1 ANIMAL NUTRITION. 2 Figure 41.1 Homeostatic regulation of cellular fuel.
Chapter 43 The Animal Body and Principles of Regulation.
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Transcript of Chapter 43 The Animal Body and Principles of Regulation.
Chapter 43
The Animal Body and Principles of Regulation
Organization of the Vertebrate Body
• There are levels of organization in the vertebrate body
-cells
-tissues
-organs
-organ systems
Tissues are groups of cells of a single type and function
• Early in development, the cells of the growing embryo differentiate into the three fundamental embryonic tissues called germ layers
-endoderm
-mesoderm
-ectoderm
• Four principal kinds of tissues in adult vertebrates
-epithelial, connective, muscle, and nerve tissue
• Organs and organ systems provide specialized functions
-organs are body structures composed of several different types of tissues that form a structural and functional unit
-organ system is a group of organs that cooperate to perform the major activities of the body
• The general body plan of vertebrates is a tube within a tube, with internal support
• Vertebrates have both dorsal and ventral body cavities
-dorsal cavity is cranium and vertebrae
-ventral: thoracic (pericardial, pleural) cavity and abdominopelvic (peritoneal) cavity
Epithelial Tissue
• Rows of cells exposed to open area and anchored down by a basement membrane to connective tissue
• Three types of epithelial cell structures
-squamous, cuboidal, and columnar
• Classified as simple or stratified
• Function in protection, transport, and secretion
-examples?
Tissues: groups of cells with a common structure and function (4 types)
• Anatomy: structure
• Physiology: function
• 1- Epithelial: outside of body and lines organs and cavities; held together by tight junctions
• basement membrane: dense mat of extracellular matrix
• Simple: single layer of cells
• Stratified: multiple tiers of cells
• Cuboidal (like dice)
• Columnar (like bricks on end)
• Squamous (like floor tiles)
• mucous membrane
Connective Tissue
• All CT are widely spaced apart cells in a matrix of extracellular material
• CT function in protecting (bone), support (cartilage), food storage (fat or adipose tissue)
• CT can be either proper or special
CT Proper May Be Either Loose or Dense
• Fibroblast cells produce and secrete the extracellular matrix (collagen and elastin fibers)
• Loose CT consists of cells scattered within a matrix that contains a large amount of fluid material and fibers. They provide support, insulation, food storage, and nourishment for epithelium
-Adipose tissue is fat tissue
• Dense CT has a lot more collagen than Loose CT making it structurally stronger. They provide flexible, strong connections
-tendons of muscles
Special CT have unique characteristics
• Cartilage provides flexible support and is a shock absorber (intervertebral disks)
• Bone protects internal organs and provides rigid support for muscle attachment
• Blood functions as highway of immune system and primary means of communication between organs
Tissues, II• 2- Connective: bind and support other tissues; scattered cells through matrix; 3 kinds:• A-Collagenous fibers (collagen protein) B-Elastic fibers (elastin protein) C-Reticular fibers
(thin branched collagen fibers)• Loose connective tissue: binds epithelia to underlying tissue; holds organs• 1-Fibroblasts- secretes extracellular proteins 2-Macrophages- amoeboid WBC’s;
phagocytosis 3-Adipose tissue- fat storage; insulation• Fibrous connective tissue: parallel bundles of cells• 1-Tendons- muscles to bones 2-Ligaments- bones to bones; joints (BOBOLI)• Cartilage: collagen in a rubbery matrix (chondroitin); flexible support• Bone: mineralized tissue by osteoblasts• Blood: liquid plasma matrix; erythrocytes (RBC’s) carry O2; leukocytes (WBC’s) immunity
Muscle Tissue
• Muscles are the motors of the vertebrate body
• Three types
-skeletal: voluntary, moves the body
-smooth: involuntary, control most actions of organs
-cardiac: involuntary, controls the heart
Tissues, III
• 4- Muscle: capable of contracting when stimulated by nerve impulses; myofibrils composed of proteins actin and myosin; 3 types:
• A- Skeletal: voluntary movement (striated)
• B- Cardiac: contractile wall of heart (branched striated)
• C- Smooth: involuntary activities (no striations)
Nerve Tissue
• Composed of nerve cells (neurons) and their supporting cells (neuroglia) that are specialized to produce and conduct electrochemical events (impulses)
• Two divisions of the nervous system coordinate activity
-central nervous system (CNS): the brain and spinal cord
-peripheral nervous system (PNS): nerves and ganglia, collections of neuron cell bodies
Tissues, IV
• 3-Nervous: senses stimuli and transmits signals from 1 part of the animal to another
• Neuron: functional unit that transmits impulses
• Dendrites: transmit impulses from tips to rest of neuron
• Axons: transmit impulses toward another neuron or effector
Organ systems
• Organ: organization of tissues
• Mesentaries: suspension of organs (connective tissue)
• Thoracic cavity (lungs and heart)
• Abdominal cavity (intestines)
• Diaphragm (respiration)• Organ systems…...
• Digestive-food processing• Circulatory-internal distribution• Respiratory-gas exchange• Immune/Lymphatic-defense• Excretory-waste disposal;
osmoregulation• Endocrine-coordination of body
activities• Reproductive-reproduction• Nervous-detection of stimuli• Integumentary-protection• Skeletal-support; protection• Muscular-movement; locomotion
Homeostasis
• The dynamic constancy of the internal environment
• Negative feedback mechanisms keep values within range
-hypothalamus is the body’s thermostat
• Antagonistic effectors act in opposite directions
• Positive feedback mechanisms enhance a change
-less common and have specialized functions in body
Internal regulation• Interstitial fluid: internal fluid
environment of vertebrates; exchanges nutrients and wastes
• Homeostasis: “steady state” or internal balance
• Negative feedback: change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation; i.e., body temperature
• Positive feedback: physiological control mechanism in which a change in some variable triggers mechanisms that amplify the change; i.e., uterine contractions at childbirth
Metabolism: sum of all energy-requiring biochemical reactions
• Catabolic processes of cellular respiration
• Calorie; kilocalorie/C• Endotherms: bodies warmed by
metabolic heat• Ectotherms: bodies warmed by
environment• Basal Metabolic Rate (BMR):
minimal rate powering basic functions of life (endotherms)
• Standard Metabolic Rate (SMR): minimal rate powering basic functions of life (ectotherms)
The Evolution of Organ Systems
• The digestive system
-Sponges flipped their stomachs inside out and ate stuff
-earth worms obtained a one way digestive tract
-vertebrates developed specialized organs for their digestive tracts
The Respiratory System
• The respiratory system
-fishes have gills and let O2 diffuse in
-amphibians breathe in cutaneously and have lungs
-reptiles have straight up lungs
-birds are weird and have a bunch of air sacs
-mammals have well developed lungs
The Heart
• Fish have a 2 chambered heart• Amphibians have a 3 chambered heart• Reptiles have a 3 and a half chambered heart• Mammals have a 4 chambered heart
The Brain
• Cephalization and the development of a brain were important steps in animal evolution
-the concentration of the nervous system toward the anterior end of the organism
• the flat worms were the first to cephalize
• efficient response to a stimulus (during movement sensory organs encounter the environment first
• Ectoderm gives rise to the nervous system
-development of notochord
-neural tube develops into brain
-spinal column/vertebrae/cranium protect the CNS
-notochord signals or directs the development of neural tube
THE END