Nervous system and endocrine system

Homeostasis is the regulation of the internal environment to keep it constant. In that way organisms sense the changes in the external environment and adapt themselves to these changes or react to the changes. Nervous system and endocrine system work together for homeostasis.

Nervous system Endocrine system Nervous system reacts rapidly to the internal and external stimuli. Neurons play role in nervous system The effect of the nervous system is short term Endocrine system reacts slowly. Endocrine glands and blood play role in endocrine system The effect of the endocrine system is long term

Evolution of nervous system There is no nervous system, but cilia are connected to each other by their basal bodies within their membrane.

Nervous system in Invertebrates Coelenterates, cnidarians, and echinoderms have their neurons organized into a nerve net. These creatures have radial symmetry and lack a head . Bilaterally symmetrical animals have a body plan that includes a defined head and a tail region. Development of bilateral symmetry is associated with cephalization,

Neuron types Sensory neurons typically have a long dendrite and short axon, and carry messages from sensory receptors to the central nervous system. Motor neurons have a long axon and short dendrites and transmit messages from the central nervous system to the muscles (or to glands). Inter neurons are found only in the central nervous system where they connect neuron to neuron.

Transmission of impulses The plasma membrane of neurons has an unequal distribution of ions and electrical charges between the two sides of the membrane. The outside of the membrane has a positive charge, inside has a negative charge. This charge difference is a resting potential and is measured in millivolts. Passage of ions across the cell membrane passes the electrical charge along the cell. The voltage potential is -65mV of a cell at rest . http://www.mind.ilstu.edu/flash/synapse_1.swf

Nerve impulses are action potentials that move along the axons

Resting potential results from differences between sodium and potassium positively charged ions and negatively charged ions in the cytoplasm. Sodium ions are more concentrated outside the membrane, while potassium ions are more concentrated inside the membrane. This imbalance is maintained by the active transport of ions by sodium potassium pump. ATP is spent. Changed polarity of the membrane is called as action potential, it is caused by the transmission of the nerve impulse along the membrane. An action potential is a temporary change in the electrical potential along the membrane for a few milliseconds. To cause this change sodium and potassium channels open. At first Sodium channels open quickly and they enter the neuron. And inside becomes positively charged. Potassium channels open and they pass to the outside of the membrane. Eventually enough potassium ions pass to the outside to restore the membrane charges to those of the original resting potential. Some times more K ions pass and cell hyperpolarized. Then cell uses Na/K pump to to become polarized again.

The action potential begins at one spot on the membrane, but spreads to adjacent areas of the membrane, propagating the message along the length of the cell membrane. After passage of the action potential, there is a brief period, the refractory period, during which the membrane cannot be stimulated. polarization Depolarization Repolarization

Steps in an Action Potential At rest the outside of the membrane is more positive than the inside. Sodium moves inside the cell causing an action potential, the influx of positive sodium ions makes the inside of the membrane more positive than the outside. Potassium ions flow out of the cell, restoring the resting potential net charges. Sodium ions are pumped out of the cell and potassium ions are pumped into the cell, restoring the original distribution of ions.

Synapse The junction between a nerve cell and another cell is called a synapse. Messages travel within the neuron as an electrical action potential. The space between two cells is known as the synaptic cleft. To cross the synaptic cleft requires the actions of neurotransmitters. Neurotransmitters are stored in small synaptic vessicles clustered at the tip of the axon.

Speed of the impulse The strength of the impulse doesn’t effect the speed of the action potential. Speed can change with the myelin layer and the diameter of the axon. But the strength of the impulse can only increase frequency of the action potential. The frequency of the action potential can be changed with: The strength of the impulse The length of the impulse The frequency of the impulse.

Saltatory conduction in motor nerves In motor neurons schwann cells(glia cells) wrap axons to form myelin sheath. The gaps between myelin sheath are called nodes of Ranvier, where the axon is not covered with myelin. Myelin electrically insulates the axon; that is, charged ions cannot cross the regions of the plasma membrane that are wrapped. Action potentials therefore appear to jump from node to node down the axon. This form of impulse conduction is called saltatory (jumping) conduction and is much quicker than continuous propagation of action potentials down an unmyelinated axon.

Unipolar- Only one hücre gövdesinden sadece akson uzantısı çıkar Bipolar- karşılıklı iki uzantı vardır. Multipolar- Bu hücrelerde çok sayıda dendrit ve bir akson bulunur.

Human nervous system The Central Nervous System (CNS) includes the brain and spinal cord. The Peripheral Nervous System (PNS) connects the CNS to other parts of the body, and is composed of nerves (bundles of neurons). CNS The Central Nervous System (CNS) is composed of the brain and spinal cord .It collects all data and evaluates them for response. The brain is composed of three parts: the cerebrum (seat of consciousness), the cerebellum, and the medulla oblongata .

