WIUC PHYSIOLOGY II - ALL - 08.24 Past Paper PDF

PHYSIOLOGY II NUR 104 2 CREDIT HOURS LECTURER: PETER OSEI 29-Aug-24 Peter Osei, Physiology 2, WIUC 1  LEARNING OUTCOMES By the end of the course, the students will: Describe the mechanism of muscle contractio...

PHYSIOLOGY II NUR 104 2 CREDIT HOURS LECTURER: PETER OSEI 29-Aug-24 Peter Osei, Physiology 2, WIUC 1  LEARNING OUTCOMES By the end of the course, the students will: Describe the mechanism of muscle contraction; State the hormonal secretions of the glands of the endocrine system; Describe the mechanism of urine formation; Explain the transmission of impulses in the nervous system; Outline the physiology of the special senses – sight, hearing, taste, touch and smell; Discuss the functions of the male and female reproductive system. 29-Aug-24 Peter Osei, Physiology 2, WIUC 2  Course Content Unit 1: Urinary System: Fluid and electrolyte balance; Kidney; Nephrons and functions; Formation of urine; Disorders of renal function Unit 2: Reproductive System: Functions of female reproductive system; Male reproductive system and function; Some problems of both female and male reproductive system Unit 3: Endocrine System: Hypothalamus; Pituitary glands and hormones; Thyroid gland and hormones; Adrenal gland and hormones; Pancreas and hormones Unit 4: Gonads (glands) and hormones: Some disorders of endocrine system 29-Aug-24 Peter Osei, Physiology 2, WIUC 3  Course Content (Cont’d) Unit 5: Nervous System: Autonomic nerves and function; Motor and sensory nerve Unit 6: Special Sensory Organs: Physiology of sight; Physiology of hearing; Sensation of taste; Sensation of smell; Tactile sensation; Some clinical problems of the nervous system and special senses Unit 7: Musculoskeletal System: Physiology of muscle contraction; Physiology of smooth muscles; Chemistry of skeletal muscles including energy source; Some disorders of musculoskeletal system 29-Aug-24 Peter Osei, Physiology 2, WIUC 4  STUDENTS’ EVALUATION Continuous Assessment (40 %) Assignments, Presentation, Quiz and Attendance – 20 % Mid-semester examination – 20 % End of Semester Examination – 60 % TOTAL 100 % 29-Aug-24 Peter Osei, Physiology 2, WIUC 5  GRADING SYSTEMS A = 80 – 100 B+ = 75 – 79 B = 70 – 74 C+ = 65 – 69 C = 60 – 64 D+ = 55 – 59 D = 50 – 54 E = 00 – 49 29-Aug-24 Peter Osei, Physiology 2, WIUC 6  Reading List Amerman, E. (2006). Exercises for the Anatomy & Physiology Laboratory. 6th ed. Englewood, CO: Morton Publishing Company Graff, K. Van De Graff, (1995).Concept of human anatomy & physiology. 4th ed. New York. McGraw-Hill Companies Inc. Gunstream, S.E (1992). Anatomy and physiology: a text-workbook. New York: W.M.C. Brown Publishers. Hall, J.E. (2011). Guyton and Hall textbook of Medical physiology. 12th ed. Sounders, U.S.A. Martin, T. R. et al. (1998). Essentials of human anatomy and physiology.6th ed. New York: McGraw-Hill Companies, Inc. Saladin, K. S. (2010). Anatomy & Physiology. The unity of form and function. 5th ed. New York:McGraw-Hill Higher Education. 29-Aug-24 Peter Osei, Physiology 2, WIUC 7  Reading List (Cont’d) Seeley, R. R; Stephens, T. D (2005). Essentials of anatomy and physiology. 5th ed. Boston: McGraw-Hill. Singh, Inderbir (2005). Anatomy and physiology for nurses. New Delhi: Jaypee Brothers medical publishers. Starr, c. & Macmillan, B. (2010). Human Biology. 8th ed. Bookslock, Belmont, U.S.A. Van De Graaff, K., Morton, D., & Crawley, J. (2010). A Photographic Atlas for the Anatomy and Physiology Laboratory. 6th ed., Englewood, CO., Morton Publishing Company. 29-Aug-24 Peter Osei, Physiology 2, WIUC 8  Instructor and Office Hours Instructor: Peter Osei Office: Academic Block, First floor, Room 321 Office Hours: By appointment (To avoid undue waiting) Telephone: 0242519481 Communication Email: [email protected] Assignment Email: [email protected] 29-Aug-24 Peter Osei, Physiology 2, WIUC 9  The Urinary System 29-Aug-24 Peter Osei, Physiology 2, WIUC 10  Organs of the Urinary system Kidneys Ureters Urinary bladder Urethra 29-Aug-24 Peter Osei, Physiology 2, WIUC 11  Functions of the Urinary System Elimination of waste products Regulate aspects of – Nitrogenous wastes homeostasis – Toxins – Water balance – Drugs – Electrolytes – Acid-base balance – Blood pressure – RBC production – Activation of vit.D 29-Aug-24 Peter Osei, Physiology 2, WIUC 12  Regions of the Kidney Renal cortex – outer region Renal medulla – inside the cortex Renal pelvis – inner collecting tube 29-Aug-24 Peter Osei, Physiology 2, WIUC 13  NEPHRONS The nephron is the tiny filtering structure in the kidneys. The structural & functional units of the kidneys Responsible for forming urine Main structures of the nephrons – Glomerulus – Renal tubule Each kidney contains more than a million tiny filtering nephrons that help clean the blood. 29-Aug-24 Peter Osei, Physiology 2, WIUC 14  Nephron anatomy 29-Aug-24 Peter Osei, Physiology 2, WIUC 15  Glomerulus A specialized capillary bed Attached to arterioles on both sides (maintains high pressure) – Large afferent arteriole – Narrow efferent arteriole 29-Aug-24 Peter Osei, Physiology 2, WIUC Figure 15.3c 16  Glomerulus Capillaries are covered with podocytes from the renal tubule The glomerulus sits within a glomerular capsule (the first part of the renal tubule) 29-Aug-24 Peter Osei, Physiology 2, WIUC Figure 15.3c 17  Renal Tubule Glomerular (Bowman’s) capsule Proximal convoluted tubule Loop of Henle Distal convoluted tubule 29-Aug-24 Peter Osei, Physiology 2, WIUC 18  Types of Nephrons Cortical nephrons – Located entirely in the cortex – Includes most nephrons Juxtamedullary nephrons – Found at the boundary of the cortex and medulla 29-Aug-24 Peter Osei, Physiology 2, WIUC 19  Urine Formation Processes Filtration Reabsorption Secretion 29-Aug-24 Peter Osei, Physiology 2, WIUC Figure 15.4 20  Filtration Nonselective passive process Water and solutes smaller than proteins are forced through capillary walls Blood cells cannot pass out to the capillaries Filtrate is collected in the glomerular capsule and leaves via the renal tubule 29-Aug-24 Peter Osei, Physiology 2, WIUC 21  Reabsorption The peritubular capillaries reabsorb several materials – Some water – Glucose – Amino acids – Ions Some reabsorption is passive, most is active Most reabsorption occurs in the proximal convoluted tubule 29-Aug-24 Peter Osei, Physiology 2, WIUC 22  Materials Not Reabsorbed Nitrogenous waste products – Urea – Uric acid – Creatinine Excess