alleles of a gene is heterozygous. Complete set of alleles is called genotype. Sex-linked inheritance The expression of a genotype is termed a phenotype depends on genes located on sex chromosomes X-linked-if the genes located only on the X Polygenic Traits Come from Several Genes Combined chromosome Inheritance of phenotypic traits that depend on many genes is called Y-linked - if the gene is located only on the Y chromosome. polygenic inheritance. X-linked inheritance seen because many of the genes on the X Combined expression of several genes chromosome are not related to sex determination at all. For example, eye color is controlled by at least three relatively few well-documented examples of Y-linked inheritance- genes, yielding a range of different eye color the Y chromosome is relatively small and many of its genes relate phenotypes from nearly black to light blue. to “maleness.” Skin and eye color; many variations due to the amount and distribution of melanin. Chromosomes may be altered in number or structure X-linked disease An example- hemophilia (bleeder’s disease). Hemophiliacs lack a blood- clotting factor that is encoded by an X-linked gene with two alleles. The recessive allele (Xh) is a mutant that cannot produce the clotting factor, whereas the dominant allele (XH) produces the clotting factor. Individuals have the disease only  Homeostasis Factors homeostatically regulated include: Concentration of nutrient molecules The environment that surrounds the cells of a multicellular Concentration of water, salt, and other electrolytes organism (their external environment) is the internal Concentration of waste products environment of the organism. Concentration of O2 = 100mm Hg and CO2 = 40 mmHg Relative constancy of the conditions within the internal pH = 7.4 environment is called homeostasis (homeo- “un- changing” or Blood volume 4-6 L and pressure 120 /80 mm of Hg “the same,” and -stasis “standing” Temperature = 37℃ Maintenance of Homeostasis Homeostatic Control Systems Nervous system Control systems are grouped into two classes – Controls and coordinates bodily activities that require rapid responses – Intrinsic controls – Detects and initiates reactions to changes in external environment Local controls that are inherent in an organ Endocrine system – Extrinsic controls – Secreting glands of endocrine regulate activities that require duration Regulatory mechanisms initiated outside an organ rather than speed Accomplished by nervous and endocrine systems – Controls concentration of nutrients by adjusting kidney function, controls internal environment’s volume and electrolyte composition Feed forward - term used for responses made in anticipation of a change omeostasis is continually being Feed back - refers to responses made after change has been detected disrupted by – Types of feedback systems – External stimuli Negative - fixes or opposes the initial change heat, cold, lack of oxygen, pathogens,toxins Positive - Keep the change going in the direction it is already moving - Produce more of the product that is accumulating – Internal stimuli Body temperature Negative feedback A controlled variable. A control center. Blood pressure receives input from the sensor and compares it to Concentration of water, glucose, salts, The focal point of any negative feedback control loop. the correct, internally any physical or chemical property that might vary from time to time and oxygen, etc. set value of the controlled variable- the set that must be controlled to maintain homeostasis. Physical and psychological distresses Examples : blood pressure, body temperature, and the concentration of point. Disruptions can be mild to severe glucose in blood. When the current value and the set point are not If homeostasis is not maintained, ii. A sensor (or receptor). in agreement, the control center sends signals death may result The sensor monitors the current value of the controlled variable and sends (again, via either nerves or hormones) to an the information (via either nerves or hormones) to the control center. effector. Homeostatic control Systems iv. An effector. In order to maintain homeostasis, control system must takes the necessary action to correct the be able to imbalance, in accordance with – Detect deviations from normal in the internal environment Positive feedback the signals it receives from the control center. that need to be held within narrow limits Positive feedback amplifies events – Integrate this information with other relevant information a change in the controlled variable sets in motion a series of events that amplify the original change. – Make appropriate adjustments in order to restore factor to Example : the process of childbirth. Once labor has started is governed its desired value by positive feedback mechanisms. Variables produce a change in the body To terminate positive feedback events - The contractions of childbirth The three