Brain Forebrain 1.4 kg has a surface areo of 2200 cm2 Cortex part(outer- grey matter ) 3-4 cm thick Grey matter contains cell bodies of the neurons. White matter is at the inside . White matter only contains axons(fibers) and glia cells. Brain Forebrain Cerebrum: It has 2 hemispheres.They are connected to each other by corpus callosum. The conscious brain includes the cerebral hemispheres. In reptiles, birds, and mammals, the cerebrum coordinates sensory data and motor functions. The cerebrum governs intelligence and reasoning, learning and memory Diencephalon: It contains hypothalamus, thalamus and hypophysis. They are very important or homeostasis. Brain membranes (meninges) Dıştan içe; sert zar, örümceksi zar ve ince zar. Cerebrospinal fluid is found between the meninges and in the central canal of the spinal cord. Cerebrospinal fluid: protects CNS .

Pituitary (hypophysis) Hypothalamus Thalamus Pituitary (hypophysis) The hypothalamus regulates homeostasis. It has regulatory areas for thirst, hunger, body temperature, water balance, and blood pressure, and links the Nervous System to the Endocrine System. It is related to the hypophysis(pituitary gland). The thalamus serves as a central relay point for incoming nervous messages. All senses except smell passes from this area. Pituitary is the important endocrine gland which controls many endocrine gland within the body.

Yarımkürelerin her biri vücudun zıt tarafını denetlemektedir. Sağ ve sol yarımküre Yarımkürelerin her biri vücudun zıt tarafını denetlemektedir. İnsanların %90-95'inin sol yarımküresi baskındır. El hareketini denetleyen motor alanlar sol yarımkürede baskın olduğu için insanların büyük çoğunluğu sağ elini kullanır. Herhangi bir nedenle sol yarımküre zarar görürse sağ yarımkürede baskın özellikler gelişebilir. Önemli işlevlerde öne çıkan yarımküre baskındır. Baskın yarımkürenin üstlendiği işlevler arasında dil öğrenimi, matematik, mantık gibi konular vardır. Baskın olmayan yarımküre ise müzik, resim ve yüzlerin tanınması gibi alanlarda etkindir.

Beyin Yarımküreleri Sağ yarımküre Sol elin denetlenmesi Tek sözcük anlamlan, ses perdeleri   Sezgisel mantık yürütme   Bütünleştirme   Görme, hayal, tasarım   Müzik, sanat yeteneği   Duyusal imge belleği   Yeniliği sever   Bakar, yapar Sol yarımküre Sağ elin denetlenmesi   Konuşma, ses, gramer Düşünme ve mantığa dayalı   Analiz   Dakiklik   Matematiksel olgularda yetenekli   Kısa süreli işitsel bellek   Otomatik tekrarları sever   Dinler, konuşur  

Homunculus-Duyular beyindeki alanları http://www.brainconnection.com/topics/?main=gal/homunculus

Midbrain Hind brain Midbrain contains reflex centers for visual, auditory and tactile responses . It is a passage way for these nerves. It contains Cerebellum and brain stem The cerebellum is the second largest part of the brain, after the cerebrum. It functions for muscle coordination and maintains normal muscle tone and posture. The cerebellum coordinates balance. Brain stem has medulla oblangata and pons. The medulla oblongata is closest to the spinal cord, and is involved with the regulation of heartbeat, breathing, vasoconstriction (blood pressure), and reflex centers for vomiting, coughing, sneezing, swallowing, and hiccuping. Pons, helps medulla .

Spinal cord Reflex center Connects peripheric nervous system to the brain. It is protected by the vertebrae. Grey matter is inside and white matter is outside the spinal cord. Grey matter can be seen as butterfly in cross section.

Transmission of impulse between neurons (synapse types) Single impulse spreads to different organs Single neuron is stimulated by many neurons Effect of an impulse is increased synapse feedback

REFLEX Reflexes are quick responses without evaluation of the information. receptors sensory neurons (dorsal) interneurons in spinal cord (effector)Muscles (Ventral) motor neurons Response is quick so brain can’t interfere with it. But information is conducted to the brain.

Peripheral Nervous system Nerves in the peripheric nervous system connect central nervous system to the other organs. 12 pairs come out of the brain and conrol sense organs, muscles, endocrine glands 31 pairs come out of the spinal cord-they are either sensory or motor neurons Nerves of the peripheral nervous system are grouped into 2 according to their job. Somatic Nervous system: includes sensory and motor nerves. They extend from CNS to muscles. Their axons are myelinated, diameter is large and impulse conduction is fast. They control the voluntary activities. Running, singing, writing Autonomic Nervous system: Controls the activities of the internal organs. They are not myelinated. They control involuntary activities. Sympathetic- Parasympathetic- http://itc.gsw.edu/faculty/gfisk/anim/autonomicns.swf

The autonomic nervous system is divided into two parts: the sympathetic and parasympathetic divisions. These two divisions work in opposition to each other in their effects on most organs, one causing an increase in activity and the other causing a decrease.