water 29-Aug-24 Peter Osei, Physiology 2, WIUC 23  Secretion – Reabsorption in Reverse Some materials move from the peritubular capillaries into the renal tubules – Hydrogen and potassium ions – Creatinine Materials left in the renal tubule move toward the ureter 29-Aug-24 Peter Osei, Physiology 2, WIUC 24  Formation of Urine 29-Aug-24 Peter Osei, Physiology 2, WIUC 25  Ureters Slender tubes attaching the kidney to the bladder – Continuous with the renal pelvis – Enter the posterior aspect of the bladder Runs behind the peritoneum Peristalsis aids gravity in urine transport 29-Aug-24 Peter Osei, Physiology 2, WIUC 26  Urinary Bladder Smooth, collapsible, muscular sac Temporarily stores urine 29-Aug-24 Peter Osei, Physiology 2, WIUC Figure 15.6 27  Urinary Bladder Trigone – three openings – Two from the ureters – One to the urethrea 29-Aug-24 Peter Osei, Physiology 2, WIUC Figure 15.6 28  Urinary Bladder Wall Three layers of smooth muscle (detrusor muscle) Mucosa made of transitional epithelium Walls are thick and folded in an empty bladder Bladder can expand significantly without increasing internal pressure 29-Aug-24 Peter Osei, Physiology 2, WIUC 29  Urethra Thin-walled tube that carries urine from the bladder to the outside of the body by peristalsis Release of urine is controlled by two sphincters – Internal urethral sphincter (involuntary) – External urethral sphincter (voluntary) 29-Aug-24 Peter Osei, Physiology 2, WIUC 30  Female Urethra 29-Aug-24 Peter Osei, Physiology 2, WIUC 31  Male Urethra 29-Aug-24 Peter Osei, Physiology 2, WIUC 32  Sphincters Internal Smooth muscle Autonomic (Automatic) Controlled by spinal cord 29-Aug-24 Peter Osei, Physiology 2, WIUC 33  Sphincters External Skeletal muscle Cerebral control Micturition Expel urine from bladder 29-Aug-24 Peter Osei, Physiology 2, WIUC 34  Urethra Gender Differences Length – Females – 3–4 cm (1 inch) – Males – 20 cm (8 inches) Location – Females – along wall of the vagina – Males – through the prostate and penis 29-Aug-24 Peter Osei, Physiology 2, WIUC 35  Urethra Gender Differences Function – Females – only carries urine – Males – carries urine and is a passageway for sperm cells 29-Aug-24 Peter Osei, Physiology 2, WIUC 36  Hormonal Regulation of Water Intake/Output Hormones regulate reabsorption of water and electrolytes by the kidneys – Antidiuretic hormone (ADH) Hypothalamus tells posterior pituitary to release ADH prevents excessive water loss in the urine increases water reabsorption – Aldosterone (produced by adrenal cortex) increases sodium and water reabsorption; decreases potassium reabsorption Cells in the kidneys and hypothalamus are active monitors 29-Aug-24 Peter Osei, Physiology 2, WIUC 37  The Link Between Water and Salt Changes in electrolyte balance causes water to move from one compartment to another – Alters blood volume and blood pressure – Can impair the activity of cells 29-Aug-24 Peter Osei, Physiology 2, WIUC 38  THE THIRST MECHANISM Osmoreceptors: cells in the hypothalamus – Activated by small changes in blood composition Results in a dry mouth Reinforces the drive to drink water 29-Aug-24 Peter Osei, Physiology 2, WIUC 39  The Renin-angiotensin mechanism Regulates blood pressure – The juxtaglomerular (JG) apparatus of the renal tubules sense drop in BP or solute concentration Causes release of the enzyme renin into blood Renin produces angiotensin II – Acts directly on the blood vessels to vasoconstrict The goal is to reduce filtrate volume 29-Aug-24 Peter Osei, Physiology 2, WIUC 40 Maintaining Acid-Base Balance in Blood Most acid-base balance is maintained by the kidneys Urine pH varies from 4.5 to 8.0 Other acid-base controlling systems – Blood buffers – Respiration 29-Aug-24 Peter Osei, Physiology 2, WIUC 41  Control of pH by the kidneys Most acid-base balance is maintained by the kidneys When blood pH rises (basic): – Bicarbonate ions are excreted – Hydrogen ions are retained by kidney tubules When blood pH falls (acidic): – Bicarbonate ions are reabsorbed – Hydrogen ions are secreted 29-Aug-24 Peter Osei, Physiology 2, WIUC 42  DISORDERS OF RENAL FUNCTION 29-Aug-24 Peter Osei, Physiology 2, WIUC 43  Kidney Sites Susceptible to Renal Disease General: Renal medulla: – Low oxygen environment: Ischemia Glomerulus: – Structure predisposes it to immune complex deposition and complement fixation Tubules: “Post-Renal” Structures (ureters, bladder) – Malformations, Obstruction, 29-Aug-24 Masses (i.e. cancer) Peter Osei, Physiology 2, WIUC 44  Categorization of Renal Disease Generalized Site of Disease: –Prerenal: Inadequate renal blood flow –Intrarenal: Nephron damage –Postrenal: Obstruction, Structural defects 29-Aug-24 Peter Osei, Physiology 2, WIUC 45  DISORDERS OF RENAL FUNCTION Some disorders of the renal function include the following: Diabetic nephropathy Kidney stones Pyelonephritis Glomerulonephritis READING ASSIGNMENT Renal Failure Diabetes Insipidus Urinary tract infections (UTI's) 29-Aug-24 Peter Osei, Physiology 2, WIUC 46  Diabetic nephropathy Also known as Kimmelstiel-Wilson syndrome and intercapillary glomerulonephritis Is a progressive kidney disease caused by angiopathy of capillaries in the kidney glomeruli. It is characterized by nodular glomerulosclerosis. It is due to longstanding diabetes mellitus, and is a prime cause for dialysis in many Western countries. 29-Aug-24 Peter Osei, Physiology 2, WIUC 48  Kidney stones Also known as nephrolithiases, urolithiases or renal calculi, are solid accretions (crystals) of dissolved minerals in urine found inside the kidneys or ureters. They vary in size from as small as a grain of sand to as large as a golf ball. Kidney stones typically leave the body in the urine stream; if they grow relatively large before passing (on the order of millimeters), obstruction of a ureter and enlarged with urine can cause severe pain most commonly felt in the flank, lower abdomen and groin. Kidney stones are unrelated to gallstones. 