A&P Final

What is homeostasis?

ability of the body to maintain a stable internal environment despite changes in external conditions.

Positive Feedback vs Negative Feedback

Positive feedback amplifies changes, leading to a greater response (e.g., childbirth). Negative feedback counteracts changes to maintain stability (e.g., temperature regulation).

Facilitated diffusion vs Active transport

Facilitated diffusion is a passive process that requires no energy, while active transport requires energy to move substances against their concentration gradient.

What is osmosis?

movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration.

Causes of osmosis

differences in solute concentration across a membrane.

Normal plasma osmolarity

280-300 mOsm/kg.

Effect of hyper, hypo, and iso-tonic solutions on osmosis

Hyperotonic solutions cause cells to shrink, hypotonic solutions cause cells to swell, and isotonic solutions do not change cell volume.

Role of the Na+/K+ pump

active transport that helps maintain the electrochemical gradient by pumping sodium out of and potassium into the cell.

What are the 4 basic types of tissues in the human body?

epithelial, connective, muscle, and nervous tissue.

Most diverse and abundant tissue

Connective tissue

Most superficial layer of the epidermis

stratum corneum.

Deepest layer of the epidermis

stratum basale.

Source of keratinocytes

originate from the stratum basale.

Formation of Vitamin D

the skin, liver, and kidneys, activated by UV radiation.

Types of burns

first-degree (epidermis), second-degree (epidermis and part of dermis), and third-degree (all layers including deeper tissues).

Immediate life-threatening risks associated with burns

infection, dehydration, and loss of thermoregulation.

Types of cancer

basal cell carcinoma being the most common, squamous cell carcinoma, and melanoma, with melanoma being the most dangerous.

Two types of bone tissue

cortical (compact) bone and trabecular (spongy) bone.

Types of cells found in bone

osteoblasts (build bone), osteocytes (maintain bone), and osteoclasts (break down bone).

Process used to form the majority of the fetal human skeleton

Endochondral ossification

What is appositional growth?

process by which bones increase in thickness and occurs in both children and adults.

Site of bone growth in length

The epiphyseal plate

Epiphyseal plate vs Epiphyseal line

The epiphyseal plate is made of cartilage (growth plate), and the epiphyseal line is made of bone (indicating that growth has stopped).

Wolff’s Law of Bone

bone adapts to the pressure it is put under

Effect of PTH vs Calcitonin

Parathyroid hormone (PTH) increases blood calcium levels, while calcitonin decreases blood calcium levels.

What triggers the release of PTH and calcitonin?

PTH is triggered by low blood calcium levels, while calcitonin is triggered by high blood calcium levels.

What is a sarcomere?

basic contractile unit of muscle tissue, responsible for muscle contraction.

What type of neuron stimulates skeletal muscle contraction?

Motor neurons

What is the NMJ?

the synapse between a motor neuron and a skeletal muscle fiber.

Structure of the NMJ

The NMJ consists of the axon terminal of the motor neuron and the motor end plate on the muscle fiber.

What is the neurotransmitter at the NMJ?

acetylcholine (ACh).

What is required for muscle relaxation?

active transport of calcium ions back into the sarcoplasmic reticulum.

What happens if AchE is inhibited?

prolonged contraction as acetylcholine remains in the synaptic cleft.

Difference between spastic and flaccid paralysis

Spastic paralysis is characterized by continuous muscle contraction, while flaccid paralysis is characterized by muscle weakness and loss of tone.

Two cell types in the nervous system

neurons (transmit signals) and glial cells (support and protect neurons).

How do neurons communicate?

electrical impulses and chemical signaling via neurotransmitters.

Divisions of the nervous system

central nervous system (CNS) and the peripheral nervous system (PNS).

Components of the CNS

brain and spinal cord.

Subdivisions of the PNS

sensory (afferent) and motor (efferent) divisions.

Gray matter vs White matter

Gray matter consists of neuronal cell bodies, while white matter consists of myelinated axons.

Basics of an action potential

rapid change in membrane potential that propagates along the neuron.

Resting Membrane Potential: is it negative or positive?

negative

Depolarization is caused by which ion?

influx of sodium ions (Na+) into the cell.

Repolarization is caused by which ion?

efflux of potassium ions (K+) out of the cell.

Action potential conduction in myelinated vs unmyelinated axons

saltatory conduction in myelinated axons and continuous conduction in unmyelinated axons; saltatory conduction is faster.

Protective membranes surrounding the brain and spinal cord

dura mater, arachnoid mater, and pia mater.

Four main regions of the brain

cerebrum, cerebellum, brainstem, and diencephalon.

General functions of the cerebrum

higher brain functions, including thought, action, and sensory processing.

Functions of the Frontal lobe

voluntary movement, planning, problem-solving, and emotional regulation.

Functions of the Parietal lobe

process sensory information and integrates it with spatial awareness.

Functions of the Temporal lobe

processing auditory information and memory.

Functions of the Occipital lobe

primarily responsible for visual processing.

Parts of the Limbic System

the amygdala, hippocampus, and hypothalamus, involved in emotion and memory.

Functions of the Diencephalon

the thalamus (sensory relay) and hypothalamus (homeostasis regulation).

Functions of the Brainstem

vital functions, including heart rate, breathing, and blood pressure.

General function of the Cerebellum

voluntary movements, balance, and posture.

Spinal nerves vs cranial nerves

Spinal nerves are 31 pairs, cranial nerves are 12 pairs; both are part of the peripheral nervous system (PNS).

Where does the spinal cord begin and end?

base of the skull (foramen magnum) and ends at the lumbar region (L1-L2).

Cauda equina

bundle of spinal nerves that extends beyond the spinal cord.

Lumbar puncture site

between L3-L4 or L4-L5.

Location of CSF

subarachnoid space surrounding the brain and spinal cord.

What is gray matter made of?

neuronal cell bodies, dendrites, and unmyelinated axons.

What is white matter made of?

myelinated axons, organized into tracts.

Ascending and descending tracts

Ascending tracts carry sensory information to the brain, while descending tracts carry motor commands from the brain.

Which tract is responsible for fine motor control below the neck?

The corticospinal tract

Information carried in ventral and dorsal roots

Dorsal roots carry sensory information to the spinal cord, while ventral roots carry motor information out to muscles.

Nerve plexuses and innervation areas

cervical, brachial, lumbar, and sacral plexuses, innervating respective regions of the body.

Results of spinal cord transection (>C4, T1-L1)

Transection above C4 results in quadriplegia, while transection between T1-L1 results in paraplegia.

Characteristics of ANS

part of the peripheral nervous system and includes the sympathetic and parasympathetic divisions.

Divisions of the ANS

sympathetic (fight or flight) and parasympathetic (rest and digest) divisions.

Characteristics of pre/postganglionic fibers

Sympathetic preganglionic fibers are short and postganglionic fibers are long, while in the parasympathetic system, preganglionic fibers are long and postganglionic fibers are short.

Cranial nerves carrying PSNS fibers

III (oculomotor), VII (facial), IX (glossopharyngeal), and X (vagus).

Neurotransmitters released in ANS

The sympathetic division releases norepinephrine, while the parasympathetic division releases acetylcholine.

Typical SNS pathway

preganglionic fibers stemming from the thoracolumbar region.

SNS pathway to adrenal gland and sweat gland

The sympathetic pathway to the adrenal gland bypasses the ganglia and synapses directly on adrenal medulla, while sweat glands have postganglionic sympathetic fibers.

What is dual innervation?

organs receiving input from both the sympathetic and parasympathetic divisions.

Exceptions of dual innervation

blood vessels and adrenal medulla that are innervated only by the sympathetic division.