Final Exam

What is the primary function of myosin in the muscle contraction process?

motor protein that interacts with actin filaments during muscle contraction.

heads bind to actin and perform power strokes by using ATP, pulling actin filaments inward and causing the muscle to contract.

Describe the layers of a long bone and their functions.

Periosteum: Outer fibrous layer providing protection and a surface for tendon and ligament attachment.

Compact bone: Dense layer for strength and support.

Spongy bone: Contains red bone marrow for blood cell production.

Medullary cavity: Hollow chamber filled with yellow marrow for fat storage.

Which bones make up the appendicular skeleton?

Limbs (arms and legs),

pectoral girdle (clavicle and scapula),

and pelvic girdle (hip bones).

List the major bones of the arm, forearm, and hand.

Arm: Humerus

Forearm: Radius and ulna

Hand: Carpals, metacarpals, and phalanges

What is the chemical composition of bone, and how does it contribute to its function?

Organic components: Collagen fibers for flexibility and tensile strength.

Inorganic components: Calcium phosphate and other minerals for hardness and support.

Where does the somatic nervous system exit the spinal cord, and what is the primary neurotransmitter used in the pathway?

Exits through the ventral roots of the spinal cord; the primary neurotransmitter is acetylcholine (ACh).

Afferent nerves (sensory nerves):

Carry sensory signals from the body to the central nervous system (CNS).

Efferent nerves (motor nerves):

Transmit motor signals from the CNS to muscles and glands

Identify the function of the postcentral gyrus in the parietal lobe.

It processes somatic sensory information such as touch, pressure, and pain.

What is the role of glial cells in the central nervous system?

Provide support, protection, and insulation for neurons, as well as maintain homeostasis

What structures are involved in controlling the autonomic nervous system, and where are they located?

Hypothalamus: Regulates autonomic functions from the brain.

Medulla oblongata: Manages vital functions like heart rate and respiration.

Spinal cord: Contains autonomic reflex centers.

What is the role of myelin in the conduction of nerve impulses?

Myelin insulates axons, increasing the speed of nerve impulse conduction through saltatory conduction.

Explain the process of muscle contraction, from action potential to the cross-bridge cycle.

Action potential triggers calcium release from the sarcoplasmic reticulum.

Calcium binds to troponin, exposing actin binding sites.

Myosin heads form cross-bridges with actin and perform power strokes using ATP.

What is an EPSP, and how does it contribute to action potential generation?

An excitatory postsynaptic potential (EPSP) is a depolarization event that brings the membrane potential closer to the action potential threshold.

Compare and contrast skeletal, cardiac, and smooth muscle tissue in terms of structure and function.

Skeletal: Striated, voluntary, multi-nucleated, and attached to bones.

Cardiac: Striated, involuntary, and found in the heart.

Smooth: Non-striated, involuntary, and found in organs.

Describe the role of acetylcholine at the neuromuscular junction.

Acetylcholine binds to receptors on the muscle cell membrane, triggering depolarization and initiating muscle contraction.

What are the main components of a synovial joint, and what is the function of each?

Articular cartilage: Reduces friction and absorbs shock.

Synovial fluid: Lubricates and nourishes the joint.

Joint capsule: Encases the joint, providing stability.

Ligaments: Connect bones and stabilize the joint.

What is the function of the meninges in protecting the brain and spinal cord?

The meninges are protective membranes that cushion the CNS, providing structural support and acting as a barrier against infections.

Identify the function of the thalamus and hypothalamus in the brain.

Thalamus: Relays sensory signals to the cerebral cortex.

Hypothalamus: Regulates homeostasis, emotions, and the endocrine system.

What is the difference between ionic and covalent bonds? Provide an example of each.

Ionic bond: Transfer of electrons (e.g., NaCl).

Covalent bond: Sharing of electrons (e.g., H2O).

What is the process of passive transport, and how does it differ from active transport?

Passive transport: Movement of molecules without energy input (e.g., diffusion).

Active transport: Requires energy to move molecules against their concentration gradient.

What is the function of the sodium-potassium pump in maintaining cell homeostasis?

Pumps 3 sodium out and 2 potassium into the cell, maintaining electrochemical gradients essential for nerve impulses.

