Bio1152
Chapter
49
Sensory and Motor Mechanisms
A sensory
receptor
converts stimulus energy into a
potential, or a change in the membrane potential, to the
CNS.
sense
stimuli
such as pressure, stretch, motion, and
sound.
detect
solutes in a solution or specific molecules such as
.
receptors detect
electromagnetic
radiation
including
light and
.
In the human ear,
detect settling particles or moving fluid, which are perceived as
sound
in the
lobe
of the cerebrum. The
,
, and
canals in the
ear function in balance and
equilibrium.
Chemoreceptor cells for
(taste) are modified epithelial cells organized into
taste
in the tongue; nerve signals are then sent to the
lobe.
Humans can detect five tastes:
,
,
,
, and
(elicited by glutamate). Much of what humans
taste
is really
Chemoreceptor cells for
(smell) line the upper, mucus portion of the nasal
cavity;
potentials are transmitted to neurons in the
bulb, and relayed to the
lobe.
Vertebrates
eyes
focus light by changing the
shape
of the
. The human retina contains two types of
in the retina:
are sensitive to dim light, while
can distinguish
colors.
Signals from rods and cones travel
from
cells to
cells, whose axons form the optic
and transmit the signal to the
brain.
Review:
Vertebrate eye
Humans have an
endoskeleton
consisting of an
skeleton and an
skeleton, which are connected at
by
, and to muscles
at
.
Review:
Human Axial Skeleton
Skeletal muscles are
attached
to the skeleton in
pairs and consist of bundles of
made of smaller myofibrils, which are composed of overlapping
and
filaments formiog repeating
units.
Review:
Skeletal Muscle Structure
Muscle
occurs when the filaments slide past each other: the "head" of a
molecule binds to an
filament, forming a cross-bridge and
pulling
the thin filament toward the center of the
.
Review:
Muscle Contraction
Bio1152
Chapter
50
An Introduction to Ecology and the Biosphere
Ecology is the study of the
interactions
between
and the
environment,
including both
(nonliving) and
(living)
components.
Biotic factors such as
,
, and other
interactions
among species can affect the distribution of organisms.
factors that affect the distribution of organisms include
sunlight,
,
wind,
water,
and
soil.
is a major influence on the
distribution
of organisms. The angle of the sun changes due to the
of the
Earth,
leading to
climate changes every year.
Large bodies of
water
have a
effect on the climate of nearby terrestrial environments. Lakes experience
seasonal
in temperate regions.
Mountains
can block
winds and cast a rain
on the
side. The biotic and abiotic
factors
determine the nature of broad associations, called
.
biomes are divided into
and
biomes
based on
, and
stratified
into
by light penetration, temperature, and depth.
Lakes
Wetlands
Streams and rivers
Estuaries
Intertidal zones
Oceanic pelagic biome
Coral reefs
Marine benthic zone
Review:
Aquatic Biomes
biomes are largely determined by the
and the types of vegetation adapted to the
and
of an
area.
Tropical forest
Desert
Savanna
Chaparral
Temperate grassland
Coniferous forest
Temperate broadleaf forest
Tundra
Review:
Terrestrial Biomes