Anatomy & Physiology

Transcription

1 Anatomy & Physiology Unit 2 Review of Body Systems Paul Anderson Jan 2012

2 Systems Connecting External & Internal Environments The Cardiovascular system connects the Integumentary, Digestive, Respiratory and Urinary Systems that are in contact with the external environment with body cells so cells can receive nutrients and oxygen and get rid of wastes, via the blood. Integumentary Digestive Urinary Respiratory Cardiovascular 2 From Martini & Bartholomew, fig 1-2

3 Overview of Body Systems food DIGESTIVE INTEGUMENTARY heat Gas exchange tissue exchange AIR Breathing RESPIRATORY Lumen of respiratory tract Interstitial fluid (IF) Lumen of alimentary canal Body s External Environment Elimination of feces absorption CARDIO- VASCULAR Urine formation by kidney tubule URINARY IF Lumen of urinary tract Elimination of urine Body s Internal Environment Blood Plasma 3 From Marieb

4 Major Functions of the Digestive System The digestive system prepares food molecules in the external environment) for use by body cells in the internal environment. This involves the physical/chemical breakdown food (digestion) in the lumen of the alimentary canal and then transfer of products of digestion to the internal environment (absorption). The digestive system therefore replenishes the internal environment with nutrients and water from the external environment. FOOD IN EXTERNAL ENVIRONMENT DIGESTION in lumen of alimentary canal CELLS INTERNAL ENVIRONMENT ABSORPTION into blood or lymph 4

5 Digestion & Absorption of Nutrients Diet Polymers starch protein fats Chemical Digestion (hydrolysis) Absorption Hepatic portal vein blood Monomers glucose amino acids fatty acids liver

6 Digestive System Organs Primary Digestive Organs Form hollow Alimentary Canal. Site for digestion/absorption. Site for ingestion of food, swallowing & elimination. Stomach & duodenum are endocrine organs. Mouth Salivary gland Pharynx Esophagus Liver Stomach Gallbladder Accessory Digestive Organs Provide secretions to alimentary canal for digestion & absorption. Liver metabolises (processes) and stores food molecules. Liver and pancreas help regulate the internal environment (e.g. control blood sugar level). Martini & Bartholomew fig 1-2i Large intestine Small intestine Pancreas Martini & Bartholomew fig 10-13

7 Primary Digestive Organs Mouth Ingestion Chewing Starch digestion Swallowing Large intestine Absorption of water, salt & vitamins Formation, storage & elimination of feces Martini & Bartholomew fig 16-1 Pharynx - Swallowing Esophagus -Swallowing Stomach Secretes gastric juice for Protein digestion. Storage of food. Some Absorption. Secretes a Digestive Hormone Small intestine Main site for digestion & absorption Duodenum secretes Digestive Hormones 7

8 Accessory Digestive Organs Liver Secretes bile for fat digestion/absorption. Receives, stores & metabolises products of digestion. Receives all blood from gastro-intestinal tract, filters it & controls composition of blood. Martini & Bartholomew fig 16-1 Salivary Glands secrete saliva, a lubricating fluid with enzymes for carbohydrate digestion. Gall Bladder Stores, concentrates & expels bile into duodenum Pancreas Exocrine pancreas secretes pancreatic juice with variety of digestive enzymes. Endocrine pancreas secretes hormones. 8

9 Liver & Endocrine Pancreas help Control Blood Glucose Levels Insulin lowers the blood glucose level by causing increased uptake of glucose & formation of glycogen by liver and muscle cells. Glucagon raises the blood glucose level by causing breakdown of glycogen in liver cells and release of glucose into the blood. Food alimentary canal Absorption of nutrients Blood capillary 90mg/dL plasma glucose insulin ENDOCRINE PANCREAS glucagon 90mg/dL plasma glucose LIVER glucose glycogen glucose

10 Respiratory System: Organs & Major Functions Major Organs/Cavities Nasal cavity Major Functions BREATHING Pumping of air in & out of lungs Breathing involves Respiratory System Muscular System Skeletal System Nervous System GAS EXCHANGE Diffusion of O 2 /CO 2 between blood & air in lungs Gas Exchange involves Respiratory System Cardiovascular System Martini & Bartholomew fig 1-2h Pharynx Larynx Trachea Bronchi Lung (with bronchioles & alveoli) Diaphragm (a voluntary muscle) Respiratory System through Breathing & Gas Exchange supplies O 2 to internal environment & removes excess CO 2 /H + so controls O 2 /CO 2 levels & ph of internal environment.

