Anatomy Exam 3 Content

Chapters 13, 9-11

Neurology

The study of the nervous system that includes the brain, spinal cord, and nerves.

Central Nervous System

Confined within the dorsal cavity, includes the brain and spinal cord.

Peripheral Nervous System

Includes cranial, peripheral, and spinal nerves, divided into the somatic nervous system and autonomic nervous system. Contains sensory and motor neurons.

Neurons

Functional cells of the nervous system that include fibrous extensions called dendrites and axons.

Dendrites

Neuron fibers that function as receptors and conduct impulses to the cell body, highly branched.

Axons

Neuron fiber that conducts impulses away from the cell body to another neuron, gland, or muscle.

Myelin Sheath

White, fatty substance that insulates and protects some axons.

Schwann Cells

Entire cells wrapped around the axon in the PNS.

Synapse

Tiny gap where impulses transfer at junction points between cells.

Synaptic Cleft/Node of Ranvier

Tiny gaps in the myelin sheath.

Neuroglia/Glial Cell

A support cell that surrounds the neuron.

Nerve

Many neurons bundled together in the PNS.

Tract

Many neurons bundled together in the CNS.

Fascicles

Organized nerves/tracts bound together by connective tissue.

Sensory/Afferent Neurons

Conduct impulses to the spinal cord and brain.

Motor/Efferent Neurons

Carry impulses from the CNS to muscles and glands.

Interneurons/Central/Association Neurons

Carry impulses from place to place within the CNS.

Bipolar Neurons

Contain a single dendrite at one end and a single axon on the other end.

Multipolar Neuron

Contain several dendrites at one end and a single axon on the other end.

Spinal Cord

Link between spinal nerves and the brain, coordinates actions that do not involve the brain, extends from the foramen magnum to the last lumbar rib, cauda equina, filum terminal.

Cauda Equina

Individual nerves that fan out from the end of the spinal cord like a horse’s tail within the vertebral canal.

Filum Terminal

Non-nervous tissue tip that stabilizes the distal spinal cord.

Myelinated Axons

Axons surrounded by white matter/myelin sheath.

Encephalon

Brain

Gyri

Elevations in the brain tissue.

Sulci

Furrows in the brain tissue.

Brain: Ventricles

4 cavities within the brain: right lateral, left lateral, 3rd ventricle, 4th ventricle.

Choroid Plexus

Capillaries that line each ventricle and produces cerebrospinal fluid.

Cerebrospinal Fluid

Circulates around the brain and spinal cord to support nervous tissue and cushion in the event of shock, deposited into the subarachnoid space of the meninges.

Meninges

3 layers of protective membrane that surround the brain and spinal cord: Pia Mater, Arachnoid Mater, Dura Mater, (Subarachnoid Space).

Pia Mater

Inner layer of the meninges.

Arachnoid Mater

Middle layer of the meninges loosely attached to the pia mater to form space for the cerebrospinal fluid.

Dura Mater

Outermost layer of the meninges that is fused to cranial bones.

Subarachnoid Space

Space between the layers of the meninges to allow cerebrospinal fluid to flow.

CNS: Parts of the Brain

Cerebrum, Diencephalon, Brain Stem, Cerebellum.

Cerebrum

Largest and most superior portion of the CNS. Divided into left and right hemispheres by a longitudinal fissure.

Corpus Callosum

Bridge between the 2 hemispheres of the cerebrum.

Cerebral Cortex

Thin layer of grey matter that covers each hemisphere of the cerebrum, responsible for conscious thought, reasoning, and abstract mental functions.

4 Lobes of the Cerebrum

Frontal, parietal, temporal, occipital.

Cerebrum: Frontal Lobe

Involved in thinking, memory, behavior, and movement.

Cerebrum: Parietal Lobe

Involved with language and touch.

Cerebrum: Temporal Lobe

Involved with hearing, learning, and feelings.

Cerebrum: Occipital Lobe

Involved with sight and associating sight with meaning.

CNS: Diencephalon

Located between the cerebral hemispheres and the brain stem, includes thalamus and hypothalamus.

Thalamus

Sorts out all sensory impulses and directs them to certain areas of the cerebral cortex.

Hypothalamus

Control center for body temperature, food intake, and water balance.

CNS: Brain Stem

Most inferior portion of the brain that connects other regions to the spinal cord, responsible for breathing, heart rate, and temperature. Divided into 3 sections: Midbrain, Pons, and Medulla Oblongata.

Brain Stem: Midbrain

Center for certain eye and ear reflexes.

Brain Stem: Pons

Important connecting link between cerebellum and the rest of the nervous system.

Medulla Oblongata

Control Center for blood gas levels and blood pressure.

CNS: Cerebellum

Comprised of 2 lateral hemispheres and a middle portion, coordinates voluntary muscles and helps maintain balance and muscle tone.

