Anatomy + Physiology Flashcards
What are the 4 main things a cell contains?
Membrane
Cytoplasm
Mitochondria
Nucleus
Tissue level of organisation
What are the 4 components of it?
Epithelia - cover exposed surfaces, line internal pathways + chambers + produce glandular secretions
Connective - fill internal spaces, provide support, store energy
Muscle - contracts for movement
Neural - conducts electrical impulses + carries info
What is an organ?
A discrete collection of 2 or more tissues cooperatively performing a functions (heart, femur, biceps brachii muscle)
Name and briefly describe the 11 key systems
- Integumentary - protection, sensation
- Skeletal - support, protection
- Muscular - tendons + ligaments = movement
- Nervous - communication
- Endocrine - regulate body processes
- Cardiovascular - distribute blood
- Lymphatic - coordinating a response
- Respiratory - movement of gases, speech
- Digestive - breaking down food = energy
- Urinary - excretion of waste
- Reproductive - formation of life
What are the anatomical landmarks for the following areas?
- armpit, arm, forearm, wrist, hand
- thumb, big toe
- breast, chest
- head, nose, neck
- back, back of elbow, back of knee
Armpit = axilla
Arm = brachium
Forearm = antebrachium
Wrist = carpus
Hand = manus
Thumb = pollex
Big toe = hallux
Breast = mamma
Chest = thoracis
Head = cephalon
Nose = Nasus
Neck = cervicis
Back = dorsum
Of elbow = olecranon
Of knee = popliteus
What is the anatomical position?
Standing
Facing forward
Feet together
Arms by sides
Hands supinated (palms forward)
What are the directional terms for…
1. Closer / further from ORIGIN
2. Away / toward MIDLINE
3. Top / bottom
4. At head / at tail
5. Front / back (2)
- Proximal OR Distal
- Lateral OR Medial
- Superior OR Inferior
- Cranial OR Caudal
- Ventral/Anterior OR Dorsal/ Posterior
What are the 2 terms associated with imaging of a body?
Superficial (at surface) and deep (inside body)
What are the 3 planes?
Frontal = front + back sections - splits posterior + anterior sections
Sagittal = separates left + right
Transverse = top + bottom sections - horizontal in anatomical position
What are the 2 main body cavities + describe them
- Dorsal cavity = brain + spinal cord
- Ventral cavity = thoracic, abdominal + pelvic organs
- thoracic cavity = pleural (around lungs) + pericardial cavity (around heart) = organs move smoothly past each other
- abdominopelvic cavity = peritoneal cavity, abdominal + pelvic cavity (digestive organs)
What is homeostasis + the 2 types of feedback?
Maintenance of a constant internal environment
- negative feedback opposes variations from normal e.g. thermoregulation
- positive feedback exaggerates variations e.g. blood clotting
What are the main roles of the nervous system + what are they performed by?
- Monitors the internal + external environments (via thermo, chemo, baro, photoreceptors)
- Integrates sensory information
- Coordinates voluntary + involuntary responses of many organ systems
- performed by neurons and supported by neuroglia
Name and describe the 2 anatomical subdivisions of nervous system
CNS = central nervous system
- brain + spinal cord
- integrates + coordinates processing of sensory data + transmission of motor commands
- coordinates higher functions
PNS = peripheral nervous system
- includes all neural tissue outside of CNS
- delivers sensory information to CNS
- carries motor commands to peripheral tissues + systems
What are the 4 different types of neurons?
Anaxonic
Bipolar
Unipolar
Multipolar
What is an anaxonic neuron?
- found in brain + special sense organs
- very small
- no anatomical features that distinguish dendrites from axon (no axon)
- Functions poorly understood
What is a bipolar neuron?
- have 2 processes - 1 dendrite and 1 axon with the cell body between them
- rare as only occur in special sense organs
What is a unipolar neuron?
- dendrites + axon are continuous with cell body lying off to one side
- found in most sensory neurons of PNS
What is a multipolar neuron?
- has 2 or more dendrites + a single axon
- most common neurons in CNS
- all motor neurons that control skeletal muscles are multipolar
What are the 2 main roles of the spinal cord?
- major passageway of sensory + motor impulses to/from brain
- integrates info on its own + controls spinal reflexes + automatic motor responses
Describe the rough outline of a spinal cord
- 31 segments (8 cervical, 12 thoracic, 5 lumbar, 5 sacral + 1 coccygeal)
- each segment contains a pair of dorsal root ganglia containing cell bodies of sensory neurons
- dorsal roots bring sensory info to spinal cord
What do ventral roots contain in spinal cord?