Engelleme Bir uyarı sinapstan geçerken bir diğer uyartı etkisiz hale getirilebilir. Buna engelleme denir. Kolaylaştırma Bir uyarı sinapstan geçerken bir diğer uyartıyı daha şiddetli hale getirilebilir. Bu sayede daha kolay geçebilir. Buna kolaylaştırma denir. Alışkanlık kazanma Dans etmek, bisiklete binmek alışkanlıktır. Bu hareketler önce beyin kontrolünde öğrenilir sonra otomatikleşir ve omurilik tarafından kontrolü devam eder.

Sinir hücresinden sinir hücresine uyartı geçişi Sinaps Seçici direnç

Senses Sensory cells transduce (convert) physical or chemical stimuli into signals that are transmitted to other parts of the nervous system for processing and interpretation. Sensory cells are generally called receptors. Animals receive information about chemical stimuli through chemoreceptors. Chemoreceptors, such as those for taste and smell, are stimulated by changes in the chemical concentration of substances such as the level of carbon dioxide in the blood Mechanoreceptors are sensitive to mechanical forces. (touch, heat, vibrations) Thermoreceptors, such as the temperature receptors in the skin, are stimulated by changes in temperature. Pain receptors, such as those in skin, are stimulated by tissue damage. Photoreceptors, which are only located in the eye, are stimulated by light energy.

Some sensory cells give gradually diminishing responses to repeated stimulation. This phenomenon is known as adaptation (desensitization), and it enables an animal to ignore background or unchanging conditions while remaining sensitive to changes or to new information. When you dress, you feel each item of clothing touch your skin, but the sensation of clothes touching your skin is not constantly on your mind throughout the day.

Taste organ- tongue The sensory receptors for the sense of taste are located in taste buds. Taste buds are embedded in epithelium primarily on the tongue. We have at least four primary types of taste, but the taste buds for each are located throughout the tongue. The tip of the tongue is most sensitive to sweet tastes; the margins to salty and sour tastes; and the rear of the tongue to bitter tastes. When these molecules bind to receptor proteins, nerve impulses are generated in associated sensory nerve fibers. These nerve impulses go to the brain, including the cortical areas, which interpret them as tastes. Food should be moist to be tasted. Chemicals receptors sensory neurons thalamus taste center in brain

Sense of smell- nose Our sense of smell is dependent on olfactory cells located within olfactory epithelium high in the roof of the nasal cavity. Receptor cells are covered with mucus . The molecules should be soluble in the mucus layer. The olfactory bulbs have direct connections with the limbic system and its centers for emotions and memory. Actually, the sense of taste and the sense of smell work together to create a combined effect when interpreted by the cerebral cortex Chemicals receptors(olfactory cells) sensory neurons olfactory bulb centers in brain

Sense of touch-skin The skin is composed of two layers: the epidermis and the dermis. The dermis contains cutaneous receptors, which make the skin sensitive to touch, pressure, pain, and temperature (warmth and cold)

Sense of sight- Eye The outer layer, the sclera, is white and fibrous except for the cornea, which is made of transparent collagen fibers. The cornea is the window of the eye. The middle, thin, darkly pigmented layer, the choroid, is vascular and absorbs stray light rays that photoreceptors have not absorbed. Toward the front, the choroid becomes the donut-shaped iris. The iris regulates the size of the pupil, a hole in the center of the iris through which light enters the eyeball. Behind the iris, the choroid thickens and forms the circular ciliary body. The ciliary body contains the ciliary muscle, which controls the shape of the lens for near and far vision. The lens, attached to the ciliary body by ligaments, divides the eye into two compartments; the one in front of the lens is the anterior compartment, and the one behind the lens. Blind spot is the place on retina where all optic nerves are collected together. This part is insensitive to light. http://faculty.washington.edu/chudler/chvision.html

The third layer of the eye, the retina, is located in the posterior compartment, which is filled with a clear, gelatinous material called the vitreous humor. It nourishes the cornea and the lens.It also responsible for the eye pressure. The retina contains photoreceptors called rod cells and cone cells. The rods are very sensitive to light, but they do not see color; there­fore, at night or in a darkened room, we see only shades of gray. The cones, which require bright light, are sensitive to different wavelengths of light, and therefore we have the ability to distinguish colors. There are 3 types of cones-blue,green,red-. If all have defect, person is called as color-blind. The retina has a very special region called the fovea centralis where cone cells are densely packed. Light is normally focused on the fovea when we look directly at an object. This is helpful because vision is most acute in the fovea centralis. Sensory fibers from the retina form the optic nerve, which takes nerve impulses to the brain.

