Exam 3 - Notes
Chapter 40
Intro to Animal Structure(Form) & Function
Key concepts
- organization of animal bodies
- the relationship between structure and function
- homeostasis
All Animals:
- Exchange materials with their surroundings
- Obtain energy from organic molecules
- synthesize complex molecules
- reproduce themselves
- detect and respond to signals in their immediate surroundings
Levels of Animal Organization
- Cellular
- Phylum Porifera
- Tissue
- Phylum Cnidaria
- Phylum Ctehotophora
- Organ System
- All advanced animal groups
Internal Organization of Animals
- Cells with similar properties group together to form tissues
- Tissues combine together to form organs
- Organs are linked together to form organ systems
- Organ Systems form an organism
Tissues
Tissue
- An association of many cells that have a similar structure and function
Types
- Epithelial tissue
- Connective tissue
- Muscle tissue
- Nervous tissue
Epithelial
- Sheets of densely-packed cells that:
- cover the body or enclose organs
- line the walls of the body cavity and organs
- Specialized to protect and secrete/absorb ions and organic molecules
- cells have a variety of shapes
- cuboidal
- squamous
- columnar
- arranged to form different types of tissues
- simple
- one layer
- stratified
- multi layer
- pseudo-stratified
- one layer, but appears stratified
- simple
- All are asymmetrical or polarized
- One side rests on the basal lamina (basement membrane)
- the other faces the environment
Types of Epithelial Tissue
- Simple squamous
- one layer of flat cells
- Simple cuboidal
- one layer of square cells
- Simple columnar
- single layer of rectangular cells
- Pseudo-stratified columnar
- 1 cell thick with all at basement barrier
- Stratified squamous
- multi-layered flattened cells
- Transitional
- stretchable tissue
All may be involved with secretions/absorption/protection
Connective tissues
Connect, surround, anchor, bind, & support
- For extracellular matrix (ECM) around cells
- provides scaffolds for attachment
- protects and cushions
- mechanical strength
- transmit information
- transport
Types of Connective tissue
- Blood
- transport and protection
- adipose (fat)
- insulation, protection, support, and storage
- bone
- support, protections, and movement
- cartilage
- support and flexibility
- loose connective tissue
- holds internal organs in place
- dense connective tissue
- strength and support
Muscle Tissues
Cells specialized to contract, generating mechanical force
Types of muscle tissue
- Skeleton muscle
- attached to bone(via connective tissue) or exoskeleton for locomotion
- elongated fibers
- voluntary control
- striated
- Smooth muscle
- surrounds tubes and body cavities for propulsion of contents
- flattened cells
- involuntary control
- cardiac muscle
- only in the heart
- elongated fibers
- involuntary control
- striated
- branched
Nervous tissue
- complex networks of neurons (nerve cells)
- initiate and conduct electrical signals from one part of the body to another
- electrical signals produced in one neuron may stimulate or inhibit other neurons
- initiate new electrical signals
- stimulate muscle cells to contract
- stimulate glandular cells to release chemicals
- also contains neuro-glial cells
- more numerous than neurons
- provide metabolic support, maintenance, ion balance, and cleaning for the neurons
Organ Systems
10 organ systems that we will cover (not in this order)
Structure and function
- organization of structure(form) can predict the function of a structure
- we will concentrate of the increasing complexity of structural(form), and thus the increasing complexity of organismal function
- most emphasis on vertebrates
Homeostasis
- changing variables in environmental:
- air temperature
- water temperature
- food supply
- water supply
- pH
- O2 Concentration
- Process of adjusting to the external environment and maintaining a stable internal environment
Integumentary System
Apparently there is no chapter/section for this in the book?
