animal form and function

Animal Form and Function

Chapter 40

Tissuesorgansorgan systems

• Epithelial– Sheets, tightly packed, protective barrier, outside or inside

• Connective– Supports, binds;cells within a matrix, cartilage, tendons,

ligaments, bone and blood• Muscle

– Actin and myosin; smooth (visceral), skeletal, cardiac– Nervous– Neuron, senses stimuli, transmits signals

Feedback control loops

• Homeostasis– Set point; detect stimulus above or below and return

to set point• Negative

– Response to reduce stimulus; body temp rises, sweat evaporating cools

• Positive– Mechanisms amplify rather that reverse ex. childbirth

Thermoregulation

• Endotherms– Warmed by heat generated by metabolism

• Ectotherms– Gain heat from external sources (behavior)

• Countercurrent exchange– Antiparallel arrangement of blood vessels that warm

blood from core transfers heat to blood from extremities

Animal NutritionChapter 41

Essential Nutrients-required by animal-must get from dietabout half of amino acidsfatty acids-linoleic acidvitamins-B and Eminerals-calcium and phosphorus

Food Processing

• Ingestion• Digestion• Absorption• Elimination• Intracellular vs extracellular digestion• Gastrovascular cavity• Alimentary canals-complete digestive tract

• Peristalsis• Sphincters• Oral cavity• Amylase• Bolus• Pharynx• Epiglottis• Esophagus• Stomach• Gastric juice

– Hydrochloric acid– pepsin

• Acid chyme• Small intestine

– Duodenum• bicarbonate fluid, bile

Chemical DigestionCarbohydrates

Starch and glycogen begin in mouth-salivary amylase

Pancreatic amylase disaccharide maltosemonosaccharides

Proteins

• Pepsin• Trypsin• Chymotrypsin• Dipeptidases• Carboxypeptidase• Aminopeptidase

Absorption

• Villi• Microvilli• Lacteal• Hepatic portal vessel

Hormones

• Gastrin• Enterogastrone• Secretin and cholecystokinin (CCK)

Large intestine

• Colon• Cecum• Appendix• Rectum

Evolutionary adaptations

• Dentition• Length of digestive tract

Circulation and Gas Exchange

• Chapter 42

Problem of Exchange

• Gastrovascular cavity• Circulatory system

– Blood– Vessels– Heart

2 kinds of systems

• Open– Fluid bathes organs– Hemolymph– sinuses

• Closed– Stays in vessels

Vessels

• Arteries• Veins• Capillaries

Variations in animals

• Fish• Amphibians• Reptiles• Mammals and birds

Double Circulation

• Vena cava pulmonary vein• R atrium left atrium• Tricuspid valve bicuspid valve• R ventricle left ventricle• Pulmonary semilunar valve aortic semilunar• Pulmonary arter y aorta• Lungs

Cardiac Cycle

• Systole• Diastole• Heart rate

– Affected by 3 factors-sympathetic nerves speed up; parasympathetic slows; epinephrine increases as does hi body temp

• SA node• AV node• Blood pressure

Lymphatic system

• Lymph• Lymph nodes

Blood

• Plasma• RBCs-erythrocytes-hemoglobin

– Biconcave disks-increases surface area; each contains 250 million molecules of hemoglobin-each binds 4 molecules of oxygen

• WBCs-leukocytes• platelets

Gas Exchange

• Uptake of oxygen and discharge of carbon dioxide

• Partial pressure• Respiratory medium• Respiratory surface

– Moist– Surface area/volume ratio– Closely associated with vascular system

• Gills• Countercurrent exchange• Tracheal systems• Lungs• Larynx• Trachea• Bronchi-bronchioles• Alveoli

Breathing

• Diaphragm• Intercostals• Control• Carbonic acid

Pigments• Hemoglobin-respiratory pigment in most vertebrates• Bohr shift-lowering of pH in blood lowers affinity of

hemoglobin for oxygen• CO2 carried in form of bicarbonate ions (70%), 23%

carried by hemoglobin and 7% in solution of plasma• Carbonic anhydrase-enzyme in RBCs –catalyzes

formation of carbonic acid-dissociates into bicarbonate ion and H ion. As Blood pH drops, rate and depth of respiration will increase

Immune System Chap 43• Innate Immune Response

– Barrier• Skin, mucous membranes• Secretions-keep pH of skin 3-5; lysozyme

– Cellular• Phagocytic WBC

– Neutrophils-ingest-phagocytosis– Monocytes-dev into macrophages– Eosinophils-against parasites

