Chapter 42 circulation and gas exchange Cardiovascular system (verts) Blood vessels  Heart ->Arteries -> arterioles -> capillaries -> venule -> veins ->heart Heart 2 or more chambers atrium or ventricle  Gas exchange organs Fishes- gills Amphibians – lungs and skin Reptiles and mammals-lungs Fishes- single loop circulation 2 chambers 1 atrium and 1 ventricle Blood from body is received by the atrium -> ventricle -> gills (picks up O2, lets off CO2) -> rest of body > atrium of heart Amphibians – mammals- double circulation Heart -> lungs (pulmonary circuit) heart -> body( systemic circuit) Amphibians- 2 atrium and 1 ventricle Reptiles –3 chambered but crocodilians 4 chambered heart Birds and mammals- 4 chambered 2 atrium and 2 ventricle Mammalian heart Rt. atrium – (rt. Atrioventricular valve)-> rt. Ventricle Rt. Ventricle – ( rt. semilunar valve) -> pulmonary artery Lt. atrium –( lt. Atrioventricular valve)-> lt. ventricle  Lt. ventricle – ( lt. semilunar valve)-> aorta  Cardiac cycle Heart rate- “pulse” – number of beats per minute Stroke volume – amount of blood pumped in a single contraction  Cardiac output- volume of blood pumped into your systemic system per minute Sinoatrial (SA) node In upper wall of right atrium “pacemaker”  Atrioventricular (VA) node Juncture of right atrium and ventricle Blood vessels Arteries- carry blood from heart (endothelium, smooth muscle, connective tissue) smooth muscle is thicker-> wall thicker, velocity high, blood pressure is high. Veins- carries blood to the heart (endothelium, smooth muscle, connective tissue) thinner walls, lower velocity, low blood pressure, both smooth and skeletal muscle contractions pushblood back to heart, one-way valves keep blood flowing toward heart. Capillaries- sites of exchange, very slow velocity, low pressure, 2 tissues : endothelium and basal membrane, Lymphatic system Lacteals (vessels) and nodes (lymphocyte white blood cells) Lacteal absorbing fats from digestive system Reabsorb fluids lost from the capillaries (H2O) Edema- swelling of body parts due to inactive lymph vessels Blood composition- closed systems, blood remains in vessels Connective tissue-  blood cell -(45% of blood comp.)(erythrocytes- red blood cells- carries O2, leukocytes- white blood cells- body defense, platelets- cell fragments- blood clotting dispersed within a liquid matrix -> plasma (55% of blood comp.)(90%water, 10% ions, proteins, nutrients) Figure 4.17  Cardiovascular diseases Heart attack- death of cardiac muscles due to a blockage of one or more coronary arteries Stroke- death of nervous tissue due to a blockage or rupture of blood vessels, arteries in head or brain Hypertension- high blood pressure, promotes atherosclerosis (hardening of arteries) increase risk of heart attack and stroke  Respiratory organs Gills- aquatic Lungs- terrestrial Skin- Gas exchange occurs at specialized respiratory surfaces where O2 is taken in, CO2 is released Gasses will diffuse down their concentration gradient  Less O2 available in H2O compared to air Counter current gas exchange in gills- Direction of H2O flow across gills is opposite in direction of blood flow in gills High surface area with a moist respiratory surface for exchange of materials Alveoli are places of gas exchange- surfactant secrete in alveoli coats interior surface to keep it from sticking together Process Breathing process Alternating between inhalation of air and exhalation of air from lungs Amphibians use- positive pressure breathing- air is pushed into lungs Mammals use negative pressure breathing- creates a vacuum so air rushes into respiratory tract.- - expand the thoracic cavity by expanding the rib cage and depressing the diaphragm. Tidal volume- volume of air inhaled with each breath Max tidal volume = vital capacity Residual volume – air will remain in the lungs after exhalation Chapter 44: osmoregulation Osmoregulation- balancing water and ions Excretion- getting rid of nitrogenous waste and metabolites Osmolarity- the solute concentration of a solution Osmoconformers- (inverts) conform to environment Osmoregulaters- (verts) have to regulate body fluids to environment Kidney-> renal artery -> renal vein -> ureter -> urinary bladder -> urethra Chapter 46: animal reproduction Reproduction Asexual- creation of offspring without the fusion of egg and sperm More common amongst inverts and common in stable environments Lack of genetic diversity *disadvantage* Reproduction can occur at a faster rate *advantage* Sexual- creation of offspring with the fusion of egg and sperm -> zygote Both inverts and vert Widespread -> confers genetic diversity. *Advantage* Required more energy- find mates, gamete production *disadvantage* External fertilization- aquatic verts- amphibians Higher production of gametes and zygotes Higher mortality Internal fertilization -terrestrial verts Higher chance of fertilization Lower production of gametes and zygotes Offspring are protected by amniotic situation Higher parental care Female reproductive anatomy Ovaries- female gonads-  enclosed in a protective capsule contains follicles- one egg developing surrounded by layers of follicle cells after egg is released from follicle, the follicle becomes corpus luteum – secreting hormones (progesterone) helps to maintain uterine lining (endometrium) egg will travel through oviduct to the uterus Fertilization occurs in the oviduct. Male reproductive anatomy Testes- male gonads Consists of somniferous tubules where sperm are produced Epididymis- sperm are stored Vas deferens – carries sperm from the Epididymis to urethra  Seminal vesicles-contributes 60% of liquid volume of semen Prostate gland- secretes other nutrients into semen Bulbourethral gland- secretes a mucus which neutralizes the acidity of female vagina. Reproductive cycle of the human cycle  Menstrual cycle – 28 days Day 1 is first day of menstruation Brain  Hypothalamus- release GnRH-> anterior pituitary -> FSH (follicle stimulating hormone) and LH ( luteinizing hormone -> ovulation peak in LH from rise in estrogen Ovary Production and release of estrogen and progesterone->