Animal structure and function

1
Animal structure and function

2
(No Transcript)
3
Tissues

• Epithelial
• Connective
• Muscle
• Nervous

4
Epithelial tissue

• Epithelial tissue (epithelium)
• Covers all surfaces of the body
• Epidermis (ectoderm)
• Outer portion of skin
• Endoderm
• Lining of inner surfaces of digestive tract
• Mesoderm
• Inner surface of body cavities

5
Epithelial tissue

• Closely packed
• Tight junctions
• One/or few cell layers thick
• Selective absorption in the intestines
• Rapid gas exchange in lungs
• Protection from microbes, water loss

6
Epithelial tissue

• Regenerative capabilities
• Liver (gland from epithelial tissues)
• Epidermis every 2 weeks
• Stomach lining every 2-3 days

7
Epithelial tissue

• Types
• Based on cell thickness
• Shape on exposed surface
• Simple
• One layer thick
• Stratified
• Multiple layers of cells

8
Epithelial tissue

• Shapes of cells
• Cuboidal
• As wide as they are tall (like dice)
• Columnar
• Taller than wide (like bricks on end)
• Squamous
• Flat like floor tiles

9
Epithelial tissue

• Simple squamous
• Stratified squamous

10
Epithelial tissue

• Simple squamous
• Lining of lungs, capillary walls and blood
  vessels
• Simple cuboidal
• Lining of some glands
• Simple columnar
• Lining of stomach, intestines and parts of
  respiratory tract

11
(No Transcript)
12
Epithelial tissue

• Stratified squamous
• Outer layer of skin and mouth
• Keratin
• Water resistant protein

13
Epithelial tissue

• Exocrine glands (duct system)
• Derived from epithelial tissue
• Duct
• Connection from gland to tissue
• Secrete/absorb chemical solutions
• Sweat and sebaceous glands
• Lining of intestines lungs that secrete mucous

14
Glands
15
Epithelial tissue

• Endocrine glands (ductless glands)
• Derived from epithelium
• Hormones
• Secreted into blood stream

16
Connective tissue

• Loosely packed cells
• Derived from mesoderm
• Scattered in an extracellular matrix
• Matrix
• Composed of a web of fibers in a foundation
  (liquid, jellylike or solid)
• Fibers (proteins) are collagen, elastic, or
  reticular

17
Connective tissue

• Collagen
• Non-elastic-doesnt tear easily
• Elastic
• Makes tissue elastic
• Elastin (protein)
• Reticular
• Thin, branched, joins connective tissue to
  adjacent tissues

18
Connective tissue types

• 1. Loose connective tissue
• Beneath skin between organs
• Support, insulation, food storage
• Adipose tissue (fat)
• Cells become larger when gain weight
• Shrink with weight loss

19
Connective tissue

• In the loose connective tissue
• Fibroblasts
• Cells that produce secrete extracellular matrix
• Macrophages
• Engulf foreign bodies and debris
• Mast cells and heparin

20
Connective tissue

• 2. Dense connective tissue
• Tendons, ligaments, sheath around organs
  (periosteum), dermis of skin
• Support, strong connections
• 3. Special connective tissue
• Cartilage, bone, blood,

21
Connective tissue
22
Special connective tissue

• Cartilage
• Consists of chondroitin (glycoprotein) collagen
• Strong, flexible tissue, absorb stress
• Joints, ear pinna, nose, intervertebral discs,
  larynx
• Chondrocytes
• Cartilage cells

23
Cartilage
24
Bone

• Embryos consist of more cartilage
• Cartilage is replaced with bone cells or
  osteocytes
• Matrix hardens with crystals of calcium phosphate
  mixed with collagen

25
Bone

• Osteoblasts
• Lay down new bone
• Osteoclasts
• Dissolve bone
• Haversian system (osteons)
• Unit of bone structure
• Contains calcified matrix, osteocytes, nerve
  fibers, blood vessels

26
Bone

• Flat bones
• Long bones
• Spongy bone
• Contains marrow
• Blood cells formed
• Compact bone
• More dense, gives strength

27
Bone
28
Bone
29
Blood

• Plasma (matrix)
• Cells
• RBC (erythrocytes)
• Contain hemoglobin (carries oxygen)
• WBC (leukocytes)
• Neutrophils, eosinophils, basophils, lymphocytes,
  monocytes
• Platelets (thrombocytes)

