4th Bimonthly Oral Exam.docx

NEURO 1.

2 major divisions of pituitary gland; cell types of anterior pituitary PITUITARY GLAND (HYPOPHYSIS CEREBRI) Major Divisions ADENOHYPOPHYSIS Embryonic Origin Dorsal evagination from roof of embryonic pharynx Supporting Cells Folliculo-stellate cell Subdivisions a. Pars distalis b. Pars tuberalis c. Pars intermedia

NEUROHYPOPHYSIS Downgrowth of diencephalon Pituicytes a. Median eminence of tuber cinereum b. Infundibular stem c. Infundibular process

Cell types of Anterior pituitary ACIDOPHILS – stains with eosin CELL TYPE HORMONES Somatotrophs Growth hormone Mammotrophs Prolactin BASOPHILS – stains with H&E, periodic-acid-Schiff reaction Corticotrophs ACTH Gonadotrophs FSH & LH Thyrotophs TSH CHROMOPHOBES – little affinity for histological dyes 2.

CORTICOBULBAR TRACT Trace from origin to medulla Specific location in different parts of segments of the CNS Manner of termination in ff. Cranial Nerve Nuclei: IV, VI, VII, XII, Ambiguus  Originate mainly from AREA 4  From CORTEX, fibers would pass through CORONA RADIATA and would converge to pass through GENU of INTERNAL CAPSULE  Fibers descend into BRAINSTEM to terminate in the different MOTOR NERVE NUCLEI  Terminate BILATERALLY in the following nuclei:  Oculomotor Nucleus (III)  Trigeminal Nucleus (V)  Facial Nucleus (VII) [only to the part supplying the upper part of the face]  Nucleus Ambiguus (IX, X, XI) [only partly supplying muscles of the pharynx and larynx except uvula]  Terminate MAINLY CONTRALATERALLY  Abducens Nucleus (VI)  Hypoglossal Nucleus (XII)  Terminate ONLY CONTRALATERALLY  Facial Nucleus (VII) [only to the part supplying the lower part of the face]  Nucleus Ambiguus (IX, X, XI) [only partly supplying muscles of the uvula]  Terminate IPSILATERALLY  Trochlear Nucleus (IV)  Does not Terminate in the ff:  Optic Nucleus (I)  Olfactory Nucleus (II)  Auditory Nucleus (VIII)  Lesions produce paralysis either same or opposite sides.

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CORTICAL AREAS Functions of areas 5 & 7, 9-10-11-12, 19, 39, 43 Effect of stimulation on areas 3-1-2, 41 Effect of lesion/ablation on areas 22, 6, 44 &45  5 & 7 [Sensory Association Area of the Parietal Lobe]  Function: for body scheme or image [knowing the relation of the different body parts]  Ablation: loss of body image [person cannot determine parts of his own body]  9-10-11-12 [Pre-Frontal Areas]  Function: concerned with thinking, judgment, and other complex thought processes or activities  Ablation: on one side, does not produce any defect; if both sides, changes in personality and behavior [Frontal Lobe Syndrome]  Stimulation: produce autonomic responses [such as sweating, salivation]  19 [Occipital Eyefield]  Function: conjugate eye deviation and eye fixation for vertical plane  Ablation: loss of conjugate eye movements and eye fixation [nystagmus]  Stimulation: visual hallucinations  39 [Visual speech center]  Function: interpretation of written language  43  Function: gustatory (not sure hehe)  3-1-2 [Somesthetic Area or Primary Cortical Center for Sensation]  Function: receives complex sensory perception such as discriminative senses [stereognosis, spatial recognition, two-point discrimination, determine grades of temperature]  Ablation: severe impairment of sensation on opposite side of the body  Stimulation: numbness and tingling but never pain  41 [Primary Cortical Center for Audition]  Function: receive auditory impulses  Ablation: partial bilateral deafness, worse on the opposite side  Stimulation: ringing, buzzing, chirping, or rearing sounds

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22 [Auditory Speech Center]  Function: comprehension and understanding of sounds heard  Ablation: Auditory Receptive Aphasia or Word Deafness [cannot understand what others are talking about and cannot take down notes] 6 [Pre-Motor Area]  Function: controls large part of muscles for mass, unskilled, crude and stereotype movements on opposite side of the body  Ablation: muscle spasticity and hyperactivity of deep tendon reflexes  Stimulation: produce aversive movements associated with autonomic responses 44 & 45 [Speech Areas of Broca]  Function: controls the apparatus for speech  Ablation: Broca’s Aphasia [expressive or motor aphasia – cannot express ideas but can understand]  Stimulation: no data