29-Aug-24 Peter Osei, Physiology 2, WIUC 49  Pyelonephritis When an infection of the renal pelvis and calices, called pyelitis, spreads to involve the rest of the kidney as well, the result is pyelonephritis. It usually results from the spread of fecal bacterium Escherichia coli from the anal region superiorly through the urinary tract. In severe cases, the kidney swells and scars, abscesses form, and the renal pelvis fills with pus (discharge). Left untreated, the infected kidney may be severely damaged, but administration 29-Aug-24 of antibiotics usually achieve Peter Osei, Physiology 2, WIUC a total cure. 50  Glomerulonephritis Inflammation of the glomerular can be caused by immunologic abnormalities, drugs or toxins, vascular disorders, and systemic diseases. Glomerulonephritis can be classified as diffuse proliferative, focal proliferative , membranous etc. Two major changes in the urine are distinctive of glomerulonephritis: hematuria and proteinuria with albumin as the major protein. There is also a decrease in urine as there is lower GFR (glomerular filtration rate). Renal failure is associated with oliguria (less than 400 ml of urine output per day). 29-Aug-24 Peter Osei, Physiology 2, WIUC 51  Renal Failure Uremia is a syndrome of renal failure and includes elevated blood urea and creatinine levels. Acute renal failure can be reversed if diagnosed early. Acute renal failure can be caused by reduced renal blood flow,, damaged kidney, and obstruction to the outflow of urine. It is considered to be chronic renal failure if the decline of renal 29-Aug-24 function to less than 25%. Peter Osei, Physiology 2, WIUC 52  Diabetes Insipidus (DI) This is caused by the deficiency of or decrease of ADH. The person with (DI) has the inability to concentrate their urine in water restriction, in turn they will void up 3 to 20 liters/day. There are two forms of (DI), neurogenic, and nephrogenic. In nephrogenic (DI), the kidneys do not respond to ADH. Usually the nephrogenic (DI) is characterized by the impairment of the urine concentrating capability of the kidney along with concentration 29-Aug-24 of water. Peter Osei, Physiology 2, WIUC 53  Urinary tract infections (UTI's) The second most common type of bacterial infections seen by health care providers is UTI's. Out of all the bacteria that colonize and cause urinary tract infections, the main one is Escherichia coli. In the hospital indwelling catheters and straight catheterizing predispose the opportunity for urinary tract infections. In females there are three stages in life that predispose urinary tract infections, that is menarche, manipulation between intercourse, 29-Aug-24 and menopause. Peter Osei, Physiology 2, WIUC 54  Urinary tract infections (UTI's) However, a small of men and children will get urinary tract infections. In men it is usually due to the prostate gland growth which usually occurs in older age men. In children it can occur 3% to 5% in girls and 1% in boys, In uncircumcised boys, it is more common than circumcised ones; in girls it may be the result of onset of toilet training 29-Aug-24 Peter Osei, Physiology 2, WIUC 55  THE REPRODUCTIVE SYSTEM 29-Aug-24 Peter Osei, Physiology 2, WIUC 56  Introduction Male and female reproductive systems – Function together to produce offspring – Female reproductive system nurtures developing offspring – Produce important hormones 29-Aug-24 Peter Osei, Physiology 2, WIUC 57  Male Reproductive System 29-Aug-24 Peter Osei, Physiology 2, WIUC 58  Male Reproductive System Testes Scrotum – sac that holds the – Primary organs testes Develop in the abdominal pelvic cavity of fetus Seminiferous tubules Descend into scrotal sac shortly – On top of testes before or after birth – Filled with spermatogenic cells – Produce the male sex cells that produce sperm cells (sperm) Interstitial cells produce – Produce the male hormone testosterone testosterone 29-Aug-24 Peter Osei, Physiology 2, WIUC 59  Sperm Cells Head Tail – Nucleus with 23 – Flagellum that propels chromosomes sperm forward – Acrosome – enzyme-filled sac Helps sperm penetrate ovum Midpiece – Mitochrondria that generate cell’s energy 29-Aug-24 Peter Osei, Physiology 2, WIUC 60  Male Internal Accessory Organs Epididymis Seminal vesicle – Sits on top of each testis – Secrete Fluid rich in sugar used to make energy – Receives spermatids from seminiferous Prostaglandins – stimulate muscular tubules contractions in female to propel sperm – Spermatids become sperm cells forward – Seminal fluid Vas deferens Released into vas deferens just before ejaculation – Tube connected to epididymis 60% of semen volume – Carries sperm cells to urethra 29-Aug-24 Peter Osei, Physiology 2, WIUC 61  Male Internal Accessory Organs (cont.) Prostate gland Bulbourethral (Cowper’s) glands – Surrounds urethra – Produce a mucus-like fluid Secreted just before ejaculation – Produces and secretes a milky, alkaline Lubricates end of penis fluid into urethra just before eja culation – Fluid protects sperm in the acidic Semen environment of the vagina – Alkaline mixture Nutrients – 40% of semen Prostoglandins – 1.5 to 5.0 ml per ejaculate – Sperm count of 40 to 250 million/mL 29-Aug-24 Peter Osei, Physiology 2, WIUC 62  Male External Accessory Organs Scrotum Penis – Shaft – Holds testes away from body Erectile tissues surround urethra – Glans penis – Temperature 1° below body Cone-shaped structure on end of penis temperature – Prepuce – Lined with serous membrane Skin covering glans penis in uncircumcised males that secrets fluid – Functions Testes move freely Deliver sperm Urination 29-Aug-24 Peter Osei, Physiology 2, WIUC 63  Erection, Orgasm, and Ejaculation Erection – Parasympathetic nervous system stimulates erectile tissue – Becomes engorged with blood Orgasm – Sperm cells propelled out of testes into urethra – Secretions from accessory organs also released into urethra Ejaculation – Semen is forced out of urethra – Sympathetic nerves then stimulate erectile tissue to release blood – Penis returns to flaccid state 29-Aug-24 Peter Osei, Physiology 2, WIUC 64  Male Reproductive Hormones Hypothalamus –Gonadotropin-releasing hormone (GnRH) Stimulates anterior pituitary to release –Follicle-stimulating hormone (FSH) – initiates spermatogenesis –Luteinizing hormone (LH) – stimulates interstitial cells in the testes to produce testosterone –Testosterone Secondary sex characteristics Maturation of male reproductive organs Regulated by negative 29-Aug-24 feedback Peter Osei, Physiology 2, WIUC 65  Spermatogenesis These are the stages involved in sperm formation. Stage 1: formation of spermatocytes: spermatogonia divide by mitosis to produce two daughter cells, one remains in the germ line (to continue regeneration of more spermatogonia) and the other one goes on to become sperm. Stage 2: Meiosis: this is a reduction division that takes a cell through two rounds of division. At the end four genetically distinctive cells (spermatids) are created which will each mature into a sperm. Stage 3: Spermiogenesis: spermatids mature into sperm, the cell develops a long flagella, a mid piece with high mitochondria count, and a “head” filled with DNA (the nucleus). At the tip of the head lies a sac filled with digestive enzymes called the acrosome. Other cells in the testicles perform jobs like assisting the cells to mature and exit the scrotum (referred to as nurse cells), produce male androgen (like testosterone), and muscular cells that cause tiny contractions to push the sperm out of the testes. When sperm leaves 29-Aug-24 Peter Osei, the seminiferous Physiology 2, WIUC tubules it travels down the 66 efferent tubules towards the epididymis. 