What are the components of an atom, and how do they contribute to its overall charge?

Protons: Positive charge

Neutrons: Neutral

Electrons: Negative charge; overall charge depends on the balance between protons and electrons.

how many AP are released in temporal summation?

single AP

how many AP are released in spatial summation?

multiple APs

excitatory indicates...

depolarization

inhibitory indicates...

repolarization

what causes depolarization?

an influx of Na+ when voltage-gated Na+ channels open in the cell membrane

What causes repolarization?

an influx of K- when voltage-gated K- channels open in the cell membrane

AP jumps from...

node to node

acetylcholine acts as a...

triggers the fight or flight response by stimulating the release of norepinephrine

GABA (gamma-aminobutyric acid)

A major inhibitory neurotransmitter. Undersupply linked to seizures, tremors, and insomnia.

relative action potential

a period of time during which you can

trigger an action potential, but it requires more depolarization than normal due to a refractory period

broca's area

controls language expression - an area, usually in the left frontal lobe, that directs the muscle movements involved in speech.

nerve plexus

network of interweaving anterior rami of spinal nerves

Cranial Nerve III: Oculomotor

Motor nerve that innervates four of the extrinsic eye muscles

Passes through the superior orbital fissure to enter the orbit.

Cranial Nerve V: Trigeminal

motor and sensory nerve for face, conducts sensory impulses from mouth, nose, eyes; motor fibers for muscles of mastication. Control of jaw movements

Cranial Nerve VII: Facial

Both - Moves face, tastes, salivates, Sensory information from taste buds on anterior 2/3 of tongue

Proprioceptive information from face and scalp

Motor information for facial expression and closing the eye

Autonomic information for crying and salivation

Cranial Nerve IX: Glossopharyngeal

gagging; swallowing - sensory; taste

Cranial Nerve X: Vagus

Sensory from visceral organs (Heart, Lungs, Digestive system) and smooth muscle contraction.

simple reflex

Controlled at the spinal cord - connecting a two-neuron pathway from the receptor to motor

no interneuron

crossed extensor reflex/complex

when a withdrawal reflex is initiated in one lower limb, the crossed extensor reflex causes extension of opposite lower limb

needs interneuron

dorsal root ganglion (DRG)

associated with the dorsal horns; cell bodies of sensory neurons are located here

ventral root ganglion (spinal cord)

the location where preganglionic sympathetic neurons leave the spinal cord

They are motor neurons that give rise to the function of effector organs.

When the preganglionic sympathetic neurons reach the sympathetic chain ganglia, it was synapse with a post ganglionic neuron, who's axon will leave through the spinal nerve and travel to whichever organ it needs to supply. This is the route the majority of preganglionic sympathetic neurons take.

Exceptions

• Preganglionic sympathetic neurons may not synapse at the sympathetic chain ganglia. It it will go through either upward or downward through the trunk and synapse at a higher or lower level ganglion.

• Some may leave through the ventral root and travel through the chain ganglia without synapsing at them. They will synapse at a different ganglion (ex: celiac ganglion).

• Some may leave through the central root at synapse at the same level ganglia, but the postganglionic neurons will not leave through the central root. It will travel to a higher centre (upper cervical segments or the brain) for decision making (the brain controls autonomic reflexes).

Central Nervous System (CNS)

consists of the brain and spinal cord

Peripheral Nervous System (PNS)

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations

what is the difference between sympathetic and parasympathetic nervous system neurons?

Parasympathetic:

-long preganglionic fiber (axon)

-no chain ganglion

-short post ganglionic fiber (axon)

-ACh

Sympathetic:

-short preganglionic fiber (axon)

-has chain ganglion

-long post ganglionic fiber (axon)

-NE

frontal lobes function

control skilled voluntary movements of limbs and trunk

coordinate muscles involved in speech

control voluntary movements of eyes and eyelids

concentration, problem-solving, and planning

parietal lobe function

somatic sensory processing

Sensory areas provide sensations of temperature, touch, pressure, and pain involving the skin.