PUPILLARY LIGHT REFLEX Trace from Receptor to Eye Important structures, crossing Visual Receptors: RODS AND CONES ↓ BIPOLAR CELLS (1st Order Neuron) ↓ AMACRINE CELLS ↓ GANGLION CELLS (2nd Order Neurons) Axons CONVERGE to form ↓ Optic Nerve ↓ Cranial Cavity: through Optic Foramina, unite to form ↓ OPTIC CHIASM Partially decussate, fibers of NASAL halves cross to OPPOSITE sides TEMPORAL halves remaining uncrossed forms the ↓ OPTIC TRACT ↓ PRE-TECTAL NUCLEI (Bilateraly) ↓ Nucleus of EDINGER-WESTPHAL ↓ Occulomotor Nerve ↓ Ciliary Ganglion ↓ Ciliary Nerve ↓ CONSTRICTOR PUPILLAE MUSCLE

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RELAY NUCLEI OF THALAMUS AFFERENT CONNECTIONS Ventral Posteromedial (VPM) Dorsal and Ventral Trigeminal Tracts

EFFERENT CONNECTIONS Thalamocortical tract to AREA 3-1-2

Ventral Posterolateral (VPL)

Thalamocortical reactions to AREA 3-1-2

Medial Geniculate Body (MGB) Ventral Lateral (VL) Ventral Anterior (VA) 6.  

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Medial Lemniscus Lateral Spinothalamic Tract Ventral Spinothalamic Tract Lateral Lemniscus Dentatorubrothalamic Thalamic Fasciculus Mamilothalamic Tract of Vicq d’ Azyr

Geniculotemporal Tract to AREA 41 Thalamocortical Tract to AREA 4 & 6

FUNCTIONS Pain and Thermal Sense Pressure Touch proprioception (upper face area/ upper half of the body) Proprioception Pain and Thermal sense (body and lower limbs) Relay auditory impulses Cerebellar and Basal Ganglia Relay

Thalamocortical Tract to AREA 23, 24 & 32

Relay for Limbic System

CIRCLE OF WILLIS AND CSF Formed from anastomosis between: a. 2 internal carotid arteries b. 2 vertebral arteries Other vessels that contribute to the circle: c. Anterior communicating artery d. Anterior cerebral artery e. Internal carotid artery f. Posterior communicating artery g. Posterior cerebral artery Allows blood that enters by either internal carotid or vertebral arteries to be distributed to any part of both cerebral hemispheres, Source: Snell If one part of the circle becomes blocked or narrowed (stenosed) or one of the arteries supplying the circle is blocked or narrowed, blood flow from the other blood vessels can often preserve the cerebral perfusion well enough to avoid the symptoms of ischemia, Source : wiki

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Trace CSF from secretion to Dural Sinuses

ependymal cells in the choroid plexus ↓ the interventricular foramina (foramen of Monro) ↓ third ventricle ↓ cerebral aqueduct (aqueduct of Sylvius) ↓ fourth ventricle ↓ two lateral apertures (foramina of Luschka) ↓ Lateral recesses of the fourth ventricle

one median aperture (foramen of Magendie) ↓ Cerebellomedullary cistern ↓ Subarachnoid spaces 7.

ASCENDING AND VISUAL PATHWAY Ascending: Pain and Thermal Sense Pathway from Body and Limbs to Cortical Areas  Important Tracts, Nuclei, Decussation, Specific Receptors Naked Nerve Endings: End Bulb of Krause, Cylinders of Ruffini ↓ Dorsal Root Ganglion (1st Order Neuron) ↓ Spinal Cord ↓ Ascend 1 or 2 segments of the Spinal Cord ↓ Nucleus of Rolando (2nd Order Neuron) ↓ Fibers CROSS midline at VENTRAL WHITE COMMISURE of Spinal Cord ↓ Lateral Funiculus ↓ Ascends as the LATERAL SPINOTHALAMIC TRACT ↓ VENTRAL POSTEROLATERAL NUCLEI of Thalamus (3rd Order Neuron) ↓ THALAMOCORTICAL TRACT ↓ AREA 3-1-2 of Cerebral Cortex