Somatic Nervous System

Subdivision of the PNS for voluntary control. Ex: skeletal muscles.

Autonomic Nervous System

Subdivision of the PNS for unconsciously controlled/involuntary actions. Ex: smooth muscle, cardiac muscle, glands.

PNS: Spinal Nerves

31 pairs named for vertebra superior to emergence. Attaches to spinal cord by the dorsal/ventral root. branches into posterior and anterior divisions which interlace to form plexuses.

Plexus

Branches of spinal nerves that interlace to form networks.

Dorsal Root

Attaches spinal nerves to spinal cord, sensory nerves.

Ventral Root

Attaches spinal nerves to spinal cord, motor nerves.

5 Plexuses

Cervical nerves, thoracic nerves, lumbar nerves, sacral nerves, coccygeal nerves.

Cervical Nerves

Plexus with 8 pairs of spinal nerves.

Thoracic Nerves

Plexus with 12 pairs of spinal nerves.

Lumbar Nerves

Plexus with 5 pairs of spinal nerves (superior).

Sacral Nerves

Plexus with 5 pairs of spinal nerves (inferior).

Coccygeal Nerves

Plexus with 1 pair of spinal nerves.

PNS: Cranial Nerves

12 pairs that extend from the inferior surface of the brain. Carries 4 types of signals: special sensory impulses, general sensory impulses, somatic motor impulses, and visceral motor impulses.

Special Sensory Impulses

Responsible for smell, taste, vision, and hearing.

General Sensory Impulses

Responsible for pain, touch, temperature, pressure, and vibration.

Somatic Motor Impulses

Controls skeletal muscles.

Visceral Motor Impulses

Controls glands, smooth muscles, and cardiac muscles.

PNS Cranial Nerves: Olfactory

detection of odors, sense of smell.

PNS Cranial Nerves: Optic

Detection of light and color.

PNS Cranial Nerves: Oculomotor

Responsible for the contraction of most eye muscles.

PNS Cranial Nerves: Trochlear

Responsible for diagonal eye movement.

PNS Cranial Nerves: Trigeminal

Sensory nerve of the face and head, motor fibers to muscles of mastication.

PNS Cranial Nerves: Abducens

Responsible for lateral eye movement.

PNS Cranial Nerves: Facial

Controls muscles of expression.

PNS Cranial Nerves: Vestibulocochlear

Responsible for the detection of sound and equilibrium from the inner ear.

PNS Cranial Nerves: Glossopharyngeal

Sensory fibers of the tongue and motor fibers for swallowing.

PNS Cranial Nerves: Vagus

Longest nerve, responsible for motor impulses for organs in thoracic cavity.

PNS Cranial Nerves: Accessory

Responsible for movement in the neck.

PNS Cranial Nerves: Hypoglossal

Controls the tongue muscles.

Angiology

The study of the circulatory system.

Heme

A pigment containing iron, found in red blood cells.

Globin

A protein found in red blood cells.

Biliverdin

A greenish pigmented substance created when bilirubin undergoes chemical changes.

Diapedesis

The process of leukocytes passing through the walls of capillaries.

Blood

Connective tissue, cells move freely and are suspended in extracellular matrix, plasma and liquid matrix. makes up 8% of total body weight.

Functions of the Blood

Transportation, protection, and regulation.

Blood: Transportation

Gases, nutrients, waste products, hormones, and heat from warmer regions of the body.

Blood: Protection

Pathogens and blood loss at injury.

Blood: Regulation

Volume and composition to maintain homeostasis.

Viscosity

A liquid’s resistance to flow.

Blood Characteristics

slightly viscous, slightly alkaline pH, normally 38 degrees Centigrade or 100.3 degrees Fahrenheit.

Blood Constituents

Plasma and Erythrocytes.

Plasma

Liquid portion of the blood made mostly of water formed by erythrocytes, leukocytes, and thrombocytes. makes up 55% of total blood volume, contains dissolved or suspended substances (5%-8%).

Plasma: Dissolved or Suspended Substances

Proteins, clotting factors, antibodies, glucose, amino acids, lipids, electrolytes (Na, K, Ca, Mg), hormones, waste products, drugs, gases.

Plasma: Blood Proteins

Serum albumin, serum globulin, fibrinogen.

Serum

Plasma that has all clotting factors removed.

Erythrocytes

Red blood cells, no nucleus, oxygen bound to hemoglobin, most abundant type of blood cell, circulates for approximately 120 days before deteriorating by liver and spleen (bilirubin).

Leukocytes

White blood cells with prominent nuclei of varying shapes and sizes, active in immune functions. Identified by size, shape of nuclei, and appearance of granules when stained.

Granulocytes

Leukocytes that show visible granules in the cytoplasm, named for the dye they take up: neutrophils (most abundant), eosinophils, and basophils.