Unit 3: Anatomy & Physiology

1. Unit 3: Anatomy & Physiology Veterinary Medical Applications I

2. Directional Terminology Unit 3: Anatomy & Physiology

3. Introduction • It is very important for the veterinary assistant to be familiar with basic anatomical terminology. • This knowledge helps to better understand medical conditions and treatments, follow instructions from the veterinarian, perform basic veterinary medical procedures Unit 3: Anatomy & Physiology

4. Anatomical Terminology • Being familiar with anatomical terminology is important, and the terms used here will be repeated throughout this and other units. • These terms will be used in the description of bones, the names of muscles, as well as in the description of clinical cases. Unit 3: Anatomy & Physiology

5. Anatomical Terms Unit 3: Anatomy & Physiology

6. ANTERIOR • The front of the animal Unit 3: Anatomy & Physiology

7. POSTERIOR • The rear of the animal Unit 3: Anatomy & Physiology

8. CRANIAL • Towards the head Unit 3: Anatomy & Physiology

9. CAUDAL • Towards the tail Unit 3: Anatomy & Physiology

10. DORSAL • Along the back or uppermost surface Unit 3: Anatomy & Physiology

11. VENTRAL • Along the belly or undermost surface Unit 3: Anatomy & Physiology

12. PROXIMAL • Part of the limb closest to the body Unit 3: Anatomy & Physiology

13. DISTAL • Part of the limb furthest from the body Unit 3: Anatomy & Physiology

14. Three-Dimension Planes Unit 3: Anatomy & Physiology

15. FRONTAL PLANE • Body plane that divides the animal into dorsal and ventral parts Unit 3: Anatomy & Physiology

16. MEDIAN PLANE • Body plane that divides the animal into equal, symmetrical right and left halves. Unit 3: Anatomy & Physiology

17. SAGITTAL PLANE • Any body plane that is parallel to the median plane. Unit 3: Anatomy & Physiology

18. TRANSVERSE PLANE • Body plane that divides the animal into cranial and caudal parts. Unit 3: Anatomy & Physiology

19. SUPERFICIAL • Closer to the surface Unit 3: Anatomy & Physiology

20. DEEP • Further from the surface • Example: superficial and deep flexor tendons Unit 3: Anatomy & Physiology

21. Skeletal System Unit 3: Anatomy & Physiology

22. Skeletal System • The skeleton is a framework of structures, made of bones and cartilage that support and protect the body. • Axial Skeleton: includes the skull, vertebrae, ribs, and sternum. • Appendicular Skeleton – the fore and hind limbs Unit 3: Anatomy & Physiology

23. Unit 3: Anatomy & Physiology

24. Appendicular: Forelimb Scapula – “shoulder blade” attached with muscle Clavicle – the cat is the only domestic animal with a clavicle! Humerus – forms the upper arm Ulna – forms the elbow joint, fused with the radius in herbivores Radius – forms the forearm Carpus – commonly called the “knee” in horses, the “wrist” in dogs and humans Metacarpals – commonly called the cannon region of the forelimb. Number depends on species: a) Humans: 5 b) Horses: 1 plus 2 accessory metacarpals, called “splint bones” c) Dogs and cats: 4 plus the dewclaw d) Cattle: 1 that splits at bottom into a cloven hoof and two dewclaws e) Pigs: 4 (2 toes and 2 dewclaws) Unit 3: Anatomy & Physiology

25. Appendicular: Forelimb Continued Proximal phalanx (P1) – bones of the finger, hoof, and claw Intermediate phalanx (P2) Distal phalanx (P3) – the coffin bone in horses Proximal sesamoids – tucked in behind P1 Distal sesamoid – tucked in underneath P3 Unit 3: Anatomy & Physiology