11 Respiratory System & Control of ph Systemic tissues add CO 2 to blood Equations pushed to right in systemic blood, adding H + and lowering ph. Addition of CO 2 lowers ph of systemic blood to 7.35 CO 2 removed from blood in lungs Systemic blood H 2 O + CO 2 H 2 CO 3 HCO - + H + 3 carbonic acid bicarbonate Pulmonary blood Removal of CO 2 raises ph of pulmonary blood to 7.45 Equations pushed to left in pulmonary blood, removing H + and raising ph. Respiratory Disease causes acidosis

12 Urinary System: Organs & Functions Major Functions Excretes urine to control the chemistry and volume of the internal environment i.e. controls fluid, ph and electrolyte balance. Urine contains N - wastes (e.g. urea, NH 3 ) and excess amounts of needed chemicals (e.g. water, electrolytes). Organs Kidney forms urine from blood Ureter transports urine Urinary bladder stores & voids (eliminates) urine Urethra eliminates urine Stores and voids (eliminates) urine Martini & Bartholomew fig 1-2j

13 Three Processes that form Urine A. Filtration from blood plasma into kidney tubule (leaves only cells & proteins behind). B. Reabsorption into blood of essential nutrients (glucose, amino acids, electrolytes). C. Secretion (=Excretion) from blood plasma into kidney tubule of wastes & excess electrolytes). Renal Blood vessel C B A Kidney tubule

14 Urinary System: Organs & Functions 2 Renal vein Renal artery Renal Blood vessel C B A Urine Kidney tubule Ureters Urinary bladder Urethra 14

15 Cardiovascular (Circulatory) System: Organs & Functions Heart: a double pump Right ventricle pumps deoxygenated blood into pulmonary arteries (PA). Left ventricle pumps oxygenated blood into systemic arteries (SA) Arteries: carry blood away from heart under high pressure. Pulmonary Circuit (Circulation) Right PA Ventricle Left SA Ventricle LUNGS Systemic Circuit (Circulation) CO 2 PV O 2 CO 2 SYSTEMIC CAPILLARIES SV Left Atrium O 2 Right Atrium Pulmonary Capillaries Site for gas exchange Systemic Capillaries Site for tissue exchange Veins: return blood to heart under low pressure: Systemic veins (SV) return deoxygenated blood to right atrium: Pulmonary veins (PV) return oxygenated blood to left atrium. Martini & Bartholomew fig 1-2f

16 Cardiovascular (Circulatory) System Major Functions Circulates Blood which Transports chemicals (O 2, CO 2, nutrients, wastes, electrolytes, hormones) and heat within internal environment and between internal and external environments and so controls chemistry, volume and temperature of internal environment. Defends body against infection (via white blood cells and antibodies in blood) and prevents fluid loss (via coagulation).

17 Cardiovascular (Circulatory) & Lymphatic Systems CO 2 Pulmonary Arteries LUNGS O 2 Pulmonary Veins Gas Exchange Pulmonary Circulation Lymphatic vessel Systemic Veins Right heart Systemic Circulation Left heart Systemic Arteries Lymph nodes Systemic Capillaries Lymphatic Capillaries drain excess IF O 2 CO 2 Systemic tissue cell Tissue Exchange