Axons of motor neurons
What do the following parts contain in a spinal cord…
- gray matter
- white matter
- contains cell bodies + neuroglia cells
- myelinated + unmyelinated axons
What is a dermatome?
Specific region of a body surface relating to the parts of the body that spinal nerves monitor
Explain the 5 steps regarding a reflex arc
- Arrival of stimulus + activation of stimulus
- Activation of sensory neuron
- Info processing in CNS
- Activation of motor neuron
- Response by peripheral effector
What is the role of Golgi tendon organs?
Senses tension in tendons when a muscle contracts
- has an inhibitive (negative) afferent neuron
- when excessively large forces are generated, feedback from these causes activation of muscle to decrease = PROTECTIVE
What are muscle spindles + what do they do?
Highly specialised encapsulated muscle fibres parallel to normal muscle fibres
- sensitive to changes in length
- afferent neuron wraps around muscle spindle
- efferent neuron (gamma) causes muscle spindles to contract to maintain tension in middle of fibres
- if muscle is stretching rapidly - vigorous contraction to prevent overstretching
Name and briefly describe the 6 key regions of the brain
Cerebrum - conscious thought processes, memory storage + regulation of skeletal muscle contractions
Diencephalon - contains thalamus (relay + processing centre for sensory information) + hypothalamus (controls emotions, autonomic functions + hormone production)
Midbrain - processes visual + auditory info, generates reflexive isolation motor responses
Pons - relays sensory info to cerebellum + thalamus
Medulla Oblongata - relay sensory info to thalamus + brain stem + regulation of visceral function
Cerebellum - coordinates complex somatic motor patterns
What’s are the 2 types of brain protection?
(Physical)
- bones of cranium
- cranial meninges
- cerebrospinal fluid
(Biochemical)
- blood-brain barrier
Explain how cranial meninges + cerebrospinal fluid help to protect the brain
Cranial meninges:
- 3 layers = dura matar, arachnoid matar, pia matar
- continuous with spinal meninges = protects brain from trauma
Cerebrospinal fluid:
- surrounds all exposed surfaces of CNS
- interchanges with interstitial fluid of brain
- cushions, supports + transports nutrients, chemical messengers + waste products
List the 12 cranial nerves
I. Olfactory - smell
II. Optic - vision
III. Occulomotor - eye position during movement
IV. Trochlear - movement of eyes superior oblique muscle
V. Trigeminal - sensory innervation to face
VI. Abducens - abduction of eye to look sideways
VII. Facial - motor innervation to facial muscles
VIII. Vestibulocochlear - hearing, balance
XI. Glossopharyngeal - sensory info to mouth + throat
X. Vagus - heart rate, digestion
XI. Accessory - motor info to sternocleidomastoid + trapezius
XII. Hypoglossal - tongue movement
What is the resting membrane potential - what’s on the outside/ inside etc?
-70mV resting potential
This means there is an excess of +ive charged on the outside (Na+ and Cl-) and -ive charged on inside (K+ and Pr-)
What is the word to describe the resting cell membrane?
Polarised
What does it mean by selective permeability of cell membranes?
Ions can enter/leave the cell with help from channels/ carrier proteins
- leak channels (always open) are more permeable to K+
- gated channels (open/close depending on circumstances)
Describe the passive movement of ions across cell membranes
- K+ move out of the cell and Na+ move into the cell (K+ move out faster)
- the +ively charged outer membrane surface repels K+ ions - At the same time -ively charged inner membrane attracts Na+
- the chemical gradient is stronger than electrical repelling force so K+ still move out - Therefore there is a net loss of +ive ions
- 3 Na+ for every 2K+
What causes changes to membrane potential?
Any stimulus that…
- alters membrane permeability to Na+ or K+
- alters the activity of exchange pump
…will disturb the resting potential
Describe an overview of how chemically gated ion channels work to disturb the resting potential
- The opening of gated Na+ channels increases Na+ entry into the cell
- As the number of +ive charged ions increase on inner surface, the membrane potential shifts towards 0mV
- This is called depolarisation
- When the stimulus is removed, repolarisation occurs to restore the resting membrane potential
What is hyperpolarisation?
When the membrane potential exceeds -70mV
- could be due to opening of gated K+ channels so more K+ leave the cell = more negative inside
What are the 3 main types of gated channels?
