Bio 2 Exam 3

Ch. 32


Body Plans


  • Small, unicellular organisms get nutrients through diffusion

  • Cell size is constrained by the surface area to volume ratio

    • As cells get larger, this ratio decreases (not good)

  • Larger organisms don't have larger cells; they have more cells (multicellular)

  • Must provide nutrients and oxygen to all cells with specialized cells, organs, and organ systems

    • Larger animals have lesser area to volume ratio, less diffusion 


Bioenergetics


  • Energy from nutrients is used in the animal body to fuel anabolic reactions

    • Nutrients are always converted to ATP

  • Basal metabolic rate 

    • The average amount of energy used by an organism in a non-active state

    • Endothermic animals maintain their own temps

    • Ectothermal relize on the environment for temperature

  • Excess energy is given off as heat

  • Smaller endothermic organisms have a higher BMR than larger ones 

    • Compensates heat lost from large surface area

  • Active animals have a higher BMR than inactive ones 


Body Planes and Cavities


  • The sagittal plane divides the body into right and left

    • Parasigital is not exactly in the middle

  • The midsagittal plane divides exactly in the middle

    • Midian

  • The frontal plane separates the front from the back

    • Also coronal plane

  • The transverse plane divides into upper and lower portions

    • Also horizontal plane

    • Also cross section

    • If the transverse cut is at an angle, called an oblique plane


Types of multicellular animal tissues

  • 4 types

    • Epithelial 

      • Lines cavities, open spaces, surfaces

      • Can secrete things

      • Classified by the number of layers and the shape of the cell

      • Single layer = simple, multiple layers = stratified 



  • Simple squamous

    • Looks flat, one layer of cells

  • Stratified squamous

    • Layered 

  • Cuboidal 

    • Secrets from the gland 

  • Simple columnar 

    • Seen as collumes 

  • Pseudostratified ciliated columnar

    • Found in the respiratory trace

    • Helps movement of mucus and trapped particles 

    • Will also see goblet cells

      • Also produces mucus 

  • Transitional

    • Round and simple, but looks stratified

    • Only in urinary bladder

    • Helps with the stretch response 

      • The urge to pee



  • Connective tissues

    • Connects tissues together, providing support, ligaments, tendons, blood, and bone

    • Misoderm

    • Consists of cells (fibroblasts) embedded in a non-cellular matrix

      • Will produce something

    • Matrix usually composed of a ground substance

      • Ground substance usually contains a combination of collagen, elastic or reticular fibers



  • Cartilage

    • Fatal bones are mostly cartilage 

  • Bone

    • Any osteo prefix

    • Will break down if low on calcium

  • Adipose

    • Fat

    • Energy storage

  • Blood

    • White blood cells help with the immune response


































 Muscles 

  • Generate movement

  • Also connective tissue

  • 3 kinds 

    • Skeletal - voluntary, striated

    • Smooth - involuntary, no striation

      • Can contract in all directions

      • In organs, the blood supply

    • Cardiac - involuntary 

      • Special structures, intercalated disks, help pass a signal to contract

      • heart

  • Actin and myosin

    • Both proteins that make up the muscle








  • Neurons

    • Generate and send electrical signals

    • The nerve cell

    • Neuroglia (glia)

      • Supportive cells

      • Oligodendrocyte 

        • Has myelin wrapped around to insulate 

    • Action potential

    • Generate and transmit electrical impulses

    • Dendrites receive impulses

    • Axons send out signals

      • Action potential

      • To increase the speed of the message (velocity of the action potential), myelin can be used

    • In the brain, myelin gives the white color to the white matter 




Homeostasis / Thermoregulation


  • Aims to keep internal conditions around the set point

  • If conditions stray too far from the set point, homeostatic mechanisms kick in

  • The set point can potentially change over time (alteration), but homeostasis will still work toward the set point

  • Acclimatization 

    • Changes in one organ system to maintain a set point in another organ system 

      • Altitude will cause more blood cells to be produced


  • Negative feedback loop

    • Counteracts any internal changes (reverse the direction of the change)

    • Most biological systems are negative

    • Temp, glucose, pH, blood calcium


  • Positive feedback loop

    • Maintains and potentially strengthens the response to a stimulus

    • Birth (releases oxytocin to continue uterine contractions)

  • Must maintain a relatively constant internal temp to keep enzymes efficient and avoid denaturation

  • Thermoregulatory control by the hypothalamus

  • Endotherm vs ectotherm

  • Temperature is maintained in several different ways 

  • Radiation

    • Sun

    • Emission of electromagnetic heat waves

  • Convection

    • Currents of air that remove heat as air passes over it

  • Conduction

    • Heat transfers through surfaces through direct contact

  • Evaporation

    • Removal of heat with a liquid


Herbivors

  • Plant-based food

Carnivores

  • Eat other animals

  • Obligate carnivores 

    • Rely entirely on animal flesh

  • Facultative carnivores

    • Also eat non-animal food, but mostly animals

Omnivores 

  • Both plants and animals

Digestive Tracts


Incomplete

  • Single opening 

    • Gastrovascular cavity

  • Ex. Planarian 

  • Food enters through the mouth and the muscular pharynx

  • Waste also exists through the mouth and the muscular pharynx

  • Lacks specialized parts


Complete

  • Two openings 

    • Alimentary canal

  • Ex. Earthworms

  • Food enters through the mouth

  • Waste exits through the anus



VERTEBRATE DIGESTIVE SYSTEM


Monogastic 

  • Humans and Herbivores

    • Like a tube

    • Humans’ most absorbed in the small intestine

    • Rabbits digest twice

Birds

  • Crop stores food

  • 2 stomachs

    • Proventriculus (enzymes) 

