Bio Nervous System

Biology

Neurons

Transmit electrical impulses

Glial Cells

Support both structure and function of neurons

Capillary to Tissue Cells

Water, Glucose, Amino Acids, Oxygen

Tissue Cells to Capillary

Water, Wastes, Carbon Dioxide

Spinal Cord

Column of nerves that runs from the base of the skull down the back of an animal, connecting the brain to the rest of the body; part of CNS; ONLY unconscious processing

Unconscious Processing

Occurs when awake or asleep; Involuntary-can’t intentionally cause/prevent a process; coordinated by brain and spinal cord (secretion by glands, contraction of smooth muscles)

Blinking, breathing, swallowing can be conscious and unconscious processes

Conscious Processing

Occurs when awake only; voluntary-can intentionally carry out a process

Sensory Neurons

transmit sensory information to CNS

Interneurons

Facilitate processing of information

Motor Neurons

Coordinates response to muscles and glands

Dendrite

Finger-like projections act as primary site for receiving sensory information

Cell Body

Contains nucleus and other organelles

Axon

Long, thin extension carries electrical signals

Axon Terminal

Part of neuron that releases neurotransmitters into synapse to transmit signals to other neurons/cells

Schwann Cell

Glial cells that wrap around the axon and form the myelin sheath

Myelin Sheath

Layers of lipid acts as electrical insulator and allows for faster signal transmission along axon/ speeds up electrical impulse (process called saltatory conduction)

Neuromuscular Junction

Port of contact between motor neuron and muscle fiber, nerve transmits electrical impulse to muscle to cause it to contract

Cerebrum

Part of brain that controls voluntary muscle functions and speech, thought, emotions, reading, writing, and learning

Primary Motor Cortex

Region of the cerebrum that controls voluntary movement via motor neurons to skeletal muscles in the body

Central Nervous System

The brain and the spinal cord

Peripheral Nervous System

The nerves outside the brain and the spinal cord

Nerve

Part of peripheral nervous system; bundle of neurons (nerve cells) and supportive tissues surrounded by a protective sheath

Epineurium

Outermost layer of a peripheral nerve

Perineurium

Protective sheath of tissue that surrounds bundles of nerve fibers withing peripheral nerves

Reflex

Automatic, involuntary response to stimulus that occurs through neural pathways in the NS; Benefit - rapid response to stimulus, immediate reactions without conscious thought

Reflex Arc

The basic process of a reflex

1. Receptor - Initial signal activates a sensory receptor

2. Sensory Neuron - Carries the signal from the sensory receptor to the spinal cord

3. Interneuron - Receive and process the information from the sensory neuron before activating a motor neuron

4. Motor Neuron - Exits the spinal cord and stimulates an effector muscle or gland

5. Effector Muscle - Causes the response of the reflex

Cerebellum

Part of brain, located in the back of the head, between the brainstem and the cerebrum; modifies the commands of the cerebral hemispheres to fine-tune the muscle contractions for balance and timing

Functions of Cerebellum

1. Maintenance of balance and posture

2. Coordination of voluntary movements

3. Facilitates motor memory

Ingestion

Process of taking in food of other substance into the body by swallowing

Digestion

Hydrolysis of the large polymer molecules in food into monomers like amino acids, fatty acids, glucose; catalyzed by enzymes in mouth, stomach, small intestine

Absorption

Taking in of the digested molecules by cells in the small intestine (glucose)

Egestion

Removal of undigested food, fluid, old cells from digestive tract lining; large intestine absorbs water from waste, turning it into stool; stool is stored in the rectum until it’s eliminated through the anus

Alimentary Canal

Long tube of organs of the digestive system that runs from the mouth to the anus; contains muscles that help move food through digestive system

Smooth Muscles

Line walls of the alimentary canal; contract and relax involuntarily in a process called peristalsis, moves food through the digestive tract in one direction

Skeletal Muscles

Found in the mouth, pharynx, and external anal sphincter; allow for voluntary control over swallowing and egestion

The Central Nervous System Controls

Processing of sensory information about food, triggering salivary glands and stomach prepares for food

Swallowing and movement of food from mouth into the esophagus

Egestion of feces from rectum via the anus

Enteric Nervous System

Mesh-like system of neurons within the walls of the alimentary canal; acts independently of the CNS (“Brain of the Gut”)

Enteric Nervous System Controls

Local blood flow and secretion of digestive juices from glands

The muscles controlling peristalsis

The vomiting reflex