18 Lymphatic (Lymphoid) System: Organs & Functions The Lymphatic System drains excess interstitial fluid, filters out bacteria, adds cells (lymphocytes) and antibodies and returns the fluid (lymph) to venous blood. This process provides immunity from disease, controls fluid balance and prevents Edema (excess IF). Lymphoid organs and tissues (lymph nodes, spleen, thymus, tonsils) form the Immune System with cells (lymphocytes and macrophages) that provide immunity. Lymphocytes chemically destroy bacteria or form antibodies, that neutralise antigens and prevent infection. Macrophages engulf bacteria and, in the spleen, old red blood cells. Martini & Bartholomew fig 1-2g Cervical Lymph nodes Thymus gland Axillary Lymph nodes Spleen Inguinal Lymph nodes Lymphatic vessel Lymph Flow: IF -----> LYMPH venous blood (subclavian veins)

19 Integumentary System: Organs & Functions Functions 1. Forms a protective Barrier between internal and external environments. Skin protects against: water loss via keratin & sebaceous glands. physical trauma (by forming calluses, thickened skin, self healing of wounds & fat storage). UV rays (via pigment melanin, head hair). Organs Hair Skin with exocrine glands. nails Martini & Bartholomew fig 1-2a

20 Integumentary System: Functions 2. Body Temperature Control (via sweat glands, thermoreceptors, fat and blood vessels). Vasoconstriction Vasoodilation HEAT LOSS + fat sweating 3. Excretion (e.g. of H 2 O, NaCl in sweat). Martini & Bartholomew fig 1-2a Sweat contains H 2 O NaCl Excessive sweating may cause dehydration hyponatremia

21 Integumentary System: Functions 4. Sensation Martini & Bartholomew fig 1-2a Skin is a sense organ with receptors for pain, temperature, pressure and touch. 5. Synthesis of Vitamin D (in sunlight). Vitamin D promotes Ca and P absorption from the diet. Bones & teeth via blood Increased absorption of Ca/P Cholesterol in skin Small Intestine sunlight Calcitriol via blood diet Vit D precursor (vit D3) via blood Kidney activates vit D3 to hormone calcitriol (activated vit D) via blood Liver stores vit D3

22 Reproductive System: Organs Ductus (vas) deferens or sperm duct Seminal vesicles Mammary gland (Breast) Prostate gland Urethra (urinary & reproductive) Penis Testis Uterine tube Ovary Uterus Vagina Primary organs: gonads Accessory organs: ducts & glands Martini & Bartholomew fig 1-2k Martini & Bartholomew fig 1-2l

23 Reproductive System: Functions Sexual Reproduction of the species 1. Produces and transports gametes (sperm, ova). 2. Provides appropriate environment for Fertilization and Development of Offspring. Fertilization is in Uterine (Fallopian) tube Development is in Uterus 3. Secretes Sex Hormones (mainly estrogens, androgens) which control sexual maturation, menstrual cycle, growth (of muscles/bones) and sex drive. 4. Produces milk for nourishment of offspring. Breast feeding provides nourishment, antibodies (passive immunity) & maternal bonding.

24 Male Testis: Functions Produces sperm Testis Produces male sex hormones (androgens, e.g. testosterone) brain Reproductive organs, skin larynx) Bones & muscles Sex drive (libido) Secondary sexual changes of puberty (growth of reproductive organs, body hair, larynx) Growth spurt of puberty & cessation of growth

25 Female Ovary: Functions Produces ova Ovary Adrenal cortex androgens Produces female sex hormones (estrogens - target many organs, progesterone - targets uterus & breast only) Reproductive organs- breasts, skin) Bones & muscles brain Sex drive (libido) Secondary sexual changes of puberty (growth of reproductive organs - breasts, body hair) Maintenance of pregnancy Menstrual cycle of uterus Growth spurt of puberty & cessation of growth

26 Skeletal System: Organs Components: Bones major organs of system, have all functions of system. Cartilages connect & protect bones at joints, form smooth articular surfaces of moveable bones. Ligaments connect bones at joints & stabilise joints. Joints form fulcrum of levers. Moveable fulcrum of lever Costal (rib) cartilages Meniscus cartilage Patellar ligament cranium clavicle scapula humerus Pelvis femur patella Elbow joint Knee joint Martini & Bartholomew fig 1-2b