26. Appendicular: Hindlimb Pelvis a) Tuber coxae – part of pelvis that forms the “point of hip” b) Ischiatic tuberosity- part of pelvis that forms the “seat bones” Femur Patella – forms the “stifle” joint in horses, sometimes called the “knee” in dogs, equivalent to the human knee Tibia – main bone of the gaskin of the horse Fibula – fused with the tibia & considered vestigial in herbivores Tarsus – commonly called the “hock”, equivalent to the human “ankle”. Metatarsal – cannon region in the hind limb. Number depends on species. Unit 3: Anatomy & Physiology

27. Classification of Bones • Short bone – cube shaped, i.e. carpus and tarsus • Flat bone – plate of bone, i.e. scapula, rib, skull • Irregular bone – complex shaped, i.e. vertebrae • Sesamoid – small, seed-shaped bone, i.e. proximal and distal sesamoids, patella • Long bone – bone is longer that it is wide, i.e.femur, tibia, humerus, etc. Unit 3: Anatomy & Physiology

28. Bone Anatomy Epiphysis Diaphysis Periosteum Medullary cavity Endosteum Bone marrow Metaphysis Unit 3: Anatomy & Physiology

29. Classifications of Fractures Fissured Greenstick Transverse Comminuted Unit 3: Anatomy & Physiology

30. Muscular System Unit 3: Anatomy & Physiology

31. Types of Muscle • Skeletal muscle – allows for all voluntary movement, appears to be striated when looked at under a microscope. • Cardiac muscle – controls the involuntary beating of the heart, appears striated under a microscope. • Smooth muscle – responsible for all other involuntary movement, such as breathing, digestion, peristalsis, blinking, etc. Unit 3: Anatomy & Physiology

32. Muscle Movement • Ambulation: moving from one place to another • Abduction: moving away from the median plane • Adduction: moving towards the median plane • Flexion: moving the distal part of the limb towards the body • Extension: moving the distal part of the limb away from the body Unit 3: Anatomy & Physiology

33. Muscle Function • All muscles can do is CONTRACT or RELAX, so they generally work in pairs. For any particular action, the muscles involved can be classified as: • Agonist – prime mover of a joint • Antagonist – opposes movement of the agonist • Ex: for elbow flexion, the agonist is the bicep, and the antagonist is the tricep. For elbow extension, the agonist is the tricep, and the antagonist is the bicep. Unit 3: Anatomy & Physiology

34. Major Muscles Brachiocephalicus Latissimus dorsi Masseter External abdominal oblique Trapezius Gluteals Pectorals Semitendinous Deltoid Gastrocnemius Triceps brachii Biceps femoris Intercostal Unit 3: Anatomy & Physiology

35. Description/Function of Muscles • Masseter – superficial muscle of the cheek • Trapezius – superficial triangular muscle of the shoulder • Latissimusdorsi – long, superficial, dorsal muscle that attaches the humerusto the lumbar region of the back • Abdominal obliques – large flat muscles that support digestive and reproductive organs • Gluteals– large muscle of the upper hindquarters • Biceps femoris – lateral superficial muscle, one of three which forms the “hamstrings” • Biceps brachii – primary flexor of the elbow joint • Triceps brachii – primary extensor of the elbow joint • Pectorals – primary adductors of the forelimbs • Serratusventralis – attaches forelimb to trunk (no collarbone!) Unit 3: Anatomy & Physiology

36. Nervous System Unit 3: Anatomy & Physiology

37. Vocabulary Axon – sends impulses away from cell Brain – major organ of nervous system; contained within the skull Brainstem – connects the cerebrum with the spinal cord; contains the Medulla oblongata Central nervous system – contains brain and spinal cord Cerebellum – coordinates movement and muscle activity, balance Cerebrum – largest portion of brain; responsible for receiving and storing information and signaling for voluntary movement

38. Connecting neuron – carries impulses from one neuron to another Dendrites – branch-like; receive impulses Homeostasis – state of balance of the physiologic systems within the body Impulse – electrical signal that is transmitted through nervous tissue Medulla oblongata – part of the brain responsible for all life functions including: heart rate, breathing, and reflex actions (coughing, sneezing, swallowing, and vomiting) Meninges – protective layer covering the brain; has three layers Motor neuron – carries impulses from the brain towards the muscles and glands