29-Aug-24 Peter Osei, Physiology 2, WIUC 67 29-Aug-24 Peter Osei, Physiology 2, WIUC 68  Summary of Spermatogenesis Spermatogonia (46 chromosomes) Mitosis – makes primary spermatocytes Undergo meiosis → two secondary spermatocytes Divides – two spermatids = 4 spermatids Develop flagella to become mature sperm cells with 23 chromosomes 29-Aug-24 Peter Osei, Physiology 2, WIUC 69  Diseases and Disorders of the Male Reproductive System Disease/Disorder Description Benign prostatic Nonmalignant enlargement of the prostate gland; hypertrophy (BPH) common in older men Epididymitis Inflammation of an epididymis; usually starts as an urinary tract infection Impotence or erectile Disorder in which erection cannot be achieved or dysfunction (ED) maintained; about 50% of males between 40 and 70 have some degree of ED 29-Aug-24 Peter Osei, Physiology 2, WIUC 70  Diseases and Disorders of the Male Reproductive System Disease/Disorder Description Prostate cancer Malignant growth in the prostrate gland Prostatitis Inflammation of the prostate gland; may be acute or chronic Testicular cancer Malignant growth in one or both testicles; more common in males 15–30 years; more 29-Aug-24 aggressive malignancy Peter Osei, Physiology 2, WIUC 71  Female Reproductive System 29-Aug-24 Peter Osei, Physiology 2, WIUC 72  Female Reproductive System Ovaries (2) – Primary sex organs produce Sex cells called ova Hormones estrogen and progesterone – Located in the pelvic cavity – Medulla Inner area; contains nerves, lymphatic vessels, and blood vessels – Cortex Outer area; contains ovarian follicles – Covered by epithelial and dense connective tissues 29-Aug-24 Peter Osei, Physiology 2, WIUC 73  Internal Female Organs 29-Aug-24 Peter Osei, Physiology 2, WIUC 74  Female Internal Accessory Organs Fallopian tube – oviduct – Infundibulum and fimbriae Fringed, expanded end of fallopian tube near ovary Function to “catch” an ovum – Muscular tube Lined with mucous membrane and cilia Propels ovum toward uterus 29-Aug-24 Peter Osei, Physiology 2, WIUC 75  Female Internal Accessory Organs (cont.) Uterus – Wall of uterus – Hollow, muscular organ Endometrium – Receives embryo and sustains – Innermost lining its development – Vascular – Tubular glands – mucus – Divisions Myometrium Fundus – domed upper portion – Middle, thick, muscular layer Body – main portion Perimetrium Cervix – narrow, lower section – Thin layer covering the myometrium extending into vagina (cervical – Secretes serous fluid to coat and orifice) protect uterus 29-Aug-24 Peter Osei, Physiology 2, WIUC 76  Female Internal Accessory Organs (cont.) Vagina – Tubular, muscular organ – Extends from uterus to outside body (vaginal introitus) – Muscular folds – rugae – enable expansion Receive erect penis Passage for delivery of offspring and uterine secretions – Wall Innermost mucosal layer Middle muscular layer Outer fibrous layer 29-Aug-24 Peter Osei, Physiology 2, WIUC 77  External Accessory Organs Mammary glands – Secretion of milk – Structures Nipple – Oxytocin induces lactiferous ducts to deliver milk through openings Areola – pigmented area around nipple Alveolar glands – within mammary glands – Make milk when stimulated by prolactin 29-Aug-24 Peter Osei, Physiology 2, WIUC 78  External Genitalia Collectively known as the vulva (often incorrectly referred to as the vagina) Labia majora (analogous to the scrotum) – Rounded folds of adipose tissue and skin – Protect other external reproductive organs Labia minora – Folds of skin between labia majora – Very vascular – Merge to form hood over clitoris – Vestibule – space enclosed by labia minora Bartholin’s glands secrete 29-Aug-24 Peter mucus during Osei, Physiology sexual arousal 2, WIUC 79  External Genitalia (cont.) Clitoris (analogous to the penis) – Anterior to urethral meatus – Contains female erectile tissue – Rich in sensory nerves Perineum – Between vagina and anus – Area for episiotomy, if needed, during birth process 29-Aug-24 Peter Osei, Physiology 2, WIUC 80  External Genitalia (cont.) 29-Aug-24 Peter Osei, Physiology 2, WIUC 81  Erection, Lubrication, and Orgasm Nervous stimulation – Clitoris becomes erect – Bartholin’s glands activate – lubrication – Vagina elongates Orgasm – Sufficient stimulation of clitoris – Walls of uterus and fallopian tubes contract to propel sperm up tubes 29-Aug-24 Peter Osei, Physiology 2, WIUC 82  The ovaries The size of an almond, this paired organ is suspended by mesenteries and ligaments. It is surrounded by a fibrous capsule and can be divided into a cortex and medulla. The cortex houses the developing ova and the medulla holds vascular tissue. The ovary is the site of oogenesis and female sex hormone production. It responds to follicle-stimulating hormone that signals the maturation of an ovum. Typically only one egg is released from an ovary every month, the ovaries alternate in releasing the egg. Every time an egg is released the ovaries become scarred. Hormones that affect the menstrual cycle and female sex organs are also released 29-Aug-24 by the ovaries; estrogen and Peter Osei, progesterone. Physiology 2, WIUC 83  The ovaries 29-Aug-24 Peter Osei, Physiology 2, WIUC 84  Ovarian cycle This concerns the changes in the ovary during the menstrual cycle. Females are born with all the potential ova they can produce in a life time. These are called the primordial follicles which consist of a single immature oocyte and a single layer of follicular cells. These cells respond to FSH and being the maturation of an oocyte. Follicular phase: during the first two weeks of the menstrual cycle one follicle matures up until the stage when it is able to release an oocyte. Other primordial follicles may get activated but die out along the way. The primordial follicle becomes the primary follicle and continues to develop until it becomes the vesicular follicle. At this point the oocyte is surrounded by follicle cells that form a fluid filled cavity. 