animal anatomy and physiology

cells

-all vertebrates are composed of different cell types

-smallest division of life

-all life is cellular

-all cells come from preexisting cells

tissues

-groups of cells similar in structure and function

-germ layers are tissues

germ layers

-endoderm

-mesoderm

-ectoderm

—all germ layers generate epithelium

—can be membranes and glands

primary tissues

-epithelial (skin, glands)

-connective

-muscle

-nerve

organs

-composed of atleast 2 tissue types, function as a single unit

-heart, muscle and blood vessels, nerves, connective tissue

organ systems

-collections of organs that perform major activities of the body

-the vertebrate body contains 11 principal organ systems

circulatory system

-transport blood throughout body

body plan

-a tube within a tube

—inner tube: digestive track

—outer tube: main vertebrate body

—-supported by a skeleton

—outermost layer: skin and its accessories

identifiable body cavities

-dorsal body cavity: inside skull and vertebral column

-ventral body cavity

—thoratic body cavity: above diaphragm

—abdominopelvic cavity: below diaphragm

epthelial cells

-attached to underlying connective tissues by a fibrous membrane

—epithelium has polarity

-basal surface: secured side

-apical surface: free side

epithelial layers

-one layer allows for diffusion, absorption, and secretion

-several layers create a dense barrier to abrasion and chemicals (skin / lining of stomach)

epithelial shape

-fall cells allow materials to diffuse through (squamous)

-cubed cells absorb and secrete moderately

-columnar cells absorb, secrete, and process chemicals at the greatest rate

epithelial types: glands

-special epithelial tissue

-form from invaginated epithelial

—exocrine glands (has an exit)

-ex) salivary, sweat, sebaceous

—endocrine glands: ductless, connects gland to other systems

-ex) hormones, insulin

epithelial types: connective tissue

-derive from embryonic mesoderm

—divided into two major classes

-proper connective tissue: loose and dense

-special connective tissue: cartilage, bone, blood

epithelial types: proper connective tissue

—fibroblasts

-cells that produce and secrete protein fibers in ECM

-fibers: thick, tough collagen fibers. Stretchable elastic fibers

-matrix: extracellular material. protein fibers, gels, salts, fluids, fats (“jello soup”)

epithelial types: dense vs loose connective tissue

-ratio of cells to matrix

-strengthened by protein fibers

-collagen fibers may be parallel to one another

-adipose cells (fat cells): also occur in loose connective tissue

—develop in large groups in certain areas forming adipose tissue (white and brown)

tendons

-bone to muscle

ligaments

-bone to bone

special connective tissue: cartilage

-chrondrocytes: cartilage cells

-matrix: chrondroitin, collagen / elsatin fibers

-flexible with great tensile strength

-found in joint surfaces and other locations

special connective tissue: bone

-osteocytes (bone cells)

—hardened with calcium salts around collagen fibers

special connective tissue: blood

-cells: erythrocytes, leukocytes, thrombocytes

-matrix: plasma

special connective tissue: smooth muscles

-walls of blood vessels and visceral organs

-mono-nucleated

-involuntary, nerves regulate, dont have to think about moving these cells

special connective tissue: skeletal muscles

-attached to bone by tendons

-cells are long and multi nucleated

-voluntary, nerves instigate (think about doing it)

-striated: myofibrils (fibers of actin and myosin)

special connective tissue: nerve tissue

-composed of neurons

-neuroglia do not conduct electrical impulses

-works kind of link an insulator

-eliminate foreign materials in and around neurons

3 parts of a neuron

-cell body: contains nucleus, biggest part

-dendrites: highly branched extensions (directly towards)

—conduct electrical impulses toward the cell body

-axon: single cytoplasmic extension (away)

—conduct impulses away from cell body

organ systems: nervous/endocrine

-sensory: the 5 senses

-detect external stimuli

-coordinate the bodys response

-communication and integration

organ systems: musculoskeletal system

-support and movement

-consists of 2 interregulated organ systems

-calcified bone skeleton

-hydrostatic skeleton in many invertebrates

organ systems: digestive, circulatory, respiratory, urinary

-regulation and maintenance

-regulate and maintain the bodys chemistry

organ systems: integumentary, immune

-defense

organ systems: reproductive system

-reproductions and development

-spreading genes

-nurtures the developing embryo and fetus

cell size

-even if you keep everything else the same, making an organism bigger will change its physiology

—SA: area covering an object

—vol: space the object takes up

-AS AN ORGANISM GETS LARGER—> SA:VOL RATIO GETS SMALLER

gas exchange is dependent on SA

-oxygen must be diffused down a concentration gradient

-SA/V low — SA higher

smaller organisms

-dont need specialized breathing structures

-exchange gas through skin

larger organisms

-have lungs, gills (specialized)

-these structures add SA without changing volume

increasing respiratory complexity improves rates of diffusion

-increasing SA

-decreasing the distance diffusion happens over

-increasing the local concentration of oxygen

internal gills (early lung structure)

-similar function to invertebrate / external gills

-dervied from pharyngeal slits found in all chordates at one time

-there are several gill arches on each side of an animals head

—mouth used as pump

—covered by operculum

-each is composed of two rows of gill filaments which consist of lamellae

—countercurrent flow: what the gills are doing

oxygen diffusion in gills

-countercurrent flow: blood flows opposite to direction of water movement

—water will ALWAYS have higher oxygen than blood

-maximizes oxygenation of blood

-concurrent does no oxygenate as well

terrestrial vertebrates

-gills were replaced in terrestrial animals

—air is less supportive than water

—needed structure to retain moisture

-lung: minimizes evaporation by moving air through a branched tubular passage

-extensive internal SA: gas exchange

—reptiles and mammals have negative pressure breathing

—expand thoratic cage by muscular contractions

—creates empty space (hence lower pressure)

—air rushes inside lungs to fill empty space

-two directional flow (mix old air with new air)

-lungs of mammals are packed with millions of alveoli

—inhaled air passes through trachea

—bifurcates into right and left bronchi

—enter each lung and subdivide into bronchioles

—extensive capillary network surround alveolar sac

mammalian circulation

-start with blood returning to heart through right atrium and r ventricle

-right ventricle pumps to lungs

—drops off CO2

—pick up O2

-oxygenated blood returns to the left atrium

—then to left ventricle

-left ventricle pumps blood to the aorta and out of body

—drops off CO2

—pick up O2

undirectional breathing

-best seen in modern birds

—O2 is absorbed through one way tubes called parabronchi

—achieved through the action of anterior and posterior sacs

-deoxygenated air does not need to be exhaled before oxygenated air can be inhaled

first cycle of undirectional breathing

-cycle 1

—inhaled air is drawn from the trachea into the posterior air sacs

—exhaled into lungs

second cycle of undirectional breathing

-cycle 2

—air drawn from the lungs into the anterior air sacs

—exhaled through trachea

hemoglobin

-4 polypeptide chains

—each chain is associated with a heme group

—each heme group has an iron atom

——iron can bind to a molecule of O2

—oxidixed- lose electrons

—reduction- gain electrons

-hemoglobin loads up with O2 in lungs

—delivers all along the way to capillaries

—some molecules lose O2 in capillaries

Bicarbonate buffer system

CO2 + H2O —> H2CO3 —> HCO3- + H+