      • chemical

    • Gizzard (grinding) 

      • mechanical

Ruminants

  • Goats

  • 4 stomachs

    • Rumen and reticulum 

      • Contain prokaryotes and protists to digest cellulose fiber

    • Cud is regurgitated, chewed, and swallowed in the third stomach, the omasum 

      • Removes water

    • Cud then passes into the abomasum 

      • Most similar to human stomachs

      • Enzymes produced by the animal


Adaptations to Diet


  • Dentition differs with the mode of nutrition 


  • Omnivores 

    • Variety of specializations

    • Accommodate both vegetision and meat

  • Herbivores

    • Incisors for clipping

    • Premolars and molars for grinding

  • Carnivores

    • Pointed incisors and enlarged canines

    • Shear off pieces small enough to swallow


Quadrant of human teeth

  • Incisors

    • 2

  • Canines

    • 1

  • Pre-molars

    • 2

  • Molars

    • 3


Human Digestive Tract


  • Complete (alimentary canal)

  • Part of a tube within a tube body plan

  • Begins with a mouth and ends in an anus

  • Digestion entirely extracellular

    • Digestive enzymes are secreted by

      • Wall of the digestive tract

      • By nearby glands (saliva)

  • Mouth

    • 3 major pairs of salivary glands

      • Saliva contains salivary amylase

      • Salivary amylase initiates starch digestion

    • Tongue is composed of striated muscle

      • Mixes chewed food with saliva

      • Form the mixture into a bolus

  • Pharynx

    • Where the digestive and respiratory passages come together

    • The soft palate closes off the nasopharynx 

    • Epiglottis

      • Covers opening into the trachea

      • Keeps food from the air passages 




  • Stomage

    • The wall has deep folds 

      • Rugae

      • Folds that help with expansion

    • Maximum 1 liter 

    • The epithelial lining of the stomach has millions of gastric pits, which drain gastic glands

      • Pepsin is a hydrolytic enzyme that acts on proteins to produce peptides





  • Chyme

    • Food mixing with gastric juices

      • Justin between stomach and small intestine controlled by a sphincter

      • When spincter relaxes, small quantity of chyme passes into small intestin

  • Small Intestine

    • First segment is duodenum

    • Chyme from stomach enters

    • Mixes with secretions from liver and pancreas

  • Pancreas

    • Exocrine gland

    • Produces pancreatic juice and digestive enzymes into the duodenum

      • Pancreatic amylase digests starch into maltose

      • Trypsin digests protein into peptides

      • Lipase digests fat droplets into glycerol and fatty acids

    • Epithelial cells of the intestine also produce enzymes 

      • Complete digestion of peptides and sugars

  • Liver

    • Produce Bile, stored in the gallbladder

    • Bile contains bile salts, which break up fat into fat droplets via emusifcation 

    • Helps maintain glucose concentration in blood by converting excess into glycogen 

  • Pyloic 

    • Pyloris = gatekeeper



Absorbtion 


  • Mucous membrane of small intestine

    • Has ridges and furrows that give it a corrugated surface

    • Willi ar eridges on the surface, which contain even smaller ridges, microvilli

      • Increases absorptive area

      • Each villus contains blood capillaries and a lymphatic capillary (lacteal)

Protein Digestion 

  • In the duodenum, trypsin, elastase, and chymotrypsin act on peptides, reducing them to smaller peptides

  • Bile helps with lipid digestion 


  • Large Intestine 

    • Includes cecum, colon, rectum, and anal canal

    • Larger in diameter, shorter in length

      • Absorbs water, salts, and some vitamins

      • Dehydrates feces

    • The cecum has a small projection 

      • Appendix

    • Colon subdivided into the ascending, transverse, descending, and sigmoid colon

    • Opening to the anal canal 

      • Anus for elimination 


Nutrition: Carbohydrates


  • Sugars, starch, fibers

  • Fruits, vegetables, milk, honey (sugars)

  • Monocaccharides

    • Glucose 

    • Fructose

  • Disaccharides

    • Lactose

    • Sucrose (table sugar)

  • All sugars are converted to glucose

    • Preferred direct energy source in cells

  • Plants store glucose as starch

  • Animals store glucose as glycogen



Fiber


  • Important for bulking stool

  • Includes undigestible carbohydrates derived from plants


Protiens

  • 20 different types of amino acids

  • Adults need 8 children need 9


  • Essential

    • Methionine

    • Valine

    • Threonine

    • Phenylalanine

    • Leucine

    • Isoleucine

    • Tryptopphan

    • Lysine


Lipids


  • Fat, oils, and cholesterol

  • Essential storage and activity of fat-soluble vitamins A, D, E, and K

  • Provides energy

  • Saturated fats (solud at room temp

    • Usually from animals


Vitamins


  • Organic compounds the body is unable to produces but required for metabolic purposes

  • Obtained externally

  • Water or fat soluble

  • Some vitamin deciciencens can have dramatic effect on health

  • Antioxidants

    • Cellular metabolism generates free radicals that carry extra electron

    • Vitamin C, E, and A believed to defend body against free radicals

  • Water soluble

    • B and C

  • Fat soluble 

    • A, D, E, K 


Osmoregulation


  • Process of maintenance of salt and water balance (osmotic balance across membranes within body fluids