27 Muscles, Bones & Joints form Levers Tendon of muscle pulls on bone Joint (allows movement) Movement of bone

28 Skeletal System: Major Functions: 1. Supports soft tissues. 2. Body shape. 3. Protection of vital organs (e.g. brain, heart, lungs). Cranium, rib cage 4. Allows for adaptive (i.e. homeostatic) movements - forms attachment sites for muscles - has moveable joints that form levers with muscles 5. Produces blood cells (in bone marrow). - in adult red bone marrow forms all red blood cells, platelets & most white blood cells 6. Stores minerals (Ca/P) in bone matrix & fat (in yellow marrow) - minerals harden bones for their normal functions - Bone deposition & resorption are controlled by hormones (e.g. PTH) - vit D required for absorption of Ca/P Diet Vit D Blood Ca +2 PO 4-3 Bone deposition PTH Bone resorption Bone matrix Ca/P stored as hydroxyapatite

29 Muscular System: Organs Components: Skeletal or Voluntary Muscles, (which pull on bones via tendons). Muscles are in antagonistic pairs Biceps brachii is prime mover for flexion (bending) of elbow & antagonist for extension (straightening). Triceps brachii is prime mover for extension of elbow & antagonist for flexion. tendon of Biceps humerus Biceps brachii Rectus abdominis Tendons Elbow joint ulna Martini & Bartholomew fig 6-38 tendon of Triceps Martini & Bartholomew fig 1-2c

30 Muscular System: Major Functions: Contraction (generation of a force which pulls on bones) and Relaxation for: 1. Powering adaptive movements, both voluntary and reflex ( behaviour ). muscles provide energy for adaptive (homeostatic) movements, e.g. withdrawal reflex, breathing. Muscle contractions may be isotonic (muscle shortens) or isometric (muscle does not shorten). Prime mover muscles contract isotonically causing movement, antagonists relax & other muscles contract isometrically to help stabilise nonmoving parts (e.g. when elbow bends, shoulder must be stable). 2. Support and shape, (e.g. abdominal wall muscles). 3. Heat production (for body temperature control). e.g. shivering : muscles are major source of body heat 4. Posture ("anti-gravity" muscles). Posture is alignment of body parts against gravity: extensors of legs, back, neck maintain upright posture. 5. Protection of abdominal organs (via abdominal flexors, e.g. Rectus abdominis).

31 Endocrine System: Functions The Endocrine System is the body s slow acting communication and control system. It slowly coordinates and controls bodily functions via hormones ("chemical messengers") secreted into the blood. Stimuli for Hormone Secretion Biochemical Changes (e.g. increased blood sugar level causes release of insulin from the pancreas). Nervous Stimuli (e.g. stretching of uterus causes release of oxytocin from the pituitary gland). Trophic Hormones (e.g. TSH from anterior pituitary causes secretion of thyroxine from thyroid gland). Hormones may circulate for long periods and cause long lasting effects. Many endocrine glands are subject to control from the hypothalamus which controls the pituitary gland (the body s master endocrine gland): the pituitary, in turn, sends out trophic hormones which control secretions of the other endocrine glands, mainly the thyroid gland, gonads and adrenal cortex.