Chemically gated = ions
Voltage gated = charges inside/ outside cell
Mechanically gated = pressure
What are graded potentials?
Also called local potentials
- they only affect a limited portion of the cell membrane + cannot spread far from site of replication
Describe the 3 steps involved in graded potentials
- Resting membrane is exposed to chemicals
- Na+ channels open so Na+ enter into cell
- membrane potential rises and depolarisation occurs - Movement of Na+ through channel produces a local current
- this depolarises nearby cell membrane - When stimulus is removed, repolarisation occurs
What are action potentials?
An electrical signal that affects the entire membrane surface
- skeletal muscle fibres + axons have excitable membranes that will conduct action potentials
What must occur for an action potential to be generated?
The membrane must depolarises sufficiently to a level known as the threshold
= all or none principle
Describe the 4 steps involved in generating an action potential
- The membrane is depolarised and exceeds the threshold of -60mV
- Na+ channels are activated and rapid depolarisation occurs (+10mV)
- Inactivation of Na+ channels and activation of K+ channels (as potential reaches +30mV)
- Brief hyperpolarisation + return to normal permeability and resting state
(2-3) absolute refractory period = membrane cannot respond to further stimulation
(4) relative refractory period = membrane can respond but only to larger than normal stimuli
Describe the 4 steps involved in propagating an action potential
- AP in segment 1 depolarises membrane to +30mV
- Local current whereby Na+ spread away from channel = depolarisation of segment 2 to threshold
- Second segment develops an AP (first segment in refractory period)
- Local current depolarises next segment + cycle repeats
What are myelinated axons?
Axon is wrapped in layers of myelin except at nodes
- oligodendrocytes = bundles of much smaller cells around
- Schwann cells = one cell wraps around
What is saltatory propagation?
Continuous propagation cannot occur as depolarisation only occurs at nodes
- an AP jumps from node to node = much faster than continuous propagation
Describe the 4 steps involved in saltatory propagation
- An AP occurs at initial segment
- Local current produces a graded depolarisation that brings the axolemma at next node to threshold
- An AP develops at node 2
- Local current produces a graded depolarisation that brings the axolemma at next node to threshold
What is a synapse + how do info transfer occur?
The site of communication between a nerve cell and some other cell
- info transfer occurs through release of neurotransmitters from synaptic terminal
- occurs in 1 direction
What are the 2 kinds of effects neurotransmitters can have?
Excitatory = causes depolarisation of postsynaptic membrane + promote APs
Inhibitory = causes hyperpolarisation of post synaptic membranes = suppresses APs
What neurotransmitter is released at cholinergic synapses?
Acetylcholine
Describe the steps that occur at cholinergic synapses
- An arriving AP depolarises the axon terminal of a presynaptic neuron
- Ca2+ enter the cytosol of the axon terminal = results in ACh release from the synaptic vesicles by exocytosis
- ACh diffuses across the synaptic cleft + binds to receptors on the postsynaptic membrane. (Sodium channels open producing a graded depolarisation)
- Depolarisation ends as ACh is broken down into acetate and choline by AChE - axon terminal reabsorbs choline from the synaptic cleft and uses it to resynthesise ACh
Aside from acetylcholine, what are the other 4 important neurotransmitters?
Norepinephrine/ noradrenaline = excitatory effect, released by adrenergic synapses
Dopamine = in CNS, both excitatory/ inhibitory effects
Serotonin = regulation of sleep/wake cycle, lack of serotonin = depression
GABA = inhibitory effect to reduce anxiety
What is the function of epithelial tissues?
Layers of cells that form linings of membranes + glands
What are the 2 types of layers of epithelial cells and what are the 4 types of shapes of epithelial cells?
Layers:
- simple = 1 layer
- stratified = many layers
Shape:
- squamous = flat
- cuboidal = cube shaped
- columnar = rectangle
- transitional = can change shape
What is the function of simple and stratified squamous epithelial tissues?
Simple squamous = linings of blood vessels + alveoli
- to reduce friction, assist in absorption + secretion (flat so short diffusion distance)
Stratified squamous = skin
- provides physical protection (lots of cells) against abrasion, pathogens + chemical attack
What is the function of simple and stratified cuboidal epithelial tissues?
Simple cuboidal = glands, ducts (kidney tubule)
- limited protection but good for secretion + absorption
Stratified cuboidal = linings of some ducts (rare) - sweat glands
- protection, secretion, absorption
What is the function of simple and stratified columnar epithelial tissues?
