Functional Anatomy

The human nervous system is divided into how many parts, and what are they?

• 2

• Central Nervous System

• Peripheral nervous system

Neurons

• Nerve cell

• Receive, conduct, and transmit electrochemical signals

• 1 neuron can receive signals from 100

Glial cells

physical and structural support for neurons

How many neurons and glial cells in humans

• 86 billion

• 100 billion

List all the parts of the neuron

Soma body, dendrites, mylin sheaths, axon, Axon terminals

Soma body

is responsible for maintaining the cell's health and function by housing the nucleus and organelles. It integrates signals received from dendrites and determines whether to send an action signal down the axon.

Dendrites

Where signal is received

myelin sheath

a protective layer that surrounds nerve fibers, allowing electrical impulses to travel quickly and efficiently between nerve cells. It also helps maintain the strength of these signals as they move along the axon, similar to insulation on electrical wires.

Axon

is responsible for transmitting electrical impulses, known as action potentials, away from the cell body to other neurons

Axon terminals:

send out signals through neurotransmitters

Parts of the Central nervous system

Brain and spinal cord

Types of neurons in the Central Nervous System

1. Sensory/ afferent neurons

2. Motor/ efferent neurons

3. Interneurons

Sensory/ afferent neurons

• Detects changes in the internal or external environment.

• Sends messages to the CNS

Motor/ efferent neurons

• controls muscle contraction or gland secretion

• sends messages away from the CNS

Interneuron

helps transmit signals between the sensory neuron and the motor neuron

Parts of the peripheral nervous system

everything except for the brain and spinal cord

Subsections of the peripheral nervous system

• Somatic nervous system

• Automatic nervous system

Somatic Nervous system

• Receive sensory info from sensory organs and controls movement of muscles

• controls spinal and cranial nerves

Autonomic Nervous system

Regulates the involuntary physiological processes to maintain the body’s internal balance or homeostasis.

Things regulated by ANS

• Dilation of pupils

• sneezing

• monitoring light level in the eye, changes in blood pressure, and heart rate

• sweating when exercising

• movement of food through the gut,

• breathing rate

Subsections of Autonomic Nervous System

• Sympathetic

• Parasympathetic

Sympathetic system (energy? when? where are the nerves concentrated?)

• Energy expenditure

• “Fight or flight”

• Nerves concentrated in the small of the back and chest area of the spinal cord

Parasympathetic system (energy? when? where are the nerves concentrated?)

• Energy conservation

• “Rest and digest”

• Nerve concentrated in cranial and lower back region of the spinal cord.

Sympathetic and parasympathetic systems

counteract eachother.

Peristalsis

movement of food through digestive system

What does Sympathetic system do?

• Increase heart rate, blood pressure, blood flow to skeleltal pressure, sweating

• Decreased saliva production, blood flow to digestive organs, peristalsis

• Bronchodilation

• Dilation of pupils

What does the parasympathetic system do?

• Decreases heart rate, blood pressure, blood flow to skeletal muscle, sweating

• Increases saliva production, blood flow to digestive organs, peristalsis

• Bronchoconstriction

• Constriction of pupils

CNS Protection

• Cerebrospinal fluid

• Meninges

• Blood-brain barrier

Cerebrospinal fluid

• circulates through the ventricles, spinal cord, and subarachnoid space

• Flows through the lateral ventricles, 3rd and 4th ventricles.

What produces CSF?

Choroid plexus

Meninges. what are they

• Dura: closest to the skull

• Arachnoid membrane: where the CSF membrane

• Pai meter: thin layer adheres to the brain

Blood Brain Barrier

• Impedes passage of many toxic substances from the blood to the brain

• Capillaries are tightly lined compared to the rest of the body’s capillaries

Brain blood supply

• Carotid arteries - either side of the neck

• Vertebral arteries - travel up through the back of the skull

Dorsal and Ventral

Dorsal refers to the back or upper side of an organism, while ventral refers to the front or lower side.

Medial and Lateral

Medial refers to a position closer to the midline of the body, while lateral describes a position further away from the midline. For example, the arms are lateral to the torso, and the nose is medial to the ears

Superior and inferior

• Position closest to the head

• position closest to the feet.

Planes of Section

• Ways of cutting the brain

• generates 2-dimensional representations of a 3-dimensional brain

How many planes of section and what are they? What directions do they show?

• Coronial(frontal)

• sagital

• Horizontal (axial)

Dependent variable

dependent variable is the outcome or effect that is measured in an experiment