30
Blood
31
Blood

• Plasma contains
• Wastes, nourishment
• Hormones
• Na, Ca2, other ions
• Fibrinogen, albumin, antibodies

32
Muscle tissue

• Movement
• Organization of actin myosin filaments
• Smooth, skeletal cardiac muscles
• Striated muscles skeletal and cardiac
• Skeletal muscles voluntary control
• Smooth cardiac muscles involuntary control

33
Muscle tissue

• Smooth muscle
• Walls of blood vessels, stomach, intestines
• Viscera
• Internal organs
• Made of sheets of cells each with a single nucleus

34
Muscle tissue

• Skeletal muscle
• Attached by tendons to bones
• Contract move bones

35
Muscle tissue
36
Muscle tissue

• Cardiac muscle
• Small interconnected cells
• Linked by gap junctions
• Openings allow small substances electrical
  charges to pass between cells
• Myocardium
• Single functioning units

37
(No Transcript)
38
Nerve tissue

• Neurons
• Cell body, dendrites, axon
• Neuroglia
• Supporting cells
• Insulate neurons
• Eliminate foreign bodies

39
Nerve tissue

• Dentrites
• Thin, branched extensions
• Receive impulses
• Axons
• Single extension of cell body
• Carries impulse away
• Myelin sheaths, insulating cover

40
Neurons
41
(No Transcript)
42
Neurons

• Sensory neurons
• Eye,ears, surface of skin
• Motor neurons
• Brain spinal cord
• Interneurons
• Brain spinal cord
• Neurons within the CNS

43
Neurons
44
Summary

• Epithelial tissues
• Simple or stratified
• Cuboidal, columnar, squamous
• Connective tissues
• Loosely packed, tightly packed
• Special (bone, cartilage, blood)
• Matrix

45
Summary

• Muscle tissues
• Smooth, cardiac, skeletal
• Nerve tissues
• Neurons (cell body, dentrites, axons)
• Sensory, motor and interneurons

46
Coordination

• Hormones
• Nervous system
• Homeostasis

47
Homeostasis

• Dynamic constancy of internal environment
• Dynamic because conditions fluctuate
• Narrow range
• pH
• Temp
• Glucose
• Oxygen

48
Regulation

• 1. Negative feedback loops
• 2. Positive feedback loops

49
Negative feedback

• media\40_08NegativeFeedback_A.html

50
Positive feedback
media\40_08PositiveFeedback_A.html
51
Negative feedback loops

• Sensors
• Measure internal environment
• Integrating center
• Receives information from sensors
• Compares to normal range
• Responds

52
Negative feedback loops

• Effectors
• Muscles or glands
• Receive information from center
• Response

53
Negative feedback loops

• Temperature 98.6oF (37oC)
• Temperature increase
• Hypothalamus senses deviation
• Sends signals to relieve heat
• Sweating vasodilation
• Reach baseline negative feedback stops response

54
Negative feedback loops

• Temperature decrease
• Hypothalamus sends signals
• Shiver, vasoconstriction
• Temp to baseline negative feedback stops response

55
Thermoregulation
56
Fig. 40-9
(a) A walrus, an endotherm
(b) A lizard, an ectotherm
57
Negative feedback loops

• Glucose (eat a meal)
• Elevated blood level
• Islets of Langerhans (sensor, center)
• Insulin
• Lowers blood sugar (uptake in muscle, fat and
  liver)
• Negative feedback stops insulin release

58
Positive feedback loops

• Uterine contractions
• Pressure from baby on uterus
• Causes contractions
• Causes more stretching
• More contractions
• Continues until birth

59
Positive feedback loop

• Blood clotting
• Clotting factors stimulate the formation of more
  factors
• Clot forms
• Maintain blood volume

60
Bioenergetics

• Overall flow transformation of energy in an
  animal
• Determines nutritional needs
• Animal size, activity and environment

61
Fig. 40-17
Organic molecules in food
External environment
Animal body
Digestion and absorption
Heat
Energy lost in feces
Nutrient molecules in body cells
Energy lost in nitrogenous waste
Carbon skeletons
Cellular respiration
Heat
ATP
Biosynthesis
Cellular work
Heat
Heat
62
Metabolic rate

• Amount of energy an animal uses in a unit of time
• Torpor
• Physiological state of low activity with low
  metabolism
• Hibernation
• Long term torpor