    • Both electrolytes and non-electrolytes contribute

  • Important ions

    • Cations: sodium, potassium, calcium, magnesium

    • Anions: chloride, carbonate, bicarbonate, and phosphate

  • Cells in a hypertonic environment shrink due to loss of water

  • In a hypotonic environment, a cell will swell with water intake


Osmoregulators 

  • Most marine organism must live in specific environments 

  • Evolved to adapt to a variety of environments


Osmoconformers


  • The internal environment is osmotic relation to external environment

    • Restricted to certain environments, spends less energy on osmoregulation 


Body Fluid Regulation


  • Water tends to move into the region with the lowest water concentration

  • Marine environment

    • High concentration of dissolved salts

    • Promote the osmotic loss of water 

    • Gain ions by drinking water

    • Marine invertebrates are normally isotonic to seawater

    • Blood of cartilaginous fish contains enough urea to match the tonicity of seawater

  • Freshwater environment

    • Tends to promote the gain of water by osmosis

    • Loss of ions as excess water is excreted


Human Kidneys


  • Located on either side of the vertebral column, just below the diaphragm

    • Each is connected to the ureter

    • Conducts urine from the kidney to the urinary bladder

    • Urine voided through the urethra

      • Tube between the bladder and the exit


Nephrons


  • Each kidney is composed of many tubular nephrons

    • Functional part of the kidney

    • About a million per kidney

  • Each nephron is composed of several parts

    • Glomerular capsule 

      • Bowmans capsule 

    • Glomerulus

      • The capillaries/blood supply

      • + capsule = renal corpuscle

    • Proximal convoluted tubule

    • Loop of the nephron

      • Loop of Henle

    • Distal convoluted tube

    • Collecting duct

      • Gose to ureter



  • Filters water and salts through these tubes











  • Renal cortex

    • Outer region

    • Granular appearance

  • Renal medulla

    • Cone-shaped renal pyramids

    • Collection of the collecting ducts

    • Drains into the minor calyx

      • Those drain into the major calyx

        • Multiple drains into the renal pelvis

  • Renal pelvis

    • Hollow-chamered innermost part of the kidney

      • Leads to the ureter

    • Renal pelvis, artery, and vein at hylum of the kidney

      • Hylum = input/output section


Urine Formation

  • Urinary production requires 3 distinct processes

    • Glomerular filtration in glomerular capsule

    • Tubular reasbsorption at the proximal convoluted tubule

      • Water is reabsorbed

    • Tubular secretion at the distal convoluted tubule

      • Sodium and chloride leave henly


  • Excretion of hypertonic urine

    • Dependent upon the reabsorption of water

      • Absorbed from

        • Loop of the nephron

        • Collecting ducts

    • Osmotic gradient within the renal medulla causes water to leave the descending limb along its entire length

  • Antidiuretic hormone (ADH)

    • Plant a role in water reabsorption 

    • Released by the posterior lobe of the pituitary gland 


Invertebrates


  • Some unicellular organisms excrete wastes by exocytosis



Excretory organs


Aquatice animals


  • Invertebrates

    • Most are isotonic with the water they live in 

    • Osmoconformers


  • Body fishes

    •  Body fluids with only a moderate amount of salt

    • Osmoregulators

    • Some manage to adjust to both salt and fresh water (salmon), but most cannot


Hemodialysis


  • Clinical purification of blood 

  • Takes away salts, urea


Nitrogenous waste products


  • Catabolism of amino acids and nucleic acids results in ammonia

    • Urea causes a loss of much water per unit of nitrogen

      • Mammals and amphibians

      • Must drink lots of water

    • Uric acid requires much less water per unit of nitrogen excreted

      • Reptiles, birds, arthropods

      • Allows invasion of drier habitats far from standing water


Nerves and Nervous System


Invertebrate


  • Hydras

    • Nerve is composed of neurons in contact with one another 

    • Also in contact with contractile epitheliomuscular cells

    • Helps with motion

  • Planarians

    • Ladder-like nervous system

    • Cephalization - concentration of ganglia and sensory receptors in the head

    • Central nervous system

  • Annelids, Arthopods, and Mullusks

    • Complex

    • True nervous system


Human Nervous System


  • Division of Nervous system

    • Central nervous system (CNS)

      • Includes brain and spinal cord

      • Lies in the midline of the body

    • Peripheral Nervous system (PNS)

      • Contains cranial nerves and spinal nerves

        • Gather info from sensors and conduct decisions to effectors

        • Lies outside the CNS


  • Nervous system has 3 specific functions

    • Receiving sensory input

    • Preforming integration

    • Generating moter output


Nervous Tissue


  • Neurons

    • Also contains nucleus and mitochondria

    • Cell body contains nucleus

    • Dendrites receive signals from sensory receptors

    • Axon conducts nerve impulse

      • Covered by myelin sheath

      • Any long axon called nerve fiber


Types of neurons 

  • Motor neurons

    • Efferent = starts in the brain, goes into nervous system to cause response

    • Accept nerve impulses from the CNS

    • Transmit them to muscular or glands

    • Multipolar 

  • Sensory neurons

    • Afferent = starts in nervous system, goes into brain to cause response

    • Accepts impulses from sensory receptors

    • Transmits to CNS

    • Bipolar

    • psudounipolar

  • Interneurons

    • Convey nerve impulses between various parts of the CNS

    • Concetion of neurons (seonsory to sensory, sensory to motor, motor to moter)