29-Aug-24 Peter Osei, Physiology 2, WIUC 85  Ovarian cycle Ovulation (midpoint) phase: at about the mid cycle LH is release to signal the follicle to rupture and release the oocyte from the ovary. The ovum is surrounded by a group of cells that continue to nourish it, they are called the corona radiata. When the egg cell is released it enters the peritoneal cavity but is swept into the fallopian/uterine tubes by fimbriae. Luteal phase: after ovulation and during the last two weeks of the cycle, the follicle that held the oocyte becomes the corpus luteum, it is now considered an endocrine gland that releases progesterone. If no implantation occurs it becomes the corpus albicans (now scar tissue). 29-Aug-24 Peter Osei, Physiology 2, WIUC 86  Ovarian cycle 29-Aug-24 Peter Osei, Physiology 2, WIUC 87  Uterine cycle Also called the menstrual cycle. It relates to changes occurring in the endometrium of the uterus that are induced by female sex hormones. It involves the following phases: – Menstrual phase – Proliferative phase – Secretory phase 29-Aug-24 Peter Osei, Physiology 2, WIUC 88  Menstrual phase Days 1-5 During this phase, the endometrium is shed. 29-Aug-24 Peter Osei, Physiology 2, WIUC 89  Proliferative phase Days 6-14 During this phase, the endometrium builds a new stratum functionalis as it responds to rising estrogen levels. As the layer thickens, glands release a clear sticky mucus secretion that assist the sperm in finding the egg. 29-Aug-24 Peter Osei, Physiology 2, WIUC 90  Secretory phase Days 15-28 During this point the stratum functionalis is highly vascularized and there is secretion of glycoproteins to support a developing embryo in case fertilization occur. These changes are a response to progesterone released by the corpus luteum in the ovary. If there is no fertilization the progesterone levels drop signaling changes that cause death of the stratum functionalis. The arteries constrict cutting out blood supply and suddenly open again but the weak capillaries fragment and the menstrual phase begins again. 29-Aug-24 Peter Osei, Physiology 2, WIUC 91 29-Aug-24 Peter Osei, Physiology 2, WIUC 92  Uterine cycle 29-Aug-24 Peter Osei, Physiology 2, WIUC 93 29-Aug-24 Peter Osei, Physiology 2, WIUC 94  Diseases and Disorders of the Female Reproductive System Disease/Disorder Description Breast cancer Uncontrolled growth of abnormal cells in the breast Cervical cancer Uncontrolled growth of abnormal cells in the cervix Cervicitis Inflammation of the cervix usually due to an infection Dysmenorrhea Condition with severe menstrual cramps that limit normal activities 29-Aug-24 Peter Osei, Physiology 2, WIUC 95  Diseases and Disorders of the Female Reproductive System Endometriosis Tissues of uterine lining growing outside of the uterus Fibrocystic breast Abnormal cystic tissue in the breast; size varies disease related to menstrual cycle; common in 60% of women between 30 and 50 Fibroids Benign tumors in the uterine wall. Ovarian cancer Uncontrolled growth of abnormal cells in the ovary 29-Aug-24 Peter Osei, Physiology 2, WIUC 96  Diseases and Disorders of the Male Reproductive System Premenstrual Collection of symptoms occurring just syndrome (PMS) before a menstrual period Vaginitis/ Inflammation of the vulvovaginitis vagina/inflammation of vagina and vulva; both associated with abnormal vaginal discharge Uterine Uncontrolled growth of abnormal cells (endometrial) in the uterus. cancer 29-Aug-24 Peter Osei, Physiology 2, WIUC 97  ENDOCRINE SYSTEM 29-Aug-24 Peter Osei, Physiology 2, WIUC 98  Endocrine glands are scattered throughout the body, many of them with no apparent connection to each other. 29-Aug-24 Peter Osei, Physiology 2, WIUC 99  The endocrine system The system broadcasts its hormonal messages to essentially all cells by secretion into blood and fluid that surrounds cells. Like a radio broadcast, it requires a receiver to get the message - in the case of endocrine messages, cells must bear a receptor for the hormone being broadcast in order to respond. 29-Aug-24 Peter Osei, Physiology 2, WIUC 100 Principal functions of the endocrine system Maintenance of the internal environment in the body (maintaining the optimum biochemical environment). Integration and regulation of growth and development. Control, maintenance and instigation of sexual reproduction, including gametogenesis, coitus, fertilization, fetal growth and development and nourishment of the newborn. 29-Aug-24 Peter Osei, Physiology 2, WIUC 101  Functions regulated by the Endocrine System Growth Healing Water balance & Blood Pressure Calcium Metabolism Energy Metabolism Stress Regulation of other Endocrine Organs 29-Aug-24 Peter Osei, Physiology 2, WIUC 102  Control of Endocrine Activity The physiologic effects of hormones depend largely on their concentration in blood and extracellular fluid. Almost inevitably, disease results when hormone concentrations are either too high or too low, and precise control over circulating concentrations of hormones is therefore crucial. 29-Aug-24 Peter Osei, Physiology 2, WIUC 103  Control of Endocrine Activity The concentration of hormone as seen by target cells is determined by three factors: Rate of production Rate of delivery Rate of degradation and elimination 29-Aug-24 Peter Osei, Physiology 2, WIUC 104  Control of Endocrine Activity Rate of production: Synthesis and secretion of hormones are the most highly regulated aspect of endocrine control. Such control is mediated by positive and negative feedback circuit. 29-Aug-24 Peter Osei, Physiology 2, WIUC 105  Control of Endocrine Activity Rate of delivery: An example of this effect is blood flow to a target organ or group of target cells - high blood flow delivers more hormone than low blood flow. 29-Aug-24 Peter Osei, Physiology 2, WIUC 106  Control of Endocrine Activity Rate of degradation and elimination: Hormones, like all biomolecules, have characteristic rates of decay, and are metabolized and excreted from the body through several routes. Shutting off secretion of a hormone that has a very short half-life causes circulating hormone concentration to fall, but if a hormone's biological half-life is long, effective concentrations persist for some time after secretion ceases. 