ch 4 Flashcards
unicellular
- one cell
-depend on immediate external environment - earliest organisms
multicellular
-larger size (100 microns)
-maintains/seeks a favourable external environment
-specialize and contribute to wellbeing of other cells
define tissue
-groups of specialized cells that are similar in structure and have a common function
-may be grouped to form an organ
4 types of tissue
epithelial
connective
muscle
nervous
what does epithelial tissue do
-covers body surfaces and cavities, protects underlaying tissues
-glandular epithelia (cells adapt to form glands)
-tissue development
-functions as stem cells
what is a gland
epithelial tissues specialized to synthesize and secrete products
types of glands
-exocrine-secretes products into hollow organs or ducts
-endocrine-hormones into blood so it goes around body
Epithelial tissue classification
shape
# of layers
shapes of cells in epithelial tissue
squamous-flat, outer surfaces of skin, lines blood vessels, lungs, throat
cuboidal-cube shaped, lining of kidney tubules, glandular tissue
columnar-column shaped, line digestive tract, larynx, certain reproductive organs, may include goblet cells that secrete mucus
classification based on # of layers
simple: single layered
stratified: multiple layers
number of layers: simple (what-adapted for and where)
-adapted for diffusion across cell barriers
-lines glands, and respiratory, digestive, reproductive systems
number of layers- stratified (what and where)
-provides protection
ex. skin surface
what is the purpose for pseudostratified layers
decongestion of cells…allows to pack more stuff in the region
what does the basement membrane do
-structural support to overlying cells
-attaches epithelial layer to underlying connective tissue
*problem here=problem for epithelial cells
where is the basement membrane
-noncellular layer directly beneath epithelial tissue
what is the basement membrane made of
-its noncellular
- proteins secreted by epithelial cells and connective tissues
what do cell junctions do?
hold adjacent cells together
types of cell junctions
-tight junctions (seals plasma membrane together)
- adhesion junctions (spot desmosomes)
- gap junctions (direct transfer of water and ions between adjacent cells)
where, and what are tight junctions
-digestive tract lining, bladder lining
-seal plasma membranes tightly together
- anchored to cytoskeleton
where and what are adhesion junctions
-skin
- flexible and pliable
-movement between cells…allows tissues to stretch and bend
- spot desmosomes
where and what are gap functions
-protein channels that allow movement of materials between adjacent cells
- provides a direct transfer of water and ions between adjacent cells
-bridge gap
- liver, heart, nervous system
functions of connective tissues
-supports and connects body parts
-store fat and insulates
- produces (red) blood cells
- contains cells embedded in the living extracellular ground substance (matrix…which provides strength)
two general types of connective tissue
fibrous
specialized
fibrous connective tissue (what and made of waht)
-provides strength and elasticity
- contains fibers and cells embedded in gel-like ground substance (matrix)
- has cells (fibroblasts, macrophages, lymphocytes and neutrophils)
- has fibers (collagen, elastic, reticular)
what is a ground substance
matrix
what and where is a ground substance
-intercellular material gives the connective tissue its characteristics
- gel-like to rubbery consistency
- contains water, proteins and polysaccharides
what are the fibers in fibrous connective tissue
*collagen fibers-strong, slightly flexible
* reticular fibers - thin interconnective fibers of collagen.. provide internal structure framework for soft organs
*elastic fibers- thinner, can stretch
what are soft organs
liver, spleen, lymph nodes
4 general types of fibrous connective tissue
*loose
*dense
*elastic
*reticular
loose fibrous connective tissues (called what and where-inter…)
-called areolar connective tissues
- surrounds internal organs, muscles and blood vessels
- few collagen and elastic fibers..no pattern
dense fibrous connective tissue forms what
- forms tendons, ligaments, deeper layers of skin
- many collagen fibers in parallel agreement
elastic fibrous c.t
-surrounds hollow organs (stomach and bladder) that change shape or size regularly
- many elastic fibers
reticular fibrous c.t
- makes up internal framework of soft organs and the lymphatic system
types of specialized c.t.
