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 push blood 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 maintain endometrium After 450 cycles Menopause cessation of menstruation and ovulation