29-Aug-24 Peter Osei, Physiology 2, WIUC 107  Feedback Control of Hormone Production Feedback loops are used extensively to regulate secretion of hormones in the hypothalamic-pituitary axis. An important example of a negative feedback loop is seen in control of thyroid hormone secretion 29-Aug-24 Peter Osei, Physiology 2, WIUC 108 Hypothalamus 29-Aug-24 Peter Osei, Physiology 2, WIUC 109  Hypothalamus The hypothalamus, which is attached to the posterior pituitary, is the link between the central nervous system and the endocrine system. The hypothalamus controls the secretions of the pituitary gland. The activities of the hypothalamus are influenced by hormone levels and other substances in the blood and by sensory information collected by the central nervous system. The hypothalamus contains the cell bodies of neurosecretory cells whose axons extend into the posterior 29-Aug-24 pituitary. Peter Osei, Physiology 2, WIUC 110  Anterior Pituitary “Releasing” hormones regulate AP aka adeno hypo physis “glands” “under” “growth” All proteins TSH (thryoid stimulating hormone/thyrotropin) ACTH (adrenocorticotropic hormone) FSH (gonadotropin) LH (gonadotropin) Tropins/tropic hormones GH (growth hormone) Prolactin-releasing H 29-Aug-24 Peter Osei, Physiology 2, WIUC 111  Anterior Pituitary 29-Aug-24 Peter Osei, Physiology 2, WIUC 112 29-Aug-24 Peter Osei, Physiology 2, WIUC 113  Anterior P. Homeostatic Imbalances Growth hormone (GH or hGH) Promotes mitosis, cell division Elongation of long bones, etc. Healing of wounds Lack of hGH retards growth Hypersecretion in youth produces giantism Hyposecretion in childhood produces pituitary dwarfism Hypersecretion in adult produces acromegaly 29-Aug-24 Peter Osei, Physiology 2, WIUC 114  Pituitary—Posterior lobe Oxytocin Stimulates smooth muscle contraction of uterus & mammary glands. Antidiuretic H. Stimulates water reabsorption in collecting ducts. Stimulates vasoconstriction (vasopressin) Lack → diabetes insipidus 29-Aug-24 Peter Osei, Physiology 2, WIUC 115 Posterior Pituitary Homeostatic Imbalances ADH Hyposecretion produces diabetes insipidus “tasteless” Excessive thirst and urination central or neurogenic DI gestagenic or gestational DI nephrogenic DI dipsogenic DI Diabetes Insipidus Foundation, Inc. 29-Aug-24 Peter Osei, Physiology 2, WIUC 116 29-Aug-24 Peter Osei, Physiology 2, WIUC 117  Thyroid Gland Location in neck Inferior to larynx Anterior & lateral to trachea Composed of follicles Follicle cells produce thyroglobulin Thyroxin (T4) Triiodothyronine (T3) Both “thyroid hormone”, body’s major metabolic hormone Parafollicular/ C cells Calcitonin Decreases blood Ca2+ by depositing it in bones 29-Aug-24 Peter Osei, Physiology 2, WIUC 118  Homeostatic imbalances Hypothyroidism results Myxedema (in adults) Goiter—low levels of iodine Cretinism (in children) Hyperthyroidism results Graves disease 29-Aug-24 Peter Osei, Physiology 2, WIUC 119  Parathyroid Glands Four small glands embedded in posterior of thyroid Parathyroid hormone (PTH) Stimulates osteoclasts to free Ca2+ from bone Stimulates Ca2+ uptake from intestine & kidney 29-Aug-24 Peter Osei, Physiology 2, WIUC 120  Parathyroid Homeostatic Imbalances Severe hyperparathyroidism causes massive bone destruction If blood Ca2+ fall too low, neurons become overactive, resulting in tetany 29-Aug-24 Peter Osei, Physiology 2, WIUC 121 Feedback Loop Negative feedback in calcium homeostasis. A rise in blood Ca2+ causes release of calcitonin from the thyroid gland, promoting Ca2+ deposition in bone and reducing reabsorption in kidneys. A drop in blood Ca2+ causes the parathyroid gland to produce parathyroid hormone (PTH), stimulating the release of Ca2+ from bone. PTH also promotes reabsorption of Ca2+ in kidneys and uptake of Ca2+ in intestines. 29-Aug-24 Peter Osei, Physiology 2, WIUC 122  Adrenal Glands One on top of each kidney Cortex Corticosteroid glandular Medulla Catecholamines neurohormonal Epinephrine Norepinephrine 29-Aug-24 Peter Osei, Physiology 2, WIUC 123  Adrenal Cortex Cortex Activity stimulated by ACTH Controls prolonged responses by secreting corticosteroids. Mineralcorticoids Aldosterone→ regulate salt and water balance Glucocorticoids Cortisol→ regulate glucose metabolism and the immune system. Gonadocorticoids Androgens Estrogens 29-Aug-24 Peter Osei, Physiology 2, WIUC 124  Adrenal Cortex Imbalances Hypersecretion leads to Cushing’s disease ACTH-releasing tumors or side effects of corticoid drugs. Hyposecretion leads to Addison’s Disease Deficits in glucocorticoids and mineralcorticoids 29-Aug-24 Peter Osei, Physiology 2, WIUC 125  Adrenal Medulla Medulla The adrenal medulla mediates short–term responses by secreting catecholamine hormones. Cells are modified neurons (lack axons) Epinephrine (adrenaline) Norepinephrine (noreadrenaline) enable a rapid ( fight-or-flight ) responses to stress by increasing blood glucose and blood pressure and directing blood to the heart, brain, and skeletal muscles. 29-Aug-24 Peter Osei, Physiology 2, WIUC 126 29-Aug-24 Peter Osei, Physiology 2, WIUC 127  Pancreas Consists of two major types of secretory tissues which reflects its dual function Exocrine gland secretes digestive juice localized in the acinar cells Endocrine gland releases hormones localized in the islet cells (islets of Langerhans) 29-Aug-24 Peter Osei, Physiology 2, WIUC 128  Pancreatic Islets “About a million” embedded in pancreas Control centers for blood glucose Insulin from beta cells Glucagon from alpha cells 29-Aug-24 Peter Osei, Physiology 2, WIUC 129  Insulin Glucagon 29-Aug-24 Peter Osei, Physiology 2, WIUC 130  Islets of Langerhans Insulin stimulates glucose uptake, glycogenesis Glucagon stimulates glycogenolysis, glucose release from liver (vs gluconeogenesis) 29-Aug-24 Peter Osei, Physiology 2, WIUC 131 Feedback Loop A rise in blood glucose causes release of insulin from beta cells the pancreas, promoting glucose uptake in cells and storage as glycogen in the liver. A fall in blood glucose stimulates alpha cells in the pancreas to secrete glucagon, which causes the liver to break down glycogen and release glucose. 