Lecture 4 - Human Nervous System

what is the central nervous system

the brain and the spinal cord

what is the peripheral nervous system

all parts of the nervous system found outside of the skull and spinal column

describe the structure of the nervous system

what is the somatic nervous system

the part of the nervous system that controls voluntary movements and sensory inputs (sensory and motor)

what are efferent neurons

carry motor signals to the periperhy

what are afferent neurons

carry sensory information to the CNS

what are cranial nerves?

12 pairs of nerves that emerge directly from the brain (primarily the brainstem), rather than the spinal cord. They control a wide range of sensory and motor functions, mostly in the head and neck.

what are spinal nerves

31 pairs of mixed nerves that emerge from the spinal cord

each spinal nerve connects to the spinal cord trhough

• dorsal root (sensory input)

• ventral root (motor output)

what is the autonomic nervous system

the part of the peripheral nervous system that controls involuntary bodily functions

what is the sympathetic nervous system

the part of the autonomic nervous system that mobilizes energy resources in threatening situations

what is the main neurotransmitter for the sympathetic nervous system?

epinephrine (aka adrenaline)

what is the para-sympathetic nervous system

the part of the autonomic nervous system that promotes calming and energy conservation activities in the body

what is the main neurotransmitter in the para-sympathetic nervous system

acetylcholine

organize the following ANS actions into sympathetic and parasympathetic

Sympathetic

Increase heartbeat

• Dilate pupils (open)

• Stimulate secretion by sweat glands

• Inhibit saliva production

parasympathetic

Decrease heartbeat

• Constrict pupils (close)

• Contract bladder

• Dilate blood vessels in the digestive system

what is autonomic ganglia?

groups of neurons located outside the CNS

what are preganglionic neurons

they run from the CNS to the autonomic ganglia

what are postganglionic neurons

they run from the autonomic ganglia to targets in the body

what is the third major division of the autonomic nervous system

enteric nervous system

what is the enteric nervous system

a third major division of the autonomic nervous system that is a local network of neurons that governs function of the gut and maintains fluid and nutrient balance in the gut

describe Rene Descartes contributions to our understanding of the brain

proposed dualism — humans have a non-material soul as well as a matreial body

what is phrenology

assigned separate functions to different bumps on the skull

describe Broca’s contributions to our understanding of the brain

language ability is restricted to a small area of the brain called Broca’s area

what is cerebral cortex

the outermost layer of the brain—a thin, wrinkled sheet of gray matter that covers the cerebrum

describe all of the anatomic conventions

horizontal: divides the brain into an upper and lower part

sagittal: divides the body into left and right halves

coronal: divides the body into front (anterior) and back (posterior) regions

what is white matter

axons

what is grey matter

cell bodies

what is the difference between white matter and grey matter

axons are myelinated

how does white matter and grey matter function together

white matter allow grey matter to communicate with each other and connects the two hemispheres of the brain

the cortex has 4 lobes…

frontal

parietal

occipital

temporal

what are the primary functions of the 4 lobes in the cortex

frontal: movement and high-level cogntiion

parietal: spatial cognition, sensory processing

occipital: visual processing

temporal: auditory processing, sense of smell, aspects of learning

what is the postcentral gyrus?

is a strip of cortex behind the central cortex that is important for touch

what is the sensory homunculus

the human body maps onto the seomatosensory cortex (part of the parietal lobe)

what is the precentral gyrus

in the frontal lobe, important for motor control

what is the motor homunculus

motor control is somatotopically mapped along the precentral gyrus

describe the basic brain anatomy

Describe the basic developmental stages of the human brain.

25 days — neural tube and divided into three primary vesicles

1. forebrain

2. midbrain

3. hindbrain

50 days — 3 regions further subdivided

• forebrain

  • telencophalon

  • diencephalon

• midbrain

  • mesencephalon

• hindbrain

  • metencephalon

  • myelencephalon

how to remember the sub regions of the hindbrain

myel — marrow, spinal cord

myelencephalon

met — beside/after

metencephalon

what is the primary structure that results from the myelencephalon

medulla

what is the purpose of the medulla

regulates breathing and HR

what are the primary structures that result from the metencephalon

pons (brainstem)

cerebellum

what is the pons

a “bridge” that connects medulla to midbrain

what is the cerebellum

responsible for balance and coordination

how to remember the sub regions of the midbrain

mes — middle

mesencephalon

what is the function of the midbrain

sensroy and motor function

reticular formation, sleep,arousal, temperature control, motor control

how to remember the sub regions of the forebrain

tel — far off distanct

telencephalon

di — two

diencephalon

what are the primary structures that result from the diencephalon

thalamus

hypothalamus

what is the thalamus

replay station for all incoming sensory information

what is the hypothalamus

below the thalamus, contains nuclei with many vital functions (hunger, thirst, temperature regulation, sex, and more)

what is the primary structure that result from the telencephalon

cerebral cortex

what is the cerebral cortex responsible for

higher cortical functioning