    • Unipolar

    • Bipolar 


Glial Cells


  • Support, protect and nourish neurons

  • Outnumber neurons (10 to 1) in the brain

  • Fulfill many vital function

  • Most brain tumer caused by mutation of glia


  • In CNS

    • Oligodendrocytes 

      • Form myelin sheath around axons

    • Astrocytes 

      • Provides nutrients and structural support

    • Ependymal cells

      • Produce cerebrospinal fluid that cushions naurns

      • Link up with blood suply

    • Microglia

      • Scavenge pathogens and dead cells


  • In PNS

    • Schwann cells

      • Forms the myelin sheath

    • Satellite cells

      • Provide nutrients and structural support to neurons


  • Nerve communication through an action potential

    • An electrical signal that passes from nerve to nerve

    • Turns on functions in the body 


CNS: Brain and Spinal Cord


  • Wrapped around 3 protective layers (Meninges)

    • Spaces between meninges are filled with cerebrospinal fluid - subarachnoid space (space between arachnoid and pia mater)

    • Fluid is continuous with that of the central canal of the spinal cord and the ventricles of the brain

    • Dura matter (outermost)

      • Tough matter mother

    • Arachnoid mater (middle)

    • Pia mater (inermost)

      • Thinnest 


Spinal Cord


  • 2 main functions

    • Center for many reflux actions

      • Reflux arch

    • Means of communication between brain and spinal nerves

      • Efferent (mortor response)

      • Mostly from the back

      • Afferent (sensory to brain)

  • Composed of gray matter and white matter

    • Cell bodies and short unmyelinated fibers give the gay matter its colro

    • Myelinated long fibers of internaurons running in tracts give white matter its color


Reflux arch 


  • Spinal reflex

  • Stretch sense









The Brain


  • Cerebrum is the largest portion of the human brain

    • Commnicates with and coordinates the activities of the other parts of the brain

    • Longitudinal fissure divides into left and right cerebral hemispheres





  • Cerebral cortex

    • Thin but highly convoluted outer layer of gray matter 

      • Make up the gyri (squiggles of brain)

    • Covers cerebral hemispheres

    • Contains motor areas and sensory areas as well as association areas




  • Frontal

    • motor

    • Personality

    • Planing 

  • Parietal 

    • Sesory

    • Associastion 

  • Oxipital

    • Vision

  • Temporal

    • Hearing

    • Smell (olfation)

    • Emotions / memory

Diencephalon (structures end in “thalamus”)

  • Region encirling third ventricle

  • Consists of hypothalamus and thalamus

    • Hypothalamus controls endocrine system via pituitary; thermostat

      • Hormones (vasopressin/antidioretic - water retention) (oxitosin - positive feedback loops)

    • Thalamus make of 2 masses of gray matter located in sides and roof of the third ventricle

      • Gateway to and from cortex

      • Relay ceter

  • Pineal gland

    • REM sleep

      • Rapid eye movement

    • Dreaming

    • Located in diencephalon

    • Secretes meletonin


  • Cerebellum 

    • Motor refinement

    • Eyes, ears, joints, muscles

    • Balance and coordination

      • Sends motor impulses out the brain stem to the skeletal muscles

    • Awareness of body in space

  • Brain stem = midbrain, pons and medulla oblongata

    • Midbrain

      • Acts as a relay station for tracts passing between cerebrum and spinal cord / cerebellum

    • Pons

      • Helps regulate breathing and head movements, heartrate 

        • Not regulation just action

    • Medulla oblongata

      • Reflex for vomiting, coughing, sneezing, hiccups, and swallowing


Peripheral Nervous System


  • Somatic System

    • Cranial nerves

      • 12 pairs, head and neck 

    • spinal nerves

      • 31 pairs 

    • Gathers info form soncors and conduct decisions to effectors 

    • Controls skeletal muscles

    • Conscious activity


  • Autonomomic system

    • Controls smooth muscle, cardiac muscles, and glands

    • Usually unaware of actions

      • 2 divisions

        • Sympathetic

          • Fight or flight 

          • Accelerates heartbeat and dilates bronchi

        • Parasympathetic 

          • Promotes interal responses associated with relaxed state 

          • Promotes digestion and slows heartbeat




Neurodegenerateive disorders


  • Alzheimers

    • Accelerated brain cell death


  • Parkinsons

    • Cell death of motor parts of brain


Resporation 


Gas Exchange Bwteen alveoli an blood 


  • Gas diffution happens at aqueous respitory epithelial cells (lines respiratory organs)

    • Numesights (cells of alvioli) in lungs

      • Type 1 = gas exchange 

      • Type 2 = produces surfactat 

  • Diffusion is passive, divine only by the difference in O2 and CO2 concentration on the 2 sides of membranes and their relative solubility in the plasma membrane

    • Trachea to bronchi to alvioli 

    • If High O2 in Alveoli into blood (capilaries) 

    • If High CO2 in blood into Alveoli 

  • Opposite occues in the tissue (more O2 in blood, put into organ / muscle) 


  • Gases diffse directly into unicellualr organisms

    • Dircely into membrane

    • bacteria

  • Small organisms can rely on direct diffusion of gases (skin)

  • Most mulicellular animals require system adaptations to enhance gas exchange

    • Amphibians across skin as well as lungs

    • Insects have extensive tracheal system

    • Fish use gills

    • Mammals use lung syststm


  • Gills

    • Cutainous design

    • Increase surface area (lots of folds)

    • Move water into mouth, through gills, and out of fish through open operculum / gill cover


  • Lungs

    • Gills were replaces in terrestrial animals

    • Minimizes evaporation by moving air through branched tubular passage

      • Convered in mucus to prevent direct contact o lung tissue with air

      • Psudostratifated cilliated lumnar with Goblet cells (goblet makes mucus)