29-Aug-24 Peter Osei, Physiology 2, WIUC 132  Pancreas Homeostatic Imbalances: Diabetes mellitus Symptoms: Polyuria Polydipsia Polyphagia 29-Aug-24 Peter Osei, Physiology 2, WIUC 133  Gonads Ovaries Estrogens Progesterone Testes Testosterone 29-Aug-24 Peter Osei, Physiology 2, WIUC 134  Pineal gland Melatonin Inhibits early puberty Day/night cycles Timing of sleep, body temperature, appetite Secretes melatonin during darkness Participates in setting the body’s clock Melatonin is a potent antioxidant Melatonin is high when young and is reduced as we age 29-Aug-24 Peter Osei, Physiology 2, WIUC 135  Thymus Thymus gland Thymopoietins, thymic factor, thymosins Influence development of T lymphocytes 29-Aug-24 Peter Osei, Physiology 2, WIUC 136  SENSES 29-Aug-24 Peter Osei, Physiology 2, WIUC 137  Introduction to Senses Senses are the physiological methods of perception. Sense is a faculty by which outside stimuli are perceived. Our senses are split into two different groups. Exteroceptors: detect stimulation from the outsides of our body. For example smell, taste and equilibrium. Interoceptors: receive stimulation from the inside of our bodies. For instance, blood pressure dropping, changes in the gluclose and Ph levels. 29-Aug-24 Peter Osei, Physiology 2, WIUC 138  Introduction to Senses There are generally five senses; Sight (eye), hearing (ear), touch (skin), smell (nose), taste (tongue). However, it is generally agreed that there are at least seven different senses in humans, and a minimum of two more observed in other organisms. Sense can also differ from one person to the next. has to do with how the brain interprets the stimuli that are received. all have specialized sensory receptors that collect and transmit information to specific areas of the brain. 29-Aug-24 Peter Osei, Physiology 2, WIUC 139 General Properties of Sensory Systems Stimulus Internal External Energy source Receptors Sense organs Transducer Afferent pathway CNS integration Perception 29-Aug-24 Peter Osei, Physiology 2, WIUC 140  General Properties of Sensory Systems 29-Aug-24 Peter Osei, Physiology 2, WIUC 141 Figure 10-4: Sensory pathways  Comparison of General and Special Senses General Senses Special Senses Include somatic sensations Include smell, taste, vision, (tactile, thermal, pain, and hearing and equilibrium. proprioceptive) and Anatomically distinct visceral sensations. structures and Scattered throughout the concentrated in specific body. locations in the head. Simple structures. Complex neural pathway. 29-Aug-24 Peter Osei, Physiology 2, WIUC 142  SPECIAL SENSES 29-Aug-24 Peter Osei, Physiology 2, WIUC 143  SENSE OF SMELL: OLFACTION Olfactory epithelium contains 10-100 million receptors. Olfactory receptor- a bipolar neuron with cilia called olfactory hairs. - Respond to chemical stimulation of an odorant molecule. Supporting cells- provide support and nourishment. Basal cells- replace olfactory receptors. 29-Aug-24 Peter Osei, Physiology 2, WIUC 144 Olfactory Epithelium and Olfactory Receptors 29-Aug-24 Peter Osei, Physiology 2, WIUC 145 Olfactory Epithelium and Olfactory Receptors (cont’d) 29-Aug-24 Peter Osei, Physiology 2, WIUC 146  PHYSIOLOGY OF SMELL The physiology of smell in humans begins in the nasal cavity. There, a huge number of receptors (over 40 million) are located in the upper roof of the cavity. The receptors have cilia projections that stick out into the cavity space. These increase the surface area and the sensitivity of the receptors. One reason for the receptor sensitivity concerns the mechanics of airflow in the nasal cavity. The air rushes in quickly (at about 250 milliliters per second) and is turbulent. Thus, not all of a particular odor will have a chance to contact a receptor. So, a receptor must be able to swiftly detect a low concentration of a molecule. The olfactory receptor cells are replaced every three to four weeks. The receptors are responsible for detecting a large number of odours (about 2,000, depending on the individual). A group of genes is known to encode proteins associated with the receptors that may function in the specific detection 29-Aug-24 of an odor. There may be upwards of1471,000 Peter Osei, Physiology 2, WIUC very specific odor receptors.  PHYSIOLOGY OF SMELL (cont’d) Odors reach a receptor by diffusing through the air and physically contacting the receptor. Surrounding the cilia is a mucous membrane. It is into this membrane that an odor dissolves. The binding of an odor molecule to a receptor stimulates the activation of a protein called the G-protein and the release of calcium from the receptor membrane. These events begin the process whereby an electrical potential is generated. The potential constitutes the signal that is sent off to the brain. A signal is relayed to the anterior olfactory nucleus, which is essentially a collection point for the receptor signals. The signals are then routed to a region of the brain responsible for the processing of the information. This region is known as the primary olfactory cortex. Following the stimulation of a receptor, the odor molecule is rapidly destroyed and the stimulation ended. This frees the receptor for stimulation by another odor molecule. In this way the sensitivity of the smell sensory system is maintained. Dogs have a much greater sense of smell than humans. Their receptors have almost 20 times the surface area as human receptors, and there are 100 times more receptors per 29-Aug-24 Peter Osei, Physiology 2, WIUC 148 square centimeter in a dog's nasal cavity than in a humans.  SENSE OF TASTE: GUSTATION 29-Aug-24 Peter Osei, Physiology 2, WIUC 149 29-Aug-24 Peter Osei, Physiology 2, WIUC 150  Gustation: Sense of Taste, cont’d 29-Aug-24 Peter Osei, Physiology 2, WIUC 151  Physiology of Gustation Five types of taste: sour, sweet, bitter, salty and umami. Tastant dissolves in saliva → plasma membrane of gustatory hair→ receptor potential→ nerve impulse via cranial nerves VII, IX and X→ medulla→ thalamus→ primary gustatory area of the cerebral cortex. 29-Aug-24 Peter Osei, Physiology 2, WIUC 152 Gustatory Pathway 29-Aug-24 Peter Osei, Physiology 2, WIUC 153  SENSE OF VISION OR SIGHT Visible light: 400-700 nm. 29-Aug-24 Peter Osei, Physiology 2, WIUC 154 Anatomy of the Eyeball 29-Aug-24 Peter Osei, Physiology 2, WIUC 155  Physiology of Sight Sight begins when light rays from an object enter the eye through the cornea; the cornea is actually responsible for about sixty percent of the eyeball’s light-ray-bending capability. The cornea’s refractive power bends the light rays in such a way that they pass freely through the pupil, the size-changing hole in the iris. The iris, works like a shutter in a camera. It has the ability to enlarge and shrink, depending on how much light the environment is sending into the pupil. After passing through the iris, the light rays strike the eye’s crystalline lens. This clear, flexible structure works much like the lens in a camera – shortening and lengthening its width in order to focus light rays properly. 