Test #2 (Skeletal and Muscular) Flashcards
The long main portion of the bone
a.k.a. body, shaft
Diaphysis
The ends of the bone
Epiphyses
sing. epiphysis, adj. epiphyseal
The regions between the diaphysis and the epiphyses Contains the epiphyseal growth plate/epiphyseal line
Metaphyses
sing. metaphysis
The name for the cartilagenous area within the metaphysis of a growing bone.
Epiphyseal growth plate
When bone growth stops, what exists in place of growth plates?
Epihphyseal line
What do we call the thin layer of cartilage that covers the epiphyses, and what kind of cartilage is it?
Articular cartilage, made of hyaline cartilage.
What is the tough layer of connective tissue that surrounds bone?
Periosteum
What are some other features of the periosteum?
▪ protects, nourishes and heals bone ▪ attachment for tendons and ligaments ▪ outer layer is tough and supportive/protective ▪ inner layer has bone forming cells ▪ well vascularized and innervated
What do we call the space within the diaphysis, and what does it contain?
Medullary Cavity, contains:
1) red marrow (for blood cell formation)
2) yellow marrow (for fat storage)
What part of bone is comprised of 25% water, 25% collagen, 50% mineral salts
Matrix
Bone cells active during normal growth, responsible for healing and cyclical bone replacement are called:
Osteoprogenitor (a.k.a. osteogenic) cells
bone building cells
Osteoblast
mature bone cells
Osteocytes
bone ‘eating’ cells
Osteoclast
the external layer of all bones, which provides protection and support, is called
Compact Bone
a hole through the centre of the osteon through which blood and lymphatic vessels run (like a hole through spaghetti)
Central canal
a.k.a. Haversian canal
Rings of hard, calcified bone matrix around the central canal like rings of a tree.
Concentric Lamellae
spaces between the rings of osteon where osteocytes can be found.
Lacunae
Small channels sticking out (in all directions) from the lacunae, filled with extracellular fluid that allows osteocytes to communicate (extend cell membranes)
Canaliculi
holes which run transversely to connect the inner and outer portions of the bone
Volkmann’s Canals
How is blood supplied to the periosteum and outer compact bone (and how do they enter the bone)?
Through periosteal arteries, which enter the diaphysis at multiple points (Volkmann’s canals).
How is blood supplied to the inner compact bone, spongy bone, and red bone marrow (and how do they enter the bone)?
Through nutrient arteries, which enter the diaphysis via the nutrient foramen.
What types of arteries supply the metaphysis?
Metaphyseal arteries
What types of arteries supply the epiphysis?
Epiphyseal arteries
Bone growth is greater than bone loss in which stage of human development?
From birth to adolescence
How do bones lengthen?
Epiphyseal growth plates
How do bones thicken?
Osteoblasts in the periosteum laying new bone at the periphery
True or false: in young adults, bone loss exceeds bone growth
False, it’s about equal.
From middle age on, bone loss exceeds bone growth
What happens if the Epiphyseal growth plate is damaged in a growing bone?
The growth plate may prematurely fuse and stop growing.
Why does articular cartilage not heal well or quickly?
It’s avascular and anerval
Why is banging your knee painful?
Because periosteum is so well vascularized and innervated.
What’s one thing the bones in your trunk (hips, pelvis, spine, ribs, sternum, skull) have in common?
They all contain red marrow.
the only other bones in your body that contain red marrow are the proximal ends of your femur and humerus
What type of cells differentiate (change into) Osteoblasts?
Osteoprogenitors
What happens when an Osteoblast is finished building?
It changes into an osteocyte, and then it maintains the bone.
Which bones are the ‘Pac Man’ of the bone world (if you damage bone, these come clean it up)?
Osteoclasts
Which spaghetti-like structures are the structural units of compact bone?
Osteons
What does spongy bone have instead of osteon?
trabeculae
Spongy bone is designed for which types of areas?
Places with lower stresses or stresses from different directions.
What are the three functions of the Central Nervous System?
1) Sensory
2) Integrative
3) Motor
What two types of cells are found in nervous tissue?
Neurons and Neuroglia
What are the three basic functions of Neuroglia?
protect, nourish, support (PNS)
Nerve cells are divided into these three basic parts
cell body, axon, dendrite
What is the function of a dendrite?
to receive chemical messages from other cells (input portion of neuron)
what is the function of the cell body of the neuron?
cell processes (protein synthesis)
what is the function of the axon?
output portion of a neuron
the end of an axon divides into many small processes called ___________
axon terminals
Define a stimulus with regards to a Neuron
any change in the environment (internal or external) that is strong enough to stimulate an AP
Structurally, what are the three different types of Neurons
Unipolar
Bipolar
Multipolar
True or false: all motor neurons are multipolar
True
Structurally, what type of neurons are most sensory neurons found in the PNS?
Unipolar
Functionally, how are neurons classified? What are the three types?