• Antimicrobial proteins– Interferon– Complement system

– Inflammatory response-histamines– Natural Killer Cells

Acquired immunity• Antigens• Antibodies-

• B cells• T cells• Clonal selection• Effector cells• Memory cells• APCs-aka dendritic cells• MHCs

– Class I MHCs-found on all cells except RBCs– Class II MHCs-made by dendritic cells, macrophages and B cells

Responses• Primary• Secondary• Humoral • Cell-mediated

– Helper T– Cytotoxic T– Interleukin I-(type of cytokine)made by macrophages to

activate HelperT– Interleukin II-made by HelperT to stimulate immune

response

• Active immunity• Passive immunity• Antigens on blood cellsblood type• MHCs-organ rejection

• Allergies• Autoimmune• Immune deficiency

Osmoregulation and ExcretionChap 44

• Osmoregulation-control solute concentrations and balance water gain & loss

• Nitrogenous waste-metabolic breakdown of proteins and nucleic acids

• Excretion-remove nitrogenous waste• Transport epithelia-regulate water balance and

waste disposal

Types of N waste

• Ammonia-water soluble and toxic-aquatic • Urea-made by liver of most vertebrates;

combined with carbon dioxide-less toxic, water conserved

• Uric acid-insoluble in water-excreted in paste or crystals-birds&reptiles-can be stored in shelled eggs-not harmful to young

Survey

• Protonephridia/flame-bulb system-platyhelminthes

• Metanephridia-annelida• Malpighian tubules-insects & terrestrial

arthropods• Kidneys-vertebrates

Processes

• Filtration-glomerulus• Reabsorption-proximal and distil tubules• Secretion-proximal tubules• Excretion-filtrate leaves body-urethra• Flow of filtrate in loop of Henle-countercurrent

exchange

Parts page 944

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Regulation

• ADH-made in hypothalamus-stored and released from pituitary; keeps water

• Aldosterone-kidneys absorb more Na, so saves water—helps blood volume and pressue

• Renin-enzyme from kidney-activates angiotension II

• Angiotensin II-acts as hormone, causes arterioles to constrict; makes adrenals release more aldosterone

Hormones and Endocrine SystemChapter 45

Kinases “turn on” processesPhosphotases “turn off” processes

• Endocrine system-all hormone-secreting cells and tissues

• Endocrine glands-ductless-hormones directly into blood

• Hormones-chemical signalsresponse in target cells

• Positive and negative feedback

Cell Signaling

• Cell-surface receptors bind hormone & signal transduction pathway is triggered. – Ex. Epinephrineliver cellscascadeglycogen

glucose• Intracellular receptors-bound by hormones that

are lipid soluble. Receptor acts as transcription factorgene expression– Ex. Estrogen enter nuclei of target cell and stimulate

transcription of certain genes.

• Hormones can affect 1 tissue, a few tissues, most of the tissues, or other endocrine glandstropic hormones.

Hormonal system of communication

• Exocrine-put into a duct or tube• Endocrine-put into blood• Neurosecretory-released by neuron-

hypothalamus

Local Hormones• Growth factors-cause cell replication• Nitric Oxide-from neuron-inhibits process• -from WBC-kills pathogen• -from endothelium of blood vessel-

causes surrounding smooth muscle to dilate-relax

• Prostaglandins-inflammatory response & muscle contraction

• Cytokines-relay messages between WBC’s about pathogens

Hormone reception by cells

• Ligand(hormone) attaches to receptor proteinssignal transduction pathway– Pathway ends in cytoplasm-turn on/off enzyme– Pathway ends in nucleus- turn on/off transcription

• Steroid hormones go through bilayer-don’t need 2nd messengers

Hormonal control mechanisms• Negative feedback loops• Positive feedback loops

Hormones

• Can affect– 1 tissue– A few tissues– Most of the tissues– Other endocrine glands (tropic hormones)

The “Big Dogs”

• Hypothalamus- “Calls the shots”receives info from body and brain-initiates endocrine signals in response

• Pituitary-”Carries out orders”– Posterior

• oxytocin-uterus contraction; let down of milk• ADH-keep water

-

• Anterior pituitary– FSH-ovary or testes-form ova or sperm– LH-stimulates ovaries or testes– TSH-thyroid– ACTH-adrenal cortex-secretes glucocorticoids– GH-growth and metabolic functions– Prolactin-milk production and secretion

Thyroid

• T3 -stimulate and maintain metabolic processes• T4• Calcitonin-lowers blood calcium