interdependent components of control end when the child is born. not a mechanism for maintaining homeostasis. mechanisms: – Receptor – monitors the environments and responds to changes Thermoregulation:Cold Stress Thermoregulation:Heat Stress (stimuli) When your core temperature falls below its When your core temperature rises above its – Control center – determines the set point at which the variable is set point, the set point, the hypothalamus: maintained hypothalamus: i. Sends fewer nerve impulses to blood – Effector – provides the means to respond to stimuli i. Sends more nerve impulses to vessels in the skin, causing blood vessels in the skin, causing the blood vessels to dilate. This increases - the blood vessels to constrict. This - blood flow to your skin restricts blood flow to your skin and and promotes heat loss. reduces heat loss. ii. Activates your sweat glands. As - ii. Stimulates your skeletal muscles, perspiration evaporates from your causing brief bursts of muscular skin, you lose heat. contraction known as 8 shivering. Shivering generates heat Organ system Epithelial Tissue Tissues Epithelial tissues are widespread throughout the body. Tissues are groups of specialized cells that are similar They form the covering of all body surfaces, line body cavities and hollow organs and in structure and that perform common functions. are the major tissue in glands. Cells combine to form four primary tissues Functions: protection, secretion, absorption, excretion, Filtration, diffusion and sensory – Epithelial tissue reception. – Connective tissue Two types: – Muscle tissue – Membranous epithelia > In every membrane - – Nervous tissue form the coverings or linings of organs Connective Tissue – Glandular epithelia - In every gland Connective tissues bind structures together, form a form exocrine and endocrine glands framework and support for organs and the body as a Types of Epithelium tissues whole, Epithelial cells may be squamous, cuboidal, or columnar in shape store fat, transport substances, protect against disease, and may be arranged in single or multiple layers. and help repair tissue damage. - v Connective tissues are characterized by an abundance Osseous Tissue Double layer Seem like multilayer of intercellular matrix with relatively few cells. Consists of bone cells (osteocytes) and a calcified Connective tissue cells are able to reproduce but not as cartilage matrix rapidly as epithelial cells. Muscle Tissue Most connective tissue has a good blood supply but Muscle tissue is composed of cells that have the special ability to shorten or contract in order some do not. to produce movement of the body parts. Connective Tissue The tissue is highly cellular and is well supplied with blood vessels. Binds the cells and organs of the body together Cells are long and slender - muscle fibres, and these are usually arranged in bundles or layers –All connective tissues consist of two basic components: cells and extracellular fibers that are surrounded by connective tissue. Two types of connective tissue Actin and myosin are contractile proteins in muscle tissue. are: Muscle tissue can be categorized into –Fibrous connective tissue. skeletal muscle tissue, –Specialized connective tissue. smooth muscle tissue and An important structural component of organs. cardiac muscle tissue. –Consists of two types: Muscle Tissue Dense connective tissue Consists of specialized cells that contract when stimulated The body has three types of muscle tissue: Loose connective tissue Skeletal (voluntary) Dense connective tissue– Cardiac (involuntary) dense regular Smooth muscle (involuntary). dense irregular Nervous Tissue elastic Nervous tissue is found in the brain, spinal cord and nerves. Loose Connective Tissue It is responsible for coordinating and controlling many body activities. Areolar It stimulates muscle contraction, creates an awareness of the environment, and plays a major role Adipose in emotions, memory and reasoning. Reticular To do all these things, cells in nervous tissue need to be able to Specialized Connective Tissues communicate with each other by way of electric nerve impulses. Perform specific functions essential to homeostasis Nervous Tissue The body contains three types of specialized Contains specialized cells that conduct impulses connective tissue: Cartilage Conducting cells, called neurons, transmit impulses Cartilage –Consists of specialized cells from one region of the body to another. Bone embedded in a matrix of extracellular Non conducting cells, neuroglia, are a type of nervous system connective tissue. Blood fibers and other extracellular material Organ Systems Blood Tissues combine to form organs. –Contains blood cells, platelets, Organs are discrete structures that have evolved to perform specific functions plasma Most organs do not function alone, they are part of a group of cooperative organs, called an organ system  Sensory (afferent) Divisions