Integument
- the skin and all accessory structure (hair, feathers, scales)
Skin
- The largest vertebrate organ
- major part of the integument system
Vertebrate integument and derivatives
Functions
- Protection form abrasion
- protects against water loss
- barrier to disease causing pathogens
- protection from UV light
- temperature regulation
- contains sensory receptors
- excretion (limited)
Vertebrate Integument
- skin and all other accessories
- skin is the largest organ o vertebrates
- skin consists of 2 layers
- epidermis
- dermis
Epidermis
- outer layer
- nutrients diffuse into the epidermis form the dermis
- stratified squamous epithelial cells
Cell types
- langerhans cells
- defensive cells
- Melanocytes
- produce pigment melanin
- skin coloration
- protect form UV light
- Merkel cells
- touch receptors
- Keratinocytes
- primary cell type
- produce insoluble protein Keratin
- amount of keratin increases from the inside to outside
- keratin fill cytoplasm and impairs nutrient diffusion, cell dies
Dermis
- Inner layer of skin
- thinner than dermis
- highly vascularized
- contains:
- sensory structures
- vessels
- nerves
- glands
- Origin of hair/scales/feathers in vertebrates
- Sensory structures
- Meissner's corpuscles
- light touch
- Pacinian corpuscles
- deep vibrations
- Meissner's corpuscles
Sweat Glands
- temperature regulation
- produce sweat (primarily water)
- evaporating cooling
- release of waste ions
- 2.5 million on the body
- release of heat
Sebaceous Glands
- all over body, except palms and soles
- large on face, neck, and upper chest
- produce sebum
- lubricates and soften hair and skin
- water proofing in aquatic mammals
Hypodermis
- subcutaneous layer
- below the dermis
- not a layer of the skin
- contains much adipose (fat) tissue
- females have thicker layer of adipose tissue than males
Function
- body contour
- insulation
- support the skin
Chapter 45 & 46
Digestive System
Key Concepts
- Animal nutrition
- general principles of digestion and absorption of food
- overview of vertebrate digestive systems
- mechanisms of digestion and absorption in vertebrates
Intro to nutrition
- nutrient
- any substance taken in by an organism that is needed for:
- survival
- growth
- development
- tissue repair
- or reproduction
- any substance taken in by an organism that is needed for:
- nutrition
- process of consuming and using food for nutrients
- animals receive nutrients by consuming food
Dietary categories
- basic similarities in organ system function lead to similarities in nutritional requirements
- different animal physiologies can have different nutrient demands
- Herbivores
- eat only plants
- digestive system contains micro-organisms that help digest cellulose
- Carnivores
- eat only animal flesh or fluid
- Omnivores
- eat both
Animals are heterotrophic
- Heterotrophs
- ingest feeders
- cannot manufacture more food
- require already synthesized organic compounds of plants of other animals to supply materials
- survival
- maintenance
- growth
- reproduction
Gut Tracts
Two types
- Blind Gut
- no cavity between gut and body wall
- one opening
- primitive form
- tube-within-a-tube
- flow through digestive tube
- body cavity between git and body wall
- separate opening (mostly)
Digestion
- the breakdown of large molecules into smaller ones
Digestive enzymes (hydrolases)
- carbohydrases
- proteases
- lipases
- nucleases
Food processing in animals
Occurs in Five phases
- Ingestion
- food is taken into the body and moves into a digestive
- digestion
- food is broken down into smaller molecules
- chemical and mechanical
- transport
- absorption
- ions, water, and small molecules are transported into the circulatory system
- egestion
- undigested materials and other waste are passed from the body
- elimination or exceretion
Alimentary canal
- digestive tract or tube
- Gastrointestinal tract
- Five regions of food processing
- Single tube with opening at each end
- contains smooth muscles in walls
- lined with epithelial cells
- synthesize and secrete digestive enzymes
- secrete hormones
- transport digestive materials
- several specialized regions
- different structures for different processes
- storage area
Structure of GI Tract
- some general structure from midpoint of esophagus, to the anus or cloaca
- lumen lined by epithelial and glandular cells
- secretory cells release a protective layer of mucus
- other cells release hormones
- glands release enzymes, acids, water, and ions
- Epithelial cells linked by tight junctions and surrounded by layers of tissue made of smooth muscle, neurons, connective tissues, and blood vessels
- neurons activated by sight and smell of food and presence of food in tract
Region of Reception
Buccal cavity
- mouth and accessory structures
- ingestion site and digestion site
- chemical and mechanical
- jaws, teeth, cheek muscles, tongue, and salivary glands (saliva)
Pharynx
- back of mouth cavity
- point that respiratory and digestive system cross paths
Region of Conduction
Esophagus
-
- tube carrying materials from mouth cavity to the rest of the alimentary canal
- forces/pushes good down
- conducts food from pharynx to stomach
- Peristalsis
- rhythmic wave-like contractions which propel food forward in the GI tract
- No new digestion here
- only chemical continuation from buccal cavity
Region of digestion and storage
Stomach (mostly)
-
- saclike organ evolved for storing food
- muscular nature helps break up food
- partial protein digestion
- regulates rate of emptying into small intestine
- Secretions
- hydrochloric acid
- kills microbes
- dissolves particulate matter
- secreted by parietal cells
- Pepsinogen
- converted to pepsin to begin protein digestion
- secreted by Chief cells
- hydrochloric acid
- Epithelium coated with an alkaline mucus
- carbohydrate digestion continues from mouth
- little lipid digestion happens
- lumen (cavity) stomach
- pepsinogen + HCL -> pepsin (for protein breakdown)
Region of terminal digestion and absorption
Small intestine
- near