    • Larynx = voice box

    • Bifurcates into the right and left bronchi, which enter each lungand further subdivide into bronchioles

    • Alveoli are surrounded by an extensive capillary network

    • During inhalation, thoracic volume increases through contraction of 2 muscle sets

      • Contraction of  the external intercostal muscle expands the rib cage

      • Diaphram is primary muscle of inspiration (breathing in), expnads the volume of thorax and lungs

    • Produces negative pressure which draws air into lungs


Lung structure and function

  • Tidal volume

    • Volume of air moving in and out of lungs in a person at rest

  • Vital capacity

    • Maximum amount of air that can be expired after a forceful inspiration


Hemoglobin

  • 4 polypeptide chains 

    • Eachchain is associated with a heme group

    • Eachheme group has a central iron atom that can bind a molecule of O2

  • Hemoglobin loads up oxygen in the lungs, forming oxyhemoglobin

  • Hemoglobin’s affinity for O2, is affected by pH and temp

  • pH effect is known as the Bohr shift

    • Increased CO2 in blood increases H+

      • Lower pH reduces affinity for O2

    • Facilitates oxygen unloading in the tissue

      • If there is high leves of CO2, O2 is needed, hemoglobin will let go of O2

    • Increasing temp has similar effect


Tranportation of Carbon Dioxide 

  • Not the same as O2

  • About 8% of CO2 in blood dissovles into plasma

  • 20% of CO2 in blood is bound to hemoglobin

  • Remaining 72% diffuses into red blood cells and becomes bicarbonate


  • Hypoventilation

    • Insufficiency breathing blood has abnormally high PCO2

  • Hyperventilation

    • Excessive breathing, blood has abnormally low PCO2

  • Naurons are sinsititve to blood PCO2

  • Brain has chemorecepters that know when levels are off

    •  A rise in PCO2 will cause increased production of carbonic acid, lowering blood pH

    • Stimulates chemosensitive neurons in the aortic and carotid bodies 

    • Sends impulses to repirtory control center to increase rate of breathing

    • Brain also contains central chemoreceptors that are sensitive to change the pH of cerebrospinal fluid

    • Chemorepeptors detects chemicals

      • Carotid body

    • Baroreceptor detects blood pressure

      • Carotid sinus

    • All this will tell the blood vessles to expand or contract


Respiratory diseases

  • Chronic obstructive pulonarry disease (COPD)

    • Refers to any disorder that obstructs airflow on a long-term basis

    • Asthma

      • Allergen triggers that release histamine, causing intense constriction of the bronchi and sometimes suffocation

    • Emphysema

      • Alveolar walls break down and the lung exhibits larger but fewer alveoli

      • Lungs become less elastic

      • 80% - 90% of deaths are caused by cigarette smoking

    • Lung cancer

      • Highest death rate of cancer

      • Follows or accopanies COPD

      • Spreads so rapidly that it usually invades other organs by time of diagnoses

      • Chance of recovery is poor, only 3% surviving for 5 years after diagnosis


  • Black spots on lungs = anthracotic pigment

    • Eats dust

    • More in industrial and polluted places


  • As elevation increases, partial pressure decreases 


  • Lungs of birds have unidirectional flow


Invertebraate Circulatory system


  • Sponges, cnidarians, and nematodes lack separate circulatory system

  • Sponges circulate water using  many incurrent pores and 1 excurrent pore

  • Hydra circulate water through a gastrovasular cavity (also for digestion)

  • Nematodes are thin enough that digestive tract can also be used as circulatory system

  • Open circulatory system

    • No distinction between circulating and extracellular fluid 

    • Fluid calle hemolymph

  • Closed circulatory system

    • Discit circulatory fluid enclosed in blood vessels and transported away frrom and back to heart

    • Analids have closed circulatory system 


  • Fishes

    • Evolved to true chamber-pump heart

    • 2 chamber heart

    • Blood is pumped through gills, then to rest of body


  • Amphibians

    • Advent of lungs required a second pumping circut or double circulation

    • Pulmonary circulation moves blood between the ehart and lungs

    • Systemic circulation moves blood between the heart and the reast of the body

    • 3 chambered heart

      • Runs the risk of mixing oxygenated and deoxygenated blood 

      • Still better than 2 chambered heart

  • Reptile heart

    • 3 chambered heart (septated)

      • 2 atria and 2 ventricles

        • Incomplete separation of ventricles


Vertebrate


  • Mammals, birds, and crocidilians

    • 4 chambered heart

    • 2 separate atria and 2 separated ventricles 

    • Right atrium recives deoxygenated blood from vena cava from body and delivers to the right ventricle through atrioventricular valve (tricuspid), is pumped into lungs

      • Superior vena cava blood from head and neck

      • Inferior vena cave blood from rest of body 

    • Left atrium receives oxgenated blood from lungs and delivers to the left ventricle through left atrioventriclular valve (mitral), then pumped to rest of body out of aorta

    • Pulmonary trunk takes blood to lungs

    • 2 superior and 2 inferior veins


Blood


  • Connective tissue

    • Extracellular matric - plasma

    • Cells - RBCs, WBCs, platelets

  • Functions of circulating blood

    • Transportation

      • Oxygen

      • hormones

    • Regulation 

      • Hormones (blood pressure)

    • Protection

      • White blood cells

      • Platelets (clotting) 


Plasma


  • 92% water

  • Contains solutes

    • Nutrients, wastes, and hormones

    • Ions

    • Protains

      • Albumin

      • Fibrinogen

        • If removed, plasma called serum

Red blood cells (Erythocytes)