of the Nervous System Motors (efferent) Nervous System T Divisions ↑ CNS # 2 Division - Somatic sensory Brain and spinal cord Visceral motor Visceral sensory 1 Somatic motor General: General: stretch ~ V General: motor General: motor touch,pain,pressure, pain,temperature PNS innervation off innervation off all vibration ,chemical Central nerves and spinal nerves all skeletal skeletal temperature changes muscles muscles ,cardiac Special: Special:taste muscles to ANS hearing,equilibrium, Action potential Neuron vision and smell Sodium channels close Each neuron contains: Potassium channels open Sodium diffuses into the Potassium diffuses out of axon - Cell body with nucleus, mitochondria ,other cell organelles Loss of positive ions from cytoplasm of axon - Dendrites : fibers that receive messages from other neurons Membrane depolarizes cell – repolarization (inside - Axons : fibers that send messages to other neurons (meaning membrane of axon again negative) potential shifts from negative Neurons do NOT touch; there is a gap between them called a (-70mV) to positive (+ 30mV) synapse Messages are sent across the synapses by special chemicals called neurotransmitters Structural classification of the neurons Anaxonic Pseudounipolar Biploar No axon One axon Two fibers Interneurons Somatic sense neurons In retina for vision Multiploar Neurotransmitter Many extensions and one axon Once an action potential reaches the axon terminals of a neuron, the information inherent in it must be converted to another form for Motor neurons transmitting to its target (muscle cell, gland cell, or another neuron). the action potential causes the release of a chemical that crosses a specialized junction Myelinated neurons :it has myelin sheath between the two cells called a synapse. Unmyelinated neurons:no myelin sheath This chemical substance is called a neurotransmitter because it transmits a signal from a neuron to its target. Neuroglia cells The entire process of transmission from a neuron to its target is called - synaptic transmission. Neuroglial cells support and protect neurons. Do not generate or transmit impulse Schwann cells (in the PNS) – produce fatty Parts of Brain insulating Cerebrum largest part of human brain material – myelin Responsible for: Thought,Language,Senses,Memory,Voluntary movement Occipital Cerebellum Cerebellum at base of brain Frontal -Responsible for: Muscle coordination,Balance and Posture Lobes of the Brain Brain Stem connects brain to spinal cord Brain stem Frontal Disorders of the Nervous System -Responsible for: Breathing,Swallowing ,Heartbeat and Blood pressure Parietal Parkinson’s Disease It is a motor disorder occurring due to neurodegeneration in substantia nigra(part of basal ganglia). Occipital Alzheimer’s Disease Temporal It is a neurodegenerative disorder that results in memory loss.. Note: Occasionally, the Insula is Epilepsy considered Epilepsy is a common condition that affects the brain and causes frequent seizures. the fifth lobe. It is located deep to the Seizures are bursts of electrical activity in the brain that temporarily affect how it works. Temporal Lobe Paralysis Loss of sensation and movement of part of the body due to an injury of the spinal cord or brain  Endocrine System Classification of Hormones T They don’t have duct Protein: hormones of anterior pituitary (except ACTH),insulin ,parathyroid hormone. Endocrine:ductless organs that secrete their products Peptides :ACTH, calcitonin, glucagon, vasopressin, oxytocin, hormones of hypothalamus into interstitial fluid, lymph, and blood Derivatives of Amino acids:catecholamine(epinephrine and norepinephrine)thyroxin, ↑ They have duct triiodthyronin, hormones of epiphysis Exocrine gland: secrete products such as mucus, sweat, Steroid (cholesterol):hormone of cortex of epinephrine tears, and digestive fluids into ducts that empty into - Any hormone that end with RH is coming from the appropriate sites. The Hypothalamus Mechanism of steroid hormone Mechanism of nonsteroid hormone The hypothalamus - homeostatic control center. It is an important link action on a target cell. action on a target cell between the nervous system and the endocrine system. It receives neural input about certain internal environmental conditions such as water and solute balance, temperature, and carbohydrate metabolism. The Pituitary Gland ↓ Tropic The anterior pituitary (or adenohypophysis) is a lobe of the gland that regulates several physiological processes including stress, growth, reproduction, and lactation. The intermediate lobe synthesizes and secretes melanocyte-stimulating hormone. The posterior pituitary (or neurohypophysis) is a lobe of the gland that is functionally connected to the hypothalamus by the median eminence via a small - tube called the pituitary stalk Local Hypothalamic Control of the Anterior Pituitary Hormonal control mechanism Hypothalamic neurons synthesize releasing and inhibiting