Miyop-yakını görme kalın kenarlı camla düzeltilir Hipermetrop- uzağı görme İnce kenarlı camla düzeltilir.

Accommodation The shape of the lens is controlled by the ciliary muscle within the ciliary body. When we view a distant object, the ciliary muscle is relaxed, the lens remains relatively flat. When we view a near object, the ciliary muscle contracts, releasing the tension on the suspensory ligaments, and the lens rounds up due to its natural elasticity.

Sense of hearing-ear Outer ear(pinna) captures and directs sound waves to auditory canal. Auditary canal conducts soundwaves to eardrum. Eardrum is a part of the middle ear and it is connected to hammer, anvil, stirrup bones. These bones increase the vibrations and conduct it to oval window. Eustachian tube equalise the pressure on each side of the eardrum. Inner ear starts fron oval window.

The ear has two sensory functions: hearing and equilibrium (balance) The ear has two sensory functions: hearing and equilibrium (balance). The sensory receptors for both of these are located in the inner ear. The sense organ for hearing, called the spiral organ (organ of Corti), is located in the cochlear canal. The spiral organ consists of little hair cells(Mechanoreceptors) and a gelatinous material. The hair cells bend as pressure waves move. This movement is converted into nerve impulses and conducted in the auditory nerve to the brain.

Balance can be considered as dynamic and static equilibrium. Semicircular canals are responsible for dynamic equilibrium. Fluid inside the canals move according to the movement and we can sense the rotation with the mechanoreceptors in these canals. Utricle(tulumcuk), saccule(kesecik) are for static equilibrium. There are small crystals(otoliths) inside them and according to the gravitational force they move with the position. Mechanoreceptors sense changes and send message to brain centers

İşitme duyu hücrelerinin bulunduğu yer aşağıdakilerden hangisidir? Oval pencere Kulak zarı Beyindeki işitme merkezi Yarım daire kanalları Korti organı İnsanda sesin algılanmasında, I. Otolitlerin reseptörler üzerinde yer değiştirmesi II. Reseptörlerin (sıvıdaki dalgalar aracılığıyla) mekanik olarak uyarılması III.Uyarının mukus aracılığıyla reseptöre iletilmesi olaylarından hangileri rol oynar? A) Yalnız l B) Yalnız II C) I ve II D) I ve III E) II ve III

yargılarından hangileri doğrudur? A) Yalnızlll B) Yalnız IV C) I ve II İnsan gözüyle ilgili, I. Görüntünün retina önüne düşmesi duru­munda oluşan görme kusuru kalın kenarlı mercekle giderilir. II. Görüntünün retina arkasına düşmesi durumunda oluşan görme kusuru ince kenarlı mercekle giderilir. III. Renklerin algılanmasını sağlayan ışın dalga boyları yalnızca çomak şeklindeki reseptörleri uyarır. IV. Görme sinirinin göz yuvarlağından çıktığı bölge, görüntünün en net alındığı bölgedir. yargılarından hangileri doğrudur? A) Yalnızlll B) Yalnız IV C) I ve II D) III ve IV E) I, III ve IV Kırmızı bir bilye, gözümüzün önünde, soldan sağa doğru yavaş yavaş hareket ettirilmektedir. Bilye gözümüzün optik eksenine yaklaşırken ilk olarak şeklinin, daha sonra renginin algılanmasının nedeni aşağıdakilerden hangisi­dir? Siyah-beyazı algılayan çomakların sarı be­neğin dışında da bulunması, Renkleri algılayan konilerin sadece sarı be­neğin dışında yayılmış olması Görüntünün ilk olarak sarı beneğe düşmesi Korneanın yandan gelen ve renk duyusunu uyaran ışın dalga boylarını yansıtması Siyah-beyaz etki yapan ışınların daha etkin olması

Plant hormones

Support growth and development Stops growth and development Auxin Plant hormones Support growth and development Stops growth and development Auxin Cytokinin Giberellin Abscisic asit Ethylene Promote stem elongation, adventitious root initiation, and fruit growth; inhibit lateral bud outgrowth and leaf abscission Produced at the shoot tips. Inhibit leaf senescence; promote cell division and lateral bud outgrowth; affect root growth Promote seed germination, stem growth, and fruit development; break winter dormancy; mobilize nutrient reserves in grass seeds Maintains seed dormancy and winter dormancy; closes stomata Promotes fruit ripening and leaf abscission; inhibits stem elongation and gravitropism It is in the gas form.