Parathyroid glands

• PTH –Parathyroid hormone-raises blood calcium

Pancreas

• Insulin-lowers blood glucose level• Glucagon-raises blood glucose level

Adrenal glands

• Adrenal medulla-epinephrine and norepinephrine-raise blood glucose; increase metabolic act.; Constricts certain blood vessels

• Adrenal cortex– Mineralcorticoids-promote reabsorption of Na+ and

excretion of K+ in kidneys; – Glucocorticoids-raises blood glucose level

Gonads

• Testes-Androgens-support sperm formation; secondary sex characteristics

• Ovaries-estrogens-uterine lining growth; secondary sex characteristics– Progestins-promote uterine lining growth

Pineal gland

• Melatonin-biological rhythms

Negative feedback-more gets you less

• Know at least one example– Thyroid-parathyroid– Pancreas-glucagon and insulin

Positive feedback

• More gets you more• Oxytocin/prostaglandins

Animal Reproduction Chapter 46

• SexualOvum + sperm = zygote• Asexual-fission• Budding-hydra• Fragmentation-sea stars, sponges, cnidarians• Parthenogenesis-unfertilized eggsmale bees-

haploid

Triggers to reproduction

• Ovulation-cyclical-young produced only when viable (day length, temp, rainfall, lunar cycles)

• Hermaphroditism-barnacles, tapeworms• Sex reversal-bluehead wrasse-if male dies,

largest female in harem will become male

Fertilization-union of sperm and egg

• External ferilization• Internal fertilization• Gonads

Female anatomyOvaries-make eggs and hormonesFollicles-contain oocytes-release estrogens• Ovulation-release of egg from follicle• Oviduct-moves egg• Endometrium-inner lining of uterus• Cervix-neck of uterus• Vagina-canal through which baby comes

Male anatomy• Scrotum and penis-external structure• Testes-male gametes and sex hormones• Seminiferous tubules-where sperm are made• Leydig cells-produce testosterone and other

androgens• Epididymis-where sperm mature• Vas deferens-take sperm to urethra• Seminal vesicles, prostate, bulbourethral-contribue

secretions to semen

Spermatogenesis-seminifereous tubules; sperm begin as spermatogonia

4 sperm resultoccurs continuously

Oogenesis-development oogoniaprimary oocytessecondary oocyte

– 1 egg results– Begins prior to female’s birth– Meiosis not completed until after fertilization

Humans and primates have menstrual cycles.Other mammals-estrous cycles

• 1. Menstrual flow phase-endometrium shed• 2. Proliferative phase-endometrium begins to

regenerate• 3. Secretory phase-endometrium continues to

thicken

Ovarian cycle

• Follicular phase• Luteal phase

Pregnancy

• Human Chorionic Gonadotropin (HCG)-made by embryo; maintains the secretion of progesterone and estrogens; detected in urine

• Gestation-carrying embryo in utereus• Parturition-birth

Fertilization

• Contact• Acrosomal reaction• Fusion of sperm and egg membraneion channels

open-fast block to polyspermy-• Entry of sperm nucleus• Cortical reactionfertilization envelope-slow block

to polyspermy• Calcium ion releaseactivation of egg

• Cleavage– Blastomeres– Morula– Blastula-blastocoel

• Gastrulation– Blastopore Archenteron– Ectoderm-skin, lens of eye,nervous system– Mesoderm-skeletal and muscular, excretory,

circulatory,reproductive, blood, bone, muscle– Endoderm

• Epithelial linings, liver, pancreas

• Organogenesis-notochord• Neural plate• Neurulation• Somites

Amniote eggs

• 4 extraembryonic membranes– Amnion-protects– Allantois-disposal sac for waste– Chorion-exchange gases– Yolk sac-nutrients

Mammalian blastocyst] • Inner cell massembryo

• Trophoblast--.fetal portion of placenta• Cytoplasmic determinants-chemical signals such

as mRNAs and transcription factors• Induction-interaction among cells that influences

their fate by causing changes in gene expression• Dorsal lip of blastopore-”organizer” which induces

a series of events that result information of notochord and neural tube

Totipotent Cells

• Capable of developing into all the different cell types of that species

• Mammalian embryos remain totipotent until 16 cell stage

Muscle Contraction

• Neuronacetylcholinesarcoplasmic reticulumCa+bond with troponin which pulls the tropomyosin away from the actin binding site. With ATP, the myosin head is in the high energy position. The myosin head connects with the actin binding site and muscle contraction occurs.