  • About 5 million per microliter

  • Hematocrit is the fraction of the total blood volume occupied by red blood cells

  • Lack muclei

  • Live for 120 days

  • Spleen is graveyard for red blood cells

  • RBCs of vertebrates contain hemoglobin (is recycled for new cells)

    • Pigment that binds and transports oxygen


White blood cells (Leukocytes)


  • Less than 1% of blood cells

  • Larger than red cells and have nuclei

  • Cna migrate out of capillaries into tissue fluid

  • Types

    • Granular 

      • Neutrophils, eosinophils, and basophils

    • Agranular

      • Monocytes and lymphocytes


Platelets


  • Cell fragments that pinch off from larger cells in the bone marrow

  • Forms blood clots


Characteristics of Blood Vessels


  • Blood leaves the heart through the arteries

    • Takes blood away from the heart

    • Arterioles are the finest microscopic branches of the arterial tree

  • Blood enters arterioles and enters capillaries (gas exchange)

  • Blood is collected into venules, which lead to larger vessels, the veins

    • Carries blood back to the heart


  • 4 tissue layers

    • Endothelium, elastic fibers, smooth muscle, and connective tissue

    • Walls too thick for the exchange of materials across the wall

  • Callillaries are composed of only a single layer of endothelial cells

    • Allow rapid exchange of gases and metabolites between blood and body cells

  • Veins have valves

    • Prevents backflow


Lymphatic system


  • Water and solutes in the blood plasma filter through wall of  capilaries to form interstitial tissue fluid

  • Fluid not retired to capillaries is retired to circulation by lymphatic system

    • Lymph reuters to circulation in the subclavian vain


Mammalian heat


  • 2 pairs of valves

    • Atrioventricular valves (AV)

      • Maintain undirectional blood flow between atria and ventricles

      • Tricuspid valve = right side

      • Bicuspid / mitral valve = left side

    • Samilunar valves

      • Ensures one-way flow out of the ventricles to the vessels

      • The pulmonary valve is located at the exit of the right ventricle

      • The aortic valve is located at the exit of the left ventricle 


Cardiac Cycle


  • Valves open and close as the heart goes through the cardiac cycle

  • Ventricles relaxed and filled (diastole)

  • Ventricles contracted and pumped (systole)

  • “Lub-dub” sound with a stethoscope

    • Lub - AV valves closing

    • Dub - closing of semilunar valves

  • Heart contains “self-excitable” autorhythmic fibers

  • Most important is the sinoatrial (SA) node

    • Located in wall of right atrium

    • Acts as pacemaker

    • Autonomic nervous system can modulate rate

    • Normal heart rate = 60-100 bpm


  • Electrical activity can be recorded on an electrocardiogram (ECG or EKG)


Cardiovascular disease


  • Leading cause of death in US

  • Atherosclerosis

    • Accumilation of fatty material within arteries

    • Impedes blood flow

  • Ateriosclerosis 

    • Arterial hardening due to calcium deposition 

  • Likely to have both if heart is bad

  • Effects blood pressure 


Blood flow and blood pressure


  • Measured as systole / diastole

    • Systole = contraction

    • Diastole = relaxation

  • Increased with blood volume

  • Blood volume is regulated by 4 hormones

    • Antidiuretic hormone (ADH)

      • Increases urine output

    • Aldosterone - encourages kidney to exrete potassium and retain sodium

    • Atrial natriuetic hormone - increase sodium excretion and decrease blood pressure

    • Nitric oxide (NO) - vasodialator 

  • 120 / 80 is normal


Muscoskelatal system purpose


  • Contral movement

    • Support

      • Maintain upright position

    • Allow movement

      • Body transport

      • Manipulate objects

    • Protect


Hydrostatic


  • Ford by a fluid-filled compartment within body, coelom

  • Compartment is under hydrostatic pressure because of the fluid, supports the other organs of the organism

  • Found in soft-bodied animal such as sea anemones, earthworms, CNidariam and other invertebrates


Exoskelteon 



Endoskeleton 


  • Heard mineralized structures located within the soft tissue of organism

  • Provides support, protects internal organs, allows for movement trough contraction of muscles attached to bones


Human Axial skeleton


  • Bones of the skull, ossicles of middle ear (how we hear), hyoid bone (supports larynx), vertebral column, and rib cage



  • Cranial bones, including frontal, parietal, and sphenoid bones, cover the top of head

  • Facial bones of the skull form the face and provide cavities for the eyes, nose, and mouth 

  • Vissucrianum = bones of the face (interact with organs more, lower in the face)

  • Neurocranium (bones surrounds the brain) 


Vertebral column


  • 7 cervical vertebrae (C1-C7)

    • Lordosis curve

  • 12 thoracic vertebrae (Th1-12)

    • Kyphosis curve

  • 5 lumbar vertebrae (L1-5)

    • Lordosis curve

  • The os sacrum and the coccyx


  • Spinal curves increase the strength and flexibility of the spine


Thoracic cage


  • The thoracic cage/rib cage protects the heart and lungs 


Appendicular skeleton


  • Bones of the Appendages

  • Upper limb

    • Humorous (arm/bracium)

    • Forearm

      • Anabraium (humerous / unla)

  • 8 Carpal bones / wrist

  • 5 metacarpals (palm)

  • 14 phalanges (fingers)


Pelvic girdle

  • Females are lighter, wider, shallower, and have a broader angle of the subpubic bone


Lower limbs


  • Thigh (femur)

  • Kneecap (patella)

    • Sesamoid bone = seed-like

      • Also in thumbs

  • Leg (tibia and fibula)

  • Ankle (tarsals)

  • Foot (metatarsals and phalanges) 


Types of bones


  • Long bone 

    • Covered by articular cartilage at either end

    • Contains bone marrow (sits in the medullary cavity) 

    • Longer than wide (humerus, femur, etc.)