39. Nerve – term for one or more bundles of nerve cells Neuron – nerve cells Neurotransmitter – chemical substance that allows impulses to travel Parasympathetic nervous system – maintains and restores normal body function Peripheral nervous system – consists of all nerves that lead to and from the spinal cord and brain, known as cranial and spinal nerves Sensory neuron – carries impulses towards the brain and spinal cord Soma – cell body that contains the nucleus Spinal cord – pathway for all impulses going to and from the brain, Sympathetic nervous system – responsible for stress and emergency responses; “fight or flight” Synapse – space between neurons that contains a neurotransmitter

40. Functions of the Nervous System • Detects and processes information and formulates responses; coordinates and controls all bodily activity. • The nervous system sends and receives impulses –electrical signals that travel though the nervous system and provide information to the brain.

41. Types of Neurons Sensory neurons – carry impulses towards the brain and spinal cord. Connecting neurons – carry impulses from one neuron to another. Motor neurons – carry impulses away from the brain and spinal cord to the body.

42. Parts of a Neuron Dendrite Cell body (soma) Myelin sheath Axon Synapse http://safari.pisd.edu/?a=175072&s=00:00:00:00&e=00:00:49:00&d=25344AA

43. Parts of a Neuron 1. Cell Body – often called the soma. Contains the cell nucleus 2. Dendrite – branch-like, receives impulses 3. Axon – sends impulses away from the cell 4. Synapse – space in between neurons; contains a chemical substance called a neurotransmitter that helps impulses travel 5. Myelin – protective sheath around the neuron

44. Central Nervous System Central Nervous System – consists of brain and spinal cord. 1. Brain – major organ of the nervous system. • Meninges – three-layered protective covering of the brain. • Cerebrum – largest part of the brain. It has four lobes that receive and store information And are responsible for giving signals for voluntary movement • Cerebellum – coordinates all movement, muscle activity, and balance. d. Brainstem – connects the brain to the spinal cord and contains the medulla oblongata. e. Medulla oblongata - dictates all life functions including: heart rate, breathing, and reflex actions. f. Thalamus – a central relay system for all nerve impulses except smell. It receives the impulses and then directs them to the proper part of the brain. g. Hypothalamus – serves as a link between the nervous system and the endocrine system. h. Pituitary gland – secretes hormones important for reproduction and growth. 2. Spinal cord – pathway for all impulses going to and from the brain. Connects to the medulla oblongata.

45. Parts of the Brain Cerebrum Meninges Cerebellum Thalamus Spinal cord Pituitary gland Hypothalamus Brain stem Medulla oblongata

46. Peripheral Nervous System – consists of nerves that relay information to and from the spinal cord. • Sympathetic Nervous System– Responsible for emergency and stress responses: “fight or flight”. • Parasympathetic Nervous System – Seeks to maintain and restore normal body function, often called Homeostasis: a state of balance of the physiologic systems within the body

47. Respiratory System Unit 3: Anatomy & Physiology

48. Vocabulary Alveoli – grape-like clusters at ends of bronchioles; where exchange of oxygen and carbon dioxide gases occur Apnea – not breathing Asphyxiation – suffocation; blockage of airflow that results in a lack of oxygen Bradypnea– abnormally slow respiratory rate Bronchi – paired terminal branches of the trachea contained within the lungs; singular: bronchus

49. Bronchial tree – term that describes how bronchi get continually smaller, like a tree branch Bronchioles – smallest branches of the bronchial tree Cilia – tiny hairs inside nostrils that help to filter air Diaphragm – Muscle located below the lungs; contraction causes the lungs to draw in a breath

50. Dyspnea – difficult breathing Epiglottis – flap that covers the larynx during swallowing Exhalation – release of a breath Inhalation – drawing in of a breath Larynx – ‘voice box’ that contains vocal cords