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Visual: Trace Receptors to Primary Visual Cortex 

Neurons, Decussation, Important Structures involved Visual Receptors: RODS AND CONES ↓ BIPOLAR CELLS (1st Order Neuron) ↓ AMACRINE CELLS ↓ GANGLION CELLS (2nd Order Neurons) Axons CONVERGE to form ↓ Optic Nerve ↓ Cranial Cavity: through Optic Foramina, unite to form ↓ OPTIC CHIASM Partially decussate, fibers of NASAL halves cross to OPPOSITE sides TEMPORAL halves remaining uncrossed forms the ↓ OPTIC TRACT ↙ ↘ Small Portions continue as the BRACHIUM of LATERAL GENICULATE NUCLEUS SUPERIOR COLLICULUS ↓ Give rise to GENICULOCALCARINE TRACT ↓ SUPERIOR COLLICULI (Tracking of Visual ↓ Pass through the RETROLENTICULAR part of Stimuli) INTERNAL CAPSULE And ↓ PRETECTAL AREA (Pupillary Light Reflex) Form OPTIC RADIATIONS ↓ CALCARINE SULCUS of AREA 17 (Upper loop/Dorsal fibers terminate in the upper lip, Meyer’s loop/Ventral Fibers terminate in the lower lip)

AUDITORY PATHWAY AND 2 TYPES OF DEAFNESS Trace pathway (1) Receptor: organ of corti (2) Impulses pass through cochlear nerve whose cell bodies are found in the spiral ganglion(1st order). (3) Fibers terminate on the dorsal and ventral cochlear nuclei fibers arising from the cocolear nuclei follows 3 pathways: (4) Dorsal acoustic stria - from dorsal cochlear nuclei which crosses midline to superior olivary nuclei and trapezoid body--- then ascend as--- lateral lemniscus--terminate at inferior colliculus --- arise through brachium of inferior colliculus --- medial geniculate --- geniculotemporal tract --- area 41 Intermediate acoustic stria – from ventral cochlear nuclei and follows the same distribution and termination as the dorsal acoustic stria Ventral acoustic stria – from ventral cochlear nuclei some fibers cross, same as (a and b) some fibers terminate to superior olivary nucleus and trapezoid body on the same side 2 types of DEAFNESS as to CAUSE Deafness is usually divided into two types: (1) that caused by impairment of the cochlea or impairment of the auditory nerve, which is usually classified as “nerve deafness,” and (2) that caused by impairment of the physical structures of the ear that conduct sound itself to the cochlea, which is usually called “conduction deafness.”

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ATTENUATION REFLEX AND 2-FOLD FUNCTIONS Mechanism  LOUD SOUND  Ossicular System  CNS  Attenuation Reflex: Stapedius muscle contracts and to a lesser extent also the Tensor Tympani (TT) muscle TT muscle pulls handle of malleus inward, Stapedius muscle pulls the Stapes outward  Opposing forces  Ossicular system develops rigidity  Reduces ossicular conduction of LOW FREQUENCY sound (below 1000 cycles/sec) 2 fold function  Protect cochlea from damaging vibrations caused by VERY loud sounds  Mask low frequency sounds in loud environments – removes background noise and allows a person to concentrate on sounds above 1000 cycles/second where voice communication is transmitted. Another function of the tensor tympani and stapedius muscles is to decrease a person’s hearing sensitivity to his or her own speech. This effect is activated by collateral nerve signals transmitted to these muscles at the same time that the brain activates the voice mechanism