-cartilage (transitional tissue from which bone develops)
- bone (forms skeleton)
- blood (transports materials)
- adipose tissues (fat cells)
what does cartilage do (specialized ct)
*transitional tissue from which bone develops
*maintains shape of nose and ears
*protects and cushions(ground substances contains water for cushioning) joints and vertebrae
what is cartilage made of (specialized ct)
*dense c.t. of collagen fibers
*of chondrocytes (mature cells)
*ground substances thats made by chondroblasts
why is cartilage slow to heal when injured (specialized ct)
NO blood vessels
what do bones do (specialized ct)
forms the skeleton
what is in bones (specialized ct)
*few living cells
*matrix (ground substance) composed of calcium phosphate
*tons of blood vessels
what is in blood (specialized ct)
plasma (fluid matrix)
cells (derived from stem cells in bone marrow)
*white blood cells - defends body…immune defense
*red blood cells- transports oxygen and carries wastes away
*platelets-blood clotting
what does blood do (specialized ct)
transports materials
composition of blood (specialized ct)
plasma 55%
white blood cells and platelets 4%
red blood cells 41%
adipose tissue (specialized ct) function
- fat storage
- cushioning
*insulation
what are adipose tissues composed of (specialized ct)
*few fibers, very little ground substance, mostly cells
*adipocytes-fat ells store fat in vacuoles
what does ground substance do
fills the spaces between fibers and cells
provides support, hydration and cushioning to the tissues
where is adipose tissue located (specialized ct)
under skin
around internal organs
what do muscle tissues do and the types of muscle tissues
*contract to produce movement
1. skeletal muscle
2. cardiac muscle
3. smooth muscle
what are/how are muscle cells arranged
*muscle cells=muscle fibers
*long and thin
*arranged parallel to eachother
what do skeletal muscles do
*contract to move body parts
*connect to tendons which attach to bone
what are skeletal muscle made of
*thousands of muscle fibers arranged in parallel
*fibers have multiple nuclei
*activated by nerves
how are skeletal muscles stimulated?
*by motor neurons that synapse at a neuromuscular junction “motor end plate”
how do skeletal muscles start?
*as cells…undergoes fusion and creates myotube
cardiac muscle location and composition
*only in heart
*made up of shorter cells, blunt-ended, one nucleus per cell
role of gap junctions in heart (cardiac muscle)
*allow direct electrical connection between adjoining cells
*enables coordinated contraction of the entire heart
is a cardiac muscle moving voluntarily
no. involuntary-heart contracts rhythmically entirely on its own
what do smooth muscles do
surround hollow structures
aka. blood vessels, digestive tract, uterus, bladder
characteristics of smooth muscles
*slim cells that come together at ends
*one nucleus per cell
*has gap junctions that enable coordinated contraction
*involuntary
*self regulating
what do nervous tissues do
transmit impulses
communication network including brain, spinal cord and nerves
what is a neuron
specialized nervous system cell
what does a neuron do
generates and transmits electrical impulses
structural components of a neuron
*cell body-nucleus and most of the cytoplasm
*dendrites-cytoplasmic extensions from cell body, receives signals from other neurons
*axons-transmits electrical impulses long distances
glial cells function
*glue of the brain
*surrounds and protects neurons
*provides nutrients to neurons
*SUPPORTIVE CELLS OF CNS
what is the CNS (brain and spinal cords) encased in?