    • Shaft with 2 ends

    • Mostly compact

    • Bones of limbs




  • Short bones

    • Cube-like

    • Mostly spongy

    • Seesamoid - bones embedded in a tendon

      • Patella

  • Flat bone

    • Flat in appearance

    • Spongy bone embedded within a parallel layer of thin compact bone

      • Skull bones (frontal, occipital, etc.)

      • Also scapula

  • Irregular bone

    • Vertebra and hip bone

    • Complicated shapes

    • Mostly spongy with a thin covering of compact bone

      • Sphenoid bone (nasal)


  • Compact bone

    • Elongated cylingers parallel to bone's long axis

      • Concentric rings (lamella)

        • Unidirectional collagen fibers along long axis

        • Adjacent lamella have collagen in opposite direction 


  • Central (haversian) canal (core of osteon)

  • Blood vessels and NT

  • Perpendicular canals (perforating or volkmanns)

    • Blood supply

  • Lacunae (cavities containing osteocytes)

  • Canaliculi (connect lacunae each other and central canal) 


  • Spongy Bone

    • Trabecule (needle like flat pieces)

    • Trabeculae appear less organized than structure of compact bone

      • No osteon

      • Orgaization is based on line of stress

      • Lamella and osteocytes are irregularly organized


Inreamembranous ossification 

  • Mostly for flat bones

  • Tissues are being osstrifid

  • The sheet of membrane first

  • Ossification center forms in fibrous connective tissue 

    • Mesenchymal cells differentiate into osteoblasts

  • Bone matrix is secreted into the membrane

    • Osteoblasts secrete osteoid

  • Woven bone and periosteum are formed 

    • A network of trabeculae encloses local blood vessels

    • Exterior mesenchyme differentiates into periosteum

  • Trabeculae thicken and form born collar

    • Replaced by lamellar bone 

    • Spongy bone persists to form red marrow


Endohondral Ossification 


  • Process of bone development from hyaline cartilage

  • Periosteum is connective tissue on the outside of bone, acts as an interface between bone, blood vessels, tendons, and ligaments

  • Cartilage and bone are used as patterns for bone construction

    • Primary ossifcation center at the center of the hyaline cartilage

  • Hyaline cartilage is broken down during ossification

  • Process prior to ossification

    • Perichondrium becomes infiltrated by a blood vessel

      • Becomes periosteum 

      • Underlying mesenchymal cells differentiate into osteoblasts

  • Muscles onto bone, through tendon, periosteum

  • Ossification

    • Bone collar forms around hyaline model

    • Cartilage in center of diaphysis calcifies

    • Periosteal bud invades internal cavities

      • Bud brings vessels, NT, lymph tissue, osteoblasts, and osteoclasts

      • Osteoblasts secrete osteoid around remaining hylaline cartilage

    • Medullary cavity forms

    • Epiphyses ossify



Fibrous Joints


  • Bones of these are held together by fibrous connective tissue 

  • Sutures on bones

  • Fusion of bone as you age



Cartilaginous Joints


  • Joints  in which bones are connected by cartilage

  • Synchondrosis

    • Bones joined by hyaline cartilage

    • Found in epiphyseal plants (growing plates) of growing bones in children

  • Symphyses

    • Hyaline cartilage covers the end of the bone but the connection between bones occurs through fibrocartilage

    • Allows for very little movement

    • Between vertebra

    • Between the hip bones (pubic symphyses)

  • Gomphosis

    • Around teeth


Synovial Joints

  • On joints that have space for a synovial cavity in joint

  • The cavity is filled with synovial fluid, which lubricates the joint


Types of Synovial Joints


  • Planar 

    • Flat against each other

    • Vertebra

    • Carpal bones

  • Hinge

    • Elbow (radius and ulna) 

  • Pivot

    • Rotating movements

    • Neck joint (1st and 2nd cervical vertebra)

  • Condyloid

    • Metacarpophalangeal (nuckles) 

    • Have condaials 

    • Jaw (temporal mandibular) (bicondyloid)

  • Saddle

    • At thumb

    • Between Metacarpal and trapezium

  • Ball and socket

    • Shoulder 

    • Hip joint

    • Circumduction motions 


Muscular tissue


  • Skeletal

    • Striated

    • Protein filament chains give an appearance

    • Attached to bone

    • Surrounded by a plasma membrane called sarcolemma with cytoplasm called sarcoplasm

    • Sarcomere

      • Region from 1 Z line to another

      • Present in a myofibril (gives appearance)



  • Smooth

    • Short and tapered

    • One plump nucleus

    • Not striated

    • Haphazard

    • Walls of blood vessels and the respiratory passageway (Tunacomidia) 

    • Spherical contraction 

  • Cardiac

    • Striated 

    • Have intercalated discs that allow for contraction (pumping)


  • Sliding filament 

    • Helps to shorten the contraction of the muscle

    • Thin filament is actin

    • Thick filament is myasin 


  • ATP and muscle contraction

    • Cross-bridge muscle contraction cycle 

    • Triggered by Ca2 binding to the actin active site

    • With each contraction cycle, active moves relative to myosin


Excitation-Contraction Coupling in skeletal muscle contraction

  • The presence of calcium helps 


Endocrine system (hormones)