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ACCOMMODATION REFLEX  Define nerve signals that control it:  Mechanism that focuses the lens system of the eye, essential for a high degree of acuity.  Controlled almost entirely by the PARASYMPATHETIC nerve signals transmitted to the eye throught the 2 nd cranial nerve from the 3rd Cranial Nerve Nucleus of the Brainstem  Sympathetic nerve signals have an additional WEAKER effect in relaxing in ciliary muscle  Relationship beween ciliary muscle activity and refractive power of eye  Ciliary muscles: Meridional and Circular Fibers  Stimulation → Muscle CONRACTS → RELAXES the lens ligaments → lens thickens, INCREASE in REFRACTIVE POWER as curvature increases → Enable to focus on NEAR objects 4 clues that help lens change its length and explain  CHROMATIC ABBERATION  red light rays focus slightly less posteriorly to blue light rays because the lens bends blue rays more than red  The eyes are able to detect which of the two rays is in better focus then this clue relays info to the accommodation mechanism whether to make the lens stronger or weaker.  CONVERGENCE CAUSES A SIMULTANEOUS SIGNAL TO STRENGTHEN THE EYE LENS  this is because when the eyes fixate on a near object, the eyes must converge and the neural mechanism responsible for convergence also strengthens the lens  Because the fovea lies in a hollowed-out depression that is slightly deeper than the remainder of the retina, the CLARITY OF FOCUS IN THE DEPTH OF THE FOVEA IS DIFFERENT FROM THE CLARITY OF FOCUS ON THE EDGES – this also gives clues about which way the strength of the lens needs to be changed  THE DEGREE OF ACCOMODATION OF THE LENS OSCILLATES SLIGHTLY all the time at a frequency up to twice per second. The visual image becomes clearer when the oscillation of the lens strength is changing in the appropriate direction and become poorer when the lens strength is changing in the wrong direction. This could give rapid clues as to which way the strength of the lens needs to change to provide appropriate focus.

ENDOCRINE AND REPRO 1. INSULIN SECRETION a. Important regulator of insulin secretion  An increase in plasma glucose concentration is the most important physiologic regulator of insulin secretion. The threshold concentration for secretion is the fasting plasma glucose level (80-100 mg/dL)  Other substances causing release of insulin from the pancreas include amino acids, free fatty acids, ketone bodies, glucagon, secretin. b. Molecules and mechanisms involved  An increase of the ATP/ADP ratio results in the inhibition of ATP-sensitive K+ efflux channels. This causes depolarization of the B cell and activation of voltagesensitive calcium channels. The calcium influx results in insulin secretion. 2.

INSULIN ACTION a. Transport of glucose across skeletal and cardiac muscles: sequence of events  Insulin lowers blood glucose immediately by enhancing glucose transport into adipose tissue and muscle by recruitment of glucose transporters (GLUT 4) from the interior of the cell to the plasma membrane.  To initiate its effects on target cells, insulin first binds with & activates a membrane receptor protein. It is the activated receptor that causes the subsequent effects.  The insulin receptor is a combination of 4 sub-units held together by disulfide linkages: 2 alpha subunits & 2 beta subunits that penetrate through the membrane. Insulin binds with the alpha subunits outside the cell, but because of the linkages of the alpha subunits with the beta subunits, the latter become autophosphorylated. This activates a local tyrosine kinase, which causes phosphorylation of other enzymes. Within seconds, the membranes of muscle cells increase their uptake of glucose. b. Lipogenesis on adipose tissue: 3 biochemical mechanisms how insulin stimulates lipogenesis  Insulin stimulates lipogenesis in adipose tissue:  by providing the acetyl-coA and NADPH required for fatty acid synthesis  by maintaining a normal level of the enzyme acetyl-coA carboxylase, which catalyzes the conversion of acetyl-coA to malonyl-coA  by providing the glycerol involved in triacylglycerol synthesis.

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THYROID GLAND Iodide metabolism: Important biochemical process and reactions involved Get supplies:Iodide concentration in the thyroid is by the use of an energy dependent process which is linked to the sodium-potassium ATPase dependent thyroidal Itransporter. This is controlled by TSH. Oxidation of I- to a higher valence state  obligatory step in I- organification and thyroid hormone synthesis.  Involves a heme containing peroxidase  Thyroperoxidase plus H2O2 (oxidizing agent; from NADPH dependent enzyme resembling cytochrome c reductase)

Iodination  subsequent attachment of monoiodotyrosine and diiodotyrosine to thyroglobulin.  Iodine is not incorporated into the protein because mRNA does not recognize an iodinated tyrosine. Coupling     

DIT + MIT= T3 DIT + DIT= T4 This occurs within a thyroglobulin molecule THYROPEROXIDASE- by stimulating the free radical formation of iodotyrosine Formed thyroid hormone stays in thyroglobulin until it is degraded.

Deiodinase removes I- from inactive MIT and DIT in thyroid 4.