29-Aug-24 Peter Osei, Physiology 2, WIUC 156  Physiology of Sight, cont’d In a normal eyeball, after exiting the back of the lens, the light rays pass through the vitreous; the vitreous humor helps the eye hold its spherical shape. Finally, the light rays land and come to a sharp focusing point on the retina, which is responsible for capturing all of the light rays, processing them into light impulses through millions of tiny nerve endings, then sending these light impulses through over a million nerve fibers to the optic nerve. The optic nerve is sort of like an extension of the brain. The light impulses travel through this nerve fiber to the brain, where they are interpreted as an image. 29-Aug-24 Peter Osei, Physiology 2, WIUC 157  Refraction Abnormalities and their Correction Nearsightedness (myopia)- close objects seen clearly. Image is focused in front of the retina. Correction- use of concave lens. Farsightedness (hyperopia)- distant objects seen clearly. Image is focused behind the retina. Correction- use of convex lens. 29-Aug-24 Peter Osei, Physiology 2, WIUC 158 29-Aug-24 Peter Osei, Physiology 2, WIUC 159  SENSE OF HEARING AND BALANCING The ear is the organ of hearing and balancing 29-Aug-24 Peter Osei, Physiology 2, WIUC 160  Anatomy of the Ear 29-Aug-24 Peter Osei, Physiology 2, WIUC 161  The Internal Ear Three parts: the semicircular canals, the vestibule (both contain receptors for equilibrium) and the cochlea (contains receptors for hearing). Semicircular canals: anterior, posterior and lateral. Ampulla- Vestibule consists of two sacs: utricle and saccule. 29-Aug-24 Peter Osei, Physiology 2, WIUC 162  Physiology of Hearing Sound waves→ auricle→ external auditory canal→ tympanic membrane→ malleus→ incus→ stapes→ oval window→ perilymph of the scala vestibuli→ vestibular membrane→ endolymph in the cochlear duct→ basilar membrane →hair cells against tectorial membrane → bending of hair cell stereocilia→ receptor potential→ nerve impulse. 29-Aug-24 Peter Osei, Physiology 2, WIUC 163 Events in the Malleus Incus Stapes vibrating in oval window Helicotrema Cochlea Stimulation Sound waves Perilymph of Auditory Receptors 3 4 7 8 Scala tympani Scala 5 vestibuli 6 Basilar 1 2 9 membrane External auditory 8 canal Spiral organ (organ of Corti) Tectorial membrane Vestibular membrane Cochlear duct (contains endolymph) Tympanic membrane Secondary tympanic membrane vibrating 29-Aug-24 in round window Peter Osei, Physiology 2, WIUC Middle ear Auditory tube 164 The Auditory Pathway 29-Aug-24 Peter Osei, Physiology 2, WIUC 165  Physiology of Equilibrium Two types of equilibrium: Static- maintenance of the body position relative to the force of gravity. Dynamic- maintenance of body position (mainly head) in response to rotational acceleration and deceleration. Receptors for equilibrium are hair cells in the utricle, saccule and semicircular canals and are collectively called vestibular apparatus. 29-Aug-24 Peter Osei, Physiology 2, WIUC 166 Location and Structure of Receptors in the Maculae 29-Aug-24 Peter Osei, Physiology 2, WIUC 167  Physiology of Equilibrium Tilting of the head forward→ sliding of the otolithic membrane bending the hair bundles→ receptor potential→ vestibular branch of the vestibulocochlear nerve. 29-Aug-24 Peter Osei, Physiology 2, WIUC 168 Location and Structure of the Semicircular Ducts 29-Aug-24 Peter Osei, Physiology 2, WIUC 169  Cupula in Still Position versus Rotation 29-Aug-24 Peter Osei, Physiology 2, WIUC 170 Equilibrium Pathway Hair cells of utricle, saccule and semicircular ducts→ Vestibular branch of the vestibulocochlear nerve →brain stem → cerebellum and thalamus→ cerebral cortex. 29-Aug-24 Peter Osei, Physiology 2, WIUC 171  Musculoskeletal System 29-Aug-24 Peter Osei, Physiology 2, WIUC 172  MUSCULOSKELETAL SYSTEM The musculoskeletal system is an organ system comprising the bones, muscles and connective tissues (including cartilage, tendons and ligaments) that bind tissues and organs together. It is also known as the locomotor system The main functions of this system are to provide structure and support to the body, protect vital organs and enable movement. The problems associated with these structures are common and affect all age groups. Problems with the musculoskeletal system are generally not life-threatening, but have a significant effect on the client’s normal activities and productivity. 29-Aug-24 Peter Osei, Physiology 2, WIUC 173  MUSCULOSKELETAL SYSTEM This system describes how bones are connected to other bones and how bones are connected muscle fibers via connective tissues; ligaments and tendons respectively. The bones provide stability to the body. Muscles keep bones in place and also play a role in the movement of bones. To allow motion, different bones are connected by joints. Cartilage prevents the bone ends from rubbing directly onto each other. Muscles contract to move the bone attached at the joint ( by pull movement only) Muscles are made of groups of cells called fibres. 29-Aug-24 Peter Osei, Physiology 2, WIUC 174  Functions of the Skeletal System Muscle attached to bones!! 1. Movement: Skeletal system provides points of attachment for muscles. Your legs and arms move when the muscles pull on the bones. 2. Support: The backbone is the main support center for the upper body. It holds your head up and protects your spinal cord. 29-Aug-24 Peter Osei, Physiology 2, WIUC 175  Functions of the Skeletal System 3. Protection: The bones of your skull protect your brain. Your ribs protect your lungs and heart from injury. 4. Makes Blood: Red and white blood cells are formed by tissue called marrow, which is in the center of the bone. 29-Aug-24 Peter Osei, Physiology 2, WIUC 176  Functions of the Skeletal System 5. Storage: Bones store minerals, such as calcium and phosphorus, for use by the body 29-Aug-24 Peter Osei, Physiology 2, WIUC 177  Problems of the Skeletal System Fracture: Break Dislocation: Out of joint 29-Aug-24 Peter Osei, Physiology 2, WIUC 178  Problems of the Skeletal System Sprain: Swelling in the joint Arthritis: Inflamed and stiff joints 29-Aug-24 Peter Osei, Physiology 2, WIUC 179 Problems of the Skeletal System Scoliosis: Curvature of the spine Osteoporosis: Brittle bones 29-Aug-24 Peter Osei, Physiology 2, WIUC 180