Animal structure and function (chap 40)

1
Animal structure and function (chap 40)

2
Introduction

• Anatomy
• Biological form
• Physiology
• Biological function
• Interstitial fluid
• Fluid surrounding the cells

3
Body plan
Mouth
Gastrovascular cavity
Exchange
Exchange
Exchange
1 mm
0.1 mm
A hydra, an animal with two layers of cells
(b)
(a)
An amoeba, a single-celled organism
4
Body plan
External environment
CO2
Food
O2
Mouth
Animal body
Respiratory system
250 µm
Lung tissue (SEM)
Interstitial fluid
Heart
Nutrients
Cells
Circulatory system
Digestive system
Excretory system
100 µm
50 µm
Blood vessels in kidney (SEM)
Anus
Lining of small intestine (SEM)
Metabolic waste products (nitrogenous waste)
Unabsorbed matter (feces)
5
Tissues

• Epithelial
• Connective
• Muscle
• Nervous

6
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

7
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

8
Epithelial tissue

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

9
Epithelial tissue

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

10
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

11
Epithelial tissues
12
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

13
Epithelial tissue

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

14
Epithelial tissue

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

15
Epithelial tissue

• Endocrine glands (ductless glands)
• Hormones
• Secreted into blood stream

16
Glands
17
Connective tissue

• Holds tissues organs together
• Supports, insulates and strengthens
• Derived from mesoderm
• Loosely packed cells
• Scattered in an extracellular matrix

18
Connective tissue

• Matrix
• Composed of a web of fibers
• In a foundation of liquid, jellylike or solid
• Fibers (proteins) are collagen, elastic, or
  reticular

19
Connective tissue

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

20
Connective tissue

• Cells in matrix
• Fibroblasts
• Produce secrete extracellular matrix
• Macrophages
• Engulf foreign bodies debris
• Mast cells heparin

21
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

22
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,

23
Connective tissue
24
Special connective tissue

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

25
Cartilage
26
Bone

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

27
Bone

• Osteoblasts
• Lay down new bone
• Osteoclasts
• Dissolve bone
• Osteons
• Unit of bone structure
• Contains calcified matrix, osteocytes, nerve
  fibers, blood vessels

28
Bone

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

29
Bone
30
Bone
31
Blood

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

32
Blood
33
Blood

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

34
Connective Tissue
Blood
Loose connective tissue
Plasma
Collagenous fiber
White blood cells
55 µm
120 µm
Red blood cells
Cartilage
Elastic fiber
Fibrous connective tissue
Chondrocytes
100 µm
30 µm
Chondroitin sulfate
Adipose tissue
Bone
Nuclei
Central canal
Fat droplets
700 µm
150 µm
Osteon
35
Muscle tissue

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

36
Muscle tissue

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

37
Muscle tissue

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

38
Muscle tissue
39
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

40
(No Transcript)
41
Nerve tissue

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

42
Nerve tissue

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

43
Neurons
44
(No Transcript)
45
Neurons

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

46
Neurons
47
Nervous Tissue
Glia
15 µm
Neurons
Glia
Neuron
Dendrites
Cell body
Axons of neurons
Axon
40 µm
Blood vessel
(Fluorescent LM)
(Confocal LM)
48
Summary

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

49
Summary

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

50
Coordination

• Hormones
• Nervous system
• Homeostasis

51
(a) Signaling by hormones
(b) Signaling by neurons
STIMULUS
STIMULUS
Endocrine cell
Cell body of neuron
Nerve impulse
Axon
Hormone
Signal travels everywhere.
Signal travels to a specific location.
Blood vessel
Nerve impulse
Axons
Response
Response
52
Homeostasis

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

53
Regulation

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

54
Negative Feedback
55
Negative feedback loops

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

56
Negative feedback loops

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

57
Negative feedback loops

• Temperature increase
• Hypothalamus senses deviation
• Sends signals to relieve heat
• Sweating vasodilation
• Reach baseline
• Negative feedback stops response

58
Negative feedback loops

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

59
Thermoregulation
60
Fig. 40-9
(a) A walrus, an endotherm
(b) A lizard, an ectotherm
61
Negative feedback loops

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

62
Regulating Blood Sugar
63
Positive Feedback
64
Positive feedback loops

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

65
Positive feedback loop

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

66
Bioenergetics

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

67
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
68
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