They are classified according to the direction in which the AP is conducted with respect to the CNS.
1) sensory aka afferent neurons
2) motor neurons
3) interneurons
Where are the sensory receptors of sensory neurons located?
either at the dendritic ends or just after, within separate cells.
In which type of neurons does the AP propagate away from CNS to effectors?
Motor neurons aka efferent neurons
Which neurons are located primarily in the CNS between the sensory and motor neurons?
Interneurons aka association neurons
What’s the site of communication between two neurons or between a neuron and another type of cell? What are the two types?
Synapses. Electrical and chemical.
APs conduct directly between the plasma membranes of adjacent cells through gap junctions, allowing for synchronization of function, in this type of synapse
Electrical
What do we call the space between the pre-synaptic neuron: the neuron sending the signal, and the
post-synaptic neuron: the neuron receiving the signal?
The synaptic cleft
What do we call a chemical released by the pre-synaptic neuron to affect(excite or inhibit) the post-synaptic neuron(s) or effector (muscle/gland)?
Neurotransmitter
Continuation of AP across a synaptic cleft is less likely if the neurotransmitter is ____________ than if it is _____________
inhibitory, excitatory
Name the 4 examples of common neurotransmitters we were given and whether they excitatory or inhibitory.
acetylcholine (excitatory)
gamma-aminobutyric acid (inhibitory)
dopamine: excitatory or inhibitory (depending on the receptor)
serotonin: excitatory or inhibitory (depending on the receptor)
Which neurotransmitter helps regulate emotional
responses, addictive behaviours, skeletal muscle tone?
Dopamine
Which neurotransmitter helps regulate sensory perception, temperature regulation, mood, sleep, appetite
Seratonin
With injury and/or disease, which type of cells multiply to fill the spaces formerly occupied by neurons?
Neuroglia
Which type of Neuroglia are able to provide energy substrates, and help to form the blood-brain barrier?
Astrocytes
Which type of Neuroglia form/maintain the myelin sheath of CNS neurons
Oligodendrocytes
These Neuroglia are phagocytic cells that remove debris, phagocytize microbes.
Microglia
Which type of Neuroglia line the cavities of the brain and spinal cord, and produce/assist in the circulation of cerebrospinal fluid?
Ependymal cells
What is the name of the specialized barrier that prevents the passage of materials from the blood and the brain (and its surrounding fluid). It protects the brain from harmful substances and has a thick basement membrane, tight junctions.
Blood-brain barrier
A clear, colourless fluid that circulates around the brain and spinal cord - it protects the brain and spinal cord from injury.
Cerebrospinal Fluid
What Neuroglia exist in the PNS? What are their functions?
Schwann cells. They encircle axons in the PNS, form the myelin sheath of PNS axons, and are involved in the regeneration of PNS axons
Cranial nerves and their branches, spinal nerves and their branches, ganglia, enteric plexuses, and sensory receptors are all examples of
Structures of the PNS
A cluster of neuronal cell bodies in the CNS is called a
Nucleus
A cluster of neuronal cell bodies in the PNS is called a
Ganglion
A bundle of axons in the CNS is called a
Tract
a bundle of axons in the PNS is called a
Nerve
The spinal cord is connected to the periphery by ________ nerves
Spinal
the brain is connected to the periphery by __________ nerves
cranial
Collections of cell bodies and unmyelinated nerve fibres in the CNS are called
Grey matter
Collections of myelinated axons in the CNS are called
White matter
The spinal cord extends from the ___________ to the ___________
Brain stem to the 2nd lumbar vertebra
After the 2nd lumbar vertebra, the spinal cord tapers into the
Conus medullaris
The roots of the spinal nerves below the conus medullaris
Cauda Equina
Name the 2 grooves that divide the white
matter of the spinal cord into right and left sides.
anterior median fissure and posterior median sulcus
The small tube in the centre of the Spinal Cord that contains Cerebrospinal fluid
Central canal
Part of the grey matter of the spinal cord where axons of incoming sensory neurons and interneurons enter.
Posterior (dorsal) horn
Part of the grey matter of the spinal cord where outgoing motor pathways exit
Anterior (ventral) horn
lateral horn: present in thoracic, upper lumbar, sacral portions, they contain _____________
Sympathetic nuclei
Name the three regions of the white matter of the spinal cord
anterior (a.k.a. ventral) columns
posterior (a.k.a. dorsal) columns
lateral columns
Continuous with the Spinal Cord, this is the part of the brain between the SC and the diencephalon.
The brain stem
Part of the brain stem that contains centres (nuclei) for the control of heart rate, blood pressure, breathing, swallowing, and vomiting
Medulla Oblongata
Part of the brain stem that contains centres for the control of breathing
Pons
Part of the brain stem that contains centres for reflex visual activities (e.g. tracking moving objects, scanning stationary objects), hearing. Also contains nuclei called the substantia nigra – neurons that make dopamine extend from it.