32 Endocrine System: Functions - 2 Basic Components of Endocrine Control Endocrine Gland Hormone Negative Feedback Target tissue Endocrine Control of Blood Sugar hypoglycemia pancreas glucagon Negative Feedback glycogenolysis Increased blood sugar liver

33 Endocrine System: Functions - 3 Trophic Hormones are secreted by the Hypothalamus & Anterior Pituitary Gland Stimulus (e.g. cold) hypothalamus Trophic hormone Anterior Pituitary gland Target Cells Aerobic Respiration (catabolic effect of Thyroxine) Thyroxine ATP Heat Thyroid gland Thyroid Stimulating hormone (TSH)

34 Endocrine System: Organs - 1 Components: Endocrine Glands Hypothalamus - controls anterior pituitary via Trophic Hormones - secretes hormones (ADH, Oxytocin) Posterior Pituitary releases hypothalamic homones (ADH, Oxytocin) into blood. Anterior Pituitary secretes Growth Hormone (GH), Prolactin & 4 Trophic hormones Trophic Hormones TSH targets thyroid Gonadotropins (FSH, LH) target gonads ACTH targets adrenal cortex Pineal male Testes Pituitary Thyroid Parathyroid Endocrine Pancreas Adrenal gland Martini & Bartholomew fig 1-2e Ovaries

35 Endocrine System: Organs - 2 Thyroid Gland secretes Thyroxine. - Thyroxine targets all cells stimulating aerobic respiration for energy release. Parathyroids secrete PTH which targets bones causing bone resorption: PTH is hypercalcemic. Endocrine Pancreas (Islets) secretes insulin & glucagon for blood sugar regulation. Gonads (testes, ovaries) secrete sex hormones estrogens & progesterone from ovaries: androgens (testosterone) from testes. Adrenal Cortex secretes corticoid hormones (glucocorticoids - cortisol, mineralocorticoids - aldosterone) in chronic stress & sex hormones. Adrenal Medulla secretes epinephrine in acute stress. Pineal Pituitary Thyroid Parathyroid Endocrine Pancreas Adrenal gland male Testes Ovaries Martini & Bartholomew fig 1-2e

36 Nervous System: Major Divisions Central Nervous System (CNS) Brain Spinal cord Peripheral Nervous System (PNS) Peripheral Nerves Sense Organs Martini & Bartholomew fig 1-2d

37 Nervous System: Major Functions The Nervous System is the body s rapid communication and control system. 2. The basic function of the Nervous System is to make speedy adaptive responses to environmental changes so as to rapidly restore homeostasis. Basic Design of The Nervous System The basic design of the nervous system is that of a reflex arc which rapidly connects stimulus with response. Negative Feedback PNS stimulus receptor sensory neuron response effector PNS motor neuron CNS

38 Nervous System: Major Functions -2 To carry out this complex basic function the nervous system has the following more specific functions: Sensing Environmental Changes (external or internal stimuli). Rapid Internal Communication via nerve impulses (a) in nerve fibers and synaptic neurotransmitters (b) at synapses between nerve cells (neurons). a a a b b Control of Effectors to produce adaptive (homeostatic) responses via chemicals released at the neuroeffector junction ( c). neuron c Muscle cells

39 Nervous System: Major Functions -3 Specific Functions (cont.) Control of the Endocrine System (via hypothalamus). Species Memory of inborn adaptive responses (reflexes) e.g. suckling, smiling, crying, grasping, salivation, pupillary reflex etc. Learning of new adaptive responses via synaptic changes. Acquired Memory (storage of sensory input and of newly aquired adaptive responses). Internal Processing of information via thought - reasoning etc. ("Higher Associative Functions").

40 Nervous System: Functional Divisions Sensory neuron nerve receptor CNS Association neuron (Interneuron) Efferent (Motor) Division of PNS Motor neurons Somatic (Voluntary) NS Afferent (Sensory) Division of PNS Autonomic NS nerve +/- + Visceral Effector Skeletal Muscle

41 Nervous System: Motor Divisions of PNS Somatic NS controls Skeletal Muscles Autonomic NS controls Smooth muscle Cardiac muscle Exocrine glands CNS ANS + - Visceral Effector Dual Innervation Visceral organs receive 2 autonomic controls, excitatory (+) & inhibitory (-).

42 Functional Divisions of Peripheral Nervous System Peripheral Nervous System Sensory (Afferent) Division of PNS Motor (Efferent) Division of PNS Autonomic Nervous System Somatic Nervous System 42