BIOS 044 Parts of the Brain/Final

Cerebrum

Deals with skeletal muscle contraction, center for learning, emotion, memory and perception

Cerebral Cortex

-Component of the cerebrum

-Outer layer of cerebrum

-Involved with perception, voluntary movement and learning

Hippocampus

-Component of the cerebrum

-Structure in the middle of the temporal lobe

-Involved with short term memory

Corpus Collosum

-Component of the cerebrum

-Thick bands of axons

-Enables the right and left cerebral cortices to communicate

Cerebellum

-Coordinates movement and balance

-Helps in learning and remembering motor skills

Thalamus

-Diencephalon major component

-Main input center for sensory information going into the cerebrum

Hypothalamus

-Diencephalon major component

-Control center that includes the body's thermostat and central biological clock

Midbrain

-Component of the brainstem

-Receives and integrates sensory information and sends it to specific regions of the brain

Pons

-Component of the brainstem

-Transfers information between the PNS and the midbrain and the forebrain

Medulla Oblongata

-Component of the brainstem

-Transfer information between the PNS and the midbrain and forebrain

-Automatic functions such as breathing, heart and blood vessel activity, swallowing, vomiting and digestion

Forebrain

Processing of olfactory input, regulation of sleep, learning and any complex processing such as perceiving, producing and understanding

Hindbrain

Involuntary activities and helps coordinate some motor activities

Fusiform

-Tapered on both ends

-Found in seals, penguins and tuna

-Beneficial because water is dense and viscous and this helps animals swim quickly and experience less drag

-Example of how animal form and function are correlated

Tissues

Groups of cells with similar appearance and common function

Organs

Functional units comprised of different types of tissues

Organ systems

Groups of organs that work together

Epithelial tissue

-Covers outside of the body and lines the organs and cavities within the body

-Cells are closely packed

-Different cell shapes correlate to different functions

Connective tissue

-Holds many tissues and organs together and in place

-Sparsely population of cells scattered through an extracellular matrix

-Matrix is web of fibers

Multiple functions of connective tissues

1. Loose holds organs in place

2. Fibrous-found in tendons and ligaments

3. Bone-skeleton

4. Adipose-insulation and fuel

5. Cartilage that offers strong and flexible support

Muscle tissue

-Responsible for nearly all types of body movements

-Filaments of proteins- actin and myosin work together to enable muscles to contract

Types of muscle tissue

1. Skeletal/striated enables voluntary movement

2. Smooth enables involuntary activities

3. Cardiac muscle enables contraction of the heart

Nervous tissue

Functions in the receipt, processing and transmission of information

animals use many organ systems to manage their

-temperature

-glucose levels

-pH

-solute concentration

regulator

uses internal mechanisms to control internal change in the face of external fluctuation

conformer

allows internal condition to change with external changes

homeostasis

maintenance of internal balance even when external environment changes

negative feedback

control mechanisms that "dampens" its stimulus

stimuli registered by which systems

endocrine and nervous

hormone

secreted chemical that travels in body fluids and acts on specific target cells in other parts of the organism

thermoregulation

process by which animals maintain body temperature within normal range

Endothermic

heat comes from the internal metabolism

ectothermic

heat comes from external environment

poikilotherms

Body temperature varies with environmental temperature.

homeotherm

body temperature is constant

Adaptations that help animals thermoregulate

1. insulation

2. circulatory adaptations

3. cooling by evaporative heat loss

4. behavioral responses

5. adjusting metabolic heat production

Insulation

reduces flow of heat between animal's body and environment

circulatory adaptation

-provide major route for heat flow between interior and exterior of body

-vasoconstriction occurs in cold environments (blood bypasses surface of skin so blood returns back to heart without losing too much heat)

-vasodilation occurs in hot environments

Concurrent exchange

-Transfer of heat between fluids flowing in opposite directions and thereby reduces heat loss

Cooling by evaporative heat loss

when the environmental temperature is above that od the body so evaporation (sweating in humans or panting in dogs) keep the body temperature from rising

behavioral responses to hot and cold

hot: animals may bathe, move to cooler areas, change orientation to minimize heat absoprtion

cold: seek warm places when cold, orient towards heat sources or huddle together

thermogenesis

adjustment of metabolic heat production to maintain body temperature

examples: increased muscle activity such as moving or shivering; non-shivering thermogenesis may take place when hormones cause mitochondria to increase their metabolic activity

Neurons

process and transmit information through electrical and chemical signals

Action potential

rapid and temporary change in membrane potential

Membrane potential

voltage difference across a cell membrane which results from the unequal distribution of ions inside and outside the cell; this is measure in millivolts

Phases of action potential

depolarization, repolarization, hyperpolarization

Nerve nets