peptide hormones. Disorders of Pituitory gland These are transported to axon endings in the median eminence where they GH may be secreted in excess or there can be deficiency of GH are secreted into the hypothalamo-hypophyseal portal system to reach with different clinical manifestations receptors that regulate the secretions of anteriorpituitary hormones GH abnormalities can occur both in children and adults Excess of GH: gigantism in children and Acromegaly in adults Anterior Pituitary Trophic Hormones and Their Actions Deficiency of GH: Dwarfism in children– Rare in adults Thyroid and Parathyroid Gland Thyroid gland- below the larynx at the front of the trachea, and consists of two lobes The two main hormones produced by the thyroid gland - thyroxine and calcitonin. The four small parathyroid glands are embedded in the back of the thyroid. The parathyroid glands produce parathyroid hormone. Help to regulate calcium balance & role in controlling metabolism. Thyroid Gland Thyroid Gland Disorders Produces two very similar hormones Goitre- A goitre, or goiter, is a swelling in the neck resulting from an enlarged thyroid called thyroxine (T4) and triiodothyronine (T3). gland. The main cause is iodine deficiency Hypothroidism- Deficiency of secretion of thyroid hormones In children lack of thyroid hormones leads to stunted growth and mental retardation In adults it leads to lack of energy, dry skin and weight gain Hyperthyroidism- Increased secretion of thyroid hormone. Nervousness, irregular heart rate and weight loss The most common form of hyperthyroidism is Graves’ disease  Parathyroid hormone (PTH) Low blood calcium Inhibiting =C Adrenal Glands Controls blood calcium levels E Bone weakening Two adrenal glands, each weighs about 4 gm lie at the Parathyroid hormone (PTH) : superior poles of the two kidneys. Removes calcium and phosphate from bone, Each gland is composed of two distinct parts: Increases absorption of calcium by the digestive tract, Causes the kidneys to retain calcium and excrete phosphate. adrenal medulla (20%) and adrenal cortex (80%) Pancreas Adrenal Cortex Both an endocrine gland (secreting hormones into Zones of Adrenal gland Zona glomerulosa the blood) and an exocrine gland (secreting enzymes, fluids, and ions into the digestive Outer 15% of the adrenal cortex secrete aldosterone (mineralocorticoid) tract to aid in digestion). (aldosterone synthase) mainly controlled by : Alpha cells: secrete glucagon-raises blood sugar a) Renin- Angiotensin system Beta cells : secrete insulin-lower blood sugar b) Plasma potassium level Delta cells: secrete somatostatin Zona faciculata Middle 75% of the adrenal cortex Disorders of Pancreas Secretes Cortisol and Corticosterone; (glucocorticoids) Diabetes small amounts of adrenal androgens and estrogen Type 1 diabetes- failure of pancreas to produce enough insulin - insulin controlled by: hypothalamic-pituitary axis via ACTH dependent diabetes - an autoimmune disorder in which the person’s own Zona reticularis immune system attacks the insulin-producing cells in the pancreas. Deep layer of the cortex secretes the adrenal androgens: dehydroepiandrosterone and Type 2 diabetes (non-insulin-dependent diabetes)— cells fail to respond androstenedione adequately to insulin even when it is present. Type 2 diabetes may have a small amounts of estrogens and glucocorticoids genetic component, but lifestyle factors are thought to be the major controlled by : ACTH & cortical androgen-stimulating hormone determinants. Adrenal medulla Disorders of Adrenal Gland Addison’s disease: Too little cortisol and aldosterone Produces the nonsteroid hormones epinephrine Lack of cortisol lowers blood glucose levels, and lack of aldosterone (adrenaline) and norepinephrine (noradrenaline) and lowers blood sodium. dopamine chronic symptoms of fatigue, weakness, abdominal pain, weight loss, and Opioid peptides (encephalin) & adrenomedullin a characteristic “bronzed” skin color. Play roles in metabolism and controlling blood Cushing’s syndrome: Too much cortisol pressure and heart activity. The symptoms of Cushing’s syndrome are due to the exaggerated effects Reproductive Hormones of too much cortisol, including Reproduction is regulated by: *excessive production of glucose from glycogen and protein Gonadotrophins (FSH and LH) released by pituitary gland * retention of too much salt and water. Sex hormones released by the gonads (ovaries in females and testes in males) Hormones of endocrine glands other than hypothalamus Action of gonadal hormones and pituitary Androgens are primarily testosterone- the male sex hormone Testosterone regulate the development and function of male reproductive system During puberty they cause the appearance of male secondary sexual characteristics Estrogen and progesterone cause the development of female secondary sexual characteristics, regulate the menstrual cycle, prepare and maintain the uterus during pregnancy