HORMONES FOR Ca2+ METABOLISM Three hormones are primarily concerned with calcium metabolism the parathyroid hormone, caltriol (vit D), calcitonin  Parathyroid hormone (PTH)  secreted by the parathyroid glands  main action is to mobilize calcium from bone and increase urinary phosphate excretion.  The primary response to parathyroid hormone (PTH) by the kidney is to increase renal calcium resorption and phosphate excretion. In the kidney, parathyroid hormone (PTH) blocks reabsorption of phosphate in the proximal tubule while promoting calcium reabsorption in the ascending loop of Henle, distal tubule, and collecting tubule.  PTH promotes osteolysis by signaling the osteoblast to stimulate the osteoclast in bone resorption by doing so it increases calcium in ECF  PTH is also involve in conversion of 25-hydroxyvitamin D to its most active metabolite, 1,25-dihydroxyvitamin D-3 [1,25-(OH)2 D3], by activation of the enzyme 1-hydroxylase in the proximal tubules of the kidney.  Feedback inhibition of parathyroid hormone release occurs primarily by direct effect of calcium at the level of the parathyroid gland. Although not well elucidated, 1,25-(OH)2 D3 appears to exert a mild inhibitory effect on the parathyroid gland as well. 

Calcitriol (1,25-Dihydroxycholecalciferol)  steroid hormone formed from vitamin D by successive hydroxylations in the liver and kidneys.  Vitamin D-3 (cholecalciferol) is formed in the skin when a cholesterol precursor, 7-dehydroxycholesterol, is exposed to ultraviolet light. Activation occur when the substance undergoes 25-hydroxylation in the liver and 1-hydroxylation in the kidney.  The primary action of 1,25-(OH)2 D3 is to promote gut absorption of calcium by stimulating formation of calcium-binding protein within the intestinal epithelial cells. Vitamin D also promotes intestinal absorption of phosphate ion.  In bone, vitamin D may play a synergistic role with parathyroid hormone (PTH) in stimulating osteoclast proliferation and bone resorption.  Compared to parathyroid hormone (PTH), vitamin D exerts a much slower regulatory effect on calcium balance.

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Calcitonin  a calcium-lowering hormone that is secreted primarily by cells in the thyroid gland inhibits bone resorption. Its action is entirely the opposite of PTH.  affects blood Ca2+ levels in three ways: a) Inhibits Ca2+ absorption by the intestines b) Inhibits osteoclast activity in bones c) Inhibits calcium and phosphate reabsorption by the kidney tubules  Secretion of calcitonin is stimulated by: an increase in serum calcium, gastrin and pentagastrin.

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HORMONES AND SPERMATOGENESIS 5 Hormones that stimulate Spermatogenesis (name, cellular/tissue/organ source, functions) (pp. 998-999 GUYTON)  TESTOSTERONE  Leydig cells in the interstitium of the testes  For growth and division of the testicular germinal cells which is the first stage of sperm formation or SPERMATOGENESIS.  LUTEINIZING HORMONE  Anterior pituitary gland  stimulates Leydig cells to secrete testosterone.  FOLLICLE STIMULATING HORMONE  Anterior pituitary gland  stimulates sertoli cells and without this stimulation, SPERMIOGENESIS (seprmatids to spermatozoa) will not occur.  ESTROGEN  Formed from testosterone by the sertoli cells when stimulated by FSH.  essential for SPERMIOGENESIS  GROWTH HORMONE  Anterior pituitary gland  necessary for controlling background metabolic functions of the testes and promotes early division of Spermatogonia themselves  absence (Pituitary dwarfs) causes infertility.

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HORMONES AND PREGNANCY 4 hormones for normal pregnancy and 2 functions each.  Human Chorionic Gonadotropin (hCG)  Causes the corpus luteum to secrete even larger quantities of progesterone and estrogen for the next few months which prevent menstruation and cause the endometrium to continue to grow and store large amounts of nutrients  Exerts an interstitial cell-stimulating effect on the testes of the male fetus, resulting in the production of testosterone in male fetuses until the time of birth  Estrogen  Enlargement of the mother’s uterus and female external genitalia  Enlargement of the mother’s breasts and growth of the breast ductal structure  Progesterone  Causes decidual cells to develop in the uterine endometrium which play an important role in the nutrition of the early embryo.  Decreases the contractility of the pregnant uterus, thus preventing uterine contractions from causing spontaneous abortion