Midbrain
A net-like formation of neural tissue that spreads throughout the brain stem
Reticular formation
Contained within the reticular formation, this system helps consciousness, maintain attention, prevent sensory overload by filtering out insignificant information, regulate muscle tone
Reticular Activating System
Area of the brain posterior to the brain stem, this smoothes and coordinates skeletal muscle contraction, regulates posture and balance.
Cerebellum
Part of your brain that includes the hypothalamus, thalamus, and epithalamus
Diencephalon
Part of the diencephalon responsible for
homeostasis, controls and integrates the autonomic nervous system, hormone production, emotion and behaviour (with the limbic system), eating, drinking,body temperature,circadian rhythm (a 24 hour cycle in the biochemical, physiological and/or behavioural processes of living things)
Hypothalamus
The major relay station for most sensory input to the cerebral cortex.
Thalamus
contains the pineal gland, involved in smelling (especially emotional responses to smells)
Epithalamus
Part of the brain divided into 2 halves or hemispheres (right and left)
Cerebrum
Cerebrums outer rim of grey matter, contains sensory areas involved in perception and motor areas involved in the execution of voluntary movements.
Cerebral Cortex
Cerebrums inner layer of white matter, contains areas that deal with more complex functions like memory,
emotions, reasoning, will, judgment, personality traits, intelligence.
Association Areas
Grey matter nuclei deep within the white matter of the Cerebrum, helps to regulate the starting and stopping of movements, control subconscious contraction of skeletal muscles, suppress unwanted movement and set resting muscle tone
Basal Nuclei (Basal Ganglia is commonly used but less ‘correct’ because gaglia apply only to PNS)
Brain structure involved in emotion, smelling and memory, it includes parts of the hypothalamus, the hippocampus, amygdala, and other nearby
structures.
The limbic system
People who have suffered damage to this part of the brain often have trouble with starting and stopping movement.
Basal Nuclei (basal ganglia)
Structure in the brain that functions in memory (encoding, consolidation, and retrieval). Very important in converting short term memory into long term memory
Hippocampus
Structure in the brain that’s important in emotional function (esp. fear)
Amygdala
Tough outer layer of connective tissue that encircles the brain and Spinal cord (meninges)
Dura mater
Middle layer of connective tissue that encircles the brain and Spinal cord (meninges)
Arachnoid membrane
Inner layer of connective tissue that encircles the brain and Spinal cord (meninges)
Pia mater
The adipose and CT-filled space between the wall of the vertebral canal and the dura mater.
Epidural space
Meninges cover the brain/SC up to what point?
Up to the point where the nerves exit the spinal cord
Interstitial fluid-filled space between the dura mater and arachnoid membrane
Subdural space
CSF filled space between arachnoid membrane and the pia mater.
subarachnoid space
paths of communication between the brain and the periphery are called
Cranial nerves
paths of communication between the SC and the periphery are called
Spinal nerves
There are __ pairs of spinal nerves
31
How are the pairs of spinal nerves numbered?
according to the region and level of the vertebral
column from which they emerge
Spinal nerves C_ – C_ exit the spine above their corresponding vertebra.
C1-C7
Spinal nerve C_ exits between C_ and T_ vertebrae
C8 exits between C7 and T1 vertebrae
Spinal nerves T_ – L_ exit below their corresponding vertebra
T1 – L5 exit below their corresponding vertebra
innermost CT of a spinal nerve, covers the axon (whether it’s myelinated or not)
endoneurium
middle layer CT of a spinal nerve, covers fascicles (bundle of axons)
perineurium
outermost layer CT of a spinal nerve, covers spinal nerve
epineurium
Subdivision of the PNS in which sensory neurons (a.k.a. 1st order neurons) convey information to the CNS (e.g.
temperature, pressure, pain …) and motor neurons conduct impulses (signals) from the CNS to skeletal muscles only
Somatic Nervous System
Subdivision of the PNS that monitors (sensory) and controls (motor) body activities (cardiac, smooth muscle, glands) automatically
Autonomic Nervous System (ANS)
Subdivision of the Autonomic Nervous System responsible for fight or flight response. Activity comes from being excited, scared, threatened
Sympathetic Nervous System
Subdivision of the Autonomic Nervous System responsible for rest and digest, conserve and restore energy systems, increased digestive and urinary functions
Paraympathetic Nervous System (PaNS)
The balance between sympathetic and parasympathetic activity is called
Autonomic Tone
A few structures receive only _____________ innervation (sweat glands, arrector pilli, kidneys, most BVs, adrenal medullae) – for them, function is determined by increasing or decreasing this type of stimulation
Sympathetic
The major control and integration centre for the ANS
The hypothalamus
Sensory neurons that monitor chemical changes within the gastrointestinal (GI) tract and the stretching of its walls. “gut brain”
Enteric Nervous System