Simple columnar = lining of stomach + intestine
- protection, secretion , absorption
- likely to have microvilli on apical (top) surface
Stratified columnar = small areas of pharynx
- protection
What is the function of transitional epithelial tissues?
Primarily found in the urinary bladder
- permits expansion + recoil after stretching
What is the other kind of columnar epithelial tissue, and what is its role?
Pseudostratified Ciliated Columnar = lining of nasal cavity, trachea + bronchi
- for protection, secretion, move mucus with cilia on apical surface
How are glands classified?
According to shape - tubular, coiled, branched, alveolar
And…
Number of ducts - simple (one) and compound (many)
What are the 3 kinds of glandular secretion?
Merocrine = cell remains intact + release microscopic bubbles
Apocrine = substance accumulates in apical surface of the cell + when secreted the apical portion breaks down + has to be reformed
Holocrine = stratified - cell bursts + releases contents
What are the 3 main things connective tissues contain?
Cells e.g. fibroblasts (produces protein fibres), adipocytes (fat cell) and macrophages (immune cell)
Fibres e.g. collagen, reticular, elastic
Ground substance e.g. fluid (blood + lymph), gel (cartilage), mineral (bone)
What are the first kind of connective tissues to appear in embryos?
Mesenchymal stem cells = partly differentiated cell that can differentiate into other types of connective tissue
What makes up the blood?
Red + white blood cells
Platelets
Both in the fluid / plasma of the blood
What are the 2 types of loose connective tissues - explain where they’re found + their role
Adipose tissue = deep to the skin (at sides, buttocks, breasts, padding around eyes + kidneys)
- provides padding + cushions shocks, insulates + stores energy
Reticular tissue = around the liver, kidney, spleen, lymph nodes, bone marrow
- provides a supporting network
What are the 3 kinds of dense connective tissues - explain where they’re found + their role
Dense regular = between skeletal muscles + skeleton (tendons) + between bones (ligaments)
- provides firm attachment, conducts pull of muscles
Dense irregular = capsules of visceral organs, nerve + muscle sheaths
- provides strength to resist forces applied from many directions + helps prevent over expansion of muscles
Elastic tissue = between vertebrae of spinal column + in blood vessel walls
- stabilises, cushions shocks, allows expansion + contraction
Wheat are the 3 types of cartilage?
Hyaline cartilage = between tips of ribs + bones of sternum, covering bone surfaces at synovial joints
- provides stiff but somewhat flexible support + reduces friction
Elastic cartilage = auricle of external ear
- provides support but tolerates distortion without damage + can return to original shape
Fibrocartilage = pads within knee joint
- resists compression, prevents bone-to-bone contact, limits movement
What are the 4 types of tissue membranes - explain their role + what type of epithelium they have
- Mucous membrane = simple columnar epithelium
- coated with secretions of mucous glands - Serous membrane = simple squamous epithlium
- lines the ventral body cavities - Cutaneous membrane = stratified squamous + cuboidal epithelium
- covers body surface - Synovial membrane
- lines joint cavities + produces fluids within a joint
What’s the different layers of the fasciae?
Superficial fascia = between skin + underlying organs
- made up of areolar + adipose tissues
Deep fascia = forms a strong, fibrous internal framework
- made up of dense connective tissue
Subserous fascia = between serous membranes + deep fascia
- made up of areolar tissue
What are the 3 types of muscle tissue?
Skeletal muscle - under voluntary control
- striated + multinucleated
- controlled via nerves
Cardiac muscle - under involuntary control
- striated
- controlled by pacemaker cells
- intercalated disks allows electrical connections
Smooth muscle - under involuntary control
- not striated
- hormonal control
What are the main functions of the skeletal system?
- supports against gravity
- leverage for muscle action
- protection for soft internal organs
- storage
- blood cell production
What are the 6 shapes of bones (4 key ones)?
Flat bones - internal + external table separated by diploe (parietal bone)
Long bones - longer than they are wide (humerus)
Short bones - Same width as length (carpals, tarsals)
Irregular bones - complex shapes (vertebrae)
Sutural bones - between skull bones
Sesamoid bones - small + develop in tendons
What are the typical features of long bones?
Diaphysis (shaft) - compact dense bone + medullary cavity
Epiphysis (end/ articulating surface) - trabecular spongy bones
Articulating cartilage