  • Has to use the blood supply

  • Cell signaling systems (cell communication) 

  • Communicates through blood


Hormones 

  • Act at a distance

  • Chemical secreted intor extracellular fluid and carried by blood

  • Multicellular animals need hormones to help with homeostasis

    • Travel to cell that has receptor for that hormone


Lipid-derived hormones

  • Cholesterol based

  • Estrogen and testosterone

  • Comes from the cholesterol system

  • Steroid hormones

    • Freely pass through plasma membranes

    • Hydrophobicity allows this 

Amino acid-derived hormone

  • Epinephrin

    • Catacolomeans (grouping of molecules

    • Comes from tyrosine (ameno acid)

  • Meletonin 

    • Comes from tryptophan

      • Turkey is high in this

    • Circadian rhythm 


Peptide hormones


  • Growth hormones

  • Larger 

  • Oxytocin

  • From cholesterol or amino acids



Nervous System vs Endocrine System


  • Neuroendocrone System

    • Nervous system controls through nerves impulse conducted by axons

    • Edocrine system crotrols through hormones

    • May have widespread general effects

    • Responses occur after seconds to days / prolonged, adapts slowly


Hormones


  • Need specific receptor to work

  • Receptors change with cellular activity

    • Found on different cells or limited to small number of specialized cells

    • Number of receptors can change

    • Can be found within cell or on plasma membrane


Intracellular Receptors


  • Lipid derived hormones bind to transport proteins

    • Once at target, release carrier protein and pass through plasma membrane and bind to target 

      • Lipophillic - cross membrane and bind to intra cellular receptor


Hormonal Regulation 


  • Excretory System

    • Maintains water balance

    • Antidiuretic hormone (ADH)

    • Aldosterone (steroid hormone)

      • Produes adrenal cortex

      • Main regulator of water and electrolytes like sodium and potassium

      • Promotes reabsorbtion of water

      • Released due to signaling of renin angiotensin system, ADH is released with the function of osmoreseptors


Reproduction System


  • Follicle Stimulating Hormone (FSH)

    • Males- maturation of sperm cells


Metabolism 

  • Insulin

    • Produced by beta cells of pancreas

    • Lowers blood sugar by increasing cellular uptake and utilaztion by cells

    • Deficiency results in diabetes mellitus

  • Glucagon

    • Antagonist to insulin

    • Produced by alpha cells of pancreas

    • Raises blood sugar by targeting liver to break down glycogen


Regulation of metabolism by thyroid hormones


  • Basal metabolism rate (mound of calories required by body a rest)

    • Determined by thyroxine (T4) and Triiodothyronine (T3)

  • Released by thyroid gland in response to stimulation by TSH

    • Hypothyroidism = low metabolic rate

      • Weight gain, sensitive to cold, lethargy

    • Hyperthyroidism = high metabolic rate

      • Weight loss, irritability, increased heart rate




Hormonal control of blood calcium

  • PTH (produced by  parathyroid glands)

    • Released in response to low blood calcium 

    • Activates osteoclasts, which break down bone

  • Antagonism is Calcitonin (produced by the thyroid gland) (in bonin = osteoblast) 

    • Made by C cells (thyroid gland cells)

    • The antagonist hormone has the opposite effect on the body 

    • Activates osteoblast activity (builds bones) 


Hormonal control of growth


  • GH (Growth hormone)

    • Stimulates growth, cell production, cell regeneration

      • Increases rate of protein synthesis

      • Is glucose sparing

    • Regulated by growth hormone releaseing and inhibiting hormones from hypothalamus 


Hormonal control of stress


  • Short ternm stress

    • Epinephrine for flight or fight from adrenal gland (Adrenal medula)

  • Long term stress

    • Cortisol from adrenal gland

      • Anti-inflammatory 

    • Too much for too long suppresses the immune system


Hypothalamus

  • intergrt=ates endocrine and nervous systems

  • Synthesizes and secretes regulatory hormones that control endocrine cells in anterior pituitary

  • Collection of nuclei (cell bodies of nerons)


Pituitary gland


  • Known as hypophysis

  • Hangs by stalks from hypothalamus

  • 2 parts

    • Anterior pituitar (andenohypophsis)

    • 7 essential hormones

      • Peptide hormones 

        • Adrenocorticotrophic (ACTH) - stimulates adrenal to make cortisol

        • Melanin - stimulating (MSH) - stimulates dispersion of pigment

      • Protein

        • Growth hormone (hGH)

        • Prolactin (PL) - stimulates mammary glands

      • Glycoprotein hormones 

        • Thyroid - stimulating (TSH) - acts on thyroid

        • Luteinizing hormone (LH) - acts on ovaries, testes

        • Follicle-stimuling hormone (FSH) - development of ovarian follicles, development of sperm

      • Appears glandular

      • Not part of brain

      • Hypothalamus releases neurohormones into anterior, causing anterior to release tropic hormones (work on other endocrine glands)

    • Posterior pituitary (neurohypoophysis)

      • 2 hormones are produced in hypothalasmus and stored in special cells in posterior pituitary

        • Antidiuretc hormone (ADH)

        • Oxytocin

      • Appears fibrous because contains axons from hypothalamus

      • Part of brain

      • Releases ADH and oxytocin






Plasma membrane receptors


  • amino acid derived hormones and peptides cannot pass through plasma membrane

    • Hydrophilic - cannot pass membrane, have to bind to receptor on membrane

  • Bind receptors on the outer surface of plasma membrane and initiates signaling pathway (called second messenger system)