bone
what does myelin act as
an insulator
what is part of the peripheral nervous system
*cranial nerves
* spinal nerves
* sensory organs (eyes, nose, tongue, ears and skin)
what is an organ
structures composed of 2 or more tissue types joined together to perform specific functions
-can have multiple functions
what is the human body organized by
organ system
what is an organ system
group of organs that service broad functions important to the survival of an individual or the species
* 11 organ systems in the human body
ex. kidneys are an organ system bc of its detoxification and blood pressure regulating properties
what are the two cavities
anterior cavity
posterior cavity
anterior cavity has which other cavities in it and what is it divided by
*thoracic cavity…two pleural cavities (contains a lung each) and pericardial cavity (encloses the heart)
*divided by the diaphragm
the posterior cavity contains which cavities and what lines the body cavities
*cranial cavity
*spinal cavity (vertebral canal)
*tissue membranes (serous membranes) lines body cavities
what do tissue membranes do/ what are they
*lines body cavities
* layer of connective tissue plus layer of epithelial cells
what are the 4 types of tissue membranes
*serous membrane
* mucous membrane
* synovial membrane
* cutaneous membrane
what do serous membranes do
*line and lubricate internal body cavities
* reduce friction between organs
what do mucous membranes do
*lines airways, digestive tract and reproductive tract
* lubricates surface, capture debris
what do synovial membranes do
*lines spaces in movable joints
what do cutaneous membranes do
*forms outer covering (skin)
3 body planes
midsagittal - left and right
frontal (coronal) - front and back
transverse -top and bottom
anterior
front
posterior
back
proximal
nearer to body trunk
distal
farther from body trunk
superior
above or directed upward
inferior
below or directly downward
what does the integumentary system include
skin, hair, nails, glands
functions of the integumentary system
*protection (dehydration, injury)
*defense against microorganisms
*regulated body temp
*makes vitamin D
*sensation
what does the skin consist of (the layers)
epidermis-outer layer
dermis-under epidermis
characteristics of epidermis
*layers of stratified squamous epithelial cells
*no blood vessels
*always replaced
*two cells- keratinocytes and melanocytes
what are basal cells
actively dividing keratinocytes at base
what is a keratinocyte
tough waterproof protein
what is a melanocyte
*dark pigment (melanin)
*protects against UV
what is the dermis made of and what does it do
*dense connective tissue…collagen, elastic and reticular fibers
*supports tissues
what do fibers do and examples (dermis)
*provide strength and elasticity
- collagen and elastic
what cells are in the dermis
*fibroblasts (most of them)
* mast cells
* white blood cells
* fat cells
accessory structures of dermis
*hair
*smooth muscle (arrector pili)
*sebaceous glands
* sweat glands
*blood vessels
* sensory nerve endings
location of hair
shaft above surface
root below surface in hair follicle
(follicle-sheath of several cell layers that supports root)
where and what do smooth muscles do (hair)
*arrector pili
* hair follicle
* raises hair ex goosebumps
sebaceous glands function
secretes sebum-moistens and softens skin
what do sweat glands do
*secrete sweat to regulate temp
*antimicrobial peptide that protects against bacteria
what do blood vessels do
supply nutrients, remove waste, assist in temp regulation
what do sensory nerve endings do
detect heat, cold, touch, deep pressure, vibration
how is vitamin D activated
by the liver and kidneys
what is interstitial fluid and what does it do
*clear fluid thats in between cells
- source of nutrients
- repository for wastes
- must remain constant to sustain life
what is homeostasis and how is it maintained
conditions must stay about the same within an internal environment
*negative feedback
what is a negative feedback control system and the components of it…and an example
*deviation from normal are detected and counteracted
components:
- controlled variable
- sensor (receptor)… monitors
- control center
- effector
ex. maintaining core body temp
what do controlled variables do (neg feedback)
any physical or chemical property that might changes and needs to be controlled to keep homeostasis
what do sensors (receptors) do (neg feedback)
monitors current value for controlled variable and sends info to control centre
what do control center do (neg feedback)
receives input from senor, compares value to set point, signals the effector if necessary
what do effectors do (neg feedback)
takes action to correct the imbalance, based on information from the control center
what does positive feedback do
amplifies events
ex. childbirth
*not a mechanism for maintaining homeostasis