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Human Chorionic Somatomammotropin (Human Placental Lactogen)  Causes partial development of the breasts and in some in some instances causes lactation  Causes decreased insulin sensitivity and decreased utilization of glucose in the mother, thereby making larger quantities of glucose available to the fetus

FERTILIZATION Sperm Transport from Origin to Site of Fertilization:

Sperm deposited in the VAGINA ↓ Enter CERVIX ↓ Cervical mucus secretion aids or impedes sperm movement: Prior to ovulation: Becomes watery and guides sperm through cervical canal High progesterone: Becomes extremely viscid and disorganized, impeding movement ↓ Enter UTERUS ↓ FALLOPIAN TUBES ↓ Meets EGG Capacitation Acrosome reaction  On coming in contact with the fluids of the female genital tract, multiple  Before a sperm can fertilize the ovum, it must dissolute granulose cell layers changes occur that activate the sperm for the final processes of fertilization and then it must penetrate through the zona pellucida.  The uterine and fallopian tube fluids wash away the various inhibitory factors  Hyalorunidase depolymerizes the hyaluronic acid polymers in the intercellular that suppress sperm activity in the male genital ducts cement that hold the ovarian granulose cells together.  After ejaculation, the sperm deposited in the vagina swim away from the  Proteolytic enzymes digest proteins in the structural elements of tissue cells cholesterol vesicles upward into the uterine cavity, and they gradually lose that still adhere to the ovum. much of their other excess cholesterol over the next few hours, making the  When the sperm reaches the zona pellucid, the anterior membrane of the membranes at the head of the sperm much weaker sperm binds with receptor proteins in the zona pellucid. Then rapidly, the entire  The membrane of the sperm also becomes much more permeable to calcium acrosome dissolves, and all the acrosomal enzymes are released. ions which change the activity of the flagellum, giving it a powerful whiplash  These enzymes open a penetrating pathway for passage of the sperm head to motion. The calcium ions also causes changes in the cellular membrane of the the inside of the ovum. Within 30 minutes, the cell membranes of the sperm acrosome, making it possible for the acrosome to release its enzymes rapidly head and of the oocyte fuse with each other to form a single cell. and easily. 8.

MENSTRUAL CYCLE 4 phases: Describe appearance of endometrium – (thickness, glands, arteries, stroma) PHASE DESCRIPTION/HORMONAL CONTROL THICKNESS GLANDS Proliferative Under the influence of estrogen: stromal Increase in size due SIMPLE STRAIGHT Phase cells & epithelial cells proliferate rapidly to repair and growth TUBULAR GLANDS (D: 1-14) of denuded epithelium - Become longer (4-6 mm) - Increase in number - Glandular epithelium accumulate glycogen Secretory Occur after ovulation Increased thickening COILED TORTUOS Phase Correspond to formation of Corpus due to edema of with LATERAL (D: 15-26) Luteum stroma SACCULATIONS Glandular epithelial cells with more secretions Premenstrual Correspond to regression of Corpus Decreasing thickness HIGHL COILED but Phase Luteum (3-4 mm) stop secretion (D: 26-28; 24-28hours before menstruation) Menstrual Phase (D: 25-28)

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Due to reduction of estrogen and progesterone before and of menstrual cycle Lasts for 3-5 Days

Involution of endometrium Reduced to 65% thickness

Cease to secrete

PELVIC DIAPHRAGM AND UROGENITAL TRIANGLE 4 Muscles of Pelvic Diaphragm MUSCLE ORIGIN INSERTION Piriformis Front of Sacrum Greater Trochanter of Femur Obturator Internus Obturator membrane & Greater Trochanter of Femur Adjoining part of Hip bone Levator Ani Body of pubis, fascia of Perineal body, anococcygeal obturator internus, spine of body, walls of prostate, vagina, ischium rectum, anal canal Coccygeus Spine of Ischium Lower end of sacrum, coccyx

ARTERIES Spiral Arteries Become longer but do not extend to superficial surface

STROMA Dense Abundant ground substance with numerous mitotic cells

More coiled More tortuous but does not reach the surface epithelium

Edematous with accumulation of intracellular fluid and secretion of uterine glands

Ischemia of stratum functionale Blood flow continue to basal portion Vasospastic Intermittent contraction of blood flow Blood flow still continue to basal portion