Association areas function in understanding speech and in using words to express thoughts and feelings

Temporal lobe function

Sensory areas are responsible for hearing

Association areas interpret sensory experiences and remember visual scenes, music, and other complex sensory patterns

occipital lobe function

visual processing

cerebrum function

Largest part of the brain; two hemispheres connected bythe corpus callosum

thinking, personality, sensations, movements, memory

Basal nuclei (basal ganglia) function

Masses of gray matter deep within the cerebral hemispheres

influence complex automatic movements, affects short-term memory

diencephalon function

includes masses of gray matter (thalamus and hypothalamus)

strengthen then distributes sensory information to the appropriate brain center

Brainstem

The oldest part and central core of the brain, responsible for automatic survival functions.

Contains pons, midbrain, and medulla oblongata

Pons function

Management of sleep, arousal, and facial expressions. (4)

Relays impulses between the medulla oblongata and cerebrum; helps regulate rate and depth of breathing

Midbrain function

Contains masses of gray matter and bundles of nerve fibers that join the spinal cord to higher regions of the brain

Contains reflex centers that move the eyes and head; maintains posture

medulla oblongata function

Conducts ascending and descending impulses between the brain and spinal cord;

contains cardiac, vasomotor, and respiratory control centers and various nonvital reflex control centers

Cerebellum function

includes two lateral hemispheres connected by the vermis

process and store information, coordinates voluntary movements (posture, balance, speech)

Sensory neuron

Dendrite, cell body, and axon of a sensory neuron

Conducts an impulse from the receptor into the brain or spinal cord

Interneuron

Dendrite, cell body, and axon of a neuron within the brain or spinal cord

Serves as processing center; conducts an impulse from the sensory neuron to its synapse with a motor neuron

Motorneuron

Dendrite, cell body, and axon of a motor neuron

Conducts an impulse from the brain or spinal cord out to the synapse with an effector

grey matter in brain

consists of unmyelinated cell bodies and dendrites

white matter of brain

myelinated axons

A meniscus can be found in which joint?

Knee

While cupping your hands to hold water, in order to limit the amount leaking through your fingers you would need to perform which action?

Adduction of the fingers.

The cranium is composed of a series of bones

Fused together at sutures.

The bone extending down the distal lateral portion of the leg

Is the Fibula

What bone is referred to as the nasal septum?

Vomer

What major bones does the squamosal suture join?

Temporal and Parietal bones.

All ribs articulate with the sternum.

False

The elbow joint is made by the articulation of

The Olecranon Process of the Ulna joining the Olecranon Fossa of the Humerus.

A coxal bone includes the

Ilium, Ischium, and Pubis.

A long bone is covered externally with a sheath called the_________, whereas the marrow cavity is lined with the_________.

periosteum; endosteum

The major bone forming cells are

Osteoblasts

The glenoid cavity and acetabulum are both

Sockets where condyles of large bones articulate.

The common name of the clavicle is the

Collar bone.

Which of the following is part of the facial bones?

Maxillary bone

Which region of the hip bone is designated in green with a leader line in this picture?

Ischium

What vitamin helps absorb Calcium?

Vitamin D

What is the main mineral that bones store?

Calcium

How many ribs do humans have?

24

The joint between the diaphyses of the radius and ulna is a_________.

syndesmosis

A rounded knob that articulates with another bone is called a(n)_________.

condyle

When_________ become enclosed in lacunae, they become cells called_________.

osteocytes; osteoclasts

How many tarsals are there?

7

Which of the following is found in the palm of your hand?

Metatarsal

The external acoustic meatus is

Part of the Temporal bone and is the ear canal/tube.

When you are sitting, your body weight rests on which of the following?

Ischial tuberosity

Which of the following do costal cartilages connect?

The ribs with the sternum

What hormone gets released when blood Calcium levels are low? What is the impact?

Parathyroid hormone, bones release Calcium.

The diaphysis and epiphysis are portions of a

Long bone.

The scapula contains

The acromion and coracoid processes.

The microscopic bony chamber that houses mature bone cells are called

Lacunae

The cells responsible for removing excess bone tissue after the fracture repair process are

Osteoclasts

Both the foramen magnum and the obturator foramen are

Large holes in bones

The distal end of the Ulna is

The Trochlear Notch.

Cervical vertebrae can be distinguished from other types of vertebrae by the presence of

Transverse foramina