Light and auxin effect Phototropism Experiments showed that the tip of the coleoptile produces a hormone (auxin)that moves down the coleoptile to the growing region. If the tip is removed, the growth of the coleoptile is sharply inhibited. If the tip is carefully replaced, growth resumes, even if the tip and base are separated by a thin layer of gelatin. The hormone moves down from the tip, but it does not move from one side of the coleoptile to the other. If the tip is cut off and replaced so that it covers only one side of the cut end of the coleoptile, the coleoptile curves as the cells on the side below the replaced tip grow more rapidly than those on the other side.

Gelatin can absorb the auxin at the coleoptile Gelatin can absorb the auxin at the coleoptile. If the auxin is high at one side, this side grows fast and plant bends over the other side.

Auxin accumulates in the dark side of the plant in the stems so plant stem bends toward the light. (+ phototropism) But auxin accumulates downward in response to gravity during germination. This effect causes stem to move upward. (- geotropism)

Auxin Oksin hormonu sürgünlerin doğrudan ışık almayan kısımlarında sentezlenir. Böylece bitkinin sürgünü asimetrik olarak büyür. Bitki ışığa yönelir.

Koleoptil kesilerek oksin bir agara emdiriliyor. Agar kesilmiş sürgüne düzgün yerleştirilirse bitki düzgün uzar. Ancak agar sağ tarafa yakın yerleştirilirse bitkinin sağında oksin miktarı artar ve bitki sola yönelir. Sola yerleştirilirse solda oksin artar ve bitki sağa yönelir.

Sürgünün koleoptil ucu ışık geçirmeyen bir başlıkla kapatılırsa yönelim olmaz. Işık sağdan gelirken sol tarafa yerleştirilen mika plaka oksinin geçişini engeller ve sağa yönelim olmaz. Ancak sağa mika yerleştirilirse ve ışık sağdan gelirse bitki sağa yönelir. Koleoptil kesilerek sola kaydırılırsa sol kenarda oksin miktarı artar ve bitki sağa yönelir. Oksin içeren agar koleoptil kesilerek sol tarafa yerleştirilirse oksin solda fazlalaşır, bitki sağa yönelir.

Taxis 2. Tropism + phototropism - geotropism: 1. Nastic movement Behaviour independent on the direction of the stimulus Behaviour dependent on the direction of the stimulus Taxis only in one celled organisms + chemotaxis: chemotaxis: E.g. Sperm cells, 1. Nastic movement The response is always same at each condition photonasty: response to light Thigmonasty: response to touch 2. Tropism + phototropism - geotropism:

Tropism types( can be + or -) Chemotropism, movement or growth in response to chemicals Gravitropism (or geotropism), movement or growth in response to gravity Hydrotropism, movement or growth in response to moisture or water Heliotropism, movement or growth in response to sunlight Phototropism, movement or growth in response to lights or colors of light Thermotropism, movement or growth in response to temperature Thigmotropism, movement or growth in response to touch or contact

Bitkilerde tepe tomurcuğunda üretilen oksin (büyüme hormonu), bitkinin alt bölümlerine, tepe tomurcuğunun hemen altındaki taşıma bölgesiyle iletilir. Düzenlenen bir deneyde aynı bitkiden dört taşıma bölgesi kesilerek çıkartılmıştır. Deneydeki 1. ve 3. uygulamalarda kullanılan taşıma bölgeleri, bitkideki konumunda; 2. ve 4. uygulamalarda kullanılanlar ise ters konumda olacak şekilde, aşağıdaki şemada gösterildiği gibi, oksin içeren ve oksin içermeyen iki ağar bloğu arasına yerleştirilmiş ve belirtilen sonuçlar alınmıştır. Bu uygulamalardan elde edilen sonuçlara göre, I. Taşıma bölgesinde, oksin hormonunun iletimi tek yönlüdür. II. Yerçekimi kuvveti, oksin hormonunun taşınmasını sağlar. III. Taşıma yönünü belirlemede taşıma bölge­sindeki hücrelerin özelliklerinin rolü vardır. IV. Oksin hormonu bitkinin her bölgesine eşit olarak dağılır. yargılarından hangilerine varılır? A) I ve II B) I ve III C) I ve IV D) II ve III E) III ve IV (ÖSS 2005)

Karanlıkta büyütülen aşağıdaki yulaf filizleri­nin hangisinde bir yönelim (tropizm) hareketi gözlenebilir?

Bitkiye absisik asit verilmesi aşağıdakilerden hangisine neden olur? Boy uzamasının hızlanmasına Meyvesinin kısa sürede olgunlaşmasına Çiçek açmaya başlamasına Durgun devrenin uzamasına Yan dalları oluşturacak tomurcukların gelişmesine (ÖYS 1997)

Endocrine organs in humans

1.İnsan vücudundaki hormonların miktarlarını belirlemek amacıyla, yaygın olarak aşağıdakilerden hangisi incelenmektedir? A) Kan B) Dışkı C) Tükrük D) Gözyaşı E) Deri döküntüsü (ÖSS 1992)

Hypothalamus, pituitary gland and most of the endocrine glands work together for homeostasis. If hormone level is high the production of tropic hormones are inhibited.. But if hormone level is low then tropic hormones are stimulated to produce more hormones.

Stimulates milk production SECRETING TISSUE OR GLAND HORMONE CHEMICAL NATURE TARGET(S) IMPORTANT PROPERTIES OR ACTIONS Hypothalamus Releasing and release- inhibiting hormones Peptides Anterior pituitary Control secretion of hormones of anterior Anterior pituitary: TSH Glycoprotein Thyroid gland Stimulates synthesis and secretion of thyroxine Adrenocorticotropin(ACTH) Polypepti Adrenal cortex Stimulates release of hormones from adrenal cortex Luteinizing hormone(LH) Gonads Stimulates secretion of sex hormones from Follicle-stimulating hormone (FSH) Stimulates growth and maturation of eggs in females; stimulates sperm production in males Prolactin Protein Mammary glands Stimulates milk production Growth hormone (GH) Bones,liver, muscles Stimulates protein synthesis and growth

IMPORTANT PROPERTIES OR ACTIONS SECRETING TISSUE OR GLAND HORMONE CHEMICAL NATURE TARGET(S) IMPORTANT PROPERTIES OR ACTIONS Posterior pituitary Oxytocin Peptide Uterus, breasts Induces birth by stimulating labor contractions; causes milk flow Antidiuretic (ADH) vasopressin Kidneys Stimulates water reabsorption and raises blood pressure

Pituitary gland is the most important gland which is controlled by hypothalamus. It has 2major lobes. Anterior, posterior pituitary Anterior pituitary Growth hormone or somatotropin(ST), effects all tissues and cells for growing Prolactin(LuteoTropicH), stimulates milk production. Thyroid Stimulating hormone(TSH), stimulates thyroid gland. Follicle Stimulating hormone(FSH), Luteinizing hormone (LH), stimulates ovaries and testes. AdrenoCorticoTropicHormone(ACTH) stimulates adrenal gland.

Posterior pituitary: These hormones actually are produced by hypothalamus but they are secreted to the blood from posterior pituitary. ADH: controls the absorption of water from nephrons in kidney.If it is too low, patient loses water by urination and always drinks water. If it is too high water is absorbed more to the blood. Oxytocin: stimulates contractions of uterus and mammary gland. Intermediate pituitary: small part between lobes MSH: melanocyte stimulating hormone. Stimulates melanin synthesis, forms pigmentation.

Birdenbire karşısına çıkan bir yayaya çarpmamak için hemen fren yaparak aracını durduran bir sürücüde, kalp atım hızının artması, tansiyon yükselmesi, ağız kuruluğu gibi, sinirsel ve hormonal olarak kontrol edilen tepkiler ortaya çıkar. Tehlikenin geçmesine karşın, sürücüdeki bu tepkilerin bir süre daha aynı düzeyde kalması ve daha sonra bireyin eski haline dönmesi, hormonlarla ilgili aşağıdaki özelliklerden hangisiyle açıklanabilir? Salgılandıkları yerden farklı bir yerde iş görmesi Küçük miktarlarının bile büyük etki göstermesi Yıkımının belirli bir zaman sonra başlaması Bireyde metobolizma hızını değiştirebilmesi Etkilenen dokuya (organa) kan yoluyla taşınması

I. Böbreküstü bezi korteksinin uyarılması 8.Aniden korkup hızla kaçmaya başlayan bir insanda, kas aktivitesinin artması için, I. Böbreküstü bezi korteksinin uyarılması II.Adrenokortikotropik hormonun (ACTH un) salgılanmaya başlaması III. Hipotalamusun uyarılması IV. Hipofizin uyarılması V Epinefrinin (adrenalinin) salgılanmaya başla­ması olayları hangi sıraya göre gerçekleşir? A) I, II, IV, III, V B) II, III, IV, V, I C) III, IV, II, I, V D) IV, V, III, I, II E) V, I, II, IV, III (ÖYS 1993) 9. Aşağıdaki olayların hangisinde, böbreküstü bezleri ile pankreasın salgıladığı bazı hormonlar birlikte rol oynar? Ovulasyonun gerçekleşmesi Spermatogenezisin gerçekleşmesi Kemik ve kandaki kalsiyum tuzlarının dengelenmesi Süt bezlerinin salgı çıkarması Kandaki glikoz miktarının dengelenmesi (ÖYS 1994 İnsan vücudunda gerçekleşen bazı olaylar şunlardır: I.Hipofizden büyüme hormonunun salgılanması II. Paratiroit hormonunun salgılanması III.Tiroit hormonunun salgılanması IV Glomerüler süzüntüden kalsiyum tuzlarının geri emilmesi Normal ve ergin bir insanın kanındaki kalsiyum tuzları azaldığında, kemiklerin sertlik derecesinin ve kandaki kalsiyum tuzları miktarının dengelenmesi için bu olaylardan hangileri gerçekleşir. A) I ve II B) I ve III C) II ve III D) II ve IV E) III ve IV (ÖYS 1989) 7. Normal bir insanda, yeterli miktarda su alınmamasına bağlı olarak vücutta su yetersizliği ortaya çıktığında, I. Hipofizden salgılanan antidiüretik hormon miktarının artması II. Kanın osmotik basıncının artması III. Böbrekten suyun geri emiliminin artması Olaylarının gerçekleşme sırası aşağıdakilerin hangisinde verilmiştir? A)I., II., III B)l., III., II C) II., I., III. D) II., III., I. E) III., II., I. (ÖYS 1991)