Nonedematous but dense with leukocyte infiltration (WBC)

Invaded by leukocytes

NERVE SUPPLY Sacral Plexus Nerve to Obturator Internus from Sacral Plexus 4th Sacral Nerve, Pudendal Nerve

ACTION Lateral rotator of femur at hip joint Lateral rotator of femur at hip joint

4th and 5th sacral nerve

Assists Levator Ani to support pelvic viscera Flexes coccyx

Supports pelvic viscera, sphincter to anorectal junction and vagina

4 Muscles of Urogenital Triangle MUSCLE ORIGIN Bulbospongiosus Perineal Body

Ischiocavernosus

Ischial tuberosity

Sphincter urethrae Transverse Perineal Muscle Superficial Deep

Pubic Arch

INSERTION ♂: Fascia of bulb of penis and corpus spongiosum & cavernosum ♀: Fascia of corpus cavernosum Fascia covering corpus cavernosum Surrounds urethra

Ischial tuberosity Ischial ramus

Perineal Body Perineal Body

NERVE SUPPLY Perineal branch o f pudendal nerve

ACTION ♂: Compresses urethra and assists in erection of penis

Perineal branch of pudendal nerve

Perineal branch of pudendal nerve

♀: Sphincter of vagina and assists in erection of clitoris ♂: Assists in erection of penis ♀: Causes erection of clitoris Voluntary sphincter of urethrae

Perineal branch of pudendal nerve Perineal branch of pudendal nerve

Fixes perineal body Fixes perineal body

Perineal branch of pudendal nerve

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SEMEN  The components of semen come from two sources: sperm, and seminal plasma. Seminal plasma, in turn, is produced by contributions from the seminal vesicle, prostate, and bulbourethral glands.  Seminal plasma of humans contains a complex range of organic and inorganic constituents.  The seminal plasma provides a nutritive and protective medium for the spermatozoa during their journey through the female reproductive tract. The normal environment of the vagina is a hostile one for sperm cells, as it is very acidic (from the native microflora producing lactic acid), viscous, and patrolled by immune cells.  The components and contributions of semen are as follows: GLAND APPROX % DESCRIPTION Testes 2-5%[1] Approximately 200- to 500-million spermatozoa (also called sperm or spermatozoans), produced in the testes, are released per ejaculation. Seminal 65-75% fructose - the main energy source of sperm cells, which rely entirely on sugars from the seminal plasma for energy. vesicle prostaglandins – reacting with female cervical mucus to make it more receptive to sperm movement it also causes reverse peristaltic contraction in the uterus and the fallopian tube to move the ejaculated sperm toward the ovaries Fibrinogen – forms a weak fibrin coagulum that holds the semen in the deeper region of the vagina where the uterine cervix lies. Other contents: amino acids, citrate, enzymes, flavins, phosphorylcholine. Prostate 25-30% zinc - serves to help to stabilize the DNA-containing chromatin in the sperm cells. secrete a slightly alkaline (pH 7.29) fluid, milky or white of egg in appearance - The alkalinity of prostate fluid helps neutralize the acidity of the vaginal tract, prolonging the lifespan of sperm. Profibrinolysin – becomes fibrinolysin that causes dissolution of the coagulum 15-30mins after ejaculation allowing sperm to become highly motile. Other contents: acid phosphatase, citric acid, fibrinolysin, prostate specific antigen, proteolytic enzymes Bulbourethral < 1% mucus - during sexual arousal each gland produces a clear, viscous secretion known as pre-ejaculate. This fluid helps to lubricate glands the urethra for spermatozoa to pass through, it neutralizes traces of acidic urine in urethra, and helps flush out any residual urine or foreign matter. It is possible for this fluid to pick up sperm, remaining in the urethral bulb from previous ejaculations, and carry them out prior to the next ejaculation.

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AGING

Reduced GI absorption Altered distribution of drugs Altered binding Altered metabolism Reduced excretion Altered end organ sensitivity

↓GI motility and absorption efficiency ↓ body water and ↑body fat ↓ serum albumin 20%  ↑ free form  greater effects, faster eliminations, biotransformations ↓biotransformation of sedatives in liver ↓ GFR (30%)  ↑ circulation of drug Depletion of neurotransmitters or chemoreceptor sites on cells