Bitkiye absisik asit verilmesi aşağıdakilerden hangisine neden olur? Boy uzamasının hızlanmasına Meyvesinin kısa sürede olgunlaşmasına Çiçek açmaya başlamasına Durgun devrenin uzamasına Yan dalları oluşturacak tomurcukların gelişmesine (ÖYS 1997) 11. Normal bir insanda, I. Osein II. Kalsitonin III. D vitamini IV. Parathormon maddelerinden hangilerinin miktarının artması, kemiklerin sertleşmesini sağlar? A) Yalnız l B) I ve II C) II ve III D) II ve IV E) III ve IV (ÖYS 1997) 12. Aşağıdaki grafik, kanında normal düzeyde glikoz bulunan bir insanın sindirim yoluyla çok miktarda glikoz almasından sonra, kanındaki glikoz değişimini göstermektedir. Buna göre, bu bireyde glikoz düzeyini kontrol eden insülin ve glukagon hormonlarının I. ve II. zaman aralıklarındaki durumları aşağıdakilerin hangisinde doğru olarak verilmiştir? I. zaman aralığı II. zaman aralığı Glukagon değişmez İnsülin artar İnsülin azalır Glukagon azalır Glukagon artar insülin değişmez Glukagon azalır insülin artar Insülin artar Glukagon artar (ÖYS 1998)

Thyroid and parathyroid gland Thyroxine Iodinated amino acid derivative Many tissues Stimulates and maintains metabolism necessary for normal development and growth Calcitonin Peptide Bones Stimulates bone formation; lowers blood calcium Parathyroid Parathyroid hormone Protein Resorbs bone; raises blood calcium

If there is an iodine deficiency, the thyroid cannot make sufficient hormone. This stimulates the anterior pituitary to secrete thyroid-stimulating hormone, which causes the thyroid gland to increase in size .But it cannot produce more hormones because it does not have the necessary raw material, iodine. This type of thyroid enlargement is called simple goiter or iodine deficiency goiter.(graves) Cretinism A condition of severely stunted physical and mental growth due to the untreated congenital deficiency of thyroid hormones

Tiroit bezi: tiroksin ve kalsitonin salgılar. Tiroksin metabolizma hızını, protein sentezini etkiler. Tiroksinin yapısında iyot bulunur. Yeterli iyot alınmazsa hormon sentezlenmez. Ama uyarı alan tiroit şişer. Eğer guatr hastalığı ilerlerse metabolizma yavaşlar. Aşırı çalışması ise metabolizmayı hızlandırır (graves). Tiroksin azsa cücelik ve kretinizm görülür. Kalsitonin: kalsiyumun kandan kemiklere geçişini kolaylaştırır. Fosfatı depolamaya yardım eder. Paratiroid bezi- parathormon salgılar. Kalsiyumun ve fosfatın kana geçişini hızlandırır. Vücuttan atılımını kolaylaştırır. Eğer çok salınırsa kemiği zayıflatır. Azsa tetani görülür.

The adrenal gland is a paired gland located on top of each kidney The adrenal gland is a paired gland located on top of each kidney. Each gland is divided into an outer cortex and an inner medulla. From cortex region cortisol and mineralocorticoids are secreted. Cortisol: stimulates production of glycogen and increases blood sugar level. It is secreted under stress. Mineralocorticoids are secreted by the outermost region of the adrenal cortex. aldosterone, which acts to conserve sodium ions and water in the body. In Addison disease(lack of aldosterone) person loses so much Na. Male hormones, and female hormones, are also secreted in minimal amounts in both sexes by the adrenal cortex. Epinephrine(adrenaline) and norepinephrine (noradrenaline)are secreted from medulla region. These two hormones are secreted in response to stimulation by sympathetic nerve, particularly during stressful situations.

When the stress response begins, the hypothalamus sends a hormone called corticotropin-releasing factor (CRF) to the pituitary gland, which then sends a hormone called adrenocorticotropin (ACTH) through the bloodstream to the adrenal glands. The adrenal glands produce cortisol (in response to ACTH) and epinephrine (in response to signals sent from the brain through the nervous system), which help the body produce emergency energy and support the "fight or flight" response

If you hear footsteps behind you while walking in the dark, your brain alerts your adrenal glands to dispatch stress hormones throughout your body to prepare you to wrestle or run. These hormones, epinephrine (adrenaline) and norepinephrine (noradrenaline), make your heart beat faster, your blood pressure increase, your muscles tense, and the pupils of your eyes open wider. You become more energized and more focused. Blood drains from your stomach and intestines as digestion stops. Your awareness of pain falls.

Adrenal medulla Adrenal cortex Epinephrine, Modified Heart, blood SECRETING TISSUE OR GLAND HORMONE CHEMICAL NATURE TARGET(S) IMPORTANT PROPERTIES OR ACTIONS Adrenal medulla Epinephrine, Modified Heart, blood Stimulate fight-or-flight reactions: norepinephrine amino acids vessels, liver, fat cells increase heart rate, redistribute blood to muscles, raise blood sugar Adrenal cortex Glucocorticoids (cortisol) Steroids Muscles, immune system, other tissues Mediate response to stress; reduce metabolism of glucose, increase metabolism of proteins and fats; reduce inflammation and immune responses Mineralocorticoids(aldosterone) Kidneys Stimulate excretion of potassium ions and reabsorption of sodium ions

Pancreas Insulin Protein Muscles, liver, fat, other tissues Stimulates uptake and metabolism of glucose; increases conversion of glucose to glycogen and fat Glucagon Liver Stimulates breakdown of glycogen and raises blood sugar

Islets of Langerhans in the pancreas contains alpha and beta cells which secrete insulin and glucagon. After a meal, the amount of insulin secreted into the blood increases as the blood glucose rises. Muscle, fat, liver cells take in the glucose from blood. Then blood sugar level decreases. Glucagon's function is to cause the liver to release stored glucose from its cells into the blood. Then Glucagon increases the blood sugar level.

Yüksek dozda glikoz verilen sağlıklı bir insa­nın kanındaki glikoz miktarının birkaç saat i-çindeki değişimi, aşağıdaki grafiklerden han­gisiyle gösterilebilir? (Kandaki normal glikoz düzeyi, grafiklerde "N" harfi ile gösterilmiştir.)

Karaciğer hücrelerinde glikojenin glikoza dönüşümünün hızlanması ve kandaki glikoz miktarının artması için adrenalin, glukagon ve insülin hormonlarının miktarlarında meydana gelebilecek değişmeler aşağıdakilerin hangi­sinde doğru olarak verilmiştir? Adrenalin Glukagon insülin miktarı miktarı miktarı Artma Azalma Azalma Azalma Artma Azalma Artma Artma Azalma Azalma Artma Artma Artma Azalma Artma (ÖYS 1988)

İnsülin salgılanması azalan bir kimsede, hüc­ relere glikoz alımı ile karaciğerdeki ve kandaki glikoz miktarı bakımından aşağıdakilerden hangisi gözlenir? Hücrelere Karaciğerdeki Kandaki glikoz alımı glikoz miktarı glikoz miktarı Azalır Artar Azalır Artar Azalır Artar Artar Artar Artar Azalır Azalır Artar Azalır Azalır Azalır

Hormonal control of female reproductive system Hypothalamus Releasing Factor Ant. Pit. LTH- Luteotropic hormone acts on mammary gland Follicle stimulating hormone FSH Development of follicle Luteinizing hormone LH Ovulation Ovary Feedback Corpus luteum Folikül Estrogen Progesteron Thickening of endometrium Development of repr. organs Preparation to pregnancy

Aşağıdakilerden hangisi, insanda yumurtalık­ ların, hipofiz bezi faaliyetlerini bir dereceye kadar kontrol ettiğine bir kanıt olarak gösteri­ lebilir? Kanda östrogen arttıkça FSH nın azalması FSH hormonunun folikülleri büyütmesi Korpus luteumun LTH nın etkisi ile parça­lanması LH nın folikülleri korpus luteuma çevirmesi Progesteron salınmasını LTH nın uyarması

Hormonal control of male reproductive system Hypothalamus Releasing factor RF Ant. Hypophysis FSH Spermatogenesis LH Hormone production Testis Seminiferous tubules Testosteron Androgen Spermatogenesis Male properties

Ovaries Estrogens Steroids Breasts, uterus, other tissues Stimulate development and maintenance of female characteristics and sexual behavior Progesterone Steroid Uterus Sustains pregnancy; helps maintain secondary female sexual characteristics Testes Androgens Various tissues Stimulate development and maintenance of male sexual behavior and